Plant Size as Determinant of Species Richness of Herbivores, Natural Enemies and Pollinators across 21 Brassicaceae Species.

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Hella Schlinkert

Full Text Available Large plants are often more conspicuous and more attractive for associated animals than small plants, e.g. due to their wider range of resources. Therefore, plant size can positively affect species richness of associated animals, as shown for single groups of herbivores, but studies usually consider intraspecific size differences of plants in unstandardised environments. As comprehensive tests of interspecific plant size differences under standardised conditions are missing so far, we investigated effects of plant size on species richness of all associated arthropods using a common garden experiment with 21 Brassicaceae species covering a broad interspecific plant size gradient from 10 to 130 cm height. We recorded plant associated ecto- and endophagous herbivores, their natural enemies and pollinators on and in each aboveground plant organ, i.e. flowers, fruits, leaves and stems. Plant size (measured as height from the ground, the number of different plant organ entities and their biomass were assessed. Increasing plant size led to increased species richness of associated herbivores, natural enemies and pollinating insects. This pattern was found for ectophagous and endophagous herbivores, their natural enemies, as well as for herbivores associated with leaves and fruits and their natural enemies, independently of the additional positive effects of resource availability (i.e. organ biomass or number of entities and, regarding natural enemies, herbivore species richness. We found a lower R2 for pollinators compared to herbivores and natural enemies, probably caused by the high importance of flower characteristics for pollinator species richness besides plant size. Overall, the increase in plant height from 10 to 130 cm led to a 2.7-fold increase in predicted total arthropod species richness. In conclusion, plant size is a comprehensive driver of species richness of the plant associated arthropods, including pollinators, herbivores and their

A Holling Type II Pest and Natural Enemy Model with Density Dependent IPM Strategy

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Xia Wang

2017-01-01

Full Text Available Resource limitations and density dependent releasing of natural enemies during the pest control and integrated pest management will undoubtedly result in nonlinear impulsive control. In order to investigate the effects of those nonlinear control strategies on the successful pest control, we have proposed a pest-natural enemy system concerning integrated pest management with density dependent instant killing rate and releasing rate. In particular, the releasing rate depicts how the number of natural enemy populations released was guided by their current density at the fixed moment. The threshold condition which ensures the existence and global stability of pest-free periodic solution has been discussed first, and the effects of key parameters on the threshold condition reveal that reducing the pulse period does not always benefit pest control; that is, frequent releasing of natural enemies may not be beneficial to the eradication of pests when the density dependent releasing method has been implemented. Moreover, the forward and backward bifurcations could occur once the pest-free periodic solution becomes unstable, and the system could exist with very complex dynamics. All those results confirm that the control actions should be carefully designed once the nonlinear impulsive control measures have been taken for pest management.

Review on Natural Enemies and Diseases in the Artificial Cultivation of Chinese Caterpillar Mushroom, Ophiocordyceps sinensis (Ascomycetes).

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Lu, Zenghui; Shi, Ping; He, Yuanchuan; Zhang, Deli; He, Zongyi; Chen, Shijiang; Tu, Yongqin; Li, Li; Liu, Fei; Zeng, Wei

2015-01-01

Ophiocordyceps sinensis (syn. Cordyceps sinensis), well known as DongChongXiaCao (DCXC), is one of the most valuable traditional Chinese medicinal species. In this article, we provide a systematic review of natural enemies and diseases encountered in artificial cultivation of DCXC. Unfortunately, DCXC has been endangered over the past decades due to overharvesting and a worsening ecological environment. Therefore, the artificial cultivation of DCXC has been extensively investigated in recent years. Complete indoor artificial cultivation and semi-field cultivation are the two most common strategies used to cultivate DCXC. However, cultured DCXCs are often attacked by various natural enemies and diseases, which have resulted in substantial loss of the valuable medicinal resource. In this study, we have summarized the species of natural enemies and types of diseases confronted by DCXC. Twenty reported natural enemy species are categorized into four classes, one of which is reported for the first time in this study. Moreover, six microbial pathogens are also discussed. The recapitulation of the natural enemies and diseases in DCXC artificial cultivation not only promote the development of integrated pest management of DCXC cultivation but also provide important information to help preserve and develop this valuable resource.

Population of Tuta absoluta and natural enemies after releasing on ...

African Journals Online (AJOL)

The study was conducted to evaluate the population of tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) and efficiency of natural enemies on tomato grown greenhouse in Mediterranean Region of Turkey during 2010 and 2011. Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) ...

Plant diversification promotes biocontrol services in peach orchards by shaping the ecological niches of insect herbivores and their natural enemies

DEFF Research Database (Denmark)

Wan, Nian Feng; Ji, Xiang Yun; Deng, Jian Yu

2018-01-01

Ecological niche indicators have been scarcely adopted to assess the biological control of insect herbivores by their natural enemies. We hypothesize that plant diversification promotes the biocontrol services by narrowing the niches of herbivores and broadening the niches of natural enemies....... Our study reveals that plant diversification promotes the biocontrol services by shaping the niche of herbivores and natural enemies, and provides a new assessment method to understand the biodiversity-niche-ecosystem management interactions........ In a large-scale experiment, we found that the abundance of natural enemies was increased by 38.1%, and the abundance of insect herbivores was decreased by 16.9% in peach orchards with plant diversification (treatment) compared to ones with monoculture (control). Stratified sampling indicated...

Genetic variation in plant volatile emission does not result in differential attraction of natural enemies in the field.

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Wason, Elizabeth L; Hunter, Mark D

2014-02-01

Volatile organic chemical (VOC) emission by plants may serve as an adaptive plant defense by attracting the natural enemies of herbivores. For plant VOC emission to evolve as an adaptive defense, plants must show genetic variability for the trait. To date, such variability has been investigated primarily in agricultural systems, yet relatively little is known about genetic variation in VOCs emitted by natural populations of native plants. Here, we investigate intraspecific variation in constitutive and herbivore-induced plant VOC emission using the native common milkweed plant (Asclepias syriaca) and its monarch caterpillar herbivore (Danaus plexippus) in complementary field and common garden greenhouse experiments. In addition, we used a common garden field experiment to gauge natural enemy attraction to milkweed VOCs induced by monarch damage. We found evidence of genetic variation in the total constitutive and induced concentrations of VOCs and the composition of VOC blends emitted by milkweed plants. However, all milkweed genotypes responded similarly to induction by monarchs in terms of their relative change in VOC concentration and blend. Natural enemies attacked decoy caterpillars more frequently on damaged than on undamaged milkweed, and natural enemy visitation was associated with higher total VOC concentrations and with VOC blend. Thus, we present evidence that induced VOCs emitted by milkweed may function as a defense against herbivores. However, plant genotypes were equally attractive to natural enemies. Although milkweed genotypes diverge phenotypically in their VOC concentrations and blends, they converge into similar phenotypes with regard to magnitude of induction and enemy attraction.

Effects of crop species richness on pest-natural enemy systems based on an experimental model system using a microlandscape.

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Zhao, ZiHua; Shi, PeiJian; Men, XingYuan; Ouyang, Fang; Ge, Feng

2013-08-01

The relationship between crop richness and predator-prey interactions as they relate to pest-natural enemy systems is a very important topic in ecology and greatly affects biological control services. The effects of crop arrangement on predator-prey interactions have received much attention as the basis for pest population management. To explore the internal mechanisms and factors driving the relationship between crop richness and pest population management, we designed an experimental model system of a microlandscape that included 50 plots and five treatments. Each treatment had 10 repetitions in each year from 2007 to 2010. The results showed that the biomass of pests and their natural enemies increased with increasing crop biomass and decreased with decreasing crop biomass; however, the effects of plant biomass on the pest and natural enemy biomass were not significant. The relationship between adjacent trophic levels was significant (such as pests and their natural enemies or crops and pests), whereas non-adjacent trophic levels (crops and natural enemies) did not significantly interact with each other. The ratio of natural enemy/pest biomass was the highest in the areas of four crop species that had the best biological control service. Having either low or high crop species richness did not enhance the pest population management service and lead to loss of biological control. Although the resource concentration hypothesis was not well supported by our results, high crop species richness could suppress the pest population, indicating that crop species richness could enhance biological control services. These results could be applied in habitat management aimed at biological control, provide the theoretical basis for agricultural landscape design, and also suggest new methods for integrated pest management.

Spatial variation of important mulberry pests and their natural enemies

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A. Mohan

2017-04-01

Full Text Available Mulberry is a silkworm food plant (Bombyxmori. L that is seriously affected by many insect pests. The incidence of Diaphania pulverulentalis (Hampson, Maconellicoccus hirsutus (Green, Paracoccus marginatus (Williams and Granara de Willink, Aleurodiscus dispersus (Russels and Pseudodendrothrips mori (Niwa and their natural enemies, viz. coccinellids and spiders (/100 plants, were observed through survey and surveillance for 3 months. In February 2013, the incidence of insect pests in Vaikkalpattarai and Reddipudur villages (India was: D. pulverulentalis, 1.20 and 0.85%; P. marginatus, 6.80 and 33.10%; P. mori 42.98 and 45.50%, respectively. Further, the infestation of M. hirsutus (1.40% and A. dispersus (59.72% was also observed in February at Vaikkalpattarai. The population of coccinellids was high in December (1.02 and 0.84/100 plants, but the spider population was even higher in February and January (1.04 and 1.81/100 plants. Population of pests had a significant positive correlation with relative humidity. The population of coccinellids and spiders have positive correlation with temperature and mulberry pests infestation. The natural enemies observed in the study were mostly the ladybird beetles, Psyllobora bisoctonotata and unidentified species of spiders.

Impact of neonicotinoid insecticides on natural enemies in greenhouse and interiorscape environments.

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Cloyd, Raymond A; Bethke, James A

2011-01-01

The neonicotinoid insecticides imidacloprid, acetamiprid, dinotefuran, thiamethoxam and clothianidin are commonly used in greenhouses and/or interiorscapes (plant interiorscapes and conservatories) to manage a wide range of plant-feeding insects such as aphids, mealybugs and whiteflies. However, these systemic insecticides may also be harmful to natural enemies, including predators and parasitoids. Predatory insects and mites may be adversely affected by neonicotinoid systemic insecticides when they: (1) feed on pollen, nectar or plant tissue contaminated with the active ingredient; (2) consume the active ingredient of neonicotinoid insecticides while ingesting plant fluids; (3) feed on hosts (prey) that have consumed leaves contaminated with the active ingredient. Parasitoids may be affected negatively by neonicotinoid insecticides because foliar, drench or granular applications may decrease host population levels so that there are not enough hosts to attack and thus sustain parasitoid populations. Furthermore, host quality may be unacceptable for egg laying by parasitoid females. In addition, female parasitoids that host feed may inadvertently ingest a lethal concentration of the active ingredient or a sublethal dose that inhibits foraging or egg laying. There are, however, issues that require further consideration, such as: the types of plant and flower that accumulate active ingredients, and the concentrations in which they are accumulated; the influence of flower age on the level of exposure of natural enemies to the active ingredient; the effect of neonicotinoid metabolites produced within the plant. As such, the application of neonicotinoid insecticides in conjunction with natural enemies in protected culture and interiorscape environments needs further investigation. Copyright © 2010 Society of Chemical Industry.

Toxicity of insecticides to the sweetpotato whitefly (Hemiptera: Aleyrodidae) and its natural enemies.

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Bacci, Leandro; Crespo, André L B; Galvan, Tederson L; Pereira, Eliseu J G; Picanço, Marcelo C; Silva, Gerson A; Chediak, Mateus

2007-07-01

Efficient chemical control is achieved when insecticides are active against insect pests and safe to natural enemies. In this study, the toxicity of 17 insecticides to the sweetpotato whitefly, Bemisia tabaci (Gennadius), and the selectivity of seven insecticides to natural enemies of this insect pest were evaluated. To determine the insecticide toxicity, B. tabaci adults were exposed to abamectin, acephate, acetamiprid, cartap, imidacloprid, malathion, methamidophos, bifenthrin, cypermethrin, deltamethrin, esfenvalerate, fenitrothion, fenpropathrin, fenthion, phenthoate, permethrin and trichlorphon at 50 and 100% of the field rate (FR), and to water (untreated control). To determine the insecticide selectivity, adults of Encarsia sp., Acanthinus sp., Discodon sp. and Lasiochilus sp. were exposed to abamectin, acephate, acetamiprid, cartap, imidacloprid, malathion and methamidophos at 50 and 100% FR, and to water. Groups of each insect species were exposed to kale leaves preimmersed in each treatment under laboratory conditions. Mortality of exposed individuals was recorded 24 h after treatment. Cartap and imidacloprid at 50 and 100% FR and abamectin and acetamiprid at 100% FR showed insecticidal activity to B. tabaci adults. Abamectin at 50 and 100% FR was the least insecticidal compound to the natural enemies Acanthinus sp., Discodon sp. and Lasiochilus sp. The present results suggest that abamectin at 100% FR may decrease B. tabaci field populations but can still be harmless to predators. Implications of these results within an integrated pest management context are discussed. Copyright (c) 2007 Society of Chemical Industry.

Fire ants protect mealybugs against their natural enemies by utilizing the leaf shelters constructed by the leaf roller Sylepta derogata.

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Aiming Zhou

Full Text Available The importance of mutualism is receiving more attention in community ecology. In this study, the fire ant Solenopsis invicta was found to take advantage of the shelters constructed by the leaf roller Sylepta derogata to protect mealybugs (Phenacoccus solenopsis against their natural enemies. This protective effect of fire ant tending on the survival of mealybugs in shelters was observed when enemies and leaf rollers were simultaneously present. Specifically, fire ants moved the mealybugs inside the shelters produced by S. derogata on enemy-infested plants. Compared with that in plants without ants, the survival of mealybugs in shelters in the presence of natural enemies in plants with ants markedly improved. Both the protection of ants and the shelters provided by leaf rollers did not affect the survival of mealybugs in the absence of enemies in plants. Ants and leaf rollers significantly improved the survival of mealybugs in predator-infested plants, whereas no such improvement was observed in parasitoid-infested ones.

Lime sulfur toxicity to broad mite, to its host plants and to natural enemies.

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Venzon, Madelaine; Oliveira, Rafael M; Perez, André L; Rodríguez-Cruz, Fredy A; Martins Filho, Sebastião

2013-06-01

An acaricidal effect of lime sulfur has not been demonstrated for Polyphagotarsonemus latus. However, lime sulfur can cause toxicity to natural enemies and to host plants. In this study, the toxicity of different concentrations of lime sulfur to P. latus, to the predatory mite Amblyseius herbicolus and to the predatory insect Chrysoperla externa was evaluated. Additionally, the phytotoxicity of lime sulfur to two P. latus hosts, chili pepper and physic nut plants, was determined. Lime sulfur at a concentration of 9.5 mL L(-1) restrained P. latus population growth. However, this concentration was deleterious to natural enemies. The predatory mite A. herbicolus showed a negative value of instantaneous growth rate, and only 50% of the tested larvae of C. externa reached adulthood when exposed to 10 mL L(-1) . Physic nut had severe injury symptoms when sprayed with all tested lime sulfur concentrations. For chili pepper plants, no phytoxicity was observed at any tested concentration. Lime sulfur might be used for P. latus control on chili pepper but not on physic nut owing to phytotoxicity. Care should be taken when using lime sulfur in view of negative effects on natural enemies. Selective lime sulfur concentration integrated with other management tactics may provide an effective and sustainable P. latus control on chili pepper. © 2012 Society of Chemical Industry.

Mechanisms of symbiont-conferred protection against natural enemies: an ecological and evolutionary framework.

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Gerardo, Nicole M; Parker, Benjamin J

2014-10-01

Many vertically-transmitted microbial symbionts protect their insect hosts from natural enemies, including host-targeted pathogens and parasites, and those vectored by insects to other hosts. Protection is often achieved through production of inhibiting toxins, which is not surprising given that toxin production mediates competition in many environments. Classical models of macroecological interactions, however, demonstrate that interspecific competition can be less direct, and recent research indicates that symbiont-protection can be mediated through exploitation of limiting resources, and through activation of host immune mechanisms that then suppress natural enemies. Available data, though limited, suggest that effects of symbionts on vectored pathogens and parasites, as compared to those that are host-targeted, are more likely to result from symbiont activation of the host immune system. We discuss these different mechanisms in light of their potential impact on the evolution of host physiological processes. Copyright © 2014 Elsevier Inc. All rights reserved.

Broad spectrum pesticide application alters natural enemy communities and may facilitate secondary pest outbreaks

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Macfadyen, Sarina; Nash, Michael A.

2017-01-01

Background Pesticide application is the dominant control method for arthropod pests in broad-acre arable systems. In Australia, organophosphate pesticides are often applied either prophylactically, or reactively, including at higher concentrations, to control crop establishment pests such as false wireworms and earth mite species. Organophosphates are reported to be disruptive to beneficial species, such as natural enemies, but this has not been widely assessed in Australian systems. Neither has the risk that secondary outbreaks may occur if the natural enemy community composition or function is altered. Methods We examine the abundance of ground-dwelling invertebrate communities in an arable field over successive seasons under rotation; barley, two years of wheat, then canola. Two organophosphates (chlorpyrifos and methidathion) were initially applied at recommended rates. After no discernible impact on target pest species, the rate for chlorpyrifos was doubled to elicit a definitive response to a level used at establishment when seedling damage is observed. Invertebrates were sampled using pitfalls and refuge traps throughout the experiments. We applied measures of community diversity, principal response curves and multiple generalised linear modelling techniques to understand the changes in pest and natural enemy communities. Results There was large variability due to seasonality and crop type. Nevertheless, both pest (e.g., mites and aphids) and natural enemy (e.g., predatory beetles) invertebrate communities were significantly affected by application of organophosphates. When the rate of chlorpyrifos was increased there was a reduction in the number of beetles that predate on slug populations. Slugs displayed opposite trends to many of the other target pests, and actually increased in numbers under the higher rates of chlorpyrifos in comparison to the other treatments. Slug numbers in the final rotation of canola resulted in significant yield loss regardless

Broad spectrum pesticide application alters natural enemy communities and may facilitate secondary pest outbreaks

Directory of Open Access Journals (Sweden)

Matthew P. Hill

2017-12-01

Full Text Available Background Pesticide application is the dominant control method for arthropod pests in broad-acre arable systems. In Australia, organophosphate pesticides are often applied either prophylactically, or reactively, including at higher concentrations, to control crop establishment pests such as false wireworms and earth mite species. Organophosphates are reported to be disruptive to beneficial species, such as natural enemies, but this has not been widely assessed in Australian systems. Neither has the risk that secondary outbreaks may occur if the natural enemy community composition or function is altered. Methods We examine the abundance of ground-dwelling invertebrate communities in an arable field over successive seasons under rotation; barley, two years of wheat, then canola. Two organophosphates (chlorpyrifos and methidathion were initially applied at recommended rates. After no discernible impact on target pest species, the rate for chlorpyrifos was doubled to elicit a definitive response to a level used at establishment when seedling damage is observed. Invertebrates were sampled using pitfalls and refuge traps throughout the experiments. We applied measures of community diversity, principal response curves and multiple generalised linear modelling techniques to understand the changes in pest and natural enemy communities. Results There was large variability due to seasonality and crop type. Nevertheless, both pest (e.g., mites and aphids and natural enemy (e.g., predatory beetles invertebrate communities were significantly affected by application of organophosphates. When the rate of chlorpyrifos was increased there was a reduction in the number of beetles that predate on slug populations. Slugs displayed opposite trends to many of the other target pests, and actually increased in numbers under the higher rates of chlorpyrifos in comparison to the other treatments. Slug numbers in the final rotation of canola resulted in significant yield

[Effects of wheat-oilseed rape intercropping and methyl salicylate application on the spatial distributions of Sitobion avenae and its main natural enemies].

Science.gov (United States)

Dong, Jie; Liu, Ying-Jie; Wang, Guang; Liu, Yong

2012-07-01

A field investigation was conducted on the spatial distributions of Sitobion avenae and its main natural enemies under wheat-oilseed rape intercropping and methyl salicylate application. With the development of wheat plant, an alternation from aggregation to uniform was observed in the spatial distribution of S. avenae under the intercropping and methyl salicylate application, being more obvious under the interaction of the two practices. The spatial distribution of S. avenae natural enemies was in accordance with that of the aphid. These results could be used for the reference of sampling investigation and forecast of wheat aphid and its natural enemies in field.

Hemlock woolly adelgid and its natural enemies in Sichuan Province, China, 2005

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Jianhua Zhou; Yinbo Xiao; Yugui Xiao; Wenhua Lu; Michael Montgomery; Roy Van Driesche; Scott Salom

2007-01-01

A partnership of Chinese and American institutions was formed in 2005 to obtain natural enemies for biological control of Adelges tsugae Annand, the hemlock woolly adelgid (HWA), in the eastern United States. We report here the first 6 months (June-November) of studies done at three sites in Kangding and Baoxing Counties in Sichuan Province.

[Effects of Beauveria bassiana on Myzus persicae and its two predaceous natural enemies].

Science.gov (United States)

Zhu, Hong; Luo, Xu-mei; Song, Jin-xin; Fan, Mei-zhen; Li, Zeng-zhi

2011-09-01

A Beauveria bassiana strain Bb21 was isolated from naturally infected green peach aphid Myzus persicae (Hemiptera: Aphididae). The effects of the strain on M. persicae and its two predaceous natural enemies Chrysoperla carnea (Neuroptera: Chrysopidae) and Harmonia axyridis (Coleoptera: Coccinellidae) were investigated under laboratory conditions. Bb21 had strong pathogenicity to M. persicae, with the LD50 of 97 conidia x mm(-2) (45-191, 95% confidence interval), but was less pathogenic to the second instar nymph of C. carnea, with the LD50 of 1089 conidia x mm(-2). The LD50 for C. carnea was 10.2 times higher than that for M. persicae. The pathogenicity of Bb21 to H. axyridis was very weak, with a low infection rate of 13% even at a high concentration 5 x 10(8) conidia x mL(-1). The Bb21 at low conidia concentration had less effect on the developmental period and fecundity of the two predaceous natural enemies. However, when applied at the high concentration 5 x 10(8) spores x mL(-1), Bb21 shortened the larval stage of H. axyridis averagely by 1.4 d and decreased the adult emergence rate and fecundity by 33% and 14%, respectively, and shortened the larval stage of C. carnea averagely by 0.7 d and decreased the adult emergence rate and fecundity by 24% and 11%, respectively. Since the LD50 for green peach aphid was much lower than that for the two predaceous natural enemies, and had very low effect on the adult emergence rate and fecundity of the two predators at the concentration recommended for field spray, Bb21 could be applied as a biocontrol agent of M. persicae in the integrated management of pernicious organisms.

Arbuscular mycorrhizal fungal diversity and natural enemies promote coexistence of tropical tree species

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Benedicte Bachelot; María Uriarte; Krista L. McGuire; Jill Thompson; Jess Zimmerman

2017-01-01

Negative population feedbacks mediated by natural enemies can promote species coexistence at the community scale through disproportionate mortality of numerically dominant (common) tree species. Simultaneously, associations with arbuscular mycorrhizal fungi (AMF) can result in positive effects on tree populations. Coupling data on seedling foliar damage from herbivores...

Optimal control of soybean aphid in the presence of natural enemies and the implied value of their ecosystem services.

Science.gov (United States)

Zhang, Wei; Swinton, Scott M

2012-04-15

By suppressing pest populations, natural enemies provide an important ecosystem service that maintains the stability of agricultural ecosystems systems and potentially mitigates producers' pest control costs. Integrating natural control services into decisions about pesticide-based control has the potential to significantly improve the economic efficiency of pesticide use, with socially desirable outcomes. Two gaps have hindered the incorporation of natural enemies into pest management decision rules: (1) insufficient knowledge of pest and predator population dynamics and (2) lack of a decision framework for the economic tradeoffs among pest control options. Using a new intra-seasonal, dynamic bioeconomic optimization model, this study assesses how predation by natural enemies contributes to profit-maximizing pest management strategies. The model is applied to the management of the invasive soybean aphid, the most significant serious insect threat to soybean production in North America. The resulting lower bound estimate of the value of natural pest control ecosystem services was estimated at $84 million for the states of Illinois, Indiana, Iowa, Michigan and Minnesota in 2005. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of intercropping on maize stemborers and their natural enemies

DEFF Research Database (Denmark)

Skovgård, Henrik; Päts, Peeter

1996-01-01

The effects of maize-cowpea intercropping on three lepidopteran stemborers (Chilo partellus (Swinhoe) C. orichalcociliellus (Strand) and Sesamia calamistis Hampson) and their natural enemies were studied in Kenya. Oviposition was not affected by intercropping, but significantly fewer larvae...... and wandering spiders, were not augmented by intercropping, but an inverse relationship in abundance was found between these two predator groups. It is concluded that maize intercropped with cowpea has only limited potential as a method of controlling the key pests in maize....

Prospecting for viral natural enemies of the fire ant Solenopsis invicta in Argentina

Science.gov (United States)

Metagenomics and next generation sequencing were employed to discover new virus natural enemies of the fire ant, Solenopsis invicta Buren in its native range (i.e., Formosa, Argentina) with the ultimate goal of testing and releasing new viral pathogens into U.S. S. invicta populations to provide nat...

Toxicity of nine insecticides on four natural enemies of Spodoptera exigua

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Liu, Yongqiang; Li, Xiangying; Zhou, Chao; Liu, Feng; Mu, Wei

2016-01-01

Spodoptera exigua, which feeds on various crops worldwide, has natural enemies that are susceptible to the insecticides used against S. exigua. We investigate the toxicity and residue risk of 9 insecticides on the development of H. axyridis, C. sinica, S. manilae and T. remus. S. manilae and T. remus adults were sensitive to all 9 insecticides (LC50 less than 2.75 mg a.i. liter−1), while H. axyridis and C. sinica adults were less sensitive (LC50 between 6 × 10−5 mg a.i. liter−1 and 78.95 mg a.i. liter−1). Emamectin benzoate, spinosad, indoxacarb, alpha-cypermethrin, chlorfenapyr and chlorantraniliprole showed no toxicity on H. axyridis, C. sinica, S. manilae and T. remus pupae with the recommended field concentrations. The risk analysis indicated that chlorantraniliprole is harmless to larvae of four natural enemies and adult of H. axyridis, C. sinica and S. manilae. Emamectin benzoate and spinosad had higher safety to the development of H. axyridis, C. sinica, S. manilae and T. remus with the risk duration less than 4d. Indoxacarb, tebufenozide, chlorfenapyr, methomyl, alpha-cypermethrin and chlorpyrifos showed dangerously toxic and long risk duration on S. manilae and T. remus adults. PMID:27958333

Toxicity of nine insecticides on four natural enemies of Spodoptera exigua.

Science.gov (United States)

Liu, Yongqiang; Li, Xiangying; Zhou, Chao; Liu, Feng; Mu, Wei

2016-12-13

Spodoptera exigua, which feeds on various crops worldwide, has natural enemies that are susceptible to the insecticides used against S. exigua. We investigate the toxicity and residue risk of 9 insecticides on the development of H. axyridis, C. sinica, S. manilae and T. remus. S. manilae and T. remus adults were sensitive to all 9 insecticides (LC 50 less than 2.75 mg a.i. liter -1 ), while H. axyridis and C. sinica adults were less sensitive (LC 50 between 6 × 10 -5  mg a.i. liter -1 and 78.95 mg a.i. liter -1 ). Emamectin benzoate, spinosad, indoxacarb, alpha-cypermethrin, chlorfenapyr and chlorantraniliprole showed no toxicity on H. axyridis, C. sinica, S. manilae and T. remus pupae with the recommended field concentrations. The risk analysis indicated that chlorantraniliprole is harmless to larvae of four natural enemies and adult of H. axyridis, C. sinica and S. manilae. Emamectin benzoate and spinosad had higher safety to the development of H. axyridis, C. sinica, S. manilae and T. remus with the risk duration less than 4d. Indoxacarb, tebufenozide, chlorfenapyr, methomyl, alpha-cypermethrin and chlorpyrifos showed dangerously toxic and long risk duration on S. manilae and T. remus adults.

Assessing farmers' community readiness towards the enhancement of natural enemy population in rice fields in Malacca

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Fairuz, K.; Idris, A. G.; Syahrizan, S.; Hatijah, K.

2018-04-01

Malacca has committed to be a green technology state by the year 2020. Agriculture is one of the main industries that have been highlighted to achieve this goal especially rice farming activities. Some limitations for this issue have restricted the accomplishment of the plan including pesticide usage among rice farmers. The use of chemicals in rice field need to be reduced significantly in order to support the goal. One of the indicators to the successfulness of pesticide reduction is the increasing numbers of natural enemies' species abundance and population in the rice field. Natural enemies were important to regulate pest populations in rice field naturally. Farmers' readiness to participate in this issue is very important to ensure the successfulness. The level of readiness of farmers' community will determine whether they are ready or not to execute the plan. Unfortunately, such information in rice farmers' community was not properly measured. Thus this study was aimed to assess the readiness level of rice farmers' community to change in order to enhance natural enemies in their rice field. This study was adapting the CR model as its theoretical framework. Three rice farming area in Malacca were involved in this study namely, Jasin, Melaka Tengah and Alor Gajah. Questionnaires were used as major instrument and were randomly distributed to 224 farmers. Data collected were tested for their reliability, significance and level of readiness. Knowledge of issue, knowledge of effort and resources dimensions were found influencing the readiness dimension significantly, whilst the attitude and leadership dimensions were not. Generally, the level of readiness for farmers' community in Malacca was found in the sixth or initial stage, where some of them initially have started to practice a few related activities to enhance the natural enemies' population in their rice field. Continuous support and assistant from the leaders and local authorities are crucially needed in

Approaches to conserving natural enemy populations in greenhouse crops: current methods and future prospects

NARCIS (Netherlands)

Messelink, G.J.; Bennison, J.; Alomar, O.; Ingegno, B.L.; Tavella, L.; Shipp, L.; Palevsky, E.; Wäckers, F.L.

2014-01-01

Biological pest control in greenhouse crops is usually based on periodical releases of mass-produced natural enemies, and this method has been successfully applied for decades. However, in some cases there are shortcomings in pest control efficacy, which often can be attributed to the poor

Relative toxicity and residual activity of insecticides used in blueberry pest management: mortality of natural enemies.

Science.gov (United States)

Roubos, Craig R; Rodriguez-Saona, Cesar; Holdcraft, Robert; Mason, Keith S; Isaacs, Rufus

2014-02-01

A series of bioassays were conducted to determine the relative toxicities and residual activities of insecticides labeled for use in blueberry (Vaccinium corymbosum L.) on natural enemies, to identify products with low toxicity or short duration effects on biological control agents. In total, 14 insecticides were evaluated using treated petri dishes and four commercially available natural enemies (Aphidius colemani Viereck, Orius insidiosus [Say], Chrysoperla rufilabris [Burmeister], and Hippodamia convergens [Guérin-Menéville]). Dishes were aged under greenhouse conditions for 0, 3, 7, or 14 d before introducing insects to test residual activity. Acute effects (combined mortality and knockdown) varied by insecticide, residue age, and natural enemy species. Broad-spectrum insecticides caused high mortality to all biocontrol agents, whereas products approved for use in organic agriculture had little effect. The reduced-risk insecticide acetamiprid consistently caused significant acute effects, even after aging for 14 d. Methoxyfenozide, novaluron, and chlorantraniliprole, which also are classified as reduced-risk insecticides, had low toxicity, and along with the organic products could be compatible with biological control. This study provides information to guide blueberry growers in their selection of insecticides. Further research will be needed to determine whether adoption of a pest management program based on the use of more selective insecticides will result in higher levels of biological control in blueberry.

Nontarget effects of orchard pesticides on natural enemies: lessons from the field and laboratory

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The nontarget effects of insecticide programs used to control codling moth, Cydia pomonella were studied in large-plot field trials in apples, pears, and walnuts in the western United States. We sampled the abundance of natural enemies and outbreaks of secondary pests. The insecticides used in the f...

Natural enemy-mediated indirect interactions among prey species: potential for enhancing biocontrol services in agroecosystems

NARCIS (Netherlands)

Chailleux, A.; Mohl, E.K.; Teixeira Alves, M.; Messelink, G.J.; Desneux, N.

2014-01-01

Understanding how arthropod pests and their natural enemies interact in complex agroecosystems is essential for pest management programmes. Theory predicts that prey sharing a predator, such as a biological control agent, can indirectly reduce each other's density at equilibrium (apparent

COMPARATIVE EFFICACY OF SYNTHETIC AND BOTANICAL INSECTICIDES AGAINST SUCKING INSECT PEST AND THEIR NATURAL ENEMIES ON COTTON CROP

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M. A. Baker

2016-08-01

Full Text Available The Synthetic and botanical insecticides are relatively safer for environment and beneficial insects. The study was conducted in Rahim Yar Khan during the cotton cropping season 2014 to evaluate the comparative efficacy of two Synthetic insecticides i.e. Nitenpyram (Jasper 10% SL and Pyriproxyfen (Bruce 10.8% EC and two botanical extracts of Calotropic procera and Azadirachta indica, against sucking insect pest complex of cotton and their natural enemies. Upon reaching economic thresholds, the recommended field doses of all the insecticides were applied on cotton cultivar MNH-886. Data against sucking pests and their natural enemies was recorded 24 hours prior to insecticidal application and then 24, 48, 72 and 96 hours after insecticidal application. Results revealed that Nitenpyram was much toxic against sucking pests followed by Pyriproxyfen as compared to two botanical extracts. On the other hand, the synthetic insecticides did not prove safer for natural enemies as compared to botanical extracts. It was concluded that as an Integrated Pest Management (IPM strategy, botanical extracts can be used at low infestation levels so that ecosystem service of biological control may be sustained.

Fire Ants (Solenopsis spp.) and Their Natural Enemies in Southern South America

OpenAIRE

Briano, Juan; Calcaterra, Luis; Varone, Laura

2012-01-01

We review the fire ant research conducted by the ARS-South American Biological Control Laboratory (SABCL) since 1987 to find a complex of natural enemies in southern South America and evaluate their specificity and suitability for field release as self-sustaining biological control agents. We also include those studies conducted by the ARS-Center for Medical, Agriculture, and Veterinary Entomology in the United States with the SABCL collaboration. Ecological and biological information is repo...

Control of the Tomato Leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), in Open-Field Tomatoes by Indigenous Natural Enemies Occurring in Israel.

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Shaltiel-Harpaz, Liora; Gerling, Dan; Graph, Shaul; Kedoshim, Hendrika; Azolay, Lotem; Rozenberg, Tamir; Nachache, Yaakov; Steinberg, Shimon; Allouche, Arnon; Alon, Tamar

2016-02-01

The tomato leafminer, Tuta absoluta (Meyrick), had established in Israel by 2010, attacking both open-field tomatoes and greenhouse crops.We searched for its natural enemies in open-field tomatoes, and tried to determine their potential for controlling this pest. We surveyed the local natural enemies in open tomato fields and measured their impact on pest populations in an unsprayed field. We assessed the suppressive ability of the dominant hemipteran predator, Nesidiocoris tenuis Reuter, against T. absoluta under controlled laboratory conditions and evaluated the impact of its augmentation on T. absoluta control in open-field tomatoes. We found five natural enemy species:the predator, N. tenuis, two braconids, and two eulophids. Predation accounted for 64.5±9.2% (mean ± SE) of T. absoluta larval mortality, whereas parasitism accounted for 20.96±7.5%. Together, they eliminated the pest population at tomato harvest time. Under controlled conditions, predation by N. tenuis rose from 58 to 72% with increased density of T. absoluta, suggesting positive density dependence. The reduction of T. absoluta (83%) by N. tenuis was higher than that of Bemisia tabaci (32%), suggesting a preference of N. tenuis for T. absoluta. Augmentation of N.tenuis was as effective as conventional treatment insecticide treatment, and plant damage was low and did not seem to affect yield. Results indicate that reduced pesticide use enables indigenous natural enemies, particularly N.tenuis, to successfully control T. absoluta and prevent crop damage in open-field tomatoes.

Susceptibility of natural enemies of pests of agriculture to commonly applied insecticides in Honduras

International Nuclear Information System (INIS)

Bustamante, M.; Sabillon, A.; Velasquez, C.; Ordonez, J.; Baquedano, F.

1999-01-01

Insecticides are commonly used by Honduran farmers to control pest insects in agricultural crops such as corn, melons and tomatoes. However, the insecticides have the potential for toxicity to the natural enemies of the pest insects also. Therefore, efforts are being made to identify insecticides which, when used within the Inegerated Pest Management (IPM) programme, are selectively more toxic to the pest insects than their natural enemies. A number of selected chemical insecticides and a biological insecticide (NPV) were tested in three different tests to determine toxicity to two beneficial insects: Telenomus remus Nixon (Hymenoptera: Scelionidae) and Chrysoperla carnea Steph. (Neuroptera: Chrysopidae). All insecticides were toxic to T. remus which suffered high mortality. There was no significant difference in mortality of the insect due to the method of exposure to the insecticides. There were some differences in the toxicity of the insecticides to C. carnea, and abamectin, bifenthrin, cypermethrin, diafenthiuron, imidacloprid and fenpropathrin were relatively less toxic and could be used in IPM for the control of pest insects. (author)

[Effects of plant viruses on vector and non-vector herbivorous arthropods and their natural enemies: a mini review].

Science.gov (United States)

He, Xiao-Chan; Xu, Hong-Xing; Zhou, Xiao-Jun; Zheng, Xu-Song; Sun, Yu-Jian; Yang, Ya-Jun; Tian, Jun-Ce; Lü, Zhong-Xian

2014-05-01

Plant viruses transmitted by arthropods, as an important biotic factor, may not only directly affect the yield and quality of host plants, and development, physiological characteristics and ecological performances of their vector arthropods, but also directly or indirectly affect the non-vector herbivorous arthropods and their natural enemies in the same ecosystem, thereby causing influences to the whole agro-ecosystem. This paper reviewed the progress on the effects of plant viruses on herbivorous arthropods, including vector and non-vector, and their natural enemies, and on their ecological mechanisms to provide a reference for optimizing the management of vector and non-vector arthropod populations and sustainable control of plant viruses in agro-ecosystem.

Early-season movement dynamics of phytophagous pest and natural enemies across a native vegetation-crop ecotone

NARCIS (Netherlands)

Macfadyen, S.; Hopkinson, J.; Parry, H.; Neave, M.J.; Bianchi, F.J.J.A.; Zalucki, M.P.; Schellhorn, N.A.

2015-01-01

There is limited understanding about how insect movement patterns are influenced by landscape features, and how landscapes can be managed to suppress pest phytophage populations in crops. Theory suggests that the relative timing of pest and natural enemy arrival in crops may influence pest

Recognising one's enemies : a functional approach to risk assessment by prey

NARCIS (Netherlands)

Grostal, P.; Dicke, M.

2000-01-01

Little has been done to compare the relative importance of various mechanisms through which prey assess the potential risk from natural enemies. We used predator-naive spider mites (Tetranychus urticae, Tetranychidae) to (1) compare the responses of prey to chemical cues from enemy and non-enemy

Responses of Crop Pests and Natural Enemies to Wildflower Borders Depends on Functional Group.

Science.gov (United States)

McCabe, Ellie; Loeb, Gregory; Grab, Heather

2017-07-25

Increased homogeneity of agricultural landscapes in the last century has led to a loss of biodiversity and ecosystem services. However, management practices such as wildflower borders offer supplementary resources to many beneficial arthropods. There is evidence that these borders can increase beneficial arthropod abundance, including natural enemies of many pests. However, this increase in local habitat diversity can also have effects on pest populations, and these effects are not well-studied. In this study, we investigated how wildflower borders affect both natural enemies and pests within an adjacent strawberry crop. Significantly more predators were captured in strawberry plantings with wildflower borders versus plantings without wildflowers, but this effect depended on sampling method. Overall, herbivore populations were lower in plots with a wildflower border; however, responses to wildflower borders varied across specific pest groups. Densities of Lygus lineolaris (Tarnished Plant Bug), a generalist pest, increased significantly in plots that had a border, while Stelidota geminata (Strawberry Sap Beetle) decreased in strawberry fields with a wildflower border. These results suggest that wildflower borders may support the control of some pest insects; however, if the pest is a generalist and can utilize the resources of the wildflower patch, their populations may increase within the crop.

Exploratory survey for the emerald ash borer, Agrilus planipennis (Coleoptera: Buprestidae), and its natural enemies in China.

Science.gov (United States)

Houping Liu; Leah S. Bauer; Ruitong Gao; Tonghai Zhao; Toby R. Petrice; Robert A. Haack

2003-01-01

An exploratory survey for the emerald ash borer, Agrilus planipennis, and its natural enemies was conducted in China during October and November 2003. We examined 29 field plots in six provinces. We visually inspected living Fraxinus chinensis, F. mandshurica, F. pennsylvanica, F. rhynchophylla, and F. velutina...

Effects of weed cover composition on insect pest and natural enemy abundance in a field of Dracaena marginata (Asparagales: Asparagaceae) in Costa Rica.

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Sadof, Clifford S; Linkimer, Mildred; Hidalgo, Eduardo; Casanoves, Fernando; Gibson, Kevin; Benjamin, Tamara J

2014-04-01

Weeds and their influence on pest and natural enemy populations were studied on a commercial ornamental farm during 2009 in the Atlantic Zone of Costa Rica. A baseline survey of the entire production plot was conducted in February, along a 5 by 5 m grid to characterize and map initial weed communities of plants, cicadellids, katydids, and armored scales. In total, 50 plant species from 21 families were found. Seven weed treatments were established to determine how weed manipulations would affect communities of our targeted pests and natural enemies. These treatments were selected based on reported effects of specific weed cover on herbivorous insects and natural enemies, or by their use by growers as a cover crop. Treatments ranged from weed-free to being completely covered with endemic species of weeds. Although some weed treatments changed pest abundances, responses differed among arthropod pests, with the strongest effects observed for Caldwelliola and Empoasca leafhoppers. Removal of all weeds increased the abundance of Empoasca, whereas leaving mostly cyperacaeous weeds increased the abundance of Caldwelliola. Weed manipulations had no effect on the abundance of katydid and scale populations. No weed treatment reduced the abundance of all three of the target pests. Differential responses of the two leafhopper species to the same weed treatments support hypotheses, suggesting that noncrop plants can alter the abundance of pests through their effects on arthropod host finding and acceptance, as well as their impacts on natural enemies.

[Research progress in chemical communication among insect-resistant genetically modified plants, insect pests and natural enemies].

Science.gov (United States)

Liu, Qing-Song; Li, Yun-He; Chen, Xiu-Ping; Peng, Yu-Fa

2014-08-01

Semiochemicals released by plants or insects play an important role in the communication among plants, phytophagous insects and their natural enemies. They thus form a chemical information network which regulates intra- and inter-specific behaviors and sustains the composition and structure of plant and insect communities. The application of insect-resistant genetically modified (IRGM) crops may affect the chemical communication within and among the tritrophic levels, and thus cause disturbances to the biotic community structure and the stability of the farmland ecosystem. This has raised concerns about the environmental safety of IRGM crops and triggered research worldwide. In the current article we provided a brief summary of the chemical communication among plants, herbivores and natural enemies; analyzed the potential of IRGM crops to affect the chemical communication between plants and arthropods and the related mechanisms; and discussed the current research progress and the future prospects in this field. We hope that this will promote the research in this field by Chinese scientists and increase our understanding of the potential effects of growing of IRGM crops on the arthropod community structure.

Collective defense of Aphis nerii and Uroleucon hypochoeridis (Homoptera, Aphididae against natural enemies.

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Manfred Hartbauer

2010-04-01

Full Text Available The prevalent way aphids accomplish colony defense against natural enemies is a mutualistic relationship with ants or the occurrence of a specialised soldier caste typical for eusocial aphids, or even both. Despite a group-living life style of those aphid species lacking these defense lines, communal defense against natural predators has not yet been observed there. Individuals of Aphis nerii (Oleander aphid and Uroleucon hypochoeridis, an aphid species feeding on Hypochoeris radicata (hairy cat's ear, show a behavioral response to visual stimulation in the form of spinning or twitching, which is often accompanied by coordinated kicks executed with hind legs. Interestingly, this behaviour is highly synchronized among members of a colony and repetitive visual stimulation caused strong habituation. Observations of natural aphid colonies revealed that a collective twitching and kicking response (CTKR was frequently evoked during oviposition attempts of the parasitoid wasp Aphidius colemani and during attacks of aphidophagous larvae. CTKR effectively interrupted oviposition attempts of this parasitoid wasp and even repelled this parasitoid from colonies after evoking consecutive CTKRs. In contrast, solitary feeding A. nerii individuals were not able to successfully repel this parasitoid wasp. In addition, CTKR was also evoked through gentle substrate vibrations. Laser vibrometry of the substrate revealed twitching-associated vibrations that form a train of sharp acceleration peaks in the course of a CTKR. This suggests that visual signals in combination with twitching-related substrate vibrations may play an important role in synchronising defense among members of a colony. In both aphid species collective defense in encounters with different natural enemies was executed in a stereotypical way and was similar to CTKR evoked through visual stimulation. This cooperative defense behavior provides an example of a surprising sociality that can be found

Exchange of natural enemies for biological control: is it a rocky road?-the road in the Euro-Mediterranean region and the South American common market.

Science.gov (United States)

Coutinot, D; Briano, J; Parra, J R P; de Sá, L A N; Cônsoli, F L

2013-02-01

The access and benefit sharing (ABS) regulations from the Convention on Biological Diversity (CBD) for the use of natural resources became an important issue because the biodiversity of developing countries was heavily accessed and unilaterally exploited by pharmaceutical and seed companies. However, natural enemies used for biological control are living and unmodified genetic resources which cannot be patented and have been treated as resources such as drugs, seeds, or other commercial products. Consequently, the ABS requirements have limited not only the use of natural enemies but also the positive effects that scientifically supported biological control strategies have on the society, the environment, and the economy, reducing problems of pesticide residues, water and soil contamination, and non-target effects. During the last several years, the biological control scientific community has faced new and extremely complicated legislation dictated by a high and diverse number of governmental agencies at different levels, making the access to natural resources for biocontrol purposes a rocky road. Society at large should be aware of how the strict ABS regulations affect the use of natural enemies as biological resources to secure food production, food safety, and global environmental protection. We discuss in here the current difficulties derived from CBD for the exchange of natural enemies taking as example the Euro-Mediterranean region, Argentina, and Brazil to demonstrate how long and diverse are the steps to be followed to obtain the required permits for access and exportation/importation of natural enemies. We then argue that the public visibility of biocontrol strategies should be increased and their benefits highlighted in order to persuade legislators for the development of a less bureaucratic, more expedient, and more centralized regulatory frame, greatly favoring the practice and benefits of biological control. We finally propose a general framework in

Within-field distribution of the damson-hop aphid Phorodon humuli (Schrank) (Hemiptera: Aphididae) and natural enemies on hops in Spain

Energy Technology Data Exchange (ETDEWEB)

Lorenzana, A.; Hermoso de Mendoza, A.; Seco, V.; Campelo, P.; Casquero, P.A.

2017-07-01

A field trial was performed in a hop yard throughout 2002, 2003 and 2004 in order to determine the within-field distribution of Phorodon humuli (Schrank) (Hemiptera: Aphididae) and its natural enemies. The distribution of P. humuli was directly affected by the position of the hop plants in the garden, with significantly higher concentrations of aphids (p=0.0122 in 2002 and p=0.0006 in 2003) observed along the edge. However, in 2004 the plants located on the marginal plots had similar populations to those on the more inner plots. This can be explained by a higher wind speed which made it more difficult to land on edge plants first. The hop aphid’s main natural enemy was Coccinella septempunctata (Coleoptera: Coccinellidae), whose population was greatest where the aphids were most abundant with a significantly greater number of eggs (p=0.0230) and adults (p=0.0245) in 2003. Lacewing eggs were also frequently observed, with a significantly higher population (p=0.0221 in 2003 and p=0.0046 in 2004) where the aphid numbers were high. The number of winged aphids was greatest towards the margins of the garden in 2003. It is argued that the spatial distribution of the hop aphid and its natural enemies could be used to plan a sampling program and to estimate the population densities of these insects for use in integrated pest management programs.

Within-field distribution of the damson-hop aphid Phorodon humuli (Schrank) (Hemiptera: Aphididae) and natural enemies on hops in Spain

International Nuclear Information System (INIS)

Lorenzana, A.; Hermoso de Mendoza, A.; Seco, V.; Campelo, P.; Casquero, P.A.

2017-01-01

A field trial was performed in a hop yard throughout 2002, 2003 and 2004 in order to determine the within-field distribution of Phorodon humuli (Schrank) (Hemiptera: Aphididae) and its natural enemies. The distribution of P. humuli was directly affected by the position of the hop plants in the garden, with significantly higher concentrations of aphids (p=0.0122 in 2002 and p=0.0006 in 2003) observed along the edge. However, in 2004 the plants located on the marginal plots had similar populations to those on the more inner plots. This can be explained by a higher wind speed which made it more difficult to land on edge plants first. The hop aphid’s main natural enemy was Coccinella septempunctata (Coleoptera: Coccinellidae), whose population was greatest where the aphids were most abundant with a significantly greater number of eggs (p=0.0230) and adults (p=0.0245) in 2003. Lacewing eggs were also frequently observed, with a significantly higher population (p=0.0221 in 2003 and p=0.0046 in 2004) where the aphid numbers were high. The number of winged aphids was greatest towards the margins of the garden in 2003. It is argued that the spatial distribution of the hop aphid and its natural enemies could be used to plan a sampling program and to estimate the population densities of these insects for use in integrated pest management programs.

Seasonal abundance and development of the Asian longhorned beetle and natural enemy prevalence in different forest types in China

Science.gov (United States)

Houping Liu; Leah S. Bauer; Tonghai Zhao; Ruitong Gao; Therese M. Poland

2016-01-01

Seasonal abundance and population development of the Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), and prevalence of its natural enemies were studied on Hankow willow (Salix matsudana Koidz.) at an urban forest site (Anci) and a rural forest site (Tangerli) in Hebei province...

Integrative review of indigenous arthropod natural enemies of the invasive brown marmorated stink bug in North America and Europe

Science.gov (United States)

Since the establishment of the brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae) in North America and Europe, there has been a large, multi-group effort to characterize the composition and impact of the indigenous community of arthropod natural enemies attacking this invas...

Comparison of Relative Bias, Precision, and Efficiency of Sampling Methods for Natural Enemies of Soybean Aphid (Hemiptera: Aphididae).

Science.gov (United States)

Bannerman, J A; Costamagna, A C; McCornack, B P; Ragsdale, D W

2015-06-01

Generalist natural enemies play an important role in controlling soybean aphid, Aphis glycines (Hemiptera: Aphididae), in North America. Several sampling methods are used to monitor natural enemy populations in soybean, but there has been little work investigating their relative bias, precision, and efficiency. We compare five sampling methods: quadrats, whole-plant counts, sweep-netting, walking transects, and yellow sticky cards to determine the most practical methods for sampling the three most prominent species, which included Harmonia axyridis (Pallas), Coccinella septempunctata L. (Coleoptera: Coccinellidae), and Orius insidiosus (Say) (Hemiptera: Anthocoridae). We show an important time by sampling method interaction indicated by diverging community similarities within and between sampling methods as the growing season progressed. Similarly, correlations between sampling methods for the three most abundant species over multiple time periods indicated differences in relative bias between sampling methods and suggests that bias is not consistent throughout the growing season, particularly for sticky cards and whole-plant samples. Furthermore, we show that sticky cards produce strongly biased capture rates relative to the other four sampling methods. Precision and efficiency differed between sampling methods and sticky cards produced the most precise (but highly biased) results for adult natural enemies, while walking transects and whole-plant counts were the most efficient methods for detecting coccinellids and O. insidiosus, respectively. Based on bias, precision, and efficiency considerations, the most practical sampling methods for monitoring in soybean include walking transects for coccinellid detection and whole-plant counts for detection of small predators like O. insidiosus. Sweep-netting and quadrat samples are also useful for some applications, when efficiency is not paramount. © The Authors 2015. Published by Oxford University Press on behalf of

NATURAL ENEMIES OF DIURAPHIS NOXIA (STERNORRHYNCHA: APHIDIDAE IN SLOVAKIA

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Peter TÓTH

2009-11-01

Full Text Available A study from 2002 documented the occurrence of natural enemies (parasitoid wasps, predatory fl ies, entomopathogenic fungi associated with colonies of the Russian wheat aphid, Diuraphis noxia (Kurdjumov, 1913 (Sternorrhyncha: Aphididae, in the spring barley fi elds in Slovakia. Parasitization by wasps was low (<5.5% with Diaeretiella rapae (McIntosh, 1855 the dominant hymenopterous parasitoid (91% of emerging wasps. The remaining parasitoid guild comprised of Aphidius ervi Haliday, 1834 Aphidius rhopalosiphi DeStefani, 1902, Aphidius picipes (Nees, 1811, Ephedrus plagiator (Nees, 1811, Praon volucre (Haliday, 1833 (Hymenoptera: Aphidiidae and two hyperparasites Asaphes suspensus (Nees, 1834 (Hymenoptera: Pteromalidae and Lygocerus spp. (Hymenoptera: Ceraphronidae. Predaceous midges (Diptera: Cecidomyiidae were consistently found with densities ranging from 0.1 to 2.5 larvae per aphid colony. The most abundant predaceous midge was Aphidoletes aphidimyza (Rondani, 1847, while Lestodiplosis sp. was recorded infrequently. Four syrphids, Episyrphus balteatus (De Geer, 1776, Melanostoma mellinum (L., 1758, Sphaerophoria rueppellii (Wiedemann, 1830, Sphaerophoria scripta (L., 1758 (Diptera: Syrphidae and one pathogenic fungus, Pandora neoaphidis (Remaudière et Hennebert Humber, were recorded.

Reduced risk insecticides to control scale insects and protect natural enemies in the production and maintenance of urban landscape plants.

Science.gov (United States)

Frank, Steven D

2012-04-01

Armored scale insects are among the most difficult to manage and economically important arthropod pests in the production and maintenance of urban landscape plants. This is because of morphological traits that protect them from contact insecticides. I compared initial and season-long control of euonymus scale, Unaspis euonymi Comstock (Hemiptera: Diaspidae), by reduced-risk insecticides (insect growth regulators [IGRs], neonicotinoids, spirotetramat) to determine if they controlled scale as well as more toxic insecticides such as the organophosphate, acephate, and pyrethroid, bifenthrin. I also evaluated how these insecticides affected natural enemy abundance on experimental plants and survival when exposed to insecticide residue. All insecticides tested reduced first generation euonymus scale abundance. In 2009, reinfestation by second generation euonymus scale was highest on plants treated with acetamiprid and granular dinotefuran. In 2010, systemic neonicotinoids and spirotetramat prevented cottony cushion scale infestation 133 d after treatment whereas scale readily infested plants treated with bifenthrin and horticultural oil. Encarsia spp. and Cybocephalus spp. abundance was related to scale abundance. These natural enemies were generally less abundant than predicted by scale abundance on granular dinotefuran treated plants and more abundant on granular thiamethoxam treated plants. Bifenthrin residue killed 90-100% of O. insidiosus and E. citrina within 24 h. My results indicate that reduced risk insecticides can provide season-long scale control with less impact on natural enemies than conventional insecticides. This could have economic and environmental benefits by reducing the number of applications necessary to protect nursery and landscape plants from scale.

Impact of integrated pest management on the population of leafminers, fruit borers, and natural enemies in tomato

Directory of Open Access Journals (Sweden)

Miranda Moacyr Mascarenhas Motta

2005-01-01

Full Text Available The objective of this work was to evaluate the impact of integrated pest management (IPM in the productivity of the tomato and in the populations of leafminers, fruit borers, and natural enemies in tomato crops. The treatments were calendar (spraying twice weekly with insecticides and fungicides, IPM (spraying when action thresholds were achieved, and control (no pesticide was applied. IPM was the most efficient system of pest control due to presenting similar productivity and 65.6% less pesticide applications than in the calendar. The attack of Tuta absoluta (Meyrick (Lepidoptera: Gelechiidae and Liriomyza spp. (Diptera: Agromyzidae to the leaves only achieved the action threshold in the final phase of the cultivation. The main fruit borer was Neoleucinoides elegantalis (Guen. (Lepidoptera: Crambidae, followed by T. absoluta and Spodoptera eridania (Cr. (Lepidoptera: Noctuidae. The natural enemy populations were severely reduced by excessive pesticide applications. Predators were more abundant than parasitoids. The most abundant predators were Araneidae, Anthicus sp. (Coleoptera: Anthicidae, Cycloneda sanguinea larva (L. (Coleoptera: Coccinellidae, Staphylinidae adults (Coleoptera, Orius sp. and Xylocoris sp. (Hemiptera: Anthocoridae, Formicidae (Hymenoptera, and Phlaeothripidae (Thysanoptera. The most abundant parasitoids were Hymenoptera of the families Eulophidae, Braconidae (Bracon sp. and Chelonus sp., Trichogrammatidae [Trichogramma pretiosum (Riley] and Bethylidae (Goniozus nigrifemur Ashmead, besides Tachinidae (Diptera.

Effects of imidacloprid and clothianidin seed treatments on wheat aphids and their natural enemies on winter wheat.

Science.gov (United States)

Zhang, Peng; Zhang, Xuefeng; Zhao, Yunhe; Wei, Yan; Mu, Wei; Liu, Feng

2016-06-01

Wheat aphid (Hemiptera: Aphididae) is one of the major pests of winter wheat and has posed a significant threat to winter wheat production in China. Although neonicotinoid insecticidal seed treatments have been suggested to be a control method, the season-long efficacy on pests and the impact on their natural enemies are still uncertain. Experiments were conducted to determine the efficacy of imidacloprid and clothianidin on the control of aphids, the number of their natural enemies and the emergence rate and yield of wheat during 2011-2014. Imidacloprid and clothianidin seed treatments had no effect on the emergence rate of winter wheat and could prevent yield losses and wheat aphid infestations throughout the winter wheat growing season. Furthermore, their active ingredients were detected in winter wheat leaves up to 200 days after sowing. Imidacloprid and clothianidin seed treatments had no adverse effects on ladybirds, hoverflies or parasitoids, and instead increased the spider-aphid ratios. Wheat seeds treated with imidacloprid and clothianidin were effective against wheat aphids throughout the winter wheat growing season and reduced the yield loss under field conditions. Imidacloprid and clothianidin seed treatments may be an important component of the integrated management of wheat aphids on winter wheat. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Avoid, attack or do both? Behavioral and physiological adaptations in natural enemies faced with novel hosts

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Brown Sam P

2005-11-01

Full Text Available Abstract Background Confronted with well-defended, novel hosts, should an enemy invest in avoidance of these hosts (behavioral adaptation, neutralization of the defensive innovation (physiological adaptation or both? Although simultaneous investment in both adaptations may first appear to be redundant, several empirical studies have suggested a reinforcement of physiological resistance to host defenses with additional avoidance behaviors. To explain this paradox, we develop a mathematical model describing the joint evolution of behavioral and physiological adaptations on the part of natural enemies to their host defenses. Our specific goals are (i to derive the conditions that may favor the simultaneous investment in avoidance and physiological resistance and (ii to study the factors that govern the relative investment in each adaptation mode. Results Our results show that (i a simultaneous investment may be optimal if the fitness costs of the adaptive traits are accelerating and the probability of encountering defended hosts is low. When (i holds, we find that (ii the more that defended hosts are rare and/or spatially aggregated, the more behavioral adaptation is favored. Conclusion Despite their interference, physiological resistance to host defensive innovations and avoidance of these same defenses are two strategies in which it may be optimal for an enemy to invest in simultaneously. The relative allocation to each strategy greatly depends on host spatial structure. We discuss the implications of our findings for the management of invasive plant species and the management of pest resistance to new crop protectants or varieties.

Problems Inherent to Augmentation of Natural Enemies in Open Agriculture.

Science.gov (United States)

Michaud, J P

2018-04-01

Augmentation biological control has successfully replaced a lot of insecticide use in 'closed system' agriculture (e.g., greenhouses). The profitable commercialization of biocontrol agents in greenhouses has created an incentive to expand markets for mass-reared beneficial insects into open agricultural systems, often without sufficient scientific justification. However, the semi-contained nature of greenhouse culture is often critical to the success of augmentation and can serve to mask potential pitfalls and intrinsic limitations of this approach in open systems. Factors contributing to greenhouse successes include the reduced biological diversity of contained agroecosystems, the prevention of agent dispersal, the ability to maintain environmental conditions within a range favorable for the agent, the exclusion of competitors and natural enemies of the agent that might otherwise diminish its efficacy, and the absence of alternative prey/hosts that could divert predation/parasitism from the target pest. There are also problems arising from collection of source material from locally adapted populations, and the inadvertent imposition of artificial selection in the course of laboratory rearing. Besides highlighting these pitfalls, this paper aims to encourage more consideration of conservation approaches prior to investment in augmentation programs which entice farmers into perpetual cycles of 'rear and release.' I argue that although augmentation can benefit agriculture whenever it replaces pesticide applications, it does not constitute an ecologically sustainable solution because it requires continued inputs, and it can distract research attention away from more sustainable objectives. Sustainable biological control is best achieved through modifications to cultural practices that increasingly 'naturalize' agroecosystems, thus facilitating the natural recruitment and persistence of beneficial arthropod fauna, combined with habitat management geared to increasing

EVALUATION OF NATURAL ENEMIES IN CONTROLLING OF THE BANANA WEEVIL BORER Cosmopolites sordidus Germar IN WEST SUMATRA

Directory of Open Access Journals (Sweden)

Ahsol Hasyim

2016-10-01

Full Text Available The banana weevil, Cosmopolites sordidus Germar, is an important pest of highland banana and plantain in Africa, but it exists in low densities in presumed area of origin in Southeast Asia such as in Indonesia. This suggests a possible existence of effective co-evolved natural enemies in the origin area of Indonesia, especially West Sumatra. The objectives of this study were: (1 to evaluate banana weevil pest status at selected sites in West Sumatra, (2 to survey parasitoids and predators, and (3 to determine the control potential of the most important natural enemies. Surveys were undertaken in March 2002-August 2003 in five locations in West Sumatra, i.e., Bukittinggi, Sitiung, Pariaman, Pasaman, and Batusangkar. Five farms per site were selected randomly among all farms that contained banana stands of > 0.5 ha. Sampling for banana weevil adults and damage, and for predators was done throughout small banana stands and within a 20 m x 40 m (0.08 ha subplot on larger farms. Field-collected larvae were taken to the laboratory and reared on corm pieces (3 cm x 3 cm x 3 cm until pupation. Larvae were collected from pseudostem as well as corm residues. To estimate the abundance of non-social predators, i.e., those other than ants, 10 residues each on each farm were examined from plants that had been harvested 1-4 weeks, 5-8 weeks or 9 or more weeks before our visit to the site. Samples of the different morphospecies were saved in alcohol for later identification. The result showed that the banana weevil incidence was found to be low,  0.6-1.7 adults per trap. Plant damage indices were below 2.2%. We collected and reared 24,360 eggs and 3118 larvae, but no parasitism was detected. Phorids (Megaselia sp. and drosophilids were recovered from larval rearings, but most likely were scavengers. A complex of predators was detected, the most important of which was the histerid beetles,  Plaesius javanus Erichson. In laboratory tests, adults and larvae

Floral resource utilization by solitary bees (Hymenoptera: Apoidea) and exploitation of their stored foods by natural enemies.

Science.gov (United States)

Wcislo, W T; Cane, J H

1996-01-01

Bees are phytophagous insects that exhibit recurrent ecological specializations related to factors generally different from those discussed for other phytophagous insects. Pollen specialists have undergone extensive radiations, and specialization is not always a derived state. Floral host associations are conserved in some bee lineages. In others, various species specialize on different host plants that are phenotypically similar in presenting predictably abundant floral resources. The nesting of solitary bees in localized areas influences the intensity of interactions with enemies and competitors. Abiotic factors do not always explain the intraspecific variation in the spatial distribution of solitary bees. Foods stored by bees attract many natural enemies, which may shape diverse facets of nesting and foraging behavior. Parasitism has evolved repeatedly in some, but not all, bee lineages. Available evidence suggests that cleptoparasitic lineages are most speciose in temperate zones. Female parasites frequently have a suite of characters that can be described as a masculinized feminine form. The evolution of resource specialization (including parasitism) in bees presents excellent opportunities to investigate phenotypic mechanisms responsible for evolutionary change.

COMPARATIVE EFFICACY OF SYNTHETIC AND BOTANICAL INSECTICIDES AGAINST SUCKING INSECT PEST AND THEIR NATURAL ENEMIES ON COTTON CROP

OpenAIRE

M. A. Baker; A. H. Makhdum; M. Nasir; A. Imran; A. Ahmad; F. Tufail

2016-01-01

The Synthetic and botanical insecticides are relatively safer for environment and beneficial insects. The study was conducted in Rahim Yar Khan during the cotton cropping season 2014 to evaluate the comparative efficacy of two Synthetic insecticides i.e. Nitenpyram (Jasper 10% SL) and Pyriproxyfen (Bruce 10.8% EC) and two botanical extracts of Calotropic procera and Azadirachta indica, against sucking insect pest complex of cotton and their natural enemies. Upon reaching economic thresholds, ...

Effect of insecticides on mealybug destroyer (Coleoptera: Coccinellidae) and parasitoid Leptomastix dactylopii (Hymenoptera: Encyrtidae), natural enemies of citrus mealybug (Homoptera: Pseudococcidae).

Science.gov (United States)

Cloyd, Raymond A; Dickinson, Amy

2006-10-01

In this study, we measured, under laboratory conditions, the direct and indirect effects of insecticides on mealybug destroyer, Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae), and parasitoid Leptomastix dactylopii Howard (Hymenoptera: Encyrtidae), natural enemies of citrus mealybug, Planococcus citri (Risso) (Homoptera: Pseudococcidae). The adult stages of both natural enemies were exposed to sprays of the insecticides buprofezin, pyriproxyfen, flonicamid, acetamiprid, dinotefuran, and clothianidin at label-recommended rates to assess direct mortality after 24, 48, and 72 h, respectively. The effects of the insecticides on L. dactylopii parasitization rate and percentage of parasitoid emergence also were monitored using the label and 4x the recommended label rate. Dinotefuran was extremely detrimental to the adult parasitoid at the label rate with 100% mortality after 24 h. Buprofezin, pyriproxyfen, and flonicamid were not harmful to L. dactylopii when applied at the label rate. At 4x the recommended label rate, dinotefuran, acetamiprid, and clothianidin were all harmful to the parasitoid with 100% mortality 72 h after application. Both buprofezin and flonicamid were not toxic to L. dactylopii with 100% adult survival after 72 h. Pyriproxyfen and flonicamid, at both the label and 4x the recommended label rate, did not negatively affect L. dactylopii parasitization rate or percentage of parasitoid emergence. Acetamiprid, dinotefuran, and clothianidin were toxic to C. montrouzieri adults with 100% mortality after 48 h, whereas buprofezin, pyriproxyfen, and flonicamid demonstrated minimal (10-20% mortality after 48 h) harmful effects to the predator. Based on the results from our study, the indirect effects of the insect growth regulator (IGR) buprofezin were not decisive; however, the IGR pyriproxyfen and the insecticide flonicamid were not directly or indirectly harmful to the predator C. montrouzieri and parastioid L. dactylopii, indicating that

Natural enemies and their impacts on emerald ash borer populations in its native range, with new records of parasitism by two species of beetles

Science.gov (United States)

To investigate the natural enemies of the emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), and their role in regulating the pest population dynamics, we conducted field surveys at multiple forest sites with variable host densities in the pest’s native range (north an...

Reduced-risk insecticides for control of grape berry moth (Lepidoptera: Tortricidae) and conservation of natural enemies.

Science.gov (United States)

Jenkins, Paul E; Isaacs, Rufus

2007-06-01

A 3-yr field study was conducted at commercial grape (Vitis spp.) farms to evaluate insect management programs for control of the grape berry moth, Paralobesia viteana Clemens (Lepidoptera: Tortricidae) and conservation of natural enemies. At each farm, one vineyard received only reduced-risk insecticides for control of second and third generation P. viteana, whereas the comparison vineyard received conventional insecticides. Both vineyards received a conventional insecticide application for control of first generation P. viteana and other insect pests. Monitoring with pheromone traps showed no differences between programs in the total number of adult male moths trapped in vineyards, and oviposition by P. viteana was similar between the two programs in all 3 yr. During weekly samples of crop infestation, both programs had a similar percentage of clusters infested by P. viteana larvae. Berries infested by P. viteana were collected from vineyard borders during the second and third P. viteana generations and held under controlled conditions. In eight of the nine berry samples, survival of larvae was significantly lower in berries collected from vineyards managed under the reduced-risk insecticide program compared with the conventional program. Parasitism of P. citeana larvae in these samples was not consistently different between the two insecticide programs over 3 yr, and similar captures of natural enemies were found on yellow sticky traps in the two programs throughout the study. Our results indicate that integrated pest management programs incorporating reduced-risk insecticides for control of P. viteana can obtain similar or greater control of P. viteana compared with programs based solely on conventional insecticides, but they may not lead to measurable long-term increases in parasitism of P. viteana.

Increased seedling establishment via enemy release at the upper elevational range limit of sugar maple.

Science.gov (United States)

Urli, Morgane; Brown, Carissa D; Narváez Perez, Rosela; Chagnon, Pierre-Luc; Vellend, Mark

2016-11-01

The enemy release hypothesis is frequently invoked to explain invasion by nonnative species, but studies focusing on the influence of enemies on natural plant range expansion due to climate change remain scarce. We combined multiple approaches to study the influence of plant-enemy interactions on the upper elevational range limit of sugar maple (Acer saccharum) in southeastern Québec, Canada, where a previous study had demonstrated intense seed predation just beyond the range limit. Consistent with the hypothesis of release from natural enemies at the range limit, data from both natural patterns of regeneration and from seed and seedling transplant experiments showed higher seedling densities at the range edge than in the core of the species' distribution. A growth chamber experiment manipulating soil origin and temperature indicated that this so-called "happy edge" was not likely caused by temperature (i.e., the possibility that climate warming has made high elevation temperatures optimal for sugar maple) or by abiotic soil factors that vary along the elevational gradient. Finally, an insect-herbivore-exclusion experiment showed that insect herbivory was a major cause of seedling mortality in the core of sugar maple's distribution, whereas seedlings transplanted at or beyond the range edge experienced minimal herbivory (i.e., enemy release). Insect herbivory did not completely explain the high levels of seedling mortality in the core of the species' distribution, suggesting that seedlings at or beyond the range edge may also experience release from pathogens. In sum, while some effects of enemies are magnified beyond range edges (e.g., seed predation), others are dampened at and beyond the range edge (e.g., insect herbivory), such that understanding the net outcome of different biotic interactions within, at and beyond the edge of distribution is critical to predicting species' responses to global change. © 2016 by the Ecological Society of America.

Diversity and Activity of Insect Natural Enemies of the Bag worm (Lepidoptera: Psychidae) within an Oil Palm Plantation in Perak, Malaysia

International Nuclear Information System (INIS)

Norman Kamarudin; Othman Arshad

2016-01-01

Bag worms (Lepidoptera: Psychidae) are one of the important leaf-eating pests of oil palm in Malaysia and Indonesia. Crop losses, due to the extensive defoliation by a serious bag worm attack are inevitable. The establishment and propagation of the bag worm's parasitoids, depend very much on species of flowering plants as sources of nectar. Cassia cobanensis, was proven suitable due to its attractiveness to most bag worm parasitoids. A study to assess the diversity of bag worm's natural enemies (hymenopterous parasitoids and reduuvid predatory bugs) on the C. cobanensis plant and within the undergrowth of the oil palm planting block was evaluated by sweep net and sticky trap sampling. Environmental parameters such as light intensity, temperature and relative humidity were also recorded during the sampling to determine their possible range of influence towards the activity of the insect natural enemies. The Shannon-Wiener diversity index of insect natural enemies occurring on the C. cobanensis plant was 2.32. Among the dominant parasitoids observed on C. cobanensis plants are chalcids (Brachymeria lugubris and Brachymeria carinata) and braconids (Dolichogenidea metesae and Apanteles aluella), besides the reduuvid predator, Cosmolestes picticeps. In contrast, within the oil palm planting block, the undergrowth within the non-harvesting path only recorded a much lower diversity index of 1.09 and 1.12 each, in a block with C. cobanensis at the roadside and without, respectively. However, C. picticeps was shown to be much more dominant within both oil palm planting blocks, up to two- to three-fold, with much lesser numbers of hymenopterous parasitoids (less than five individuals). This indicates the important contribution of C. cobanensis plant towards enriching the diversity of the parasitoids, which are normally not found within the oil palm block, due to much less intense sunlight. In terms of insect activity, they are significantly more active in the

Active insecticides for Diaphania hyalinata selective for the natural enemy Solenopsis saevissima.

Science.gov (United States)

Aguiar, Alex R; Alvarenga, Elson S; Lopes, Mayara C; Santos, Izailda B Dos; Galdino, Tarcisio V; Picanço, Marcelo C

2016-09-01

The objective of this study was to determine the toxicity of the nine synthetic dienamides against the insect pest Diaphania hyalinata (melonworm) and the selectivity of these substances for the predator Solenopsis saevissima (fire ant). Four bioassays were conducted. To begin with, the dienamides that caused high mortality of D. hyalinata have been selected. In the second bioassay the dose-mortality curves of the selected dienamides have been constructed. In the third bioassay, the survival curves for D. hyalinata and the elapsed time to kill 50% of their population have been determined. In the fourth biological test, the selectivity of the substances to the predator S. saevissima has been evaluated. The most active (2E,4E)-N-butylhexa-2,4-dienamide 3d has killed 95% of the melonworm, D. hyalinata, and less than 10% of the natural enemy S. saevissima. The results presented by this compound are superior to the outcome displayed by the commercial insecticide Malathion®. Three of the dienamides prepared in this manuscript have proven to be selective in killing the pest, but not the beneficial insect.

Fire Ants (Solenopsis spp. and Their Natural Enemies in Southern South America

Directory of Open Access Journals (Sweden)

Juan Briano

2012-01-01

Full Text Available We review the fire ant research conducted by the ARS-South American Biological Control Laboratory (SABCL since 1987 to find a complex of natural enemies in southern South America and evaluate their specificity and suitability for field release as self-sustaining biological control agents. We also include those studies conducted by the ARS-Center for Medical, Agriculture, and Veterinary Entomology in the United States with the SABCL collaboration. Ecological and biological information is reported on local fire ants and their microsporidia, nematodes, viruses, phorid flies, eucharitid wasps, strepsiptera, and parasitic ants. Their biology, abundance, distribution, detrimental effect, field persistence, specificity, and phenology are discussed. We conclude that the objectives of the ARS program in South America are being achieved and that the pioneering studies have served to encourage further investigations in the United States and other countries and advanced the implementation of biological control programs to decrease imported fire ant densities and damage. Still, several promising organisms should be further investigated for eventual field release in the near future.

Conservation biological control and enemy diversity on a landscape scale

NARCIS (Netherlands)

Tscharntke, T.; Bommarco, R.; Clough, Y.; Crist, T.O.; Kleijn, D.; Rand, T.A.; Tylianakis, J.M.; Nouhuys, S.; Vidal, S.

2007-01-01

Conservation biological control in agroecosystems requires a landscape management perspective, because most arthropod species experience their habitat at spatial scales beyond the plot level, and there is spillover of natural enemies across the crop–noncrop interface. The species pool in the

Significance of the tropical fire ant Solenopsis geminata (hymenoptera: formicidae) as part of the natural enemy complex responsible for successful biological control of many tropical irrigated rice pests.

Science.gov (United States)

Way, M J; Heong, K L

2009-10-01

The tropical fire ant Solenopsis geminata (Fabricius) often nests very abundantly in the earthen banks (bunds) around irrigated rice fields in the tropics. Where some farmers habitually drain fields to the mud for about 3-4 days, the ants can quickly spread up to about 20 m into the fields where they collect food, including pest prey such as the eggs and young of the apple snail Pomacea caniculata (Lamarck) and insects such as lepidopterous larvae and hoppers, notably Nilaparvata lugens (Stäl) the brown planthopper (Bph) and green leafhoppers Nephotettix spp. Even in drained fields, the activity of S. geminata is restricted by rainfall in the wet season. The relatively few ant workers that forage characteristically into drained fields and on to the transplanted clumps of rice plants (hills) kill the normally few immigrant Bph adults but are initially slower acting than other species of the natural enemy complex. However, larger populations of Bph are fiercely attacked and effectively controlled by rapidly recruited ant workers; whereas, in the absence of the ant, the other natural enemies are inadequate. In normal circumstances, there is no ant recruitment in response to initially small populations of immigrant Bph and no evidence of incompatibility between ant foragers and other natural enemies such as spiders. However, when many ants are quickly and aggressively recruited to attack large populations of Bph, they temporarily displace some spiders from infested hills. It is concluded that, in suitable weather conditions and even when insecticides kill natural enemies within the rice field, periodic drainage that enables S. geminata to join the predator complex is valuable for ant-based control of pests such as snails and Lepidoptera, and especially against relatively large populations of Bph. Drainage practices to benefit ants are fully compatible with recent research, which shows that periodic drainage combats problems of 'yield decline' in intensively irrigated

Image of Enemy

DEFF Research Database (Denmark)

Galster, Kjeld

2004-01-01

ABSRTACT Galster, Kjeld Hald. MA (War Studies). Royal Military College of Canada. May 2004. Image of Enemy: A Naturalistic or an Expressionistic Picture. Supervisor: Dr. Michael Roi. Societies at war rely on perceptions and preconceptions of their enemies. In many ways, the perceptions are shaped......, et peut-être des guerres. D’être capable de prédire les décisions et les actions de l’ennemi, ainsi éliminant complètement l’incertitude, il faut pénétrer à l’intérieur du cerveau adverse. Cela n’arrivera toutefois pas dans un avenir rapproché – ou peut-être jamais du tout....

Invasive plants and enemy release: Evolution of trait means and trait correlations in Ulex europaeus

OpenAIRE

Hornoy , Benjamin; Tarayre , Michèle; Hervé , Maxime; Gigord , Luc; Atlan , Anne

2011-01-01

International audience; Several hypotheses that attempt to explain invasive processes are based on the fact that plants have been introduced without their natural enemies. Among them, the EICA (Evolution of Increased Competitive Ability) hypothesis is the most influential. It states that, due to enemy release, exotic plants evolve a shift in resource allocation from defence to reproduction or growth. In the native range of the invasive species Ulex europaeus, traits involved in reproduction a...

LANDSCAPE CHANGES IN A LOWLAND IN BENIN: ECOLOGICAL IMPACT ON PESTS AND NATURAL ENEMIES.

Science.gov (United States)

Boucher, A; Silvie, P; Menozzi, P; Adda, C; Auzoux, S; Jean, J; Huat, J

2015-01-01

Habitat management involving conservative biological control could be a good crop pest management option in poor African countries. A survey was conducted from August 2013 to July 2014 in a rainfed lowland region near Pélébina, northern Benin, in order to characterize spatiotemporal landscape changes and investigate their influence on the main crop pests and their associated natural enemies. The area was mapped mainly regarding crop fields and fallows. Visual observations were recorded and a database was compiled. Major landscape composition changes were noted between rainy and dry seasons, which affected the presence of both pests and natural enemies. Cereals (rice, maize and sorghum) and cotton were grown in the humid season, and then okra (Abelmoschus esculentus) was the dominant vegetable crop in dry season. These modifications impacted fallow abundance throughout the lowland. Different cotton (e.g. Helicoverpa armigera, Dysdercus sp., Zonocerus variegatus) or rice (e.g. Diopsis longicornis, D. apicalis) pests were observed during dry season in okra crops. Dry season surveys of Poaceae in two types of fallows ('humid', 'dry') revealed the presence of very few stem borers: only 0.04% of stems sampled were infested by stem borers, with a mean of 1.13 larvae per stem. Known cereal stem borer species such as Busseola fusco, Coniesta ignefusalis, Sesamia calamistis were not clearly identified among these larvae because of their diapausing stage and white color. Unexpected pollinators (Hymenoptera Apidae, genus Braunsapis, Ceratina and Xylocopa) and predators (Crabronidae, genus Dasyproctus) were found in the stems. Sweep-net collection of insects in humid fallows allowed us to describe for the first time in Benin seven Diopsidae species (23% of adults bearing Laboulbeniomycetes ectoparasitic fungi). Some of these species were captured in rice fields during rainy season. Parasitoids (adult Chalcidoidae and Ichneumonoidae) were observed during both seasons but their

Insecticides suppress natural enemies and increase pest damage in cabbage.

Science.gov (United States)

Bommarco, Riccardo; Miranda, Freddy; Bylund, Helena; Björkman, Christer

2011-06-01

Intensive use of pesticides is common and increasing despite a growing and historically well documented awareness of the costs and hazards. The benefits from pesticides of increased yields from sufficient pest control may be outweighed by developed resistance in pests and killing of beneficial natural enemies. Other negative effects are human health problems and lower prices because of consumers' desire to buy organic products. Few studies have examined these trade-offs in the field. Here, we demonstrate that Nicaraguan cabbage (Brassica spp.) farmers may suffer economically by using insecticides as they get more damage by the main pest diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), at the same time as they spend economic resources on insecticides. Replicated similarly sized cabbage fields cultivated in a standardized manner were either treated with insecticides according common practice or not treated with insecticides over two seasons. Fields treated with insecticides suffered, compared with nontreated fields, equal or, at least in some periods of the seasons, higher diamondback moth pest attacks. These fields also had increased leaf damage on the harvested cabbage heads. Weight and size of the heads were not affected. The farmers received the same price on the local market irrespective of insecticide use. Rates of parasitized diamondback moth were consistently lower in the treated fields. Negative effects of using insecticides against diamondback moth were found for the density of parasitoids and generalist predatory wasps, and tended to affect spiders negatively. The observed increased leaf damages in insecticide-treated fields may be a combined consequence of insecticide resistance in the pest, and of lower predation and parasitization rates from naturally occurring predators that are suppressed by the insecticide applications. The results indicate biological control as a viable and economic alternative pest management strategy

Sugarcane Aphid Population Growth, Plant Injury, and Natural Enemies on Selected Grain Sorghum Hybrids in Texas and Louisiana.

Science.gov (United States)

Brewer, Michael J; Gordy, John W; Kerns, David L; Woolley, James B; Rooney, William L; Bowling, Robert D

2017-10-01

In response to the 2013 outbreak of sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), on sorghum, Sorghum bicolor (L.), in North America, experiments were conducted at three southern U.S. grain sorghum production locations (Corpus Christi, TX; Winnsboro, LA; Rosenberg, TX). The objectives were to authenticate yield decline on susceptible hybrids (2014 and 2015) and to measure aphid population growth and natural enemy prevalence on susceptible and resistant hybrids with similar genetic background (2014). Yield decline on susceptible hybrids (Tx 2752/Tx430 and DKS53-67) was more substantial when aphid population growth accelerated quickly and peaked above 300 aphids per leaf (50 to nearly 100% yield decline). Location and year variation in maximum aphid density and cumulative aphid-days was high, with doubling time values on the susceptible hybrids ranging between 3.9 and 7.9 d. On resistant Tx2752/Tx2783, leaf injury and yield decline were not seen or less severe than on its paired susceptible Tx2752/Tx430. Aphids declined on Tx2752/Tx2783 after initial colony establishment (Corpus Christi) or took about 60% longer to double in population size when compared with Tx2572/Tx430 (Winnsboro). The predominant natural enemy taxa were aphelinid mummies (Hymenoptera: Aphelinidae), ladybird beetles (Coleoptera: Coccinellidae), and sryphid flies (Diptera: Syrphidae), and they were more prevalent during flowering than prior to flowering. They were generally responsive to changes in aphid density of both susceptible and resistant hybrids, but variability points to need for further study. In future research, full season observations should continue as well as more detailed study of potential compatibility of sorghum resistance and biological control. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Ecological effects of wheat-oilseed rape intercropping combined with methyl salicylate release on Sitobion avenae and its main natural enemies].

Science.gov (United States)

Dong, Jie; Liu, Ying-Jie; Li, Pei-Ling; Lin, Fang-Jing; Chen, Ju-Lian; Liu, Yong

2012-10-01

In order to explore the effects of wheat-oilseed rape intercropping in combining with methyl salicylate (MeSA) release on Sitobion avenae and its main natural enemies, a field experiment was conducted at the Tai'an Experimental Station of Shandong Agricultural University in East China from October 2008 to June 2010 to study the temporal dynamics of S. avenae and its main natural enemies as well as the ecological control effect on the aphid. In the plots of intercropping combined with MeSA release, the S. avenae apterae population reached a peak about 12 d in advance of the control, but the peak value was significantly lower than that of the control. The average annual number of S. avenae apterae per 100 wheat tillers decreased in the order of wheat monoculture > wheat-oilseed rape intercropping > MeSA release > wheat-oilseed rape intercropping combined with MeSA release. Moreover, the total number of ladybeetles was the highest in the plots of intercropping combined with MeSA release. The population densities of aphid parasitoids reached a peak about 10 d in advance of the control, which could play a significant role in controlling S. avenae at the filling stage of wheat. Taking the biological control index (BCI) as a quantitative indicator, and with the ladybeetles and parasitoids as the dominant control factors in fields, it was observed that wheat-oilseed rape intercropping combined with MeSA release could suppress the population increase of S. avenae apterae effectively from the heading to filling stages of wheat.

The destruction of the nameless public enemy: an interpretation of the political in Carl Schmitt

Directory of Open Access Journals (Sweden)

Felipe Alves da Silva

2017-10-01

Full Text Available This paper proposes a critical analysis of the essential criteria to define the concept of the political as presented by German jurist and philosopher, Carl Schmitt. Based on the essence of the political —i.e. the friend-enemy duality—, the objective is to explore the practical implications resulting from the actual possibilities of confrontation, the key scope being the analysis of a totalitarian potential from a Schmittian´s perspective. In Schmitt´s thought, this distinction is the fundamental reason for the definition of the political. Not every opponent is necessarily the enemy –—the other one, the unknown— and likely to be physically destroyed and exterminated but only a public enemy (hostis. Given its indeterminate nature, the enemy may be prescribed according to the sovereign design or, in the context of Nazi Germany where Carl Schmitt lived, in accordance with the President of the Reich´s designs. A hypothetical-deductive methodology is used in this work based on bibliographical research, in particular regarding Carl Schmitt´s theoretical constructions.

By-product mutualism with evolving common enemies.

Science.gov (United States)

De Jaegher, Kris

2017-05-07

The common-enemy hypothesis of by-product mutualism states that organisms cooperate when it is in their individual interests to do so, with benefits for other organisms arising as a by-product; in particular, such cooperation is hypothesized to arise when organisms face the common enemy of a sufficiently adverse environment. In an evolutionary game where two defenders can cooperate to defend a common resource, this paper analyzes the common-enemy hypothesis when adversity is endogenous, in that an attacker sets the number of attacks. As a benchmark, we first consider exogenous adversity, where adversity is not subject to evolution. In this case, the common-enemy hypothesis is predicted when the degree of complementarity between defenders' defensive efforts is sufficiently low. When the degree of complementarity is high, the hypothesis is predicted only when cooperation costs are high; when cooperation costs are instead low, a competing hypothesis is predicted, where adversity discourages cooperation. Second, we consider the case of endogenous adversity. In this case, we continue to predict the competing hypothesis for a high degree of complementarity and low cooperation costs. The common-enemy hypothesis, however, only continues to be predicted for the lowest degrees of complementarity. Copyright © 2017 Elsevier Ltd. All rights reserved.

By-product mutualism with evolving common enemies

NARCIS (Netherlands)

De Jaegher, K.J.M.

2017-01-01

The common-enemy hypothesis of by-product mutualism states that organisms cooperate when it is in their individual interests to do so, with benefits for other organisms arising as a by-product; in particular, such cooperation is hypothesized to arise when organisms face the common enemy of a

The open society and its enemies

CERN Document Server

Popper, Karl Raimund

2003-01-01

Written in political exile during the Second World War and first published in 1945, Karl Popper's The Open Society and Its Enemies is one of the most influential books of the twentieth century. Hailed by Bertrand Russell as a 'vigorous and profound defence of democracy', its now legendary attack on the philosophies of Plato, Hegel and Marx exposed the dangers inherent in centrally planned political systems. Popper's highly accessible style, his erudite and lucid explanations of the thought of great philosophers and the recent resurgence of totalitarian regimes around the world are just three of the reasons for the enduring popularity of The Open Society and Its Enemies, and for why it demands to be read both today and in years to come. This is the second of two volumes of The Open Society and Its Enemies.

Effects of land use and insecticides on natural enemies of aphids in cotton: First evidence from smallholder agriculture in the North China Plain

NARCIS (Netherlands)

Zhou, K.; Huang, J.; Deng, X.; Werf, van der W.; Zhang, W.; Lu, Y.; Wu, K.; Wu, F.

2014-01-01

Studies conducted in the USA and Europe have shown that diverse landscapes in general support greaternatural enemy abundance. No quantitative evidence on the relationship between land use diversity andnatural enemies has been reported from developing countries, where fields and farms are much

The Development of Enemy Images in Dutch Children: Measurement and Initial Findings

Science.gov (United States)

Oppenheimer, Louis

2005-01-01

While there is ample evidence that enemies and enemy images are prerequisites in preparedness for war, little information is available about children's understanding of enemies or the presence of enemy images. Based on a pilot study in which assessment instruments were developed and validated, the present study examined the understanding of…

Habitat affinity of resident natural enemies of the invasive Aphis glycines (Hemiptera: Aphididae), on soybean, with comments on biological control.

Science.gov (United States)

Brewer, Michael J; Noma, Takuji

2010-06-01

We integrated a natural enemy survey of the broader landscape into a more traditional survey for Aphis glycines Matsumura (Hemiptera: Aphididae), parasitoids and predatory flies on soybean using A. glycines-infested soybean, Glycine max (L.) Merr., placed in cropped and noncropped plant systems to complement visual field observations. Across three sites and 5 yr, 18 parasitoids and predatory flies in total (Hymenoptera: Aphelinidae [two species] and Bracondae [seven species], Diptera: Cecidomyiidae [one species], Syrphidae [seven species], Chamaemyiidae [one species]) were detected, with significant variability in recoveries detected across plant system treatments and strong contrasts in habitat affinity detected among species. Lysiphlebus testaceipes Cresson was the most frequently detected parasitoid, and no differences in abundance were detected in cropped (soybean, wheat [Triticum aestivum L.], corn [Zea mays L.], and alfalfa [Medicago sativa L.]) and noncropped (poplar [Populus euramericana (Dode) Guinier] and early successional vegetation) areas. In contrast, Binodoxys kelloggensis Pike, Starý & Brewer had strong habitat affinity for poplar and early successional vegetation. The low recoveries seasonally and across habitats of Aphelinus asychis Walker, Aphelinus sp., and Aphidius colemoni Viereck make their suitability to A. glycines on soybean highly suspect. The widespread occurrence of many of the flies reflects their broad habitat affinity and host aphid ranges. The consistent low field observations of parasitism and predation suggest that resident parasitoids and predatory flies are unlikely to contribute substantially to A. glycines suppression, at least during the conventional time period early in the pest invasion when classical biological control activities are considered. For selected species that were relatively well represented across plant systems (i.e., L. testaceipes and Aphidoletes aphidimyza Rondani), conservation biological control efforts

Dissemination of Aleurocanthus woglumi in citrus plants, its natural enemies and new host plants in the state of Rio de Janeiro, Brazil

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Rodrigo Garcia Alvim

Full Text Available ABSTRACT: Aleurocanthus woglumi is an exotic pest, widely disseminated in Brazil, with a high preference for citrus plants, but with a polyphagous feeding habit. The contribution of the state of Rio de Janeiro in the Brazilian production of citrus fruits is small; however, there are still public policies that encourage citrus production in the state. In 2010, the appearance of this pest in Rio de Janeiro was confirmed in the municipality of Cachoeiras de Macacu. The objectives of this research were to evaluate the dissemination of A. woglumi in this state, conduct a survey of new species of host plants, identify and evaluate the population of natural enemies present at two orchards that grow 'Tahiti' limes ( Citrus latifolia infested by the pest in Cachoeiras de Macacu, RJ, Brazil. In 19 municipalities, leaves of citrus and other species of plants presenting aleyrodid nymphs were collected, and yellow sticky traps were installed to capture adults for subsequent identification. At the 'Tahiti' lime orchards, the leaf collections were done to confirm the species of Aleyrodidae , and regarding A. woglumi , the natural enemies associated with this pest were collected directly from the infested plants. The results showed that A. woglumi is wide-spread in 12 municipalities. Three new host plants for A. woglumi were identified: Artocarpus heterophyllus ( Moraceae , Pouteria caimito ( Sapotaceae and Struthanthus flexicaulis ( Loranthaceae . In Cachoeiras de Macacu, a new species of parasitoid of A. woglumi nymphs was named: Encarsia pergandiella (Hymenoptera: Aphelinidae , while the insects in the Coccinellidae (Coleoptera family have stood out as predators of this pest.

Know Your Enemy and Know Yourself: Assessing Progress in Developing Cultural Competence to Enhance Operational Effectiveness

National Research Council Canada - National Science Library

Keene, Sean T

2007-01-01

.... Thousands of years ago, the writer of The Art of War highlighted the critical nature of cultural competence when he asserted his formula for military success, "know the enemy and know yourself...

Prospecting for viral natural enemies of the fire ant Solenopsis invicta in Argentina.

Science.gov (United States)

Valles, Steven M; Porter, Sanford D; Calcaterra, Luis A

2018-01-01

Metagenomics and next generation sequencing were employed to discover new virus natural enemies of the fire ant, Solenopsis invicta Buren in its native range (i.e., Formosa, Argentina) with the ultimate goal of testing and releasing new viral pathogens into U.S. S. invicta populations to provide natural, sustainable control of this ant. RNA was purified from worker ants from 182 S. invicta colonies, which was pooled into 4 groups according to location. A library was created from each group and sequenced using Illumina Miseq technology. After a series of winnowing methods to remove S. invicta genes, known S. invicta virus genes, and all other non-virus gene sequences, 61,944 unique singletons were identified with virus identity. These were assembled de novo yielding 171 contiguous sequences with significant identity to non-plant virus genes. Fifteen contiguous sequences exhibited very high expression rates and were detected in all four gene libraries. One contig (Contig_29) exhibited the highest expression level overall and across all four gene libraries. Random amplification of cDNA ends analyses expanded this contiguous sequence yielding a complete virus genome, which we have provisionally named Solenopsis invicta virus 5 (SINV-5). SINV-5 is a positive-sense, single-stranded RNA virus with genome characteristics consistent with insect-infecting viruses from the family Dicistroviridae. Moreover, the replicative genome strand of SINV-5 was detected in worker ants indicating that S. invicta serves as host for the virus. Many additional sequences were identified that are likely of viral origin. These sequences await further investigation to determine their origins and relationship with S. invicta. This study expands knowledge of the RNA virome diversity found within S. invicta populations.

Does enemy damage vary across the range of exotic plant species? Evidence from two coastal dune plant species in eastern Australia.

Science.gov (United States)

Tabassum, Samiya; Leishman, Michelle R

2018-02-01

Release from natural enemies is often cited as a key factor for understanding the success of invasive plant species in novel environments. However, with time invasive species will accumulate native enemies in their invaded range, with factors such as spread distance from the site of introduction, climate and leaf-level traits potentially affecting enemy acquisition rates. However, the influence of such factors is difficult to assess without examining enemy attack across the entire species' range. We tested the significance of factors associated with range expansion (distance from source population and maximum population density), climatic variables (annual temperature and rainfall) and leaf-level traits [specific leaf area (SLA) and foliar nitrogen concentration] in explaining variation in enemy damage across multiple populations of two coastal invasive plants (Gladiolus gueinzii Kunze and Hydrocotyle bonariensis Lam.) along their entire introduced distribution in eastern Australia. We found that for H. bonariensis, amount of foliar damage increased with distance from source population. In contrast, for G. gueinzii, probability and amount of foliar damage decreased with decreasing temperature and increasing rainfall, respectively. Our results show that patterns of enemy attack across species' ranges are complex and cannot be generalised between species or even range edges.

«Public Enemy»: from Lenin’s Rhetoric to Stalin’s Ideologeme

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Olga U. Popova

2012-12-01

Full Text Available The article is focused on the problem of Soviet ideologeme of the enemy from within in the period of pre-war Stalinism. Stalin’s ideologeme is considered as consistent continuity with Lenin’s enemy rhetoric. The article discloses the development of Lenin’s enemy rhetoric, singles out stages of Stalin’s enemy ideologeme establishment as a part of official ideologic policy and analyses its features.

Who are Cerverí's Worst Enemies?

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Miriam Cabré

2011-04-01

Full Text Available This reading proposes a new interpretation of a poem by Catalan troubadour Cerverí de Girona (fl. 1259-85, an interpretation that departs from the accepted, literal solution to this poem (looking for "enemies" Cerverì descries among the political or familial figures surrounding the poet to show, via an intertextual reading, that these "enemies" are only metaphorical. Cerverì is the proud successor of two centuries of troubadour tradition at the Aragonese court of Pere the Great, facing the influx of fashionable Angevin trends, especially the dance-songs imported from the court of Pere of Arragon's enemy Charles of Anjou. Like Sordello's Ensehnamen, Cerverì's poem 'Una re dey a Deu grazir’ serves as a focal point to refract his present and past career: polemical when his patron was young, more stately now that Cerverí is the public voice of a king. It is a comparison with the Portuguese trovador Johan Soarez Coelho (active at the court of Alfonso III of Portugal until 1279 that conclusively proves the "identity" of Cerveri's "enemies": his own eyes that have betrayed him. The two poets would have interacted at the Toledo court of Alfonso X of Castile in 1269.

Prospecting for viral natural enemies of the fire ant Solenopsis invicta in Argentina.

Directory of Open Access Journals (Sweden)

Steven M Valles

Full Text Available Metagenomics and next generation sequencing were employed to discover new virus natural enemies of the fire ant, Solenopsis invicta Buren in its native range (i.e., Formosa, Argentina with the ultimate goal of testing and releasing new viral pathogens into U.S. S. invicta populations to provide natural, sustainable control of this ant. RNA was purified from worker ants from 182 S. invicta colonies, which was pooled into 4 groups according to location. A library was created from each group and sequenced using Illumina Miseq technology. After a series of winnowing methods to remove S. invicta genes, known S. invicta virus genes, and all other non-virus gene sequences, 61,944 unique singletons were identified with virus identity. These were assembled de novo yielding 171 contiguous sequences with significant identity to non-plant virus genes. Fifteen contiguous sequences exhibited very high expression rates and were detected in all four gene libraries. One contig (Contig_29 exhibited the highest expression level overall and across all four gene libraries. Random amplification of cDNA ends analyses expanded this contiguous sequence yielding a complete virus genome, which we have provisionally named Solenopsis invicta virus 5 (SINV-5. SINV-5 is a positive-sense, single-stranded RNA virus with genome characteristics consistent with insect-infecting viruses from the family Dicistroviridae. Moreover, the replicative genome strand of SINV-5 was detected in worker ants indicating that S. invicta serves as host for the virus. Many additional sequences were identified that are likely of viral origin. These sequences await further investigation to determine their origins and relationship with S. invicta. This study expands knowledge of the RNA virome diversity found within S. invicta populations.

The enemies of books

CERN Document Server

Blades, William

2012-01-01

A fascinating look at the myriad enemies of the printed book, from fire, to neglect, to children, to the bookworm, to plain old ignorance. A passionate litany against all who would see printed literature destroyed, written by English printer and bibliographer William Blades.

Evolutionary dynamics of interactions between plants and their enemies: comparison of herbivorous insects and pathogens.

Science.gov (United States)

Wininger, Kerry; Rank, Nathan

2017-11-01

Plants colonized land over 400 million years ago. Shortly thereafter, organisms began to consume terrestrial plant tissue as a nutritional resource. Most plant enemies are plant pathogens or herbivores, and they impose natural selection for plants to evolve defenses. These traits generate selection pressures on enemies. Coevolution between terrestrial plants and their enemies is an important element of the evolutionary history of both groups. However, coevolutionary studies of plant-pathogen interactions have tended to focus on different research topics than plant-herbivore interactions. Specifically, studies of plant-pathogen interactions often adopt a "gene-for-gene" conceptual framework. In contrast, studies of plants and herbivores often investigate escalation or elaboration of plant defense and herbivore adaptations to overcome it. The main exceptions to the general pattern are studies that focus on small, sessile herbivores that share many features with plant pathogens, studies that incorporate both herbivores and pathogens into a single investigation, and studies that test aspects of Thompson's geographic mosaic theory for coevolution. We discuss the implications of these findings for future research. © 2017 New York Academy of Sciences.

Investigation on effect of Populus alba stands distance on density of pests and their natural enemies population under poplar/alfalfa agroforestry system.

Science.gov (United States)

Khabir, Z H; Sadeghi, S E; Hanifeh, S; Eivazi, A

2009-01-15

This study was carried out in order to distinguish the effect of agroforestry system (combination of agriculture and forestry) on pests and natural enemy's population in poplar research station. Wood is one of the first substances that naturally was used for a long period of time. Forage is an important production of natural resources too. Some factors such as proper lands deficit, lack of economy, pest and disease attacks and faced production of these materials with serious challenges. Agroforestry is a method for decrease of the mentioned problems. The stands of poplar had have planted by complete randomized design with 4 treatments (stand distance) of poplar/alfalfa include 3x4, 3x6.7, 3x8, 3x10 m and 2 control treatments, alfalfa and poplar. The results showed that Chaitophorus populeti had the highest density in poplar and 3x10 m treatments. Monosteira unicostata is another insect pest that had most density in 3x10 m treatment. And alfalfa had high density of Chrysoperla carnea. The density of Coccinella septempunctata, were almost equal in all treatments.

Knowledge and Its Enemies

Science.gov (United States)

Kruk, Miroslav

2007-01-01

As libraries are the physical manifestations of knowledge, some refection about the concept of knowledge would not be unjustified. In modern societies, knowledge plays such a central role that it requires some effort and imagination to understand on what grounds knowledge could be rejected. Karl Popper wrote about the open society and its enemies.…

Changes in defense of an alien plant Ambrosia artemisiifolia before and after the invasion of a native specialist enemy Ophraella communa.

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Yuya Fukano

Full Text Available The evolution of increased competitive ability hypothesis (EICA predicts that when alien plants are free from their natural enemies they evolve lower allocation to defense in order to achieve a higher growth rate. If this hypothesis is true, the converse implication would be that the defense against herbivory could be restored if a natural enemy also becomes present in the introduced range. We tested this scenario in the case of Ambrosia artemisiifolia (common ragweed - a species that invaded Japan from North America. We collected seeds from five North American populations, three populations in enemy free areas of Japan and four populations in Japan where the specialist herbivore Ophraella communa naturalized recently. Using plants grown in a common garden in Japan, we compared performance of O. communa with a bioassay experiment. Consistent with the EICA hypothesis, invasive Japanese populations of A. artemisiifolia exhibited a weakened defense against the specialist herbivores and higher growth rate than native populations. Conversely, in locations where the herbivore O. communa appeared during the past decade, populations of A. artemisiifolia exhibited stronger defensive capabilities. These results strengthen the case for EICA and suggest that defense levels of alien populations can be recuperated rapidly after the native specialist becomes present in the introduced range. Our study implies that the plant defense is evolutionary labile depending on plant-herbivore interactions.

Variation in herbivory-induced volatiles among cucumber (Cucumis sativus L.) varieties has consequences for the attraction of carnivorous natural enemies

NARCIS (Netherlands)

Kappers, I.F.; Hoogerbrugge, H.; Bouwmeester, H.J.; Dicke, M.

2011-01-01

In response to herbivory by arthropods, plants emit herbivory-induced volatiles that attract carnivorous enemies of the inducing herbivores. Here, we compared the attractiveness of eight cucumber varieties (Cucumis sativus L.) to Phytoseiulus persimilis predatory mites after infestation of the

The effects of strawberry cropping practices on the strawberry tortricid (Lepidoptera: Tortricidae), its naturel enemies, and the presences of nematodes

DEFF Research Database (Denmark)

Sigsgaard, Lene; Naulin, Cyril; Haukeland, Solveig

2014-01-01

of organic and conventional farms to test the hypothesis that farming practice (organic versus conventional) will affect the level of pest infestation and will affect the natural enemies. In addition, the number of years with strawberries on the farm, field age, and other factors that may affect pests...... and their natural enemies were considered. Farms were characterized by their cropping practices, cropping history, and other parameters. Field-collected larvae were laboratory reared to assess mortality from parasitoids and entomopathogenic fungi. In 2010, a survey of nematodes was made to assess the response......-year fields in 2010. Cropping practice did not lead to significant differences in the level of total parasitism or in C. aretas parasitism; however, C. aretas contributed to a higher proportion of the parasitized larvae on conventional farms than on organic farms. Mortality from unknown causes of A. comariana...

Enemy-free space and habitat-specific host specialization in a butterfly.

Science.gov (United States)

Wiklund, Christer; Friberg, Magne

2008-08-01

The majority of herbivorous insects have relatively specialized food habits. This suggests that specialization has some advantage(s) over generalization. Traditionally, feeding specialization has been thought to be linked to digestive or other food-related physiological advantages, but recent theory suggests that generalist natural enemies of herbivorous insects can also provide a major selective pressure for restricted host plant range. The European swallowtail butterfly Papilio machaon utilizes various plants in the Apiaceae family as hosts, but is an ecological specialist being monophagous on Angelica archangelica in southern Sweden. This perennial monocarp grows in three seaside habitat types: (1) on the barren rocky shore in the absence of any surrounding vegetation, (2) on the rocky shore with some surrounding vegetation, and (3) on species-rich meadows. The rocky shore habitat harbors few invertebrate generalist predators, whereas a number of invertebrate predators abound in the meadowland habitat. Here, we test the importance of enemy-free space for feeding specialization in Papilio machaon by assessing survival of larvae placed by hand on A. archangelica in each of the three habitat types, and by assessing the habitat-specificity of adult female egg-laying behavior by recording the distribution of eggs laid by free-flying adult females among the three habitat types. Larval survival was substantially higher in the rocky shore habitat than in the meadowland and significantly higher on host plants without surrounding vegetation on the rocky shore. Eggs laid by free-flying females were found in all three habitat types, but were significantly more frequent in the rocky shore habitat, suggesting that females prefer to lay eggs in the habitat type where offspring survival is highest. These results show that larval survivorship on the same host plant species can be strongly habitat-specific, and suggest that enemy-free space is an underlying factor that drives

Conservation Effort of Natural Enemies Animal by Creating The Green Park and Play Ground in Malang

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Lubna Ahmed Abo Al-Qassem Shahub

2017-08-01

Full Text Available The play grounds and green parks in Malang was developed until nowadays in the effort of enhancement the environment in Malang. With improving of the quality of services of that public area, it will increase the achievement of visitor satisfaction and their perception about its function.  The research was conducted to evaluate the existing condition in Malang City Park, to analyze the  perception of the visitors to the utilization play grounds in the city and to formulate the recommendations in improving the play ground for the conservation of natural enemies. For these purposes, questionnaires were developed and it was interviewed to the visitors of the play ground as respondents. Data collected were analyzed using Gap Analysis compared to the ideal of green park as play ground according to the governance criteria. Based on research results, most of the visitors were satisfy with the play ground, but their perception to its function were no so clear. By implementing some suggestion of the stakeholders (University and Non-Governmental Organization almost all of the criteria of ideal green open space were already similar with its from the government. The improvement in the educational characters of the play ground and be considered for the ideal multifunction play ground in Malang City. Keywords: multi function, play ground, visitor perception

Pestiviruses: old enemies and new challenges

Science.gov (United States)

The genesis for this special issue on pestiviruses was a joint meeting on pestiviruses organized by the US BVDV Symposia Committee and the European Society for Veterinary Virology that was held October 14 and 15, 2014. The theme of the meeting was “Pestiviruses: Old enemies and new challenges”. Th...

Do Refuge Plants Favour Natural Pest Control in Maize Crops?

Science.gov (United States)

Quispe, Reinaldo; Mazón, Marina; Rodríguez-Berrío, Alexander

2017-01-01

The use of non-crop plants to provide the resources that herbivorous crop pests’ natural enemies need is being increasingly incorporated into integrated pest management programs. We evaluated insect functional groups found on three refuges consisting of five different plant species each, planted next to a maize crop in Lima, Peru, to investigate which refuge favoured natural control of herbivores considered as pests of maize in Peru, and which refuge plant traits were more attractive to those desirable enemies. Insects occurring in all the plants, including the maize crop itself, were sampled weekly during the crop growing cycle, from February to June 2011. All individuals collected were identified and classified into three functional groups: herbivores, parasitoids, and predators. Refuges were compared based on their effectiveness in enhancing the populations of predator and parasitoid insects of the crop enemies. Refuges A and B were the most effective, showing the highest richness and abundance of both predators and parasitoids, including several insect species that are reported to attack the main insect pests of maize (Spodoptera frugiperda and Rhopalosiphum maidis), as well as other species that serve as alternative hosts of these natural enemies. PMID:28718835

Preliminary observations on enemies of stingless bees and ...

African Journals Online (AJOL)

Preliminary observations on enemies of stingless bees and honeybee (Apis Mellifera adansonii L.) Colonies from the Miticivanga- Tshibinda sector east of Kahuzi Biega National Park, South-Kivu Province, eastern DR Congo.

Sustainable pest regulation in agricultural landscapes: a review on landscape composition, biodiversity and natural pest control.

Science.gov (United States)

Bianchi, F J J A; Booij, C J H; Tscharntke, T

2006-07-22

Agricultural intensification has resulted in a simplification of agricultural landscapes by the expansion of agricultural land, enlargement of field size and removal of non-crop habitat. These changes are considered to be an important cause of the rapid decline in farmland biodiversity, with the remaining biodiversity concentrated in field edges and non-crop habitats. The simplification of landscape composition and the decline of biodiversity may affect the functioning of natural pest control because non-crop habitats provide requisites for a broad spectrum of natural enemies, and the exchange of natural enemies between crop and non-crop habitats is likely to be diminished in landscapes dominated by arable cropland. In this review, we test the hypothesis that natural pest control is enhanced in complex patchy landscapes with a high proportion of non-crop habitats as compared to simple large-scale landscapes with little associated non-crop habitat. In 74% and 45% of the studies reviewed, respectively, natural enemy populations were higher and pest pressure lower in complex landscapes versus simple landscapes. Landscape-driven pest suppression may result in lower crop injury, although this has rarely been documented. Enhanced natural enemy activity was associated with herbaceous habitats in 80% of the cases (e.g. fallows, field margins), and somewhat less often with wooded habitats (71%) and landscape patchiness (70%). The similar contributions of these landscape factors suggest that all are equally important in enhancing natural enemy populations. We conclude that diversified landscapes hold most potential for the conservation of biodiversity and sustaining the pest control function.

Evaluation of three neonicotinoid insecticides against the common pistachio psylla, Agonoscena pistaciae, and its natural enemies.

Science.gov (United States)

Amirzade, Najmeh; Izadi, Hamzeh; Jalali, Mohammad Amin; Zohdi, Hadi

2014-03-06

The common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae), is a key pest in pistachio orchards in Iran. Chemical control is a common method to manage this pest. Compatibility between natural enemies and pesticides is a primary concern in programs of integrated pest management of the psyllid pest. In this research, susceptibility of fifth instar nymphs of Ag. pistaciae and fourth instar larvae of the two most common predators of this pest, Adalia bipunctata L. (Coleoptera: Coccinellidae) and Coccinella undecimpunctata aegyptiaca Reiche, to acetamiprid, thiamethoxam, and imidacloprid was investigated. Probit analysis of concentration-mortality data was conducted to estimate the LC50 value. The results showed that thiamethoxam with an LC50 value of 56.35 mg a.i./L was more toxic to fifth instar nymphs of Ag. pistaciae in comparison to acetamiprid (60.75 mg a.i/L) and imidacloprid (138.21 mg a.i/L) . Imidacloprid with an LC50 value of 218.89 mg a.i/L compared to acetamiprid (222.65 mg a.i/L) and thiamethoxam (232.37 mg a.i/L) had more lethal effects on fourth instar larvae of Ad. bipunctata. However, on the fourth instar larvae of C. undecimpunctata aegyptica, acetamiprid with an LC50 value of 263.44 mg a.i/L was more toxic than thiamethoxam (296.62 mg a.i/L) and imidacloprid (447.82 mg a.i/L). The laboratory findings showed that the three tested insecticides were more toxic to the common pistachio psylla than to its natural predators. Thiamethoxam was the most toxic against Ag. pistaciae. However, its toxicity to the predators was lower than imidacloprid and acetamiprid. This result suggests that thiamethoxam is the best insecticide for control of Ag. pistaciae in combination with predatory lady beetles. This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.

Marigold (Tagetes erecta L. as an attractive crop to natural enemies in onion fields Cravo-de-defunto (Tagetes erecta L. como cultura atrativa para inimigos naturais em cultivo de cebola

Directory of Open Access Journals (Sweden)

Luís Cláudio Paterno Silveira

2009-12-01

Full Text Available Onion is the third most grown vegetable crop in São Paulo state, Brazil. Organic onion farming is expected to increase in the state due to the increasing demand. Pest management in organic onion farming is based on plant extracts with insecticide effects. However, the efficacy of such plant extracts has not been proved yet, and it was observed that they do negatively affect natural enemies. Plants surrounding onion fields, and that are attractive to natural enemies, may be a good option to farmers, since they may lead to increased diversity of arthropod species and, consequently, the natural control of pest populations. This study deals with the effect of marigold plants as a resource plant to natural enemies in onion fields. The experiment was set in a certified organic farm using marigold rows at a center of an onion field. Samples were taken from marigold and the onion plants 5 m (near and 30 m (far from the flowering strips. Higher numbers of arthropod pests were observed in onion plants 30 m from the marigold strip, while higher numbers of predators and parasitoids were found at 5 m distance. Species richness and Shannon's diversity index were higher at 5 m from marigold. Therefore, marigold rows next to onion fields resulted in higher number of entomophagous species, potentially enhancing the natural control of onion pests. In the study field, marigold strips may be an alternative to crop sprays for organic control of onion pests.A cebola é a terceira hortaliça mais cultivada em São Paulo, cujo cultivo orgânico tende a crescer devido ao grande mercado consumidor existente. O manejo das pragas na cebolicultura orgânica baseia-se nos extratos de plantas inseticidas que, além de terem eficiência não comprovada, podem afetar negativamente os inimigos naturais. A utilização de plantas atrativas a inimigos naturais no entorno dos cultivos de cebola pode ser uma boa opção para os produtores, pois potencialmente aumentam a diversidade

Invasive plants and enemy release: evolution of trait means and trait correlations in Ulex europaeus.

Science.gov (United States)

Hornoy, Benjamin; Tarayre, Michèle; Hervé, Maxime; Gigord, Luc; Atlan, Anne

2011-01-01

Several hypotheses that attempt to explain invasive processes are based on the fact that plants have been introduced without their natural enemies. Among them, the EICA (Evolution of Increased Competitive Ability) hypothesis is the most influential. It states that, due to enemy release, exotic plants evolve a shift in resource allocation from defence to reproduction or growth. In the native range of the invasive species Ulex europaeus, traits involved in reproduction and growth have been shown to be highly variable and genetically correlated. Thus, in order to explore the joint evolution of life history traits and susceptibility to seed predation in this species, we investigated changes in both trait means and trait correlations. To do so, we compared plants from native and invaded regions grown in a common garden. According to the expectations of the EICA hypothesis, we observed an increase in seedling height. However, there was little change in other trait means. By contrast, correlations exhibited a clear pattern: the correlations between life history traits and infestation rate by seed predators were always weaker in the invaded range than in the native range. In U. europaeus, the role of enemy release in shaping life history traits thus appeared to imply trait correlations rather than trait means. In the invaded regions studied, the correlations involving infestation rates and key life history traits such as flowering phenology, growth and pod density were reduced, enabling more independent evolution of these key traits and potentially facilitating local adaptation to a wide range of environments. These results led us to hypothesise that a relaxation of genetic correlations may be implied in the expansion of invasive species.

Invasive plants and enemy release: evolution of trait means and trait correlations in Ulex europaeus.

Directory of Open Access Journals (Sweden)

Benjamin Hornoy

Full Text Available Several hypotheses that attempt to explain invasive processes are based on the fact that plants have been introduced without their natural enemies. Among them, the EICA (Evolution of Increased Competitive Ability hypothesis is the most influential. It states that, due to enemy release, exotic plants evolve a shift in resource allocation from defence to reproduction or growth. In the native range of the invasive species Ulex europaeus, traits involved in reproduction and growth have been shown to be highly variable and genetically correlated. Thus, in order to explore the joint evolution of life history traits and susceptibility to seed predation in this species, we investigated changes in both trait means and trait correlations. To do so, we compared plants from native and invaded regions grown in a common garden. According to the expectations of the EICA hypothesis, we observed an increase in seedling height. However, there was little change in other trait means. By contrast, correlations exhibited a clear pattern: the correlations between life history traits and infestation rate by seed predators were always weaker in the invaded range than in the native range. In U. europaeus, the role of enemy release in shaping life history traits thus appeared to imply trait correlations rather than trait means. In the invaded regions studied, the correlations involving infestation rates and key life history traits such as flowering phenology, growth and pod density were reduced, enabling more independent evolution of these key traits and potentially facilitating local adaptation to a wide range of environments. These results led us to hypothesise that a relaxation of genetic correlations may be implied in the expansion of invasive species.

"Build That Wall!": Manufacturing the Enemy, yet Again

Science.gov (United States)

Santamaría Graff, Cristina C.

2017-01-01

The 2016 presidential campaign and the election of Donald Trump has amplified divisive anti-immigrant sentiment and has further positioned "Mexicans as enemy." Trump's "Build That Wall!" declarative has stoked nativist ire through manufactured narratives that rarely, if ever, consider the United States government's role in the…

Electronic Warfare: Comprehensive Strategy Needed for Suppressing Enemy Air Defenses

National Research Council Canada - National Science Library

2001-01-01

.... To achieve this suppression, the services use specialized aircraft designed to neutralize, destroy, or temporarily degrade enemy air defense systems through either physical attack or electronic warfare...

Natural products to agro-ecological pest management and their natural enemies of cotton plant intercropped with maize, cowpea and sesame = Produtos naturais no manejo agroecológico de pragas e seus inimigos naturais do algodoeiro consorciado com milho, feijão-caupi e gergelim

Directory of Open Access Journals (Sweden)

Gildo Pereira de Araujo

2015-06-01

Full Text Available Cotton was once the main crop grown in the northeast of Brazil; its production boosted the development of many cities and contributed to the development of the semi-arid region. Attacks by pests, low productivity, high production costs and low prices on the international market, coupled with a lack of adequate technical assistance, contributed to the decline of the crop. The aim of this study was to evaluate the natural insecticides: aqueous extract from the malagueta pepper, kaolin, Azamax®, Rotenat® and Pironat®, on the agroecological management of the principal pests, with their natural enemies, of cotton intercropped with maize, cowpea and sesame crops. The studies were carried out at the experimental area of Embrapa Algodão, in Barbalha, in the state of Ceará, Brazil (CE, where an experiment was set up to evaluate these natural products, in an experimental design of randomised blocks with four replications, represented by six treatments: T1-Control (no application, T2-Malagueta pepper, T3-Kaolin, T4-Azamax®, T5-Rotenat® and T6-Pironat®. The products were applied every seven days, followed by weekly assessments, considering the effect of the treatments on the occurrence of insect pests of the cotton plant, and on their natural enemies. Kaolin is the most effective natural product in controlling the boll weevil, Anthonomus grandis. Malagueta pepper is not effective in controlling the principle pests of the cotton plant. Natural products applied by spraying the leaves of the cotton plant every 7 days do not interfere with the presence of natural enemies = O algodão já foi a principal cultura cultivada no Nordeste, a sua produção alavancou o desenvolvimento de muitas cidades e contribuiu para o desenvolvimento da região semiárida. Ataque de pragas, baixas produtividades, alto custo de produção e baixa nos preços no mercado internacional, aliado a falta de assistência técnica adequada, contribuíram para o declínio da cultura

Natural enemies of corn silk flies: Euxesta Stigmatias (Loew, Chaetopsis Massyla (Walker and Eumecosommyia Nubila (Wiedemann in Guasave Sinaloa, México

Directory of Open Access Journals (Sweden)

Jesús Ricardo Camacho Báez

2012-09-01

Full Text Available The flies species complex of corn, known as “stigma flies”, including the corn-silk fly, Euxesta stigmatias (Loew,Chaetopsis massyla (Walker and Eumecosommyia nubila (Wiedemann, they have became an important pest problem in the state of Sinaloa. The damage is associated with decaying symptoms has severely affected the quality and yield of the crop. The objectives of this research project are to report sampling results on the presence of natural sources of biological control agents (parasitoids, predators, and entomopathogenic nematodes with biological control potential capacity to manage the populations of this flies species complex. This research was conducted during the spring-summer growingseason of 2011. Samples where collected for eight continuous weeks during the corn cob development and maturation. The sampled corn variety was the hybrid Asgrow Garañon. We collected predominat two wasp species belonging to the order Hymenoptera, families Pteromalidae and Eurytomidae, which are parasites to the pupa stage of corn silk fly. In addition, a wasp from the genus Spalangia spp. The latter has shown a stronger natural parasitic effect of 47% on Euxesta stigmatias (Loew. We also observed a population of the pirate bug Orius insidiosus (Say during the months of March-July, attacking several developmental stages of the fly. Soil samples where also processed to isolate and to identify populations of possible entomopathogenic nematodes (EPN. Larvae of Galleria melonella L. where utilized as nematode traps. Populations of nematodes from three different sites where isolated from CIIDIR-IPN Unidad Sinaloa, Guasave and Maximiliano R. Lopez, all located in the Guasave. The isolated populations are included in the Rhabditidae family, genus and specie identification is still in progress. The natural enemies found have shown potential capacity to asseses them asbiological control agents on the corn flies complex.

Structure, function and management of semi-natural habitats for conservation biological control: a review of European studies.

Science.gov (United States)

Holland, John M; Bianchi, Felix Jja; Entling, Martin H; Moonen, Anna-Camilla; Smith, Barbara M; Jeanneret, Philippe

2016-09-01

Different semi-natural habitats occur on farmland, and it is the vegetation's traits and structure that subsequently determine their ability to support natural enemies and their associated contribution to conservation biocontrol. New habitats can be created and existing ones improved with agri-environment scheme funding in all EU member states. Understanding the contribution of each habitat type can aid the development of conservation control strategies. Here we review the extent to which the predominant habitat types in Europe support natural enemies, whether this results in enhanced natural enemy densities in the adjacent crop and whether this leads to reduced pest densities. Considerable variation exists in the available information for the different habitat types and trophic levels. Natural enemies within each habitat were the most studied, with less information on whether they were enhanced in adjacent fields, while their impact on pests was rarely investigated. Most information was available for woody and herbaceous linear habitats, yet not for woodland which can be the most common semi-natural habitat in many regions. While the management and design of habitats offer potential to stimulate conservation biocontrol, we also identified knowledge gaps. A better understanding of the relationship between resource availability and arthropod communities across habitat types, the spatiotemporal distribution of resources in the landscape and interactions with other factors that play a role in pest regulation could contribute to an informed management of semi-natural habitats for biocontrol. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

The effect of insecticide applications to melon crop on melon aphid and its natural enemies

International Nuclear Information System (INIS)

Guerra, J.; Gonzalez, J.E.; Ceballos, J.; Checa, B.

1999-01-01

Melons are an important export crop for Panama and are cultivated on more than 1000 ha of land. Long growing season, extending well into January, allows several generations and build up of heavy populations of an important insect pest, Aphis gossypii, the melon aphid. Growers find it difficult to cultivate melons without several applications of insecticides. Although the insecticide applications control the aphids, they may also have adverse effects on the natural enemies of the aphid, in particular the two predatory insects Cycloneda sanguinea and Chrysoperla carnea. The purpose of this research was to evaluate the impact of insecticide applications on these insects and on the yield of melons, and to estimate residues of the applied insecticides in soil. The insecticides were applied as four different type of treatments to melon crop. The treatments were (i) three periodic applications of endosulfan (Thiodan 35EC), each at 0.52 kg a.i./ha, (ii) three applications of fenitrothion (Sumithion 50WP), each at 0.35 kg a.i./ha, (iii) two applications of fenitrothion and one of endosulfan, and (iv) grower's treatment, which included applications of six different insecticides. The effect of the insecticide applications was evaluated by estimating numbers of each of the three type of insects before and within 72 hours after the applications and estimating yield of melons. All insecticide treatments reduced the populations of Aphis gossypii, but they also reduced the numbers of the benificial insects. Endosulfan was somewhat less toxic to C. carnea than the other insecticides were, since greater number of C. carnea were recorded from the plots treated with endosulfan than the other treated plots. The best yield of melons was recorded in the plots which were sprayed with fenitrothion, followed by the plots sprayed with endosulfan. and then those with grower's insecticides. Soon after the application of endosulfan the residue in the soil was 0.2 mg/kg, but it declined to less

Múltiple natural enemies do not improve two spotted spider mite and flower western thrips control in strawberry tunnels

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Gemma Albendín

2015-03-01

Full Text Available Biological control techniques are commonly used in many horticultural crops in Spain, however the application of these techniques to Spanish strawberries are relatively recent. In this study the effectiveness of augmentative biological control techniques to control the two main strawberry (Fragaria xananassa Duchesne pest: the two-spotted spider mite (TSSM, Tetranychus urticae Koch (Acari: Tetranychidae, and the western flower thrips (WFT, Frankliniella occidentalis (Pergande (Thysanoptera: Thripidae, through releases of the predatory mites Phytoseiulus persimilis Athias-Henriot, Neoseiulus californicus (McGregor, Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae, and Orius laevigatus (Fieber (Heteroptera: Anthocoridae were tested. Two-year results on the performance of treatments using combinations of these biocontrol agents are presented. In both years, all treatments resulted in the reduction of TSSM numbers; but no treatment was better than the release of P. persimilis alone (P < 0.05. TSSM suppression varied among crop phases being greater early in the season. None of the treatments reduced significantly WFT numbers (P < 0.05, and the established economic injury level (EIL was surpassed from March to late April in both years. However, EIL was surpassed less times when treatment included O. laevigatus (2009: 20.7%; 2010: 22.7% of samples. No effect of A. swirskii was observed when this mite was released. Results corroborate that biological control techniques for TSSM and WFT are feasible for high-plastic tunnel strawberries. Under the conditions in our study no additive effects were observed, and there was not advantage in the release of multiple natural enemies.

"Autos de Resistência" As an Instrument for Extermination Policy of the "Enemy"

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Larissa Leilane Fontes de Lima

2016-12-01

Full Text Available The present article aims to analyze, through the study of "autos de resistência", its tensions with social inequality. From the understanding of the processes of criminalization - through a Marxist perspective - it was possible to make some observations about the social construction of the "enemy" to then understand how works the extermination policy of these sectors of society. The police structures in the Brazilian context of the "war on drugs", play a key role in the policy of extermination of the "enemy", which is made possible by the "autos de resistência".

Enemy Combatant Detainees: Habeas Corpus Challenges in Federal Court

Science.gov (United States)

2006-09-26

Separation of Powers Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Eliminating Federal Court Jurisdiction Where There Is No State Court Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 1 542 U.S. 466 (2004). Enemy Combatant Detainees: Habeas Corpus Challenges in Federal Court In Rasul v. Bush,1 a divided Supreme Court declared that “a state

A pan-European model of landscape potential to support natural pest control services

NARCIS (Netherlands)

Rega, Carlo; Bartual, Agustín M.; Bocci, Gionata; Sutter, Louis; Albrecht, Matthias; Moonen, Anna Camilla; Jeanneret, Philippe; Werf, van der Wopke; Pfister, Sonja C.; Holland, John M.; Paracchini, Maria Luisa

2018-01-01

Pest control by natural enemies (natural pest control) is an important regulating ecosystem service with significant implications for the sustainability of agro-ecosystems. The presence of semi-natural habitats and landscape heterogeneity are key determinants of the delivery of this service.

Molecular analysis of faecal samples from birds to identify potential crop pests and useful biocontrol agents in natural areas.

Science.gov (United States)

King, R A; Symondson, W O C; Thomas, R J

2015-06-01

Wild habitats adjoining farmland are potentially valuable sources of natural enemies, but also of pests. Here we tested the utility of birds as 'sampling devices', to identify the diversity of prey available to predators and particularly to screen for pests and natural enemies using natural ecosystems as refugia. Here we used PCR to amplify prey DNA from three sympatric songbirds foraging on small invertebrates in Phragmites reedbed ecosystems, namely the Reed Warbler (Acrocephalus scirpaceus), Sedge Warbler (Acrocephalus schoenobaenus) and Cetti's Warbler (Cettia cetti). A recently described general invertebrate primer pair was used for the first time to analyse diets. Amplicons were cloned and sequenced, then identified by reference to the Barcoding of Life Database and to our own sequences obtained from fresh invertebrates. Forty-five distinct prey DNA sequences were obtained from 11 faecal samples, of which 39 could be identified to species or genus. Targeting three warbler species ensured that species-specific differences in prey choice broadened the range of prey taken. Amongst the prey found in reedbeds were major pests (including the tomato moth Lacanobia oleracea) as well as many potentially valuable natural enemies including aphidophagous hoverflies and braconid wasps. Given the mobility of birds, this approach provides a practical way of sampling a whole habitat at once, providing growers with information on possible invasion by locally resident pests and the colonization potential of natural enemies from local natural habitats.

The Influence of Keeping Pheasants in Captivity vs. Nature on the Biological Value of Meat and its Use in Human Nutrition

OpenAIRE

Tucak, Zvonimir; Štefica; Škrivanko, Mario; Periškić, Marin; Bošković, Ivica; Jumić, Vlado

2008-01-01

The life of game birds (pheasants) in nature is coupled with a number of difficulties in all seasons of the year. This refers to finding food, breeding, laying eggs, raising the young, fleeing from their natural enemies and lack of protection from unfavorable climatic conditions. The pheasants that live in captivity – aviaries for pheasants – do not have such difficulties – they are fed regularly by quality feed for pheasants, they are protected from bad weather and natural enemies. ...

Confronting an Old Enemy: Terrorism and the Changing Face of Military Intelligence

National Research Council Canada - National Science Library

Jones, Jack

2002-01-01

.... Existing cultural biases, stove-piped operational processes, and limited analyst recruitment problems have weakened the DOD intelligence community's ability to face the twenty-first century terrorist enemy...

Eastwood and the Enemy

DEFF Research Database (Denmark)

Schubart, Rikke

2013-01-01

Taking the question of why Clint Eastwood made two movies as her point of departure, film scholar Rikke Schubart explores the construction of “us” and “them” in Letters From Iwo Jima. Rather than portray American soldiers as “us” and Japanese soldiers as “them,” the film presents both groups...... of soldiers as equally humane and capable of doing both good and evil. The enemy is not a nation, that is neither the Japanese nor the Americans, but the blind idea of nationalism. In a present day perspective, the film represents a new ethical and global awareness of a conflict between a transnational...... humanism and nationalism in the American war film. Schubart thus argues that Eastwood should be interpreted as a “minor utopian,” an expression coined by historian Jay Winter in his Dreams of Peace and Freedom (2006)....

Pseudomonas aeruginosa adaptation to lungs of cystic fibrosis patients leads to lowered resistance to phage and protist enemies

DEFF Research Database (Denmark)

Friman, Ville-Petri; Ghoul, Melanie; Molin, Søren

2013-01-01

) patients affects its survival in the presence of natural phage (14/1, ΦKZ, PNM and PT7) and protist (Tetrahymena thermophila and Acanthamoebae polyphaga) enemies. We found that most of the bacteria isolated from relatively recently intermittently colonised patients (1-25 months), were innately phage......-resistant and highly toxic for protists. In contrast, bacteria isolated from long time chronically infected patients (2-23 years), were less efficient in both resisting phages and killing protists. Moreover, chronic isolates showed reduced killing of wax moth larvae (Galleria mellonella) probably due to weaker...

Seletividade fisiológica de inseticidas aos inimigos naturais de Plutella xylostella (L. (Lepidoptera: Plutellidae em brássicas Insecticide physiological selectivity to natural enemies of Plutella xylostella (L. (Lepidoptera: Plutellidae in Brassicae

Directory of Open Access Journals (Sweden)

Leandro Bacci

2009-01-01

Full Text Available A conservação de inimigos naturais é um componente fundamental no manejo integrado de pragas. Neste trabalho, estudou-se a seletividade de sete inseticidas usados no manejo de Plutella xylostella (L. (Lepidoptera: Plutellidae ao parasitóide Oomyzus sokolowskii (Kurdjumov (Hymenoptera: Eulophidae e aos predadores Discodon sp. (Coleoptera: Cantharidae e Lasiochilus sp. (Hemiptera: Anthocoridae. Os organofosforados metamidofós e paratiom metílico e o carbamato carbaril foram altamente tóxicos aos três inimigos naturais estudados. Dimetoato apresentou seletividade em favor do Discodon sp., na dose e subdose. O inseticida acefato apresentou alto impacto ao Discodon sp., no momento da aplicação e seu efeito foi reduzido com a metade da concentração do princípio ativo. Deltametrina apresentou seletividade à O. sokolowskii nas duas dosagens. Já permetrina foi seletiva a Lasiochilus sp., somente na subdose. Discodon sp. foi mais tolerante à dose e subdose do dimetoato e à subdose do acefato do que O. sokolowskii e Lasiochilus sp. O predador Lasiochilus sp. foi mais tolerante à dose e subdose da permetrina do que O. sokolowskii e Discodon sp. O parasitóide O. sokolowskii foi mais tolerante à dose e subdose da deltametrina do que Lasiochilus sp. e Discodon sp. Os resultados desta pesquisa foram obtidos em condições de exposição extrema, portanto indicam que os inseticidas seletivos possivelmente não serão prejudiciais aos inimigos naturais, em condições de campo.The conservation of natural enemies is a fundamental component in the integrated pest management. In this work, one studied the selectivity of seven insecticides, used in the management of Plutella xylostella (L. (Lepidoptera: Plutellidae, to the parasitoid Oomyzus sokolowskii (Kurdjumov (Hymenoptera: Eulophidae, and to the predators Discodon sp. (Coleoptera: Cantharidae and Lasiochilus sp. (Hemiptera: Anthocoridae. The organophosphates methamidophos and methyl parathion

Structure, function and management of semi-natural habitats for conservation biological control

NARCIS (Netherlands)

Holland, John M.; Bianchi, Felix J.J.A.; Entling, Martin H.; Moonen, Anna Camilla; Smith, Barbara M.; Jeanneret, Philippe

2016-01-01

Different semi-natural habitats occur on farmland, and it is the vegetation's traits and structure that subsequently determine their ability to support natural enemies and their associated contribution to conservation biocontrol. New habitats can be created and existing ones improved with

Phenology, natural enemies, and efficacy of horticultural oil for control of Chionaspis heterophyllae (Homoptera: Diaspididae) on Christmas tree plantations.

Science.gov (United States)

Fondren, Kirsten M; McCullough, Deborah G

2005-10-01

Pine needle scale, Chionaspis pinifoliae (Fitch), and Chionaspis heterophyllae Cooley are important pests of Scots pine, Pinus sylvestris L., and other conifers in much of North America. On Christmas tree plantations, these insects are typically controlled by spraying broad-spectrum insecticides when the vulnerable immature stages are present. However, effective control of bivoltine populations can be difficult to achieve due to asynchronous hatch and development of the second generation. Our objectives were to 1) determine the phenology of the second generation of C. heterophyllae in Michigan; 2) characterize the natural enemy complex; and 3) assess the effectiveness of horticultural oil for control of C. heterophyllae on P. sylvestris Christmas tree plantations. We monitored scale populations in three counties in lower Michigan for 3 yr. Scale phenology was consistently associated with cumulative degree-days base 10 degrees C (DD(10 degrees C)). Second-generation egg hatch began at approximately 1230-1300 DD(10 degrees C), and continued for approximately 3 wk. The peak of the second instar coincided with 1500-1600 DD(10 degrees C). Common predators included the coccinellids Chilocorus stigma (Say) and Microweisia misella (LeConte). On average, 70% of the C. heterophyllae population in unsprayed fields was killed by predators in 1999. Two endoparasitic wasps, Encarsia bella Gahan and Marietta mexicana Howard (Hymenoptera: Aphelinidae), also were recovered. In 2000 and 2001, we applied a highly refined horticultural spray oil with a backpack mist blower at 1500-1600 DD(10 degrees). Scale mortality on trees treated with oil ranged from 66 to 80% and was similar to control achieved using conventional insecticides in both years.

Sleeping with the enemy. Trust, dependence and contract in interorganisational relationships

NARCIS (Netherlands)

Klein Woolthuis, R.J.A.

1999-01-01

'Sleeping with the enemy' refers to the fragile relationship that is built when parties have to cooperate without knowing whether their partner can be trusted. In the development of new products or technologies companies often have to establish such relationships. They depend on each other's

Soil organisms associated to the weed suppressant Crotalaria juncea (fabaceae and its importance as a refuge for natural enemies Organismos de solo associados à supressora de plantas daninhas Crotalaria juncea (fabaceae e sua importância como refúgio para inimigos naturais

Directory of Open Access Journals (Sweden)

W.S Tavares

2011-09-01

Full Text Available Soil organisms play an important role in organic crops of Crotalaria juncea (Fabaceae and are associated with the natural conservation of the environment. The present study was aimed to investigate the population of soil organisms in the organic culture of C. juncea, as well as its importance as a refuge for natural enemies. Dalbulus maidis (Hemiptera: Cicadellidae, Diabrotica sp. (Coleoptera: Chrysomelidae, Doru luteipes (Dermaptera: Forficulidae, Gryllus assimilis (Orthoptera: Gryllidae, Lagria villosa (Coleoptera: Lagriidae, Melanotus sp. (Coleoptera: Elateridae, Meloidogyne incognita (Tylenchida: Heteroderidae, Nephila clavipes (Araneae: Nephilidae, Orius insidiosus (Hemiptera: Anthocoridae, Pheidole sp. (Hymenoptera: Myrmicidae, Phyllophaga sp. (Coleoptera: Scarabeidae, Procornitermes sp. (Isoptera: Termitidae, Solenopsis sp. (Hymenoptera: Formicidae, and Utetheisa ornatrix (Lepidoptera: Arctiidae were identified in C. juncea. The organisms that were found during a 3-month period in 144 trenches in C. juncea were pest species (84.47% and natural enemies (15.53% as well. Natural enemies had an average of 11.89 individuals per 1.08 m³ of soil cultivated with C. juncea. The abundance of organisms in the pod stage (5.49% of C. juncea was lower than that in the vegetative (83.50% and flowering (11.01% stages. Crotalaria juncea plants can be used as part of a crop system for Integrated Pest Management.Organismos de solo desempenham um importante papel em cultivos orgânicos de Crotalaria juncea (Fabaceae e estão associados com a conservação natural do ambiente. O presente estudo teve como objetivo investigar a população de organismos de solo no cultivo orgânico de C. juncea, bem como sua importância como um refúgio para inimigos naturais. Dalbulus maidis (Hemiptera: Cicadellidae, Diabrotica sp. (Coleoptera: Chrysomelidae, Doru luteipes (Dermaptera: Forficulidae, Gryllus assimilis (Orthoptera: Gryllidae, Lagria villosa (Coleoptera

Influence of keeping pheasants in captivity vs. nature on the biological value of meat and its use in human nutrition.

Science.gov (United States)

Tucak, Zvonimir; Skrivanko, Mario; Posavcević, Stefica; Periskić, Marin; Bosković, Ivica; Jumić, Vlado

2008-09-01

The life of game birds (pheasants) in nature is coupled with a number of difficulties in all seasons of the year. This refers to finding food, breeding, laying eggs, raising the young, fleeing from their natural enemies and lack of protection from unfavorable climatic conditions. The pheasants that live in captivity--aviaries for pheasants--do not have such difficulties--they are fed regularly by quality feed for pheasants, they are protected from bad weather and natural enemies. Our research was aimed at determining the biological value of meat of pheasants grown in the two different settings--in captivity and in nature. The highest weight achieved wild pheasant males (1232.4 +/- 147.36 g). The differences between tested pheasant groups were statistically very high significant (P nutrition.

Olfactory responses of Plutella xylostella natural enemies to host pheromone, larval frass, and green leaf cabbage volatiles.

Science.gov (United States)

Reddy, G V P; Holopainen, J K; Guerrero, A

2002-01-01

cabbage, may be used by these natural enemies to locate their diamondback moth host.

Discourses of Dehumanization: Enemy Construction and Canadian Media Complicity in the Framing of the War on Terror

Directory of Open Access Journals (Sweden)

Erin Steuter

2009-01-01

Full Text Available This paper examines the Canadian news media’s coverage of the wars in Afghanistan and Iraq. In particular, Canadian newspaper headlines are examined for the way in which an image of the “enemy” is constructed and framed in dominant media discourse. An analysis of the data reveals a pattern of dehumanizing language applied to enemy leaders as well as Arab and Muslim citizens at large in the media’s uncritical reproduction of metaphors that linguistically frame the enemy in particular ways. Particularly, the paper argues that the Canadian media have participated in mediating constructions of Islam and Muslims, mobilizing familiar metaphors in representations that fabricate an enemy-Other who is dehumanized, de-individualized, and ultimately expendable. This dehumanizing language takes the form of animal imagery that equates and reduces human actions with sub-human behaviours. This paper argues that the repeated use of animal metaphors by monopoly media institutions constitute motivated representations that have ideological importance. The consequences of these representations are more than rhetorical, setting the stage for racist backlash, prisoner abuse and even genocide.

Characterization and mosquitocidal potential of neem cake-synthesized silver nanoparticles: genotoxicity and impact on predation efficiency of mosquito natural enemies.

Science.gov (United States)

Chandramohan, Balamurugan; Murugan, Kadarkarai; Panneerselvam, Chellasamy; Madhiyazhagan, Pari; Chandirasekar, Ramachandran; Dinesh, Devakumar; Kumar, Palanisamy Mahesh; Kovendan, Kalimuthu; Suresh, Udaiyan; Subramaniam, Jayapal; Rajaganesh, Rajapandian; Aziz, Al Thabiani; Syuhei, Ban; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Nicoletti, Marcello; Wei, Hui; Benelli, Giovanni

2016-03-01

Mosquitoes (Diptera: Culicidae) serve as important vectors for a wide number of parasites and pathogens of huge medical and veterinary importance. Aedes aegypti is a primary dengue vector in tropical and subtropical urban areas. There is an urgent need to develop eco-friendly mosquitocides. In this study, silver nanoparticles (AgNP) were biosynthesized using neem cake, a by-product of the neem oil extraction from the seed kernels of Azadirachta indica. AgNP were characterized using a variety of biophysical methods, including UV-vis spectrophotometry, FTIR, SEM, EDX, and XRD analyses. Furthermore, the neem cake extract and the biosynthesized AgNP were tested for acute toxicity against larvae and pupae of the dengue vector Ae. aegypti. LC50 values achieved by the neem cake extract ranged from 106.53 (larva I) to 235.36 ppm (pupa), while AgNP LC50 ranged from 3.969 (larva I) to 8.308 ppm (pupa). In standard laboratory conditions, the predation efficiency of a Carassius auratus per day was 7.9 (larva II) and 5.5 individuals (larva III). Post-treatment with sub-lethal doses of AgNP, the predation efficiency was boosted to 9.2 (larva II) and 8.1 individuals (larva III). The genotoxic effect of AgNP was studied on C. auratus using the comet assay and micronucleus frequency test. DNA damage was evaluated on peripheral erythrocytes sampled at different time intervals from the treatment; experiments showed no significant damages at doses below 12 ppm. Overall, this research pointed out that neem cake-fabricated AgNP are easy to produce, stable over time, and can be employed at low dosages to reduce populations of dengue vectors, with moderate detrimental effects on non-target mosquito natural enemies.

Natural biological control of pest mites in Brazilian sun coffee agroecosystems.

Science.gov (United States)

Teodoro, Adenir V; Sarmento, Renato A; Rêgo, Adriano S; da Graça S Maciel, Anilde

2010-06-01

Coffee is one of the leading commodities in tropical America. Although plantations are usually established under a canopy of trees in most producing countries in the region, Brazilian coffee is mostly produced under full sun conditions. Such simple, single-crop agroecosystems with intensive agrochemical inputs often suffer with pests like mites. Predatory mites of the family Phytoseiidae are the main natural enemies associated with pest mites in the field. However, these beneficial arthropods struggle to survive in intensive agroecosystems such as coffee monocultures due to unfavorable microclimatic conditions, widespread pesticide use, and lack of alternative food (pollen, nectar). Conservation biological control uses a range of management strategies to sustain and enhance populations of indigenous natural enemies such as predatory mites. We discuss here conservation biological control as a strategy to improve biological control of pest mites by native predatory mites in Brazilian coffee monocultures as well as some related patents.

Guantánamo Bay: A Reflection On The Legal Status And Rights Of ‘Unlawful Enemy Combatants’

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Terry D. Gill

2005-07-01

Full Text Available The United States administration’s policy of detaining ‘unlawful enemy combatants’ at the United States military base in Guantánamo Bay falls short of international and domestic law standards. The problem in the authors’ view is not that the United States has decided to designate those captured on the battlefield in Afghanistan as ‘unlawful combatants’ who (allegedly fall outside the scope of international humanitarian law. International humanitarian law has long recognized the existence of such a category. The problem is rather that international humanitarian law has been sporadically and selectively applied and in many respects has been ignored or violated with respect to the detainees held in Guantánamo and elsewhere within the context of the ‘war on terror’. In its recent judgements in Hamdi v. Rumsfeld, Rumsfeld v. Bush and Rasul v. Bush the United States Supreme Court has not passed an unambiguous and clear judgement on the United States policy towards unlawful enemy combatants. The Court may have rejected the executive’s claim that it has the authority to incarcerate people suspected of terrorist connections without any judicial review, the three decisions have not imposed on the executive a clear framework governing the detention of alleged terrorists. The Court has upheld the government’s power to hold ‘enemy combatants’ according to standards that fall short of the requirements of the Geneva Conventions. Moreover, the due process protection granted to those challenging their status as’ enemy combatant’ is so deferential to the executive that it could render review virtually insignificant.

Pseudomonas aeruginosa adaptation to lungs of cystic fibrosis patients leads to lowered resistance to phage and protist enemies.

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Ville-Petri Friman

Full Text Available Pathogenic life styles can lead to highly specialized interactions with host species, potentially resulting in fitness trade-offs in other ecological contexts. Here we studied how adaptation of the environmentally transmitted bacterial pathogen, Pseudomonas aeruginosa, to cystic fibrosis (CF patients affects its survival in the presence of natural phage (14/1, ΦKZ, PNM and PT7 and protist (Tetrahymena thermophila and Acanthamoebae polyphaga enemies. We found that most of the bacteria isolated from relatively recently intermittently colonised patients (1-25 months, were innately phage-resistant and highly toxic for protists. In contrast, bacteria isolated from long time chronically infected patients (2-23 years, were less efficient in both resisting phages and killing protists. Moreover, chronic isolates showed reduced killing of wax moth larvae (Galleria mellonella probably due to weaker in vitro growth and protease expression. These results suggest that P. aeruginosa long-term adaptation to CF-lungs could trade off with its survival in aquatic environmental reservoirs in the presence of microbial enemies, while lowered virulence could reduce pathogen opportunities to infect insect vectors; factors that are both likely to result in poorer environmental transmission. From an applied perspective, phage therapy could be useful against chronic P. aeruginosa lung infections that are often characterized by multidrug resistance: chronic isolates were least resistant to phages and their poor growth will likely slow down the emergence of beneficial resistance mutations.

Defensive strategies in Geranium sylvaticum, Part 2: Roles of water-soluble tannins, flavonoids and phenolic acids against natural enemies.

Science.gov (United States)

Tuominen, Anu

2013-11-01

Geranium sylvaticum is a common herbaceous plant in Fennoscandia, which has a unique phenolic composition. Ellagitannins, proanthocyanidins, galloylglucoses, gallotannins, galloyl quinic acids and flavonoids possess variable distribution in its different organs. These phenolic compounds are thought to have an important role in plant-herbivore interactions. The aim of this study was to quantify these different water-soluble phenolic compounds and measure the biological activity of the eight organs of G. sylvaticum. Compounds were characterized and quantified using HPLC-DAD/MS, in addition, total proanthocyanidins were determined by BuOH-HCl assay and total phenolics by the Folin-Ciocalteau method. Two in vitro biological activity measurements were used: the prooxidant activity was measured by the browning assay and antioxidant activity by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Organ extracts were fractionated using column chromatography on Sephadex LH-20 and the activities of fractions was similarly measured to evaluate which polyphenol groups contributed the most to the biological activity of each organ. The data on the activity of fractions were examined by multivariate data analysis. The water-soluble extracts of leaves and pistils, which contained over 30% of the dry weight as ellagitannins, showed the highest pro-oxidant activity among the organ extracts. Fraction analysis revealed that flavonoids and galloyl quinic acids also exhibited high pro-oxidant activity. In contrast, the most antioxidant active organ extracts were those of the main roots and hairy roots that contained high amounts of proanthocyanidins in addition to ellagitannins. Analysis of the fractions showed that especially ellagitannins and galloyl quinic acids have high antioxidant activity. We conclude that G. sylvaticum allocates a significant amount of tannins in those plant parts that are important to the fitness of the plant and susceptible to natural enemies, i

«Unclear Enemy»: Why the Guerrilla War in France in 1814 Failed

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Nikolay A. Mogilevskiy

2015-01-01

Full Text Available Abstract: Author of the article analyzes the reasons of the fail of Napoleon’s attempts to set the guerrilla war in France during the campaign of 1814. While the forces of anti-Napoleonic coalition were standing near the border of France, Napoleon did his best to recruit his new army. But the human resources of France were exhausted, and that’s why Napoleon decided to set the guerrillia. But all his proclamations and even his orders were disobeyed - French people were too tired of incessant war, and Napoleon again decided to gain his goals on the battlefield. Besides author shows great efforts of Russian headquarters to avoid the guerrilla war. Alexander I and his allies in theirs proclamations declared that they were fighting only with Napoleon, but not with the French nation. That tactic gave a brilliant result and helped to avoid the patriotic uplift in France in 1814. In this propagandistic war Napoleon was defeated and that cost him his throne. The reasons of Napoleon’s fail, firstly, was the unclear image of the enemy. French emperor didn’t manage to unite French nation against the rival. On the contrary the French Emperor, his enemies managed (in their proclamations and personal conversations to persuade the French people, that the allies had one enemy - the Emperor Napoleon, not the French nation, and the ultimate goal of war - to set peace on the European continent. That was exactly how the allies did set the disunity between Napoleon and his people. Ultimately, the combination of these factors was the reason that a guerrilla war never broke out in France.

Natural and human dimensions of a quasi-wild species: The case of kudzu

Science.gov (United States)

Li, Z.; Dong, Q.; Albright, Thomas P.; Guo, Q.

2011-01-01

The human dimensions of biotic invasion are generally poorly understood, even among the most familiar invasive species. Kudzu (Pueraria montana (Lour.) Merr.) is a prominent invasive plant and an example of quasi-wild species, which has experienced repeated introduction, cultivation, and escape back to the wild. Here, we review a large body of primary scientific and historic records spanning thousands of years to characterize the complex relationships among kudzu, its natural enemies, and humans, and provide a synthesis and conceptual model relevant to the ecology and management of quasi-wild invasive species. We documented over 350, mostly insect, natural enemy species and their impacts on kudzu in its native East Asian range. These natural enemies play a minor role in limiting kudzu in its native range, rarely generating severe impacts on populations of wild kudzu. We identified a number of significant influences of humans including dispersal, diverse cultural selection, and facilitation through disturbances, which catalyzed the expansion and exuberance of kudzu. On the other hand, harvest by humans appears to be the major control mechanism in its native areas. Humans thus have a complex relationship with kudzu. They have acted as both friend and foe, affecting the distribution and abundance of kudzu in ways that vary across its range and over time. Our conceptual model of kudzu emphasizes the importance of multiple human dimensions in shaping the biogeography of a species and illustrates how kudzu and other quasi-wild species are more likely to be successful invaders. ?? 2011 Springer Science+Business Media B.V.(outside the USA).

Masculinity : Male Traits in 1930s Portrayed in Public Enemies

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Pita Merdeka

2018-05-01

Full Text Available This article discusses the masculinity of John Dillinger as the main male character inPublic Enemies Film (2009; directed by Michael Mann, and produced by Universal Pictures. This film is clearly described that men who appear strong, physically attractive, charming, and smart fall into the category of masculine.This study used descriptive qualitative method by using Janet Saltzman Chafetz’s concept of masculinity in seven areas or forms such as the physical image, the function in life, the sexual aggressiveness, the emotion, the intelligence, the personality, and other personality characteristics. In the first part of analysis, the research reveals the characteristics of John Dillinger utilizing Edward Jones’ Characterization theory, before assigning them to the seven areas or forms of Chafetz’s concept of masculinity.The result shows that the main male character,John Dillinger adjusts his characteristics based on the person he interacts with.John Dillinger as the main male character in Public Enemies film defines his position as a man in the society in the 1930s. He plays andtakes a dominant role as a leader for his gang members; his lover, Billie Frechette,by caring, protecting, and supporting them. On the other side, Dillinger is apathetic against the authority. He also takes pride in his reputation, and believes that he can achieve ambitions to be on top of the world.DOI: 10.15408/insaniyat.v2i2.7814

Carl Schmitt's attitude towards total war and total enemy on the eve of the outbreak of WWII

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Molnar Aleksandar

2010-01-01

Full Text Available Carl Schmitt is usually perceived as the theorist of total state, total war and total hostility. In the article, the author however tries to show that from 1937 to 1944, Schmitt was arguing that total war and total hostility were dangerous for Germany (as well as for the rest of Europe and warned against perpetuation of all efforts to totalize enemy that started in 1914. In his theoretical endeavors in this period there was place for the total state only - and especially for the total state strong enough to resist temptation of declaring total war on total enemy. The total state he recommended Hitler and his Nazi comrades was German Reich, as a part of Europe ordered and divided in the huge spaces (Grossraumordnung. Positioned in the centre of Europe, between the rest of the powers (France, Italy, USSR as well as the Scandinavian states, Germany should be careful enough to wage war only against its Eastern enemies (Poland and maybe USSR and only in order to achieve 'just' borders. Occupying in this way its huge space Germany should devote itself to the task of exploitation of various peoples such as Poles, Chechs and Slovaks, which were perceived as incapable of having their states and doomed to serve the master race - the Germans.

Variation in natural plant products and the attraction of bodyguards involved in indirect plant defense

NARCIS (Netherlands)

Mumm, R.; Dicke, M.

2010-01-01

Plants can respond to feeding or egg deposition by herbivorous arthropods by changing the volatile blend that they emit. These herbivore-induced plant volatiles (HIPVs) can attract carnivorous natural enemies of the herbivores, such as parasitoids and predators, a phenomenon that is called indirect

Biotic resistance via granivory: Establishment by invasive, naturalized, and native asters reflects generalist preference

Science.gov (United States)

Dean E. Pearson; Ragan M. Callaway; John L. Maron

2011-01-01

Escape from specialist natural enemies is frequently invoked to explain exotic plant invasions, but little attention has been paid to how generalist consumers in the recipient range may influence invasion. We examined how seed preferences of the widespread generalist granivore Peromyscus maniculatus related to recruitment of the strongly invasive exotic Centaurea...

Inventaire préliminaire des ravageurs et des ennemis naturels du cotonnier du département de l'Ouémé (République du Bénin

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Tchibozo, S.

1995-01-01

Full Text Available Preliminary Inventory of Pests and Natural Enemies on Cotton in Oueme Department, Benin. The cotton plant is attacked by thousand of insects pests whose natural enemies are not well known in some producing countries. In order to make an inventory of pests and natural enemies, a first work has been realized on cotton entomological fauna in Oueme Department during agricultural campaign 1993-1994. The results obtained, allowed us to list ail the pests, and their natural enemies met on cotton per locality. The main destructors are classified according to their relative importance. For each pest the frequency of natural enemies is assessed.

Successful range-expanding plants experience less above-ground and below-ground enemy impact.

Science.gov (United States)

Engelkes, Tim; Morriën, Elly; Verhoeven, Koen J F; Bezemer, T Martijn; Biere, Arjen; Harvey, Jeffrey A; McIntyre, Lauren M; Tamis, Wil L M; van der Putten, Wim H

2008-12-18

Many species are currently moving to higher latitudes and altitudes. However, little is known about the factors that influence the future performance of range-expanding species in their new habitats. Here we show that range-expanding plant species from a riverine area were better defended against shoot and root enemies than were related native plant species growing in the same area. We grew fifteen plant species with and without non-coevolved polyphagous locusts and cosmopolitan, polyphagous aphids. Contrary to our expectations, the locusts performed more poorly on the range-expanding plant species than on the congeneric native plant species, whereas the aphids showed no difference. The shoot herbivores reduced the biomass of the native plants more than they did that of the congeneric range expanders. Also, the range-expanding plants developed fewer pathogenic effects in their root-zone soil than did the related native species. Current predictions forecast biodiversity loss due to limitations in the ability of species to adjust to climate warming conditions in their range. Our results strongly suggest that the plants that shift ranges towards higher latitudes and altitudes may include potential invaders, as the successful range expanders may experience less control by above-ground or below-ground enemies than the natives.

'War amongst the people' and the absent enemy:

DEFF Research Database (Denmark)

Mynster Christensen, Maya; Haugegaard, Rikke; Linnet, Poul

This article scrutinizes the relationship between 'war amongst the people' and the 'cultural turn' in Western military thinking. It is argued that the cultural turn in military thinking is related to an uncertainty about how to wage war in a context where the enemy defies categorisation, and where...... understanding and influencing 'the people' is regarded as essential to military success. While efforts have been made to integrate culture in military planning in order to tackle this uncertainty, there are a number of deficiencies, which prevent culture from becoming the intended enabler to successful...... operations. The purpose of this article is to shed light on these deficiencies and to introduce a new approach to culture, which can inform military planning and operations. This approach takes its departure point in how culture is co-produced in social interactions, and directs attention towards how...

Influences of Antagonistic Views of Nature on Understanding of Humanity : In the Case of Rousseau and Nietzsche

OpenAIRE

宮島, 光志

2003-01-01

The aim of this study lies in considering, in the case of Rousseau and Nietzsche, how strongly the antagonistic views of nature influenced the understanding of humanity (human nature). Both Rousseau and Nietzsche criticized the modern European civilization and sought to recover the "nature" in human beings. However, at least, Nietzsche didn't assume that Rousseau was his forerunner. On the contrary, he criticized Rousseau as the greatest enemy. The reason for it can be explained from the diff...

Effects of organic-farming-compatible insecticides on four aphid natural enemy species.

Science.gov (United States)

Jansen, Jean P; Defrance, Thibaut; Warnier, Anne M

2010-06-01

The toxicities of pyrethrins + rapeseed oil, pyrethrins + piperonyl butoxide (PBO), potassium salts of fatty acids and linseed oil were assessed in the laboratory on the parasitic wasp Aphidius rhopalosiphi (Destefani-Perez), the ladybird Adalia bipunctata (L.), the rove beetle Aleochara bilineata (Gyll.) and the carabid beetle Bembidion lampros (Herbst.). The methods selected were residual contact toxicity tests on inert and natural substrates. Both the pyrethrin products led to 100% mortality in the adult parasitic wasps and ladybird larvae on glass plates and plants. The pyrethrins + PBO formulation was toxic for B. lampros on sand and natural soil, but the pyrethrins + rapeseed oil formulation was harmless for this species. Insecticidal soaps were harmless for all these beneficial species. None of the tested products significantly affected the parasitism of the onion fly pupae by A. bilineata. The results indicated the potentially high toxicity of natural pyrethrins for beneficial arthropods. Although this toxicity needs to be confirmed in field conditions, the toxicity levels obtained in the laboratory were similar to or higher than those of several synthetic insecticides known to be toxic in the field. Insecticidal soaps could be considered as an alternative for aphid control in organic farming in terms of selectivity.

No evidence of enemy release in pathogen and microbial communities of common wasps (Vespula vulgaris in their native and introduced range.

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Philip J Lester

Full Text Available When invasive species move to new environments they typically experience population bottlenecks that limit the probability that pathogens and parasites are also moved. The invasive species may thus be released from biotic interactions that can be a major source of density-dependent mortality, referred to as enemy release. We examined for evidence of enemy release in populations of the common wasp (Vespula vulgaris, which attains high densities and represents a major threat to biodiversity in its invaded range. Mass spectrometry proteomic methods were used to compare the microbial communities in wasp populations in the native (Belgium and England and invaded range (Argentina and New Zealand. We found no evidence of enemy release, as the number of microbial taxa was similar in both the introduced and native range. However, some evidence of distinctiveness in the microbial communities was observed between countries. The pathogens observed were similar to a variety of taxa observed in honey bees. These taxa included Nosema, Paenibacillus, and Yersina spp. Genomic methods confirmed a diversity of Nosema spp., Actinobacteria, and the Deformed wing and Kashmir bee viruses. We also analysed published records of bacteria, viruses, nematodes and fungi from both V. vulgaris and the related invader V. germanica. Thirty-three different microorganism taxa have been associated with wasps including Kashmir bee virus and entomophagous fungi such as Aspergillus flavus. There was no evidence that the presence or absence of these microorganisms was dependent on region of wasp samples (i.e. their native or invaded range. Given the similarity of the wasp pathogen fauna to that from honey bees, the lack of enemy release in wasp populations is probably related to spill-over or spill-back from bees and other social insects. Social insects appear to form a reservoir of generalist parasites and pathogens, which makes the management of wasp and bee disease difficult.

No evidence of enemy release in pathogen and microbial communities of common wasps (Vespula vulgaris) in their native and introduced range.

Science.gov (United States)

Lester, Philip J; Bosch, Peter J; Gruber, Monica A M; Kapp, Eugene A; Peng, Lifeng; Brenton-Rule, Evan C; Buchanan, Joe; Stanislawek, Wlodek L; Archer, Michael; Corley, Juan C; Masciocchi, Maitè; Van Oystaeyen, Annette; Wenseleers, Tom

2015-01-01

When invasive species move to new environments they typically experience population bottlenecks that limit the probability that pathogens and parasites are also moved. The invasive species may thus be released from biotic interactions that can be a major source of density-dependent mortality, referred to as enemy release. We examined for evidence of enemy release in populations of the common wasp (Vespula vulgaris), which attains high densities and represents a major threat to biodiversity in its invaded range. Mass spectrometry proteomic methods were used to compare the microbial communities in wasp populations in the native (Belgium and England) and invaded range (Argentina and New Zealand). We found no evidence of enemy release, as the number of microbial taxa was similar in both the introduced and native range. However, some evidence of distinctiveness in the microbial communities was observed between countries. The pathogens observed were similar to a variety of taxa observed in honey bees. These taxa included Nosema, Paenibacillus, and Yersina spp. Genomic methods confirmed a diversity of Nosema spp., Actinobacteria, and the Deformed wing and Kashmir bee viruses. We also analysed published records of bacteria, viruses, nematodes and fungi from both V. vulgaris and the related invader V. germanica. Thirty-three different microorganism taxa have been associated with wasps including Kashmir bee virus and entomophagous fungi such as Aspergillus flavus. There was no evidence that the presence or absence of these microorganisms was dependent on region of wasp samples (i.e. their native or invaded range). Given the similarity of the wasp pathogen fauna to that from honey bees, the lack of enemy release in wasp populations is probably related to spill-over or spill-back from bees and other social insects. Social insects appear to form a reservoir of generalist parasites and pathogens, which makes the management of wasp and bee disease difficult.

The man-nature relationship and environmental ethics

International Nuclear Information System (INIS)

Bourdeau, Ph.

2004-01-01

Our behaviour and policies with regard to nature and the environment should be guided by a code of ethics, which is to be derived from basic principles and from a pragmatic consideration of the issues at stake. The man-nature relationship has always been ambiguous, nature being seen as both a provider and an enemy. In the Judeo-Christian tradition, man is set apart from nature and called to dominate it, although this attitude has been revised to become one of stewardship. Oriental religions, on the other hand, have a more holistic view and consider humans as an integral part of nature. Modern philosophers have views ranging from anthropocentrism to biocentrism and egocentrism. It is suggested to take a pragmatic approach by which primary human needs are met first and foremost whereas the needs of other living organisms and ecosystems are allowed to prevail over secondary human needs. A plea is made to support the Earth Charter, which embodies in its principles and prescriptions a balanced respect for nature and future human generations

The man-nature relationship and environmental ethics.

Science.gov (United States)

Bourdeau, Ph

2004-01-01

Our behaviour and policies with regard to nature and the environment should be guided by a code of ethics, which is to be derived from basic principles and from a pragmatic consideration of the issues at stake. The man-nature relationship has always been ambiguous, nature being seen as both a provider and an enemy. In the Judeo-Christian tradition, man is set apart from nature and called to dominate it, although this attitude has been revised to become one of stewardship. Oriental religions, on the other hand, have a more holistic view and consider humans as an integral part of nature. Modern philosophers have views ranging from anthropocentrism to biocentrism and egocentrism. It is suggested to take a pragmatic approach by which primary human needs are met first and foremost whereas the needs of other living organisms and ecosystems are allowed to prevail over secondary human needs. A plea is made to support the Earth Charter, which embodies in its principles and prescriptions a balanced respect for nature and future human generations.

The influence of Lasius neoniger (Hymenoptera: Formicidae) on population growth and biomass of Aphis glycines (Hemiptera: Aphididae) in soybeans.

Science.gov (United States)

Schwartzberg, Ezra G; Johnson, D W; Brown, G C

2010-12-01

In the United States, the soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), are often tended by the aphid-tending ant, Lasius neoniger Emery (Hymenoptera: Formicidae). In this study, we examined the effects of tending by ants on the density and biomass of soybean aphids on soybeans in Kentucky. We performed cage studies that limited access by ants and/or natural enemies. We used a split-plot design with natural enemy access as the main plot and ant attendance as the sub plot. We found that natural enemy access negatively affected aphid population density in the presence of tending ants, seen as a three- to four-fold increase in aphid density when natural enemies were excluded. In addition, we found that ant tending positively affected aphid biomass, both when natural enemies were given access to aphids or when natural enemies were excluded, seen by a two-fold increase in aphid biomass when ants tended aphids, both in the presence or absence of natural enemies. Biomass accumulation is seen as an important measurement for assessing aphid performance, and we argue that aphid-tending by ants can have an influence on natural field populations of soybean aphids. Agronomic practices that affect ant abundance in soybeans may influence the performance and hence pest outbreaks for this economically important pest. © 2010 Entomological Society of America

The Civil War in Spain, 1936-1939 and the Image of Enemy in the British Fascist Press

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Vera V. Malay

2017-09-01

Full Text Available The article deals with the analysis of publications of British Fascists newspapers 'Action' and 'The Blackshirt' during the Spanish Civil War, 1936-1939. The main directions of image of enemy formation are studied on the example of these papers. Forms of presentation and ways of international problems interpreting by far-right publications are studied. The fascist newspaper Action, The Fascist Week and The Blackshirt spoke from the position of nationalism, Imperial identity, anti-liberalism, anti-Soviet and anti-Semitism. The concept of "communism" in the pages of the fascist press has accumulated the most precisely the image of enemy. Articles and notes shaped confusion between "Soviet", "red" and "Communist". The USSR seemed to be "the warmonger" and the "architect of the Civil war in Spain". The destructive role of Soviet Russia in the conflict was proved in the British fascist press. Soviet Union was accused of seeking to plunge Spain and Europe into anarchy. In British fascist publications trend towards stereotyping and myth-making were noticeable, they were opposed to "Western" civilization (as individualistic and "Eastern", "Communist" (oppressive, traditionalist.

Connecting scales: achieving in-field pest control from areawide and landscape ecology studies.

Science.gov (United States)

Schellhorn, Nancy A; Parry, Hazel R; Macfadyen, Sarina; Wang, Yongmo; Zalucki, Myron P

2015-02-01

Areawide management has a long history of achieving solutions that target pests, however, there has been little focus on the areawide management of arthropod natural enemies. Landscape ecology studies that show a positive relationship between natural enemy abundance and habitat diversity demonstrate landscape-dependent pest suppression, but have not yet clearly linked their findings to pest management or to the suite of pests associated with crops that require control. Instead the focus has often been on model systems of single pest species and their natural enemies. We suggest that management actions to capture pest control from natural enemies may be forth coming if: (i) the suite of response and predictor variables focus on pest complexes and specific management actions; (ii) the contribution of "the landscape" is identified by assessing the timing and numbers of natural enemies immigrating and emigrating to and from the target crop, as well as pests; and (iii) pest control thresholds aligned with crop development stages are the benchmark to measure impact of natural enemies on pests, in turn allowing for comparison between study regions, and generalizations. To achieve pest control we will need to incorporate what has been learned from an ecological understanding of model pest and natural enemy systems and integrate areawide landscape management with in-field pest management. © 2014 Institute of Zoology, Chinese Academy of Sciences.

The behaviour of hoverfly larvae (Diptera, Syrphidae) lessens the effects of floral subsidy in agricultural landscapes

OpenAIRE

Laubertie, Elsa; Wratten, Steve; Magro, Alexandra; Hemptinne, Jean

2016-01-01

Modern agricultural landscapes favour crop pests: herbivores benefit from resource concentration and/or the absence of natural enemies in large areas of intensively farmed fields interspersed by small fragments of natural or non-crop habitats. Conservation biological control (CBC) aims at increasing the functional diversity of agricultural landscapes to make them more hospitable to natural enemies, and less to herbivores. Although natural enemies readily respond to this management, very few s...

Effect of insecticides and Plutella xylostella (Lepidoptera: Plutellidae) genotype on a predator and parasitoid and implications for the evolution of insecticide resistance.

Science.gov (United States)

Liu, Xiaoxia; Chen, Mao; Collins, Hilda L; Onstad, David; Roush, Rick; Zhang, Qingwen; Shelton, Anthony M

2012-04-01

In the laboratory and in cages in the greenhouse, we evaluated the toxicity of two insecticides (lambda-cyhalothrin and spinosad) on the parasitoid, Diadegma insulare (Cresson), and the predator, Coleomegilla maculate (DeGeer), both natural enemies of the diamondback moth, Plutella xylostella (L.). Lambda-cyhalothrin was very toxic to both natural enemies. Spinosad was less toxic to C. maculata adults and larvae, and slightly toxic to D. insulare. Both natural enemies suppressed P. xylostella populations in cages with 80% spinosad-treated and 20% nontreated plants; such suppression was not seen when lambda-cyhalothrin was used. Using broccoli, Brassica oleracea L. variety italica, a common host for P. xylostella, we also studied direct and indirect effects of both natural enemies in the presence and absence of the two insecticides and to different P. xylostella genotypes: resistant to the insecticide, susceptible, or heterozygous. Neither natural enemy could distinguish host genotype if P. xylostella were feeding on nontreated plants. They could also not distinguish between larvae feeding on spinosad-treated plants and nontreated plants, but D. insulare could distinguish between larvae feeding on lambda-cyhalothrin treated and nontreated plants. Our studies suggest that lambda-cyhalothrin has direct toxicity to these two natural enemies, can affect their host foraging and acceptance of P. xylostella and consequently would not be compatible in conserving these natural enemies in a program for suppression of P. xylostella. In contrast, our studies suggest that treatment with spinosad has much less effect on these natural enemies and would allow them to help suppress populations of P. xylostella. These findings are discussed in relation to the evolution of insecticide resistance and suppression of the pest populations.

Trait-mediated trophic cascade creates enemy-free space for nesting hummingbirds.

Science.gov (United States)

Greeney, Harold F; Meneses, M Rocio; Hamilton, Chris E; Lichter-Marck, Eli; Mannan, R William; Snyder, Noel; Snyder, Helen; Wethington, Susan M; Dyer, Lee A

2015-09-01

The indirect effects of predators on nonadjacent trophic levels, mediated through traits of intervening species, are collectively known as trait-mediated trophic cascades. Although birds are important predators in terrestrial ecosystems, clear examples of trait-mediated indirect effects involving bird predators have almost never been documented. Such indirect effects are important for structuring ecological communities and are likely to be negatively impacted by habitat fragmentation, climate change, and other factors that reduce abundance of top predators. We demonstrate that hummingbirds in Arizona realize increased breeding success when nesting in association with hawks. An enemy-free nesting space is created when jays, an important source of mortality for hummingbird nests, alter their foraging behavior in the presence of their hawk predators.

Fresh whole blood transfusions in coalition military, foreign national, and enemy combatant patients during Operation Iraqi Freedom at a U.S. combat support hospital.

Science.gov (United States)

Spinella, Philip C; Perkins, Jeremy G; Grathwohl, Kurt W; Repine, Thomas; Beekley, Alec C; Sebesta, James; Jenkins, Donald; Azarow, Kenneth; Holcomb, John B

2008-01-01

United States military doctrine permits the use of fresh whole blood (FWB), donated by U.S. military personnel on site, for casualties with life-threatening injuries at combat support hospitals. U.S. Military Medical Department policy dictates that all patients treated at military facilities during combat (coalition military personnel, foreign nationals, and enemy combatants) are to be treated equally. The objectives of this study were to describe admission vital signs and laboratory values and injury location for patients transfused with FWB, and to determine if FWB was employed equally among all patient personnel categories at a combat support hospital. This retrospective cohort study evaluated admission vital signs and laboratory values, injury location, and personnel category for all patients receiving FWB at a U.S. Army combat support hospital in Baghdad, Iraq, between January and December 2004. Eighty-seven patients received 545 units of FWB. Upon admission, the average (+/-S.D.) heart rate was 144 bpm (+/-25); systolic blood pressure, 106 mmHg (+/-33); base deficit, 9 (+/-6.5); hemoglobin, 9.0 g/dl (+/-2.6); platelet concentration, 81.9 x 10(3)/mm(3) (+/-81); international normalized ratio (INR), 2.0 (+/-1.1); and temperature 95.7 degrees F (+/-2.6). The percentages of intensive care patients who received FWB by personnel category were as follows: coalition soldiers, 51/592 (8.6%); foreign nationals, 25/347 (7.2%); and enemy combatants, 11/128 (8.5% (p = 0.38). The amount of FWB transfused by personnel category was as follows: coalition soldier, 4 units (1-35); foreign national, 4 units (1-36); and enemy combatant, 4 units (1-11) (p = 0.9). Fresh whole blood was used for anemic, acidemic, hypothermic, coagulopathic patients with life-threatening traumatic injuries in hemorrhagic shock, and it was transfused in equal percentages and amounts for coalition soldiers, foreign nationals, and enemy combatants.

Future's operation areas: new-generation suppression enemy air defence (SEAD) elements

Science.gov (United States)

Hazinedar, Ä.°lker

2015-05-01

Since air vehicles took place in the theater of operations, they have become the indispensable elements and the strongest attack power of armed forces. In the following period, with technological development, supersonic aircrafts took place in the operation area and this increased effectiveness of air vehicles much more. Air forces have used these aircrafts during important missions like strategic attack and air defense operations. On the other hand, decision makers understood that it was not feasible to intercept fighter aircrafts by executing combat air patrol flight missions. Since there is not enough reaction time to intercept the high speed aircrafts, ground stationed Surface to Air Missiles (SAM) system requirement has emerged. Therefore, SAM systems took place in the operation scene as well. Due to the fact that SAM systems emerged against the attack power, the attack aircrafts are to keep away from the fire of the ground stationed SAM systems. Hence, the requirement of Suppression Enemy Air Defense (SEAD) arose. SEAD elements take under suppression the radar of the SAM systems. In this way, attack aircrafts are able to attack without the risk of SAM systems. The purpose of this study is to find new methods or concepts in order to protect friendly attack aircrafts against ground based surface to air missiles' fires. Modernization of SAM systems and new generation SAM system producing activities have proceeded with positive acceleration. So, current SEAD elements and concepts are not able to cover the requirements due to the increased SAM system ranges. According to the concepts, SEAD weapons` ranges must be longer than the SAM weapons' ranges to protect friendly aircrafts. In this study, new concept was offered to overcome the deficiencies of current SEAD concept. The elements of new concepts were put forward. Classic SEAD concept and new generation concepts were assessed by using SWOT analysis technique. As a result, this study has revealed that, air forces

SELETIVIDADE DE INSETICIDAS AO COMPLEXO DE INIMIGOS NATURAIS NA CULTURA DO ALGODÃO (Gossypium hirsutum L. SELECTIVITY OF INSECTICIDES ON THE COMPLEX OF NATURAL ENEMIES IN COTTON CROP (Gossypium hirsutum L.

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Fábio Shigeo Takatsuka

2007-09-01

="justify">The selectivity of insecticides was evaluated in the complex of natural enemies of the cotton (Gossypium hirsutum L. crop. The cultivar Deltapine was used in a randomized block experimental design, with seven treatments and four replications. The treatments, all in their commercial formulation, were: control; thiamethoxam (300 g.ha^-1; lufenuron (300 mL.ha^-1; betacyflutrin (800 mL.ha^-1; imidacloprid (70g.ha^-1; diflubenzuron (6,0 g.ha^-1; and endosulfan (1500 mL.ha^-1. The insecticides were sprayed at 45 days after germination. Besides the initial evaluation, other evaluations were performed three and seven days after insecticide application. Each plot was sampled by the fabric beating method, with two random beatings per plot. Natural enemies were identified and counted. Three days after application, the insecticides thiamethoxam (300 g.ha^-1, lufenuron (300 mL.ha^-1, and diflubenzuron (60 g.ha^-1 did not showed negative effect on the complex of predators present in the cotton. However, seven days after application, only the lufenuron treatment maintained the selective effect over predator complex.

KEY-WORDS: Insecticide; biological control; Gossypium.

Dynamics of a Stage Structured Pest Control Model in a Polluted Environment with Pulse Pollution Input

OpenAIRE

Liu, Bing; Xu, Ling; Kang, Baolin

2013-01-01

By using pollution model and impulsive delay differential equation, we formulate a pest control model with stage structure for natural enemy in a polluted environment by introducing a constant periodic pollutant input and killing pest at different fixed moments and investigate the dynamics of such a system. We assume only that the natural enemies are affected by pollution, and we choose the method to kill the pest without harming natural enemies. Sufficient conditions for global attractivity ...

Analysing perspectives on evil, enemy and divinatory consultation among Participants in Neo-prophetic movements in Pentecostal Ghana

OpenAIRE

Tetteh, Gideon

2016-01-01

This study seeks to examine the concept of enemy evil and divinatory consultation among Ghanaian Neo-prophetic Churches in order to open up these concepts for further scholarly probe. The study employs the purposive sampling of participatory method of qualitative research methodology. The instruments used in data collection and analysis include interviews and participant observation. The study examines the historical antecedents of the prophetic phenomenon in Ghana and shows its root in the i...

The ‘enemy within’ the post-Vatican II Roman Catholic Church

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Graham A. Duncan

2013-05-01

Full Text Available The Second Vatican Council (1962–1965 is regarded as one of the most significant processes in the ecumenical church history of the 20th century. At that time, a younger generation of Roman Catholic theologians began to make their mark in the church and within the ecumenical theological scene. Their work provided an ecumenical bridge between the Reforming and the Roman Catholic ecclesiastical traditions, notwithstanding the subsequent negative response of the Roman church hierarchy. Despite important advances, recent pontificates significantly altered the theological landscape and undermined much of the enthusiasm and commitment to unity. Roman Catholic theological dissent provided common ground for theological reflection. Those regarded as the ‘enemy within’ have become respected colleagues in the search for truth in global ecclesiastical perspective. This article will use the distinction between the history and the narratives of Vatican II.

Effects of powdery mildew fungicide programs on twospotted spider mite (Acari: Tetranychidae), hop aphid (Hemiptera: Aphididae), and their natural enemies in hop yards.

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Gent, D H; James, D G; Wright, L C; Brooks, D J; Barbour, J D; Dreves, A J; Fisher, G C; Walton, V M

2009-02-01

Twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), and hop aphid, Phorodon humuli (Schrank) (Hemiptera: Aphididae), are the most important arthropod pests of hop (Humulus lupulus L.) in the Northern Hemisphere. A potential barrier for greater adoption of conservation biological control strategies for spider mites and hop aphid is the extensive use of fungicides for management of hop powdery mildew, Podosphaera macularis (Wallr.:Fr.) U. Braun & S. Takamatsu. Field studies conducted in experimental plots in Oregon and Washington in 2005 and 2006 quantified the effects of powdery mildew fungicide programs (i.e., sulfur, paraffinic oil, and synthetic fungicides) on arthropod pests and natural enemies on hop. Fungicide treatment significantly affected spider mite populations in all four studies. Multiple applications of sulfur fungicides applied before burr development resulted in 1.4-3.3-fold greater spider mite populations during summer. Near the cessation of the sulfur applications, or after a lag of 20-30 d, spider mite populations increased significantly faster on sulfur treated plants compared with water-treated plants in three of four experiments. The effect of paraffinic oil on spider mites was varied, leading to exacerbation of spider mites in Oregon and Washington in 2005, suppression of mites in Oregon in 2006, and no significant effect compared with water in Washington in 2006. Significant relative treatment effects for cone damage due to spider mite feeding were detected in Oregon in 2005 in plots treated with sulfur and paraffinic oil compared with water and synthetic fungicides. Mean populations of hop aphids were similar among treatments in Oregon, although sulfur treatment suppressed hop aphid populations in Washington in 2005 and 2006. Populations of individual predacious insect species and cumulative abundance of macropredators were not consistently suppressed or stimulated by treatments in all trials. However, predatory mite

Associações entre Cinara atlantica, seus inimigos naturais e formigas

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Susete do Rocio Chiarello Penteado

2012-09-01

Full Text Available The study of the relationship between species or populations is an excellent tool to learn about ecological phenomena. Among the possible interaction between two species, it is highlighted the mutualism between ants and insects that produce honeydew. While honeydew is "garbage" for the aphids it can be a food source for ants. The type of interaction between aphids and their natural enemies, known as "intraguild predation" or predation of natural enemies that share the same prey is an interaction that occurs in aphid communities. The majority of natural enemies in this system interact asymmetrically according to differences in body size, feeding strategy and priorities of each species. In agroecosystems, the consequence of this relation becomes particularly important for the biological control of pests of economic importance. In Brazil, few publications refer to the association among ants, aphids and their natural enemies, specifically in forest areas. Thus, this work had the objective to review studies regarding these association and discuss a field observed case involving the giant conifer aphid, Cinara atlantica (Hemiptera: Aphididae, its natural enemies and the ants Solenopsis invicta and Camponotus rufipes, occurring on Pinus taeda.

Figuring Reconciliation: Dancing With the Enemy

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Jane S. Sutton

2007-02-01

Full Text Available This essay is about fi guring “argument as dance” and one way of conceiving how to live or embody argument as such. Concretely, it displays “argument as war” alongside a road in Mississippi after a white man shoots down James Meredith as he asserts his legal right to vote. And it tells “how to” perceive the shooting as dance by turning fi rstly to the performance of dance fi gured in the beginnings of rhetoric and then secondly, setting forth demystifi ed methods and strategies of body-speech fi guring argument as dance, rather than as war, through performances of Nelson Mandela. More generally, it explores a new meaning or experience of rhetoric by explicitly conjoining two historical times, two geographies, two speakers, enemies and dancers, that are inextricably interconnected. Using a combination of description and analysis, the fi rst is a full display of three photographs picturing argument as war. The whole picture serves as a descriptive compass or guide for making our way analytically through argument as war and into dance language and behavior and their interconnections to argument. The second is a retrospective discussion of the background, dancing/argumentative practices, what is called “blinking on the behalf of the enemy,” of Nelson Mandela. Overall, the strategy of reticulating political times, chronology and political spaces, geography on the one hand, and argument as war and argument as dance on the other hand is to reconcile confl icting measures and to produce a performance practice (of rhetoric of which there is no canon. Cet article représente «l’argumentation comme danse» et présente une façon de concevoir comment éprouver et discerner ainsi l’argumentation. Concrètement, il fait voir «l’argumentation comme guerre» le long d’une route au Mississippi après qu’un homme blanc ait tiré James Meredith alors que ce dernier affi rmait son droit légal de vote. Et il relate «comment» percevoir

The influence of residence time and geographic extent on the strength of plant–soil feedbacks for naturalised Trifolium

NARCIS (Netherlands)

McGinn, Kevin J.; van der Putten, Wim H.; Hulme, Philip E.; Shelby, Natasha; Weser, Carolin; Duncan, Richard P.

2018-01-01

Release from natural enemies is considered an important mechanism underlying the success of plants introduced to new regions, but the degree to which alien plant species benefit from enemy release appears highly variable and context-dependent. Such variation could arise if enemy release is a

Complex Odor from Plants under Attack: Herbivore's Enemies React to the Whole, Not Its Parts

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van Wijk, Michiel; de Bruijn, Paulien J. A.; Sabelis, Maurice W.

2011-01-01

Background Insect herbivory induces plant odors that attract herbivores' natural enemies. Assuming this attraction emerges from individual compounds, genetic control over odor emission of crops may provide a rationale for manipulating the distribution of predators used for pest control. However, studies on odor perception in vertebrates and invertebrates suggest that olfactory information processing of mixtures results in odor percepts that are a synthetic whole and not a set of components that could function as recognizable individual attractants. Here, we ask if predators respond to herbivore-induced attractants in odor mixtures or to odor mixture as a whole. Methodology/Principal Findings We studied a system consisting of Lima bean, the herbivorous mite Tetranychus urticae and the predatory mite Phytoseiulus persimilis. We found that four herbivore-induced bean volatiles are not attractive in pure form while a fifth, methyl salicylate (MeSA), is. Several reduced mixtures deficient in one component compared to the full spider-mite induced blend were not attractive despite the presence of MeSA indicating that the predators cannot detect this component in these odor mixtures. A mixture of all five HIPV is most attractive, when offered together with the non-induced odor of Lima bean. Odors that elicit no response in their pure form were essential components of the attractive mixture. Conclusions/Significance We conclude that the predatory mites perceive odors as a synthetic whole and that the hypothesis that predatory mites recognize attractive HIPV in odor mixtures is unsupported. PMID:21765908

Complex odor from plants under attack: herbivore's enemies react to the whole, not its parts.

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Michiel van Wijk

Full Text Available Insect herbivory induces plant odors that attract herbivores' natural enemies. Assuming this attraction emerges from individual compounds, genetic control over odor emission of crops may provide a rationale for manipulating the distribution of predators used for pest control. However, studies on odor perception in vertebrates and invertebrates suggest that olfactory information processing of mixtures results in odor percepts that are a synthetic whole and not a set of components that could function as recognizable individual attractants. Here, we ask if predators respond to herbivore-induced attractants in odor mixtures or to odor mixture as a whole.We studied a system consisting of Lima bean, the herbivorous mite Tetranychus urticae and the predatory mite Phytoseiulus persimilis. We found that four herbivore-induced bean volatiles are not attractive in pure form while a fifth, methyl salicylate (MeSA, is. Several reduced mixtures deficient in one component compared to the full spider-mite induced blend were not attractive despite the presence of MeSA indicating that the predators cannot detect this component in these odor mixtures. A mixture of all five HIPV is most attractive, when offered together with the non-induced odor of Lima bean. Odors that elicit no response in their pure form were essential components of the attractive mixture.We conclude that the predatory mites perceive odors as a synthetic whole and that the hypothesis that predatory mites recognize attractive HIPV in odor mixtures is unsupported.

Enemy recognition is linked to soldier size in a polymorphic stingless bee.

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Grüter, Christoph; Segers, Francisca H I D; Santos, Luana L G; Hammel, Benedikt; Zimmermann, Uwe; Nascimento, Fabio S

2017-10-01

Many ant and termite colonies are defended by soldiers with powerful mandibles or chemical weaponry. Recently, it was reported that several stingless bee species also have soldiers for colony defence. These soldiers are larger than foragers, but otherwise lack obvious morphological adaptations for defence. Thus, how these soldiers improve colony fitness is not well understood. Robbing is common in stingless bees and we hypothesized that increased body size improves the ability to recognize intruders based on chemosensory cues. We studied the Neotropical species Tetragonisca angustula and found that large soldiers were better than small soldiers at recognizing potential intruders. Larger soldiers also had more olfactory pore plates on their antennae, which is likely to increase their chemosensory sensitivity. Our results suggest that improved enemy recognition might select for increased guard size in stingless bees. © 2017 The Author(s).

Incorporating biological control into IPM decision making

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Of the many ways biological control can be incorporated into Integrated Pest Management (IPM) programs, natural enemy thresholds are arguably most easily adopted by stakeholders. Integration of natural enemy thresholds into IPM programs requires ecological and cost/benefit crop production data, thr...

Predation pressure in Ugandan cotton fields measured by a sentinel prey method

DEFF Research Database (Denmark)

Howe, Andy G.; Nachman, Gösta; Lövei, Gabor L

2015-01-01

Pest suppression by natural enemies is an important ecosystem service, which is a valuable resource to poor smallholders in developing countries. Diverse natural enemy assemblages of arthropod predators and parasitoids are documented in various regions in Africa, but our knowledge of their impact...

A Moveable Feast: Insects Moving at the Forest-Crop Interface Are Affected by Crop Phenology and the Amount of Forest in the Landscape.

Science.gov (United States)

González, Ezequiel; Salvo, Adriana; Defagó, María Teresa; Valladares, Graciela

2016-01-01

Edges have become prevailing habitats, mainly as a result of habitat fragmentation and agricultural expansion. The interchange of functionally relevant organisms like insects occurs through these edges and can influence ecosystem functioning in both crop and non-crop habitats. However, very few studies have focused on the directionality of insect movement through edges, and the role of crop and non-crop amount has been ignored. Using bi-directional flight interception traps we investigated interchange of herbivore, natural enemy, pollinator and detritivore insects between native forest fragments and soybean crops, simultaneously considering movement direction, forest cover in the landscape and crop phenology. In total, 52,173 specimens and 877 morphospecies were collected. We found that, within most functional and taxonomic groups, movement intensity was similar (richness and/or abundance) between directions, whereas a predominantly forest-to-crop movement characterized natural enemies. Insect movement was extensively affected by crop phenology, decreasing during crop senescence, and was enhanced by forest cover particularly at senescence. Mainly the same herbivore species moved to and from the forest, but different natural enemy species predominated in each direction. Finally, our analyses revealed greater forest contribution to natural enemy than to herbivore communities in the crop, fading with distance to the forest in both groups. By showing that larger amounts of forest lead to richer insect interchange, in both directions and in four functional groups, our study suggests that allocation to natural and cultivated habitats at landscape level could influence functioning of both systems. Moreover, natural enemies seemed to benefit more than pests from natural vegetation, with natural enemy spillover from forests likely contributing to pest control in soybean fields. Thus consequences of insect interchange seem to be mostly positive for the agroecosystem

Comparison of a Canadian and a Dutch strain of the parasitoid Aphelinus mali (Hald) (Hym., Aphelinidae) for control of woolly apple aphid Eriosoma lanigerum (Haussmann) (Hom., Aphididae) in the Netherlands: a simulation approach

NARCIS (Netherlands)

Mols, P.J.M.; Boers, J.M.

2001-01-01

Woolly apple aphid, Eriosoma lanigerum is one of the important apple pests in the Netherlands. Weather conditions and natural enemies determine whether woolly apple aphid (WAA) will reach pest status. WAA may escape control by natural enemies and therefore it must be controlled using chemical

Novel multitrophic interactions among an exotic, generalist herbivore, its host plants and resident enemies in California.

Science.gov (United States)

Hopper, Julie V; Mills, Nicholas J

2016-12-01

What happens when an exotic herbivore invades and encounters novel host plants and enemies? Here, we investigate the impacts of host plant quality and plant architecture on an exotic generalist herbivore, Epiphyas postvittana (Lepidoptera: Tortricidae) and its interactions with resident parasitoids in California. Using artificial diet and five plant species, we found significant effects of diet on the fitness of E. postvittana under laboratory conditions. In the field, based on a common garden experiment with host plants of nine species, we found that larval parasitism varied among plant species by a factor of 2.1 with a higher risk of parasitism on shorter than taller plants. Parasitism of egg masses varied by a factor of 4.7 among plant species with a higher risk of parasitism on taller than shorter plants. In the laboratory, the foraging time of a resident egg parasitoid on excised leaves varied among plant species, but did not correspond to observed egg parasitism rates on these same plants in the field. On leaves of Plantago lanceolata, the probability of egg parasitism decreased with trichome density. Overall, there was a significant effect of host plant on the intrinsic rate of increase of E. postvittana and on the extent of parasitism by resident parasitoids, but no correlation existed between these two effects. The recent decline of E. postvittana in California may be due to the low quality of some host plants and to the many resident enemies that readily attack it, perhaps due to its phylogenetic relatedness to resident tortricids.

Survey of bumble bee (Bombus) pathogens and parasites in Illinois and selected areas of northern California and southern Oregon.

Science.gov (United States)

Kissinger, Christina N; Cameron, Sydney A; Thorp, Robbin W; White, Brendan; Solter, Leellen F

2011-07-01

Pathogens have been implicated as potential factors in the recent decline of some North American bumble bee (Bombus) species, but little information has been reported about the natural enemy complex of bumble bees in the United States. We targeted bumble bee populations in a state-wide survey in Illinois and several sites in California and Oregon where declines have been reported to determine presence and prevalence of natural enemies. Based on our observations, most parasites and pathogens appear to be widespread generalists among bumble bee species, but susceptibility to some natural enemies appeared to vary. Copyright © 2011 Elsevier Inc. All rights reserved.

Divergent pheromone-mediated insect behaviour under global atmospheric change

Science.gov (United States)

Edward B. Mondor; Michelle N. Tremblay; Caroline S. Awmack; Richard L. Lindroth

2004-01-01

While the effects of global atmospheric changes on vegetation and resulting insect populations('bottom-up interactions') are being increasingly studied, how these gases modify interactions among insects and their natural enemies ('top-down interactions') is less clear. As natural enemy efficacy is governed largely by behavioural mechanisms, altered...

Field responses of predaceous arthropods to methyl salicylate: a meta-analysis and case study in cranberries

Science.gov (United States)

Methyl salicylate (MeSA) is an herbivore-induced plant volatile (HIPV) that has shown potential in attracting natural enemies. Here, we conducted a meta-analysis to evaluate the magnitude of natural enemy response to MeSA in the field, and tested its attractiveness to insect predators in commercial...

Getting More Power from Your Flowers: Multi-Functional Flower Strips Enhance Pollinators and Pest Control Agents in Apple Orchards.

Science.gov (United States)

Campbell, Alistair John; Wilby, Andrew; Sutton, Peter; Wäckers, Felix

2017-09-20

Flower strips are commonly recommended to boost biodiversity and multiple ecosystem services (e.g., pollination and pest control) on farmland. However, significant knowledge gaps remain regards the extent to which they deliver on these aims. Here, we tested the efficacy of flower strips that targeted different subsets of beneficial arthropods (pollinators and natural enemies) and their ecosystem services in cider apple orchards. Treatments included mixes that specifically targeted: (1) pollinators ('concealed-nectar plants'); (2) natural enemies ('open-nectar plants'); or (3) both groups concurrently (i.e., 'multi-functional' mix). Flower strips were established in alleyways of four orchards and compared to control alleyways (no flowers). Pollinator (e.g., bees) and natural enemy (e.g., parasitoid wasps, predatory flies and beetles) visitation to flower strips, alongside measures of pest control (aphid colony densities, sentinel prey predation), and fruit production, were monitored in orchards over two consecutive growing seasons. Targeted flower strips attracted either pollinators or natural enemies, whereas mixed flower strips attracted both groups in similar abundance to targeted mixes. Natural enemy densities on apple trees were higher in plots containing open-nectar plants compared to other treatments, but effects were stronger for non-aphidophagous taxa. Predation of sentinel prey was enhanced in all flowering plots compared to controls but pest aphid densities and fruit yield were unaffected by flower strips. We conclude that 'multi-functional' flower strips that contain flowering plant species with opposing floral traits can provide nectar and pollen for both pollinators and natural enemies, but further work is required to understand their potential for improving pest control services and yield in cider apple orchards.

Making a homefront without a battlefront: The manufacturing of domestic enemies in the early Cold War culture 

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Jean-Paul Gabilliet

2012-03-01

Full Text Available Although the Cold War was an undeclared conflict without actual battlefront one of its earliest charcteristics was the emergence in the United States of a homefront-based “war culture” targetting domestic enemies. 1947 witnessed the rise in news media of anxieties over alleged threats to domestic stability: in the first few months of the year, a Crime Scare reactivating pre-war concerns about the Mob and, in the summer, the first reported UFO sightings. In both cases the media and public resp...

The Prayers and Tears of Foucault: Panopticism and the Politics of Dissent in "An Enemy of the People" and "Look Back in Anger"

Science.gov (United States)

Jeihouni, Mojtaba; Torkamaneh, Pouria

2016-01-01

Drawing on the thought of Foucault, this article argues that the anarchistic protagonists of Henrik Ibsen's "An Enemy of the People" (1882) and John Osborne's "Look Back in Anger" (1956) are engaged in a hegemonic battle which puts their identities at stake and ultimately exiles them to isolation. It points out that the very…

Landscape and biodiversity as new resources for agro-ecology? Insights from farmers' perspectives

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Nicolas Salliou

2017-06-01

Full Text Available Pesticide reduction is a key current challenge. Scientific findings in landscape ecology suggest that complex landscapes favor insect pest biological control by conservation of natural enemy habitats. A potential agro-ecological innovation is to conserve or engineer such complex landscapes to reduce pesticide use. However, whereas the relevant resources are often well known in most natural resource management situations, potential resources involved in this innovation (natural enemies and the landscape are not necessarily considered as resources in the eyes of their potential users. From the perspective that resources are socially constructed, our objective was to investigate whether and how these resources are considered by their potential users. To do so, we conducted research in an area specializing in tree-fruit (apple production in southwestern France. This site was selected for its high pest incidence and high use of insecticides on orchards and, consequently, high stakes involved for any alternative. We conducted 30 comprehensive interviews with stakeholders (farmers and crop advisors about their pest control strategies to explore their representation of their landscape and natural enemies. Our results show that natural enemies are considered by local stakeholders as public good resources, especially in the context of interventions by public institutions for their conservation, acclimation, and management. Farmers sometimes consider natural enemies as private goods when they can isolate the crop, enclosing it with nets or some other type of boundary. We also show that the landscape was not considered as a resource for biological pest control by conservation, but rather as a source of pests. We advocate for more research on the effects of landscapes on natural enemies, including participatory research based on dialogue among farmers, crop advisors, and scientists.

"Enemies of the People?" Public Health in the Era of Populist Politics

Science.gov (United States)

McKee, Martin; Stuckler, David

2017-01-01

In this commentary, we review the growth of populist politics, associated with exploitation of what has been termed fake news. We explore how certain words have been used in similar contexts historically, in particular the term "enemy of the people," especially with regard to public health. We then set out 6 principles for public health professionals faced with these situations. First, using their epidemiological skills, they can provide insights into the reasons underlying the growth of populist politics. Second using their expertise in modelling and health impact assessment, they can anticipate and warn about the consequences of populist policies. Third, they can support the institutions that are necessary for effective public health. Fourth they can reclaim the narrative, rejecting hatred and division, to promote social solidarity. Fifth, they can support fact checking and the use of evidence. Finally, they should always remember the lessons of history, and in particular, the way that public health has, on occasions, collaborated with totalitarian and genocidal regimes. PMID:29179293

Lack of phenotypic and evolutionary cross-resistance against parasitoids and pathogens in Drosophila melanogaster.

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Alex R Kraaijeveld

Full Text Available When organisms are attacked by multiple natural enemies, the evolution of a resistance mechanism to one natural enemy will be influenced by the degree of cross-resistance to another natural enemy. Cross-resistance can be positive, when a resistance mechanism against one natural enemy also offers resistance to another; or negative, in the form of a trade-off, when an increase in resistance against one natural enemy results in a decrease in resistance against another. Using Drosophila melanogaster, an important model system for the evolution of invertebrate immunity, we test for the existence of cross-resistance against parasites and pathogens, at both a phenotypic and evolutionary level.We used a field strain of D. melanogaster to test whether surviving parasitism by the parasitoid Asobara tabida has an effect on the resistance against Beauveria bassiana, an entomopathogenic fungus; and whether infection with the microsporidian Tubulinosema kingi has an effect on the resistance against A. tabida. We used lines selected for increased resistance to A. tabida to test whether increased parasitoid resistance has an effect on resistance against B. bassiana and T. kingi. We used lines selected for increased tolerance against B. bassiana to test whether increased fungal resistance has an effect on resistance against A. tabida.We found no positive cross-resistance or trade-offs in the resistance to parasites and pathogens. This is an important finding, given the use of D. melanogaster as a model system for the evolution of invertebrate immunity. The lack of any cross-resistance to parasites and pathogens, at both the phenotypic and the evolutionary level, suggests that evolution of resistance against one class of natural enemies is largely independent of evolution of resistance against the other.

Introduced pathogens follow the invasion front of a spreading alien host

Science.gov (United States)

Ann E. Hajek; Patrick C. Tobin

2011-01-01

When an invasive species first colonizes an area, there is an interval before any host-specific natural enemies arrive at the new location. Population densities of newly invading species are low, and the spatial and temporal interactions between spreading invasive species and specific natural enemies that follow are poorly understood. We measured infection rates of two...

Remembering Independence, Desiring Enemies: Reflections on Nationhood in Contemporary Lithuania

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Ignas Kalpokas

2012-06-01

Full Text Available The paper addresses the remembrance of events surrounding the restoration of Lithuanian independence, as well as their repercussions on the present, concentrating on the younger generation that does not have first-hand experience of the period and, therefore, has to rely on other people’s accounts, textbooks, and other sources.If one considers the state and, especially, its social (or communal dimension as impossible totalities, memory and history acquire significant importance as they both provide ‘a magma of significations’, out of which particular signifying structures are instituted in order to anchor meaning and exhort a unifying claim through dominant narratives that tend to subjugate the otherwise inevitable variety of discourses. The discourse of the Lithuanian history textbooks is analysed by outlining its emphasis on unity and self-sacrifice in 1988-1991, and by portraying the Lithuanian history as an unending struggle against enemies and their malevolent plots. Also, considering the accounts of young people, two tendencies are visible: first, a bias towards images of unity and self-sacrifice depicting the period concerned, second, the predilection to employ the categories of ‘aliens’ and ‘enemies’ is evident, significantly affecting perceptions of the present with widespread images of disintegration and decay in the absence of the Other.

The Image of the Enemy as a Stereotype of Thinking

Directory of Open Access Journals (Sweden)

Татьяна Андреевна Фоменко

2016-12-01

Full Text Available In this article we analyze the process of stereotype thinking and its verbal expression. We focus our attention on the symbolic vision of our society in the mind of Europeans: Russia is evil, a country where law and democracy have deteriorated. Our aim is to examine the process of mind manipulation and imprinting of the enemy image on the mind of the society by means of communication and show the difficulty of destruction of stereotypes which prevents people of the 21st century from the objective perception of reality. We conducted our study on dictionary entries, articles, B.Obama’s speech in particular, and the extract from David Mitchell’s book “Black Swan Green”. The research is based on the data worked out by a number of sciences: Cultural Linguistics, Psychology, Psycholinguistics, Cross-Cultural Communication. We used the methods of functional and pragmatic analysis of the text. A stereotype is defined as an element of the cultural code which can be decoded by means of language; itt affects the way of thinking, behavior and lexis. Thus, the proposed thesis of a stereotype is supposed to be changing but too slowly. It is concluded that the sterotype “Russia is the enemy” possesses its formal linguistic, mental, and behavioural parametres.

The enemy, his gestalt of animal (Schmitt’s and Hegel’s animal functions

Directory of Open Access Journals (Sweden)

Bojanić Petar

2003-01-01

Full Text Available The main cause of Schmitt’s and Kojève’s friendship, and consequently, their correspondence, lies in their common affinity for philosophy of Hegel. When they began corresponding in 1955, Schmitt was something of an academic pariah; in 1933, the legal scholar had joined the Nazi Party, publicly declared his anti-Semitism, was later interrogated (but not charged at Nuremberg, and retired from his post at the University of Berlin in 1946. After his famous lectures on Hegel’s Phenomenology ended in 1939, Kojève joined the Resistance. At the end of the World II War, he wound up in the French ministry of economic affairs, where he worked until his death in 1968. This text is written on the margins of two letters, one written on 14.XII.1955. by Schmitt and the other, Kojève’s answer, dated on 4.I.1956. The subject of those two letters is the interpretation of the enemy in philosophy of Hegel. .

The convenient enemy – neocons, global jihadists and the road to Iraq

Directory of Open Access Journals (Sweden)

Carlos Gustavo Poggio Teixeira

2011-05-01

Full Text Available Ideologically, the Iraq War was a product of the encounter of global jihadism and neoconservatism. Prior to September 11, 2001, both were facing enormous difficulties in keeping their appeal as compelling discourses within their respective societies. Nevertheless, 9-11 revived neoconservatism by giving them the ideological enemy neoconservatives were longing calling for, leading to the invasion of Iraq on March 20, 2003 which, in turn, reenergized global jihadism.   Em termos ideológicos, a Guerra do Iraque foi resultado do encontro entre jihadismo global e neoconservadorismo. Antes de 11 de setembro de 2001, ambos passavam por enormes dificuldades no sentido de manter seu apelo enquanto discursos legítimos no contexto de suas respectivas sociedades.Entretanto, os ataques de 11 de setembro reavivaram o neoconservadorismo na medida em que forneceu aos neoconservadores o necessário inimigo ideológico clamado pelos mesmos, levando à invasão do Iraque em 20 de março de 2003 que, por sua vez, revitalizou o jihadismo global.

The effect of within-crop habitat manipulations on the conservation biological control of aphids in field-grown lettuce.

Science.gov (United States)

Skirvin, D J; Kravar-Garde, L; Reynolds, K; Wright, C; Mead, A

2011-12-01

Within-crop habitat manipulations have the potential to increase the biological control of pests in horticultural field crops. Wildflower strips have been shown to increase the abundance of natural enemies, but there is little evidence to date of an impact on pest populations. The aim of this study was to determine whether within-crop wildflower strips can increase the natural regulation of pests in horticultural field crops. Aphid numbers in plots of lettuce grown adjacent to wildflower strips were compared with those in plots grown in the absence of wildflowers. The presence of wildflower strips led to a decrease in aphid numbers on adjacent lettuce plants during June and July, but had less impact in August and September. The decrease in aphid numbers was greatest close to the wildflower strips and, the decrease in aphid numbers declined with increasing distance from the wildflower strips, with little effect at a distance of ten metres. The main natural enemies found in the crop were those that dispersed aerially, which is consistent with data from previous studies on cereal crops. Analysis and interpretation of natural enemy numbers was difficult due to low recovery of natural enemies, and the numbers appeared to follow changes in aphid abundance rather than being directly linked to the presence of wildflower strips. Cutting the wildflower strips, to remove floral resources, had no impact on the reduction in aphid numbers achieved during June and July, but decreased the effect of the wildflower strips during August and September. The results suggest that wildflower strips can lead to increased natural regulation of pest aphids in outdoor lettuce crops, but more research is required to determine how this is mediated by natural enemies and how the impact of wildflower strips on natural pest regulation changes during the growing season.

Impacts of Natural Disasters on Swedish Electric Power Policy: A Case Study

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Niyazi Gündüz

2017-02-01

Full Text Available The future of climate and sustainable energy are interrelated. Speaking of one without mentioning the other is quite difficult. The increasing number of natural disasters pose a great threat to the electric power supply security in any part of the world. Sweden has been one of the countries that have suffered from unacceptably long blackouts. The tremendous outcomes of the power interruptions have made the field of the economic worth of electric power reliability a popular area of interest among researchers. Nature has been the number one enemy against the supply security of the electricity. This paper introduces a recent and thorough electric power reliability analysis of Sweden and focuses on the country’s struggle against climate change-related natural disasters via updating the country’s electric power policy to improve its service quality. The paper highlights the Gudrun storm of 2005 as a case study to demonstrate the severe impacts of extreme weather events on the energy systems. The economic damage of the storm on the electric power service calculated to be around 3 billion euros.

Relationship between the abundance of aphids and their natural enemies in cereal fields and landscape composition

Czech Academy of Sciences Publication Activity Database

Hassan, D. A.; Parisey, N.; Burel, F.; Plantegenest, M.; Kindlmann, Pavel; Butet, A.

2012-01-01

Roč. 2, č. 2 (2012), s. 89-101 ISSN 1805-0174 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : agroecosystems * landscape structure * crop pests * aphids * biological control * semi-natural habitats Subject RIV: EH - Ecology, Behaviour

Studies on the occurrence of true spiders as natural enemies in many Egyptian fields

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Amira A. Ibrahim

2012-01-01

Full Text Available True spiders represent one of the most important natural predatory species in Egyptian fields. In this work, common true spiders were surveyed in wheat, cotton and maize fields, and were counted weekly by using the direct method. For evaluating the feeding consumption of true spiders, five feeding cases were tested (as preys. These cases were: eggs of Ephestia kuehniella, eggs of Phthorimaea operculella, one day eggs and larvae of E. kuehniella, larvae of E. kuehniella and P. operculella and larvae of E. kuehniella only. Results obtained revealed that, the highest average daily consumption for each spider was recorded in case of feeding on eggs of P. operculella. While, the longest survival period was recorded in case of feeding on larvae of E. kuehniella.

Ecologically sustainable chemical recommendations for agricultural pest control?

Science.gov (United States)

Thomson, Linda J; Hoffmann, Ary A

2007-12-01

Effective pest control remains an essential part of food production, and it is provided both by chemicals and by natural enemies within agricultural ecosystems. These methods of control are often in conflict because of the negative impact of chemicals on natural enemies. There are already well-established approaches such as those provided by the International Organization for Biological and Integrated Control-Pesticides and Beneficial Organisms for testing, collecting, and publishing information on responses of natural enemies to chemicals based on laboratory responses of specific organisms; however, these tests do not assess the cumulative impact of chemical inputs across an entire season or consider impacts on the complex communities of natural enemies that can provide effective pest control on a farm. Here, we explore the potential of different approaches for assessing the impact of chemicals on agricultural ecosystems and we propose a simple metric for sustainable chemical use on farms that minimizes overall impact on beneficial groups. We suggest ways in which the effectiveness of metrics can be extended to include persistence and habitat features. Such metrics can assist farmers in developing targets for sustainable chemical use as demonstrated in the viticultural industry.

Macroecology of parental care in arthropods: higher mortality risk leads to higher benefits of offspring protection in tropical climates.

Science.gov (United States)

Santos, Eduardo S A; Bueno, Pedro P; Gilbert, James D J; Machado, Glauco

2017-08-01

The intensity of biotic interactions varies around the world, in such a way that mortality risk imposed by natural enemies is usually higher in the tropics. A major role of offspring attendance is protection against natural enemies, so the benefits of this behaviour should be higher in tropical regions. We tested this macroecological prediction with a meta-regression of field experiments in which the mortality of guarded and unguarded broods was compared in arthropods. Mortality of unguarded broods was higher, and parental care was more beneficial, in warmer, less seasonal environments. Moreover, in these same environments, additional lines of defence further reduced offspring mortality, implying that offspring attendance alone is not enough to deter natural enemies in tropical regions. These results help to explain the high frequency of parental care among tropical species and how biotic interactions influence the occurrence of parental care over large geographic scales. Finally, our findings reveal that additional lines of defences - an oftentimes neglected component of parental care - have an important effect on the covariation between the benefits of parental care and the climate-mediated mortality risk imposed by natural enemies. © 2016 Cambridge Philosophical Society.

Cross-species comparison of parasite richness, prevalence, and intensity in a native compared to two invasive brachyuran crabs

NARCIS (Netherlands)

Goedknegt, M.A.; Havermans, J.; Waser, A.M.; Luttikhuizen, P.C.; Velilla, E.; Camphuysen, C.J.; Van der Meer, J.; Thieltges, D.W.

2017-01-01

An introduced species’ invasion success may be facilitated by the release of natural enemies, like parasites, which may provide an invader with a competitive advantage over native species (enemy release hypothesis). Lower parasite infection levels in introduced versus native populations have

Tri-trophic interactions affect density dependence of seed fate in a tropical forest palm

NARCIS (Netherlands)

Visser, Marco D.; Muller-Landau, Helene C.; Wright, S. Joseph; Rutten, Gemma; Jansen, Patrick A.

2011-01-01

Natural enemies, especially host-specific enemies, are hypothesised to facilitate the coexistence of plant species by disproportionately inflicting more damage at increasing host abundance. However, few studies have assessed such Janzen-Connell mechanisms on a scale relevant for coexistence and no

Influence of landscape structure on the functional groups of an aphidophagous guild: Active-searching predators, furtive predators and parasitoids

Directory of Open Access Journals (Sweden)

Julie-Éléonore Maisonhaute

2011-12-01

Full Text Available A lot of studies focusing on the effect of agricultural landscapes demonstrate that many arthropod species are influenced by landscape structure. In particular, non–crop areas and landscape diversity are often associated with a higher abundance and diversity of natural enemies in fields. Numerous studies focused on the influence of landscape structure on ground beetles, spiders and ladybeetles but few on other natural enemies or different functional groups. Thus, the objective of the present study was to determine the influence of landscape structure on the functional groups, i.e., active-searching predators, furtive predators and parasitoids of aphidophagous guilds. Natural enemies were sampled on milkweed infested with aphids, growing along the borders of ditches adjacent to cornfields. The sampling occurred weekly from June to September in 2006 and 2007, in the region of Lanaudičre (Quebec, Canada. The landscapes within a radius 200 and 500 m around each site were analyzed. The abundance, richness and species composition (based on functional groups of natural enemies were related to landscape structure. The results indicated that landscape structure explained up to 21.6% of the variation in natural enemy assemblage and confirm the positive effects of non-crop areas and landscape diversity. A lower influence of landscape structure on species composition was observed (6.4 to 8.8% and varied greatly among the functional groups. Coccinellidae and furtive predators were the group most influenced by landscape structure. In conclusion, the influence of landscape varied greatly among the different species of the same functional group.

Volatile chemical interaction between undamaged plants

OpenAIRE

Glinwood, Robert

2010-01-01

This chapter discusses whether plant chemical communication is a mechanism by which plant genetic diversity can affect the natural enemies of herbivores. Plant genetic diversity influences natural enemies, and these insects use volatile chemical cues to locate suitable habitats. However, the importance of chemical communication for these interactions has not been considered. In this chapter, the latest research on chemical communication between undamaged plants is reviewed. ...

Populations of predators and parasitoids of Bemisia tabaci (Hemiptera: Aleyrodidae) after the application of eight biorational insecticides in vegetable crops.

Science.gov (United States)

Simmons, Alvin M; Shaaban, Abd-Rabou

2011-08-01

The sweetpotato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is an important pest of vegetables and many other crops worldwide. Eight biorational insecticides (based on oil, plant derivatives, insect growth regulator and fungus) were evaluated in the field for their influence on populations of six natural enemies of B. tabaci. Natural populations of two predators [Chrysoperla carnea Stephen (Neuroptera: Chrysopidae) and Orius spp. (Hemiptera: Anthocoridae)] and two genera of parasitoids [Encarsia spp. and Eretmocerus spp. (Hymenoptera: Aphelinidae)] were evaluated in eggplant (Solanum melongena L.). Also, augmented field populations of three predators [C. carnea, Coccinella undecimpunctata L. (Coleoptera: Coccinellidae) and Macrolophus caliginosus (Wagner) (Hemiptera: Miridae)] were evaluated in cabbage (Brassica oleracea var. capitata L.), cucumber (Cucumis sativus L.) and squash (Cucurbita pepo L.). Regardless of natural enemy or crop, jojoba oil, Biovar and Neemix had the least effect on abundance of the natural enemies in comparison with the other insecticides during a 14 day evaluation period. Conversely, Admiral, KZ oil, Mesrona oil, Mesrona oil + sulfur and natural oil had a high detrimental effect on abundance of the natural enemies. These results demonstrate the differential effects of biorational insecticides for whitefly control on predators and parasitoids in the field. This article is a US Government work and is in the public domain in the USA. Published 2011 by John Wiley & Sons, Ltd.

No evidence for enemy release during range expansion of an evergreen tree in northern Europe

DEFF Research Database (Denmark)

Skou, Anne-Marie Thonning; Markussen, Bo; Sigsgaard, Lene

2011-01-01

aquifolium L. in both the historical and the expanding range in Denmark to study possible effects of geographical position, small-scale distance, and plant types on presence and performance of the monophagous insect leaf-miner Phytomyza ilicis Curtis. 3. The leaf miner was present in the entire range of I....... aquifolium in Denmark, and there were no differences in emergence success depending on geographical position. Small-scale distance to existing adult plants inßuenced the activity of the insect on the transplants, and oviposition density was negatively correlated with distance to adult plants. 4. Plant type...... had an effect on leaf miner feeding, oviposition and mining, and the native provenance of I. aquifolium supported higher densities than two cultivars. 5. There was no evidence that enemy release facilitates the current range expansion of I. aquifolium....

Single-particle states vs. collective modes: friends or enemies ?

Science.gov (United States)

Otsuka, T.; Tsunoda, Y.; Togashi, T.; Shimizu, N.; Abe, T.

2018-05-01

The quantum self-organization is introduced as one of the major underlying mechanisms of the quantum many-body systems. In the case of atomic nuclei as an example, two types of the motion of nucleons, single-particle states and collective modes, dominate the structure of the nucleus. The collective mode arises as the balance between the effect of the mode-driving force (e.g., quadrupole force for the ellipsoidal deformation) and the resistance power against it. The single-particle energies are one of the sources to produce such resistance power: a coherent collective motion is more hindered by larger spacings between relevant single particle states. Thus, the single-particle state and the collective mode are "enemies" against each other. However, the nuclear forces are rich enough so as to enhance relevant collective mode by reducing the resistance power by changing single-particle energies for each eigenstate through monopole interactions. This will be verified with the concrete example taken from Zr isotopes. Thus, the quantum self-organization occurs: single-particle energies can be self-organized by (i) two quantum liquids, e.g., protons and neutrons, (ii) monopole interaction (to control resistance). In other words, atomic nuclei are not necessarily like simple rigid vases containing almost free nucleons, in contrast to the naïve Fermi liquid picture. Type II shell evolution is considered to be a simple visible case involving excitations across a (sub)magic gap. The quantum self-organization becomes more important in heavier nuclei where the number of active orbits and the number of active nucleons are larger.

``Sleeping with the enemy''—predator-induced diapause in a mite

Science.gov (United States)

Kroon, Annemarie; Veenendaal, René L.; Bruin, Jan; Egas, Martijn; Sabelis, Maurice W.

2008-12-01

Diapause in arthropods is a physiological state of dormancy that is generally thought to promote survival during harsh seasons and dispersal, but it may also serve to avoid predation in space and time. Here, we show that predation-related odours induce diapause in female adult spider mites. We argue that this response allows them to move into an area where they are free of enemies, yet forced to survive without food. Spider mites are specialised leaf feeders, but—in late summer—they experience severe predation on leaves. Hence, they face a dilemma: to stay on the leaf and risk being eaten or to move away from the leaf and risk death from starvation and thirst. Female two-spotted spider mites solve this dilemma by dramatically changing their physiology when exposed to predation-associated cues. This allows them to disperse away from leaves and to survive in winter refuges in the bark of trees or in the soil. We conclude that the mere presence of predation-associated cues causes some herbivorous mites to seek refuge, thereby retarding the growth rate of the population as a whole: a trait-mediated indirect effect that may have consequences for the stability of predator prey systems and for ecosystem structure.

Yellowstone wolves and the forces that structure natural systems.

Science.gov (United States)

Dobson, Andy P

2014-12-01

Since their introduction in 1995 and 1996, wolves have had effects on Yellowstone that ripple across the entire structure of the food web that defines biodiversity in the Northern Rockies ecosystem. Ecological interpretations of the wolves have generated a significant amount of debate about the relative strength of top-down versus bottom-up forces in determining herbivore and vegetation abundance in Yellowstone. Debates such as this are central to the resolution of broader debates about the role of natural enemies and climate as forces that structure food webs and modify ecosystem function. Ecologists need to significantly raise the profile of these discussions; understanding the forces that structure food webs and determine species abundance and the supply of ecosystem services is one of the central scientific questions for this century; its complexity will require new minds, new mathematics, and significant, consistent funding.

Pollen subsidies promote whitefly control through the numerical response of predatory mites

NARCIS (Netherlands)

Nomikou, M.; Sabelis, M.W.; Janssen, A.

2010-01-01

Several studies have shown that biological control of pests can be improved by supplying extra food to natural enemies. This increases population levels of the enemies, resulting in decreases in pest densities. In theory, however, supplying food can also have negative effects on biological control.

Dietary sugars and proline influence biological parameters of adult Trissolcus grandis, an egg parasitoid of Sunn pest, Eurygaster integriceps

NARCIS (Netherlands)

Hajirajabi, Nafiseh; Fazel, Morteza Movahedi; Harvey, Jeffrey A.; Arbab, Abbass; Asgari, Shahriar

Parasitoids are important natural enemies that are used in the biological control of insect herbivore pests. The egg parasitoid Trissolcus grandis Thompson (Hym. Scelionidae) is a major enemy of the Sunn pest, Eurygaster integriceps Puton (Hem. Scutelleridae), which in turn is one of the most

Crop domestication, global human-mediated migration, and the unresolved role of geography in pest control

Directory of Open Access Journals (Sweden)

Yolanda H. Chen

2016-05-01

Full Text Available Abstract Ecological pest management seeks to improve pest control through the manipulation of ecological processes that promote natural enemies and suppress pests. These approaches can involve cultural practices such as reduced tillage, increased use of non-crop plants that provide food and shelter for natural enemies, and intercropping to enhance the abundance and diversity of natural enemies. A major assumption of ecological pest management is that these activities can be equally effective for all insect herbivores. Here, I propose that these strategies may only be effective for a subset of pests and geographic regions because most insect pests have complex evolutionary histories that make them difficult to manage. I discuss how crop domestication and human-mediated migration are major evolutionary events that shape the geography of interactions between plants, herbivores, and natural enemies. Insect herbivores can evolve to be pests through three major modes: 1 herbivores associated with the crop wild ancestor may shift onto the domesticated crop, 2 herbivores may host-shift from native host plants onto an introduced crop, or 3 human-mediated migration can introduce insect pests into new cropping regions. The resulting geographic structure can influence the success of pest management by altering ecological factors such as: species distributions, patterns of biodiversity, community structure, and natural enemy attack rates. I discuss how the different modes of insect pest evolution structure a set of relevant questions and approaches for ecological pest management. By acknowledging how agricultural history and geography shape the ecology and evolution of insect pests, we may collectively develop a better capacity to identify where and how ecological pest management approaches can be most broadly effective.

Identification of top-down forces regulating cotton aphid population growth in transgenic Bt cotton in central China.

Directory of Open Access Journals (Sweden)

Peng Han

Full Text Available The cotton aphid Aphis gossypii Glover is the main aphid pest in cotton fields in the Yangtze River Valley Cotton-planting Zone (YRZ in central China. Various natural enemies may attack the cotton aphid in Bt cotton fields but no studies have identified potential specific top-down forces that could help manage this pest in the YRZ in China. In order to identify possibilities for managing the cotton aphid, we monitored cotton aphid population dynamics and identified the effect of natural enemies on cotton aphid population growth using various exclusion cages in transgenic Cry1Ac (Bt+CpTI (Cowpea trypsin inhibitor cotton field in 2011. The aphid population growth in the open field (control was significantly lower than those protected or restricted from exposure to natural enemies in the various exclusion cage types tested. The ladybird predator Propylaea japonica Thunberg represented 65% of Coccinellidae predators, and other predators consisted mainly of syrphids (2.1% and spiders (1.5%. The aphid parasitoids Aphidiines represented 76.7% of the total count of the natural enemy guild (mainly Lysiphlebia japonica Ashmead and Binodoxys indicus Subba Rao & Sharma. Our results showed that P. japonica can effectively delay the establishment and subsequent population growth of aphids during the cotton growing season. Aphidiines could also reduce aphid density although their impact may be shadowed by the presence of coccinellids in the open field (likely both owing to resource competition and intraguild predation. The implications of these results are discussed in a framework of the compatibility of transgenic crops and top-down forces exerted by natural enemy guild.

Maize stemborers distribution, their natural enemies and farmers ...

African Journals Online (AJOL)

SARAH

2013-04-25

Apr 25, 2013 ... parasitica Curan (Diptera: Tachnidae) with mean parasitism ranged of between 0 and 8%. Beauveria .... log(x+1) and percentage data were arcsine square root transformed ..... seasonal fluctuations of Lepidopteran cereal.

Spiders (Araneae) as polyphagous natural enemies in orchards

NARCIS (Netherlands)

Bogya, S.

1999-01-01

Spiders (Araneae) occur in high abundance in all terrestrial ecosystems including agro-ecosystems. They are a very heterogeneous group of animals with different hunting tactics and therefore they play very different ecological roles. At family level these tactics are rather similar thus

Crapemyrtle Bark Scale: A New Threat for Crapemyrtles, a Popular Landscape Plant in the U.S.

Directory of Open Access Journals (Sweden)

Zinan Wang

2016-12-01

Full Text Available Crapemyrtle bark scale, Acanthococcus (=Eriococcus lagerstroemiae (Kuwana (Hemiptera: Eriococcidae, is a newly introduced insect pest on crapemyrtles, Lagerstroemia spp. (Myrtales: Lythraceae, one of the most popular flowering shrubs in the U.S. Since first detected in Texas in 2004, this pest has spread to twelve states causing losses to stakeholders. To develop a management plan, we reviewed current knowledge about the pest’s biology and ecology, and suggested research approaches including studying its thermal tolerance, host range, plant resistance and biological control. Parasitoids and predators have been reared from A. lagerstroemiae in the U.S. and China. However, new surveys of natural enemies should be conducted in China, and studies on the host range and impacts of natural enemies on A. lagerstroemiae may help determine the potential for classical biological control. The life history, preying efficiency and rearing methods are important for coccinellid predators found in the U.S. including Chilocorus cacti L. and Hyperaspis spp. To enhance natural enemy performance, it is important to evaluate a sustainable insecticide program that considers efficacy, timing, rate and impact on pollinator health. Finally, an integrated management program of A. lagerstroemiae is discussed including planting resistant cultivars, using host specific natural enemies, and prudent use of insecticides.

Analysis of Genetic Variation and Phylogeny of the Predatory Bug, Pilophorus typicus, in Japan using Mitochondrial Gene Sequences

OpenAIRE

Ito, Katsura; Nishikawa, Hiroshi; Shimada, Takuji; Ogawa, Kohei; Minamiya, Yukio; Tomoda, Masafumi; Nakahira, Kengo; Kodama, Rika; Fukuda, Tatsuya; Arakawa, Ryo

2011-01-01

Pilophorus typicus (Distant) (Heteroptera: Miridae) is a predatory bug occurring in East, Southeast, and South Asia. Because the active stages of P. typicus prey on various agricultural pest insects and mites, this species is a candidate insect as an indigenous natural enemy for use in biological control programs. However, the mass releasing of introduced natural enemies into agricultural fields may incur the risk of affecting the genetic integrity of species through hybridization with a loca...

Pathogen avoidance by insect predators

OpenAIRE

Meyling, Nicolai V.; Ormond, Emma; Roy, Helen E.; Pell, Judith K.

2008-01-01

Insects can detect cues related to the risk of attack by their natural enemies. Pathogens are among the natural enemies of insects and entomopathogenic fungi attack a wide array of host species. Evidence documents that social insects in particular have adapted behavioural mechanisms to avoid infection by fungal pathogens. These mechanisms are referred to as 'behavioural resistance'. However, there is little evidence for similar adaptations in non-social insects. We have conducted experime...

Bagworm bags as portable armour against invertebrate predators

OpenAIRE

Sugiura, Shinji

2016-01-01

Some animals have evolved the use of environmental materials as “portable armour” against natural enemies. Portable bags that bagworm larvae (Lepidoptera: Psychidae) construct using their own silk and plant parts are generally believed to play an important role as a physical barrier against natural enemies. However, no experimental studies have tested the importance of bags as portable armour against predators. To clarify the defensive function, I studied the bagworm Eumeta minuscula and a po...

Plant-soil biota interactions and spatial distribution of black cherry in its native and invasive ranges

NARCIS (Netherlands)

Reinhart, K.O.; Packer, A.; Van der Putten, W.H.; Clay, K.A.

2003-01-01

One explanation for the higher abundance of invasive species in their non-native than native ranges is the escape from natural enemies. But there are few experimental studies comparing the parallel impact of enemies (or competitors and mutualists) on a plant species in its native and invaded ranges,

Yellowstone wolves and the forces that structure natural systems.

Directory of Open Access Journals (Sweden)

Andy P Dobson

2014-12-01

Full Text Available Since their introduction in 1995 and 1996, wolves have had effects on Yellowstone that ripple across the entire structure of the food web that defines biodiversity in the Northern Rockies ecosystem. Ecological interpretations of the wolves have generated a significant amount of debate about the relative strength of top-down versus bottom-up forces in determining herbivore and vegetation abundance in Yellowstone. Debates such as this are central to the resolution of broader debates about the role of natural enemies and climate as forces that structure food webs and modify ecosystem function. Ecologists need to significantly raise the profile of these discussions; understanding the forces that structure food webs and determine species abundance and the supply of ecosystem services is one of the central scientific questions for this century; its complexity will require new minds, new mathematics, and significant, consistent funding.

Wilhelm Reich's self-censorship after his arrest as an enemy alien: the chilling effect of an illegal imprisonment.

Science.gov (United States)

Bennett, Philip W

2014-04-01

After discussing Wilhelm Reich's place in psychoanalysis, the article explores his arrest as an 'enemy alien' in December 1941. Reich's emotional responses to his imprisonment (which was illegal and which lasted nearly a month) are explored. A number of scholars have suggested that many European radical psychoanalysts refrained from sharing their former political ideas once they emigrated to the United States. Following a brief discussion of this pattern of 'silencing,' it is argued that Reich's withholding certain documents from publication was due to a self-imposed censorship, motivated in part by the fear of further governmental interference with his life and work. This fear, however, did not extend to his discussion of his newly developed theory of orgone energy. Copyright © 2014 Institute of Psychoanalysis.

Interação entre inimigos naturais: Trichogramma e Bacillus thuringiensis no controle biológico de pragas agrícolas = Interaction between natural enemies: Trichogramma and Bacillus thuringiensis in pest control

Directory of Open Access Journals (Sweden)

Ricardo Antonio Polanczyk

2006-04-01

Full Text Available O objetivo deste trabalho foi avaliar os efeitos adversos de Bacillus thuringiensis (Bt nos parasitóides de ovos Trichogramma pratissolii e Trichogramma pretiosum. Suspensões de 6 isolados de Bt: E-3, E-10, E-15, E-16, E-19, E-20 e Bt kurstaki foram misturadas com mel (1:1, como fonte de alimento, e cartelas com ovos de Anagasta kuehniella foram fornecidas para o parasitismo. O experimento foi mantido em BOD a 25 + 1ºC, umidade relativa de 70+ 10% e fotofase de 14 horas. Foram analisados a longevidade, os parasitismos diário, acumulado e total. Não houve influência dos tratamentos sobre a longevidade e todos ostratamentos em T. pratissolii e E-3, E-10, E-16 e E- 19 em T. pretiosum diminuíram o tempo necessário para os parasitóides atingirem 80% de parasitismo. Apesar dessa aceleração do parasitismo, o Bt não influenciou o total de ovos parasitados, mostrando-se como tática de controle que pode ser usada com Trichogramma em programas de MIP.The goal of this work was to detect the possible side-effectsprovoked by Bacillus thuringiensis (Bt strains on eggs parasitoids Thichogramma pratissolii and Trichogramma pretiosum. Six strains of Bt: E-3, E-10, E-15, E-16, E-19, and E-20 and Bt kurstaki were assayed in honey drop to stimulate the feeding of the parasitoids in each treatment and offered simultaneously displays with Anagasta kuehniella eggs. The experiment was maintained in a climatized chamber at 25+ 1ºC, RH 70+ 10%, and photophase of 14 hours. The longevity, the daily, the accumulated, and the total parasitism were observed. No treatments affected the longevity of both parasitoids. All treatments in T. pratissolii and E-3, E-10, E-16, and E-19 in T. pretiosum decreased the time necessary to reach 80% of parasitism. The lack of deleterious effects of Bt on these parasitoids suggests that these natural enemies can be used together in IPM programs.

Habitat functionality for the ecosystem service of pest control: reproduction and feeding sites of pests and natural enemies

NARCIS (Netherlands)

Bianchi, F.J.J.A.; Schellhorn, N.A.; Cunningham, S.A.

2013-01-01

1 Landscape management for enhanced natural pest control requires knowledge of the ecological function of the habitats present in the landscape mosaic. However, little is known about which habitat types in agricultural landscapes function as reproduction habitats for arthropod pests and predators

Unrelated facultative endosymbionts protect aphids against a fungal pathogen.

Science.gov (United States)

Łukasik, Piotr; van Asch, Margriet; Guo, Huifang; Ferrari, Julia; Godfray, H Charles J

2013-02-01

The importance of microbial facultative endosymbionts to insects is increasingly being recognized, but our understanding of how the fitness effects of infection are distributed across symbiont taxa is limited. In the pea aphid, some of the seven known species of facultative symbionts influence their host's resistance to natural enemies, including parasitoid wasps and a pathogenic fungus. Here we show that protection against this entomopathogen, Pandora neoaphidis, can be conferred by strains of four distantly related symbionts (in the genera Regiella, Rickettsia, Rickettsiella and Spiroplasma). They reduce mortality and also decrease fungal sporulation on dead aphids which may help protect nearby genetically identical insects. Pea aphids thus obtain protection from natural enemies through association with a wider range of microbial associates than has previously been thought. Providing resistance against natural enemies appears to be a particularly common way for facultative endosymbionts to increase in frequency within host populations. © 2012 Blackwell Publishing Ltd/CNRS.

"Vem är jag nu?" Känslor och betydelser av genus och plats i digitalt spelande : Affektiva dimensioner av spelande i XCOM: Enemy Within

OpenAIRE

Andersson, Martin

2016-01-01

In this essay I analyze the ways in which gender and space are shaped and made sense of through digital gameplay. Specifically in the turn based strategy game XCOM: Enemy Within for the MacBook Air with a computer mouse as the primary input device. Using a mixed methods approach consisting of gameplay sessions of XCOM and qualitative interviews with two players regarding their gameplay I argue that earlier research on space within game studies has overlooked the ways in which the shaping of s...

Local ordinances as an instrument of social exclusion: the regulation affecting the homeless is administrative law of the enemy

Directory of Open Access Journals (Sweden)

Eduardo Melero Alonso

2017-03-01

Full Text Available This paper discusses local ordinances, especially the so-called coexistence ordinances, to the extent they affect the daily activities of the homeless. There are three areas of regulation: the prohibition of begging; a ban on sleeping, washing and perform physiological needs in public spaces; and the prohibition of sorting through garbage. This regulation is subjected to a critical analysis, focusing on the fact that has an impact on the fundamental rights of the homeless. The basic parameters of control are the reserve of law and, above all, the principle of proportionality. The conclusion reached is that, in many cases, this regulation is not only illegal, it can also be included within the category Administrative Law of the enemy.

Colonising aliens: caterpillars (Lepidoptera) feeding on Piper aduncum and P-umbellatum in rainforests of Papua New Guinea

Czech Academy of Sciences Publication Activity Database

Novotný, Vojtěch; Miller, S. E.; Čížek, Lukáš; Lepš, Jan; Janda, Milan; Basset, Y.; Weiblen, G. D.; Darrow, K.

2003-01-01

Roč. 28, - (2003), s. 704-716 ISSN 0307-6946 R&D Projects: GA AV ČR IAA6007106; GA MŠk ME 041; GA ČR GA206/99/1112 Institutional research plan: CEZ:AV0Z5007907 Keywords : enemy-free space * escape from natural enemies * herbivory Subject RIV: EH - Ecology, Behaviour Impact factor: 1.423, year: 2003

Aspectos biológicos y control de un gracilláriido (Gracillariidae: Lepidóptera) en Caesalpinia spinosa (Mol.) Kuntze (1898), en Cajamarca, Perú

OpenAIRE

Murga Orrillo, Hipólito; Abanto Rodríguez, Carlos; Polo Vargas, Ana Rosa

2016-01-01

Determine biological target, identify natural enemies, and establish appropriate periods of controlling a pest gracillariid tare. The biological aspects and natural enemies in field and laboratory were evaluated, appropriate control periods was determined by host-pest interaction. The results, egg lasts 7.8 days and measured 0.34x0.21 mm; presents four instars larvae and lasts 35.7 days, ranging from measures between 1st and the 4th instar from 0.09 to 0.65 mm diameter brain; the pupa lasts 1...

Enemy at the gates: Rapid defensive trait diversification in an adaptive radiation of lizards.

Science.gov (United States)

Broeckhoven, Chris; Diedericks, Genevieve; Hui, Cang; Makhubo, Buyisile G; Mouton, P le Fras N

2016-11-01

Adaptive radiation (AR), the product of rapid diversification of an ancestral species into novel adaptive zones, has become pivotal in our understanding of biodiversity. Although it has widely been accepted that predators may drive the process of AR by creating ecological opportunity (e.g., enemy-free space), the role of predators as selective agents in defensive trait diversification remains controversial. Using phylogenetic comparative methods, we provide evidence for an "early burst" in the diversification of antipredator phenotypes in Cordylinae, a relatively small AR of morphologically diverse southern African lizards. The evolution of body armor appears to have been initially rapid, but slowed down over time, consistent with the ecological niche-filling model. We suggest that the observed "early burst" pattern could be attributed to shifts in vulnerability to different types of predators (i.e., aerial versus terrestrial) associated with thermal habitat partitioning. These results provide empirical evidence supporting the hypothesis that predators or the interaction therewith might be key components of ecological opportunity, although the way in which predators influence morphological diversification requires further study. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Synergy between chemical and biological control in the IPM of currant-lettuce aphid (Nasonovia ribisnigri) in Canterbury, New Zealand.

Science.gov (United States)

Fagan, L L; McLachlan, A; Till, C M; Walker, M K

2010-04-01

Field trials were conducted at four Canterbury, New Zealand locations in 2005-06 to determine if the synergistic effects of biological control by natural enemies and standard drenching techniques controlled lettuce aphid populations throughout the entire growing season. Chemical usage significantly lowered aphid densities in the outer, wrapper and heart leaves compared to control plants at most times. However, in mid-summer, natural enemies, such as the brown lacewing (Micromus tasmaniae), 11-spotted ladybird beetle (Coccinella undecimpunctata) and small hoverfly larvae (Melanostoma fasciatum), were more than sufficient to control lettuce aphids without the use of insecticides. Drenching, in addition to natural enemy attack, appears to be required in early spring and late summer to maintain very low levels of lettuce aphid. Given the potential for imidacloprid resistance to develop, it may be advisable to restrict drenches to these key periods in order to allow populations of natural enemies to maintain control of prey populations. We recommend industry support the validation of action thresholds across different regions within New Zealand and focus on the seasonal biology of predators to assist growers with the sustainable long-term control of lettuce aphids. The inclusion of additional data into an economic model to compare pest damage with predator loading would be useful for growers in managing aphid problems. These results will assist in the continued improvement and development of a sustainable IPM strategy for lettuce aphids in New Zealand and elsewhere.

Manipulating field margins to increase predation intensity in fields of winter wheat (Triticum eastivum)

DEFF Research Database (Denmark)

Mansion-Vaquie, Agathe; Ferrante, Marco; Cook, S M

2017-01-01

, intraguild predation, hyperparasitism) may complicate the assumption that a higher density of natural enemies would increase the level of biological control. We investigated the natural enemy guild composition and the predation rate along flower vs. grass margins at the edge of winter wheat (Triticum...... to the two margin types: specialists (mostly parasitic wasps) were attracted by the flower margins, while generalists (ground beetles, rove beetles and spiders) were more active in grass margins. The number of artificial caterpillars attacked was significantly greater in grass margins (mean = 48.9%, SD = 24...

Impact and Selectivity of Insecticides to Predators and Parasitoids

Directory of Open Access Journals (Sweden)

Flávio Lemes Fernandes

2010-04-01

Full Text Available Problems with the use of insecticides has brought losses, such as, negative impact on natural enemies. When these beneficial insects reduce cause the eruption of pests and resurgence it’s more common. Thus principles of conservation these arthropods are extremely important in the biological natural control of pests, so that these enemies may present a high performance. Because of the negative impacts caused by insecticides on agriculture and their harmful effects on natural enemies, the objective of this article is to approach two important subjects, divided into three parts. Part I relates to the description of the main crop pests and their natural enemies; Part II involves the impact of insecticides on predators and parasitoids and Part III focuses on the selectivity of several groups of insecticides to natural enemies. Before spraying insecticides, it is necessary to choose a product that is efficient to pests and selective to natural enemies. So, it is indispensable to identify correctly the groups and species of natural enemies, since insecticides have an impact on their survival, growth, development, reproduction (sexual ratio, fecundity, longevity and fertility, and behavior (motility, orientation, feeding, oviposition and learning of insects. The mechanisms of toxicity and selectivity of insecticides are related to the properties of higher or lower solubility and molecular weight. Besides, characteristics of the cuticular composition of the integument of natural enemies are extremely important in the selectivity of a product or the tolerance of a certain predator or parasitoid to this molecules.Impacto e Seletividade de Inseticidas para Predadores e ParasitóidesResumo.Dentre os problemas advindos do uso de inseticidas, a destruição de inimigos naturais é fator importante. Estes insetos benéficos podem reduzir problemas de erupção de pragas secundárias, ressurgência de pragas e manter a praga abaixo do nível de dano econ

The Effects of Resource Limitation on a Predator-Prey Model with Control Measures as Nonlinear Pulses

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Wenjie Qin

2014-01-01

Full Text Available The dynamical behavior of a Holling II predator-prey model with control measures as nonlinear pulses is proposed and analyzed theoretically and numerically to understand how resource limitation affects pest population outbreaks. The threshold conditions for the stability of the pest-free periodic solution are given. Latin hypercube sampling/partial rank correlation coefficients are used to perform sensitivity analysis for the threshold concerning pest extinction to determine the significance of each parameter. Comparing this threshold value with that without resource limitation, our results indicate that it is essential to increase the pesticide’s efficacy against the pest and reduce its effectiveness against the natural enemy, while enhancing the efficiency of the natural enemies. Once the threshold value exceeds a critical level, both pest and its natural enemies populations can oscillate periodically. Further-more, when the pulse period and constant stocking number as a bifurcation parameter, the predator-prey model reveals complex dynamics. In addition, numerical results are presented to illustrate the feasibility of our main results.

Biologically Based Methods for Pest Management in Agriculture under Changing Climates: Challenges and Future Directions.

Science.gov (United States)

Chidawanyika, Frank; Mudavanhu, Pride; Nyamukondiwa, Casper

2012-11-09

The current changes in global climatic regimes present a significant societal challenge, affecting in all likelihood insect physiology, biochemistry, biogeography and population dynamics. With the increasing resistance of many insect pest species to chemical insecticides and an increasing organic food market, pest control strategies are slowly shifting towards more sustainable, ecologically sound and economically viable options. Biologically based pest management strategies present such opportunities through predation or parasitism of pests and plant direct or indirect defense mechanisms that can all be important components of sustainable integrated pest management programs. Inevitably, the efficacy of biological control systems is highly dependent on natural enemy-prey interactions, which will likely be modified by changing climates. Therefore, knowledge of how insect pests and their natural enemies respond to climate variation is of fundamental importance in understanding biological insect pest management under global climate change. Here, we discuss biological control, its challenges under climate change scenarios and how increased global temperatures will require adaptive management strategies to cope with changing status of insects and their natural enemies.

Biologically Based Methods for Pest Management in Agriculture under Changing Climates: Challenges and Future Directions

Directory of Open Access Journals (Sweden)

Casper Nyamukondiwa

2012-11-01

Full Text Available The current changes in global climatic regimes present a significant societal challenge, affecting in all likelihood insect physiology, biochemistry, biogeography and population dynamics. With the increasing resistance of many insect pest species to chemical insecticides and an increasing organic food market, pest control strategies are slowly shifting towards more sustainable, ecologically sound and economically viable options. Biologically based pest management strategies present such opportunities through predation or parasitism of pests and plant direct or indirect defense mechanisms that can all be important components of sustainable integrated pest management programs. Inevitably, the efficacy of biological control systems is highly dependent on natural enemy-prey interactions, which will likely be modified by changing climates. Therefore, knowledge of how insect pests and their natural enemies respond to climate variation is of fundamental importance in understanding biological insect pest management under global climate change. Here, we discuss biological control, its challenges under climate change scenarios and how increased global temperatures will require adaptive management strategies to cope with changing status of insects and their natural enemies.

CRISOPÍDEOS (NEUROPTERA: CHRYSOPIDAE: ASPECTOS BIOLÓGICOS, POTENCIAL DE UTILIZAÇÃO E PERSPECTIVAS FUTURAS

Directory of Open Access Journals (Sweden)

Carlos Eduardo Souza Bezerra

2009-01-01

Full Text Available Biological control using natural enemies has become one of the main alternatives to chemical control. Among these enemies, worth highlighting the green lacewings, known for their predatory efficiency and the ability of their larvae to seek out food. The present review aimed to gather scientific knowledge about these predators, intending to encourage the inclusion of theses insects in future biological control programs.

Insect fungi for the control of brown planthopper Nilaparvata lugens, and Malayan rice bug, Scotinophara coarctata

NARCIS (Netherlands)

Rombach, M.C.

1987-01-01

Introduction : Many potential pest organisms are normally kept at densities below damage thresholds by naturally occurring natural enemies in virtually all agricultural crops. This natural control can be enhanced by introduction of new biological agents

Deployment and Dehumanization: A Multi-Method Study of Combat Soldiers’ Loss of Empathy

DEFF Research Database (Denmark)

Brænder, Morten

2015-01-01

Studies in soldier motivation and socialization have shown that servicemen's level of compassion decreases following deployment to war. This may to some extent be explained by the transgressive nature of the combat soldier's service : the soldier puts himself in harm's way, and must if necessary...... kill the enemy. Hence, a certain 'emotional distance' may be required for him to cope with deployment life. To kill the enemy, it might be necessary for the soldier to deprive the enemy of his human capacities, to dehumanize him. However, by combining quantitative and qualitative methods, this study...... suggests that the enemy is not the only one who is dehumanized. The data analyzed were collected immediately before and after deployment of Danish combat soldiers to Helmand, Afghanistan. Quantitative findings show that the soldiers' empathetic motivation to serve civilians, compatriots and other soldiers...

Seasonal Occurrence of Key Arthropod Pests and Beneficial Insects in Michigan High Tunnel and Field Grown Raspberries.

Science.gov (United States)

Leach, Heather; Isaacs, Rufus

2018-06-06

Berry crops are increasingly produced in high tunnels, which provide growers with the opportunity to extend their production season. This is particularly beneficial for the northern region of the United States with short and unpredictable growing seasons and where rainfall limits fruit quality. However, little is known about the effect of high tunnels on the community of pests, natural enemies, or pollinators, especially in berry crops, and there are few reports of the insect community in raspberries in this region. We compared the abundance of these insects during two growing seasons in field-grown and tunnel-grown floricane and primocane producing raspberries through direct observation and trapping at five sites in southwestern and central Michigan. We found eight key pests, including spotted wing Drosophila, leafhoppers, and thrips, and seven key natural enemies including parasitoid wasps, spiders, and lacewings, that were common across all sites. Pest populations were up to 6.6 times higher in tunnels, and pests typical of greenhouse systems became more dominant in this environment. Natural enemies observed on plants under tunnels were also more abundant than in the field, but this trend was reversed for natural enemies trapped on yellow sticky cards. There was also a reduction of both honey bees and wild bees under the high tunnels, which was balanced by use of commercial bumble bees. These data not only provide much-needed information on the phenology of the insect community on raspberry plantings, they also highlight the entomological implications of protected raspberry culture.

The effectiveness of habitat modification schemes for enhancing beneficial insects: Assessing the importance of trap cropping management approach

Science.gov (United States)

Trisnawati, Indah; Azis, Abdul

2017-06-01

Many farms in regions of intensive crop production lack the habitats that historically provided resources to beneficial insects, and this lack has compromised the ability of farmers to rely on natural enemies for pest control. One of the strategies to boost populations of existing or naturally occurring beneficial insects is to supply them with appropriate habitat and alternative food sources, such as diversifying trap crop systems and plant populations in or around fields include perennials and flowering plants. Trap cropping using insectary plant that attracts beneficial insects as natural enemies, especially flowering plants, made for provision of habitat for predators or parasitoids that are useful for biological control. Perimeter trap cropping (PTC) is a method of integrated pest management in which the main crop is surrounded with a perimeter trap crop that is more attractive to pests. We observed PTC habitat modification and conventionaly-managed tobacco farms in Purwosari Village, Pasuruan (East Java) to evaluate the effectiveness of habitat modification management prescription (perimeter trap crop using flowering plant Crotalaria juncea) on agroecosystem natural enemies. Field tests were conducted in natural enemies (predator and parasitoid) abundance dynamic and diversity on tobacco field in Purwoasri, Pasuruan. Yellow pan trap, sweep net and hand collecting methods were applied in each 10 days during tobacco growth stage (vegetative, generative until reproductive/harvesting. The results showed that application perimeter trap crop with C. juncea in tobacco fields able to help arthropod conservation of natural enemies on all tobacco growth stages. These results were evidenced the increase in abundance of predators and parasitoids and the increased value of the Diversity Index (H') and Evenness Index (EH) in all tobacco growth phases. Composition of predator and parasitoid in the habitat modification field were more diverse than in the conventional field

Chemical ecology of insects and tritrophic interactions

International Nuclear Information System (INIS)

Ahmad, F.; Aslam, M.; Razaq, M.

2004-01-01

This paper reviews the chemical ecology of insects to explain the role of semiochemicals in plant-herbivore, herbivore-carnivore and plant-carnivore interactions. The semiochemical, mediating tritrophic interactions may be produced by plants, herbivores or their natural enemies (carnivores). Some semiochemicals attract the herbivores and carnivores and mediate interaction among them, while on the other hand some repel them. The semiochemicals are used by heribivores, parasites and predators as cues to locate food, host or prey. The same chemicals are also used for defensive purpose by some herbivores against their natural enemies as they are sequestered through their bodies. (author)

Patterns of temporal and enemy niche use by a community of leaf cone moths (Caloptilia) coexisting on maples (Acer) as revealed by metabarcoding.

Science.gov (United States)

Nakadai, Ryosuke; Kawakita, Atsushi

2017-06-01

The diversity of herbivorous insects is often considered a function of host plant diversity. However, recent research has uncovered many examples of closely related herbivores using the same host plant(s), suggesting that partitioning of host plants is not the only mechanism generating diversity. Herbivores sharing hosts may utilize different parts of the same plant, but such resource partitioning is often not apparent; hence, the factors that allow closely related herbivores to coexist are still largely undetermined. We examined whether partitioning of phenology or natural enemies may explain the coexistence of leaf cone moths (Caloptilia; Gracillariidae) associated with maples (Acer; Sapindaceae). Larval activity of 10 sympatric Caloptilia species found on nine maple species was monitored every 2-3 weeks for a total of 13 sampling events, and an exhaustive search for internal parasitoid wasps was conducted using high-throughput sequencing. Blocking primers were used to facilitate the detection of wasp larvae inside moth tissue. We found considerable phenological overlap among Caloptilia species, with two clear peaks in July and September-October. Coexisting Caloptilia species also had largely overlapping parasitoid communities; a total of 13 chalcid and ichneumon wasp species attacked Caloptilia in a nonspecific fashion at an overall parasitism rate of 46.4%. Although coexistence may be facilitated by factors not accounted for in this study, it appears that niche partitioning is not necessary for closely related herbivores to stably coexist on shared hosts. Co-occurrence without resource partitioning may provide an additional axis along which herbivorous insects attain increased species richness. © 2017 John Wiley & Sons Ltd.

« The glittering game » : le jeu des choses dans A Lost Lady et My Mortal Enemy de Willa Cather

OpenAIRE

Manresa, Céline

2014-01-01

Dans A Lost Lady et My Mortal Enemy, Willa Cather confère aux choses un rôle étonnamment actif au cœur de l’intrigue et un relief inédit au sein de l’écriture. Loin de demeurer tapies dans l’ombre ou figées dans l’arrière-plan des décors, les choses investissent pleinement le devant de la scène diégétique et narrative. Du costume aux détails de la décoration, les choses gouvernent les jeux de modelage réciproque entre l’habitant et l’habitat, visant à transformer l’intérieur des maisons en un...

Parasitic Wasps Can Reduce Mortality of Teosinte Plants Infested With Fall Armyworm: Support for a Defensive Function of Herbivore-Induced Plant Volatiles

Directory of Open Access Journals (Sweden)

Elvira S. de Lange

2018-05-01

Full Text Available Many parasitic wasps use volatiles emitted by plants under herbivore attack to find their hosts. It has therefore been proposed that these inducible plant volatiles serve an indirect defense function by recruiting parasitoids and other natural enemies. This suggested function remains controversial because there is little evidence that, in terms of fitness, plants benefit from the actions of natural enemies, particularly parasitoids, which do not immediately kill their hosts. We aimed to address this controversy in a semi-natural field experiment in Mexico, where we used large screen tents to evaluate how parasitoids can affect plant performance. The tritrophic study system comprised teosinte (Zea spp., the ancestor of maize, Spodoptera frugiperda Smith (Lepidoptera: Noctuidae and Campoletis sonorensis Cameron (Hymenoptera: Ichneumonidae, which have a long evolutionary history together. In tents without parasitoids, S. frugiperda larvae inflicted severe damage to the plants, whereas in the presence of parasitoid wasps, leaf damage was reduced by as much as 80%. Parasitoids also mitigated herbivore-mediated mortality among young teosinte plants. Although these findings will not resolve the long-standing debate on the adaptive function of herbivore-induced plant volatiles (HIPVs, they do present strong support for the hypothesis that plants can benefit from the presence of parasitoid natural enemies of their herbivores.

Dynamic complexities for prey-dependent consumption integrated pest management models with impulsive effects

International Nuclear Information System (INIS)

Hui Jing; Zhu Deming

2006-01-01

In this paper, we consider the prey-dependent consumption predator-prey (natural enemy-pest) models with age structure for the predator, immature and mature natural enemies are released and pesticide is applied impulsively. We prove that, when the impulsive period is no longer than some threshold, the pest-eradication solution is globally asymptotically stable, or say, the pest population can be eradicated totally. But from the point of ecological balance and saving resources, we only need to control the pest population under the economic threshold level instead of eradicating it totally, so we further prove that, when the impulsive period is longer than the threshold, pest population and natural enemy population can coexist, i.e., the system is uniformly permanent. Considering population communities always are imbedded in periodically varying environments, and the parameters in ecosystem models may oscillate simultaneously with the periodically varying environments, we add a forcing term into the prey population's intrinsic growth rate. From two aspects, i.e., when the period of forcing term is same as the impulsive period and when the two periods are different, we illustrate that, the dynamical behaviors of corresponding impulsive system are very complex

Developing Cotton IPM by Conserving Parasitoids and Predators of The Main Pest

Directory of Open Access Journals (Sweden)

Nurindah Nurindah

2015-09-01

Full Text Available On early development of intensive cotton program, insect pests were considered as an important aspect in cotton cultivation, so that it needed to be scheduled sprays. The frequency of sprays was 7 times used 12L of chemical insecticides per hectare per season. Development of cotton IPM was emphasized on non-chemical control methods through optimally utilize natural enemies of the cotton main pests (Amrasca biguttulla (IshidaHelicoverpa armigera (Hübner. Conservation of parasitoids and predators by providing the environment that support their population development is an act of supporting the natural enemies as an effective biotic mortality factor of the insect pests. The conservation could be done by improving the plant matter and cultivation techniques that include the use of resistant variety to leafhopper, intercropping cotton with secondary food plants, mulch utilization, using action threshold that considered the presence of natural enemies, and application of botanical insecticides, if needed. Conservation of parasitoids and predators in cotton IPM could control the insect pests without any insecticide spray in obtaining the production of cotton seed. As such, the use of IPM method would increase farmers’ income.

Classical Biological Control of Invasive Legacy Crop Pests: New Technologies Offer Opportunities to Revisit Old Pest Problems in Perennial Tree Crops

Directory of Open Access Journals (Sweden)

Mark S. Hoddle

2014-12-01

Full Text Available Advances in scientific disciplines that support classical biological control have provided “new tools” that could have important applications for biocontrol programs for some long-established invasive arthropod pests. We suggest that these previously unavailable tools should be used in biological control programs targeting “legacy pests”, even if they have been targets of previously unsuccessful biocontrol projects. Examples of “new tools” include molecular analyses to verify species identities and likely geographic area of origin, climate matching and ecological niche modeling, preservation of natural enemy genetic diversity in quarantine, the use of theory from invasion biology to maximize establishment likelihoods for natural enemies, and improved understanding of the interactions between natural enemy and target pest microbiomes. This review suggests that opportunities exist for revisiting old pest problems and funding research programs using “new tools” for developing biological control programs for “legacy pests” could provide permanent suppression of some seemingly intractable pest problems. As a case study, we use citricola scale, Coccus pseudomagnoliarum, an invasive legacy pest of California citrus, to demonstrate the potential of new tools to support a new classical biological control program targeting this insect.

Law enforcers recognition level emerging threats based on physical appearance and behavior signs the enemy

Directory of Open Access Journals (Sweden)

R.M. Radzievskiy

2015-02-01

Full Text Available Purpose: examine the effectiveness of the training method of differential approach to the choice of means of influence on the action of law enforcers opponent with different levels of aggressiveness. Material : the experiment involved 15 students of the Kyiv National Academy of Internal Affairs and the 15 employees of the State Guard of Ukraine. Results : presented curriculum for special physical and tactical training. The program details the conceptual apparatus of THREATS and DANGERS manifestations of different levels of aggressiveness opponent (case analysis of its motor behavior. The study participants underwent 7 day course focused training. The basis of the course is an advanced theoretical base. The base is aimed at developing knowledge and skills of employees in determining the level of danger. Including threats from testing and modeling episodes of extreme situations the options cadets. Conclusions : In the simulated collision situations with aggressive opponent to the students significantly improved the adequacy of the response to the threat of execution time and within the legal grounds. Recognition was determined by the level of aggressiveness manifest manners enemy, his emotions, motivation, motor behavior, positional arrangement for 2 - 3 seconds. The program contributed to the development of qualities: attention, orientation, perception, motor lead.

Rare fungal infectious agents: a lurking enemy [version 1; referees: 4 approved

Directory of Open Access Journals (Sweden)

Anna Skiada

2017-10-01

Full Text Available In the expanding population of immunocompromised patients and those treated in intensive care units, rare fungal infectious agents have emerged as important pathogens, causing invasive infections associated with high morbidity and mortality. These infections may present either as de novo or as breakthrough invasive infections in high-risk patients with hematologic malignancies receiving prophylactic or empirical antifungal therapy or in patients with central venous catheters. Diagnosis and treatment are challenging. Physicians should have a high index of suspicion because early diagnosis is of paramount importance. Conventional diagnostic methods such as cultures and histopathology are still essential, but rapid and more specific molecular techniques for both detection and identification of the infecting pathogens are being developed and hopefully will lead to early targeted treatment. The management of invasive fungal infections is multimodal. Reversal of risk factors, if feasible, should be attempted. Surgical debridement is recommended in localized mold infections. The efficacy of various antifungal drugs is not uniform. Amphotericin B is active against most yeasts, except Trichosporon, as well as against Mucorales, Fusarium, and some species of Paecilomyces and dimorphic fungi. The use of voriconazole is suggested for the treatment of trichosporonosis and scedosporiosis. Combination treatment, though recommended as salvage therapy in some infections, is controversial in most cases. Despite the use of available antifungals, mortality remains high. The optimization of molecular-based techniques, with expansion of reference libraries and the possibility for direct detection of resistance mechanisms, is awaited with great interest in the near future. Further research is necessary, however, in order to find the best ways to confront and destroy these lurking enemies.

Population of Tuta absoluta and natural enemies after releasing on ...

African Journals Online (AJOL)

ZINO

2013-04-10

Apr 10, 2013 ... The decrease of egg and larva numbers of T. absoluta were higher in plots released T. ..... four generations in a greenhouse of tomato production in .... Arno J, Sorribas R, Prat M, Montse M, Pozo C, Rodriguez D, Garreta A,.

Alfalfa and pastures: sources of pests or generalist natural enemies?

Science.gov (United States)

Pierce’s disease of grapevine and almond leaf scorch disease are both caused by the bacterial pathogen Xyllela fastidiosa. In the Central Valley of California, the green sharpshooter is the most common vector of X. fastidiosa. As alfalfa fields and pastures are considered source habitats for green s...

Simple landscape modifications for pollinator and arthropod natural enemy enhancement

Science.gov (United States)

Beneficial arthropods which play an important role in providing ecosystem services (pollination and pest control) have come under threat as a result of intensive agricultural practices and simplification of habitats. Ecological intensification in agricultural landscapes by diversifying the habitat r...

A compendium of insect pests and natural enemies associated with ...

African Journals Online (AJOL)

Field studies were carried out in 1992 and 1993 late cropping seasons to identify the species of insects and their effect on soyabeans in Calabar, a humid tropical environment. Two treatments were used, (that is sprayed and un- sprayed). Nuvacron (Monocrotophos), a systemic insecticide was applied at the rate of 400g ...

The potential of natural enemies to suppress rice leaffolder populations

NARCIS (Netherlands)

Kraker, de J.

1996-01-01

Rice leaffolders Cnaphalocrocis medinalis and Marasmia spp. (Lepidoptera: Pyralidae) are considered major pests in many Asian countries. Insecticide use against leaffolders is wide-spread, but may not be justified due to tolerance of the rice

Exploration for Natural Enemies of Hydrilla verticillata in Eastern Africa.

Science.gov (United States)

1980-05-01

mandibles and heads than the scavengers. Bill Beck of Florida A&M University, who identified the hydrilla midge as a species of Polypedilum, feels...that the head and mandibles of this midge resemble those of the scavenger section instead of the herbivore section of the genus, as the types occur in...Lakshmanan, K. K. 1965. " Embryological Studies in the Hydrocharitaceae. IV. Post-Fertilization Development in Hydrilla verticillata Royle," Phyton Rev

Naturally-Occurring Entomopathogenic Fungi on Three Bark Beetle Species (Coleoptera: Curculionidae in Bulgaria

Directory of Open Access Journals (Sweden)

Slavimira A. Draganova

2010-01-01

Full Text Available Bark beetles (Coleoptera: Curculionidae: Scolytinae belong to one of the most damaging groups of forest insects and the activity of their natural enemies –pathogens, parasitoids,parasites or predators suppressing their population density,is of great importance. Biodiversity of entomopathogenic fungi on bark beetles in Bulgaria has been investigated sporadically. The aim of this preliminary study was to find, identify and study morphological characteristics of fungal entomopathogens naturally-occurring in populations of three curculionid species – Ips sexdentatus Boern, Ips typographus (L. and Dryocoetes autographus (Ratz.. Dead pest adults were found under the bark of Pinus sylvestris and Picea abies trees collectedfrom forests in the Maleshevska and Vitosha Mountains. Fungal pathogens were isolated into pure cultures on SDAY (Sabouraud dextrose agar with yeast extract and were identified based on morphological characteristics both on the host and in a culture.Morphological characteristics of the isolates were studied by phenotypic methods. The fungal isolates obtained from dead adults of Ips sexdentatus, Ips typographus and D. autographus were found to belong to the species Beauveria bassiana (Bals. – Criv. Vuillemin,Beauveria brongniartii (Saccardo Petch and Isaria farinosa (Holmsk. Fries (anamorph Ascomycota, Sordariomycetes: Hypocreales, Cordycipitaceae. Morphological traits of the isolates are described.

The distribution of fruit and seed toxicity during development for eleven neotropical trees and vines in Central Panama.

Directory of Open Access Journals (Sweden)

Noelle G Beckman

Full Text Available Secondary compounds in fruit mediate interactions with natural enemies and seed dispersers, influencing plant survival and species distributions. The functions of secondary metabolites in plant defenses have been well-studied in green tissues, but not in reproductive structures of plants. In this study, the distribution of toxicity within plants was quantified and its influence on seed survival was determined in Central Panama. To investigate patterns of allocation to chemical defenses and shifts in allocation with fruit development, I quantified variation in toxicity between immature and mature fruit and between the seed and pericarp for eleven species. Toxicity of seed and pericarp was compared to leaf toxicity for five species. Toxicity was measured as reduced hyphal growth of two fungal pathogens, Phoma sp. and Fusarium sp., and reduced survivorship of brine shrimp, Artemia franciscana, across a range of concentrations of crude extract. I used these measures of potential toxicity against generalist natural enemies to examine the effect of fruit toxicity on reductions of fruit development and seed survival by vertebrates, invertebrates, and pathogens measured for seven species in a natural enemy removal experiment. The seed or pericarp of all vertebrate- and wind-dispersed species reduced Artemia survivorship and hyphal growth of Fusarium during the immature and mature stages. Only mature fruit of two vertebrate-dispersed species reduced hyphal growth of Phoma. Predispersal seed survival increased with toxicity of immature fruit to Artemia during germination and decreased with toxicity to fungi during fruit development. This study suggests that fruit toxicity against generalist natural enemies may be common in Central Panama. These results support the hypothesis that secondary metabolites in fruit have adaptive value and are important in the evolution of fruit-frugivore interactions.

The distribution of fruit and seed toxicity during development for eleven neotropical trees and vines in Central Panama.

Science.gov (United States)

Beckman, Noelle G

2013-01-01

Secondary compounds in fruit mediate interactions with natural enemies and seed dispersers, influencing plant survival and species distributions. The functions of secondary metabolites in plant defenses have been well-studied in green tissues, but not in reproductive structures of plants. In this study, the distribution of toxicity within plants was quantified and its influence on seed survival was determined in Central Panama. To investigate patterns of allocation to chemical defenses and shifts in allocation with fruit development, I quantified variation in toxicity between immature and mature fruit and between the seed and pericarp for eleven species. Toxicity of seed and pericarp was compared to leaf toxicity for five species. Toxicity was measured as reduced hyphal growth of two fungal pathogens, Phoma sp. and Fusarium sp., and reduced survivorship of brine shrimp, Artemia franciscana, across a range of concentrations of crude extract. I used these measures of potential toxicity against generalist natural enemies to examine the effect of fruit toxicity on reductions of fruit development and seed survival by vertebrates, invertebrates, and pathogens measured for seven species in a natural enemy removal experiment. The seed or pericarp of all vertebrate- and wind-dispersed species reduced Artemia survivorship and hyphal growth of Fusarium during the immature and mature stages. Only mature fruit of two vertebrate-dispersed species reduced hyphal growth of Phoma. Predispersal seed survival increased with toxicity of immature fruit to Artemia during germination and decreased with toxicity to fungi during fruit development. This study suggests that fruit toxicity against generalist natural enemies may be common in Central Panama. These results support the hypothesis that secondary metabolites in fruit have adaptive value and are important in the evolution of fruit-frugivore interactions.

Driving factors of the communities of phytophagous and predatory mites in a physic nut plantation and spontaneous plants associated.

Science.gov (United States)

Cruz, Wilton P; Sarmento, Renato A; Teodoro, Adenir V; Neto, Marçal P; Ignacio, Maíra

2013-08-01

Seasonal changes in climate and plant diversity are known to affect the population dynamics of both pests and natural enemies within agroecosystems. In Brazil, spontaneous plants are usually tolerated in small-scale physic nut plantations over the year, which in turn may mediate interactions between pests and natural enemies within this agroecosystem. Here, we aimed to access the influence of seasonal variation of abiotic (temperature, relative humidity and rainfall) and biotic (diversity of spontaneous plants, overall richness and density of mites) factors on the communities of phytophagous and predatory mites found in a physic nut plantation and its associated spontaneous plants. Mite sampling was monthly conducted in dicotyledonous and monocotyledonous leaves of spontaneous plants as well as in physic nut shrubs over an entire year. In the dry season there was a higher abundance of phytophagous mites (Tenuipalpidae, Tarsonemidae and Tetranychidae) on spontaneous plants than on physic nut shrubs, while predatory mites (Phytoseiidae) showed the opposite pattern. The overall density of mites on spontaneous plants increased with relative humidity and diversity of spontaneous plants. Rainfall was the variable that most influenced the density of mites inhabiting physic nut shrubs. Agroecosystems comprising spontaneous plants associated with crops harbour a rich mite community including species of different trophic levels which potentially benefit natural pest control due to increased diversity and abundance of natural enemies.

Multivariate ordination identifies vegetation types associated with spider conservation in brassica crops

Directory of Open Access Journals (Sweden)

Hafiz Sohaib Ahmed Saqib

2017-10-01

Full Text Available Conservation biological control emphasizes natural and other non-crop vegetation as a source of natural enemies to focal crops. There is an unmet need for better methods to identify the types of vegetation that are optimal to support specific natural enemies that may colonize the crops. Here we explore the commonality of the spider assemblage—considering abundance and diversity (H—in brassica crops with that of adjacent non-crop and non-brassica crop vegetation. We employ spatial-based multivariate ordination approaches, hierarchical clustering and spatial eigenvector analysis. The small-scale mixed cropping and high disturbance frequency of southern Chinese vegetation farming offered a setting to test the role of alternate vegetation for spider conservation. Our findings indicate that spider families differ markedly in occurrence with respect to vegetation type. Grassy field margins, non-crop vegetation, taro and sweetpotato harbour spider morphospecies and functional groups that are also present in brassica crops. In contrast, pumpkin and litchi contain spiders not found in brassicas, and so may have little benefit for conservation biological control services for brassicas. Our findings also illustrate the utility of advanced statistical approaches for identifying spatial relationships between natural enemies and the land uses most likely to offer alternative habitats for conservation biological control efforts that generates testable hypotheses for future studies.

Landscape Diversity and Crop Vigor Influence Biological Control of the Western Grape Leafhopper (E. elegantula Osborn in Vineyards.

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Houston Wilson

Full Text Available This study evaluated how the proportional area of natural habitat surrounding a vineyard (i.e. landscape diversity worked in conjunction with crop vigor, cultivar and rootstock selection to influence biological control of the western grape leafhopper (Erythroneura elegantula Osborn. The key natural enemies of E. elegantula are Anagrus erythroneurae S. Trjapitzin & Chiappini and A. daanei Triapitsyn, both of which are likely impacted by changes in landscape diversity due to their reliance on non-crop habitat to successfully overwinter. Additionally, E. elegantula is sensitive to changes in host plant quality which may influence densities on specific cultivars, rootstocks and/or vines with increased vigor. From 2010-2013, data were collected on natural enemy and leafhopper densities, pest parasitism rates and vine vigor from multiple vineyards that represented a continuum of landscape diversity. Early in the season, vineyards in more diverse landscapes had higher Anagrus spp. densities and lower E. elegantula densities, which led to increased parasitism of E. elegantula. Although late season densities of E. elegantula tended to be lower in vineyards with higher early season parasitism rates and lower total petiole nitrogen content, they were also affected by rootstock and cultivar. While diverse landscapes can support higher natural enemy populations, which can lead to increased biological control, leafhopper densities also appear to be mediated by cultivar, rootstock and vine vigor.

Changes in energy content of Podisus maculiventris (Say (Hemiptera: Pentatomidae in response to different diets

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Seyed Mohammad Ahsaei

2014-12-01

Full Text Available Nymphal instars and adults of the spined soldier bug, Podisus maculiventris, preferably feed on lepidopteran and colopteran larvae. Different prey diets can change fitness including energy reservoirs of the predator. In the present study, effects of different artificial and natural diets as well as starvation was studied on energy contents of the third and fourth nymphal instars of P. maculiventris. Total available energy calculated as the sum of the energy contents of lipids, carbohydrates, glycogen, and proteins did not significantly differ in the third and fourth nymphal instars fed on natural and artificial diets. Among the energy reservoirs, only total lipid storage of the starved nymphal instars was significantly different from that in the bugs fed on the natural diet. In conclusion, total energy reserves cannot be changed in response to artificial diet. A better understanding of the impact of artificial diets on the energy reserves of natural enemies can be considered as a biomarker for more appropriate mass rearing approaches of natural enemies.

Reconstructing community assembly in time and space reveals enemy escape in a Western Palearctic insect community.

Science.gov (United States)

Stone, Graham N; Lohse, Konrad; Nicholls, James A; Fuentes-Utrilla, Pablo; Sinclair, Frazer; Schönrogge, Karsten; Csóka, György; Melika, George; Nieves-Aldrey, Jose-Luis; Pujade-Villar, Juli; Tavakoli, Majide; Askew, Richard R; Hickerson, Michael J

2012-03-20

How geographically widespread biological communities assemble remains a major question in ecology. Do parallel population histories allow sustained interactions (such as host-parasite or plant-pollinator) among species, or do discordant histories necessarily interrupt them? Though few empirical data exist, these issues are central to our understanding of multispecies evolutionary dynamics. Here we use hierarchical approximate Bayesian analysis of DNA sequence data for 12 herbivores and 19 parasitoids to reconstruct the assembly of an insect community spanning the Western Palearctic and assess the support for alternative host tracking and ecological sorting hypotheses. We show that assembly occurred primarily by delayed host tracking from a shared eastern origin. Herbivores escaped their enemies for millennia before parasitoid pursuit restored initial associations, with generalist parasitoids no better able to track their hosts than specialists. In contrast, ecological sorting played only a minor role. Substantial turnover in host-parasitoid associations means that coevolution must have been diffuse, probably contributing to the parasitoid generalism seen in this and similar systems. Reintegration of parasitoids after host escape shows these communities to have been unsaturated throughout their history, arguing against major roles for parasitoid niche evolution or competition during community assembly. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Dialectic of the Nature-Society-System

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Christian Fuchs

2008-07-01

ecological crisis. The productive forces are in modern society socially and ecologically destructive forces. In late capitalism there is a tendency of commodification and privatization of nature and human knowledge. Especially in the later writings of Marx and Engels one can find formulations that suggest a productivist logic that sees nature as an enemy opposed to man, as a resource and object that must be mastered, exploited, and controlled. But throughout the works of Marx and Engels one can find many passages where they argue that there is an antagonism between capitalism and nature that results in ecological degradation and that a free society is also based on alternative, sustainable relationships between man and nature. The idea of an alternative society-nature-relationship and of nature conservation can already be found in the works of Marx and Engels, they are precursors of ecological thinking. In Orthodox Marxism dialectical thinking has been interpreted as deterministic and mechanic laws and misused for arguing that the Soviet system is a free society. An alternative is a dialectic that stresses human practice and that structures condition alternative possibilities for action. Dialectic thinkers like Herbert Marcuse and Ernst Bloch have argued that nature is a producing subject, a non-teleological subject (Marcuse. Describing nature as a subject implies that if man destroys nature the latter as a producing subject will probably produce uncontrollable negative effects on society and that hence nature should be appropriated in sustainable ways. Matter is a natural subject that acts upon itself, whereas man is a human self-conscious subject that acts upon nature and society.

Efficacy of a long-lasting bifenthrin-treated net against horticultural pests and its compatibility with the predatory mite Amblyseius swirskii and the parasitic wasp Eretmocerus mundus.

Science.gov (United States)

Fernández, Maria Del Mar; Colomer, Ignacio; Medina, Pilar; Fereres, Alberto; Del Estal, Pedro; Viñuela, Elisa

2017-08-01

Insecticide-treated nets (ITNs) have been investigated recently for their use in agriculture. Depending on the insecticide, the hole size and the way they are produced, these nets can target different pests and therefore they could be interesting options for use in integrated pest management (IPM). As the information on their compatibility with beneficial fauna is practically negligible, in this work we have tested the compatibility of an experimental bifenthrin long-lasting insecticide-treated net (LLITN) with Amblyseius swirskii and Eretmocerus mundus, important natural enemies of whiteflies and thrips, under laboratory, semi-field and commercial greenhouse conditions. In the laboratory, the treated net was very deleterious to adults of both natural enemies, after 72 h exposure. However, in choice tests with Y-tubes, both natural enemies were neither attracted nor repelled by the treated net and no short-term mortality was detected in individuals that had crossed it. No deleterious effects on the E. mundus beneficial capacity were detected in semi-field trials. In field trials, the LLITN proved to be compatible with A. swirskii while decreasing pest densities. Bifenthrin LLITN studied could be a valuable method for reducing pest population infestations in IPM programmes while being compatible with biocontrol agents. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Development of the herbivore Pieris rapae and its endoparasitoid Cotesia rubecula on crucifers of field edges

NARCIS (Netherlands)

Harvey, J.A.; Wagenaar, R.

2006-01-01

Several studies have reported that flowering herbs, which grow naturally or are sown adjacent to agricultural fields, may be an important source of nutrients for natural enemies. Many parasitoids readily feed on plant exudates such as floral nectar, which contain different types of sugars that

Sleeping with the Political Enemy: Woman’s Place in Discourses of Race and Class Struggle in 20th Century Central Europe

Directory of Open Access Journals (Sweden)

Dániel Bolgár

2011-01-01

Full Text Available In this paper, I shall argue that the convergence of ideologies operating through the creation of enemies like racism and Bolshevism with discourses regulating gender relations in the Central Europe of the twentieth century had the grave consequence of questioning women’s position in the political community. In short, I shall argue that in the context of racist and Bolshevik discourses, the very fact of being female was in itself a political threat to women. To demonstrate my point, I shall discuss two recent publications. First, I shall analyze the context of the convergence of racist and misogynist discourses in turn-of-the-century Vienna through discussing András Gerő’s book, Neither Woman Nor Jew. Second, I shall explore how the discourse of class struggle affected the political status of Hungarian women in the Stalinist era through discussing Eszter Zsófia Tóth’s book, Kádár’s Daughters.

Damage Control: Leveraging Crisis Communications for Operational Effect

National Research Council Canada - National Science Library

Gebara, Andrew J

2008-01-01

Despite the lopsided nature of contemporary air operations in combat against Islamo-fascism, the enemy has gained a measure of protection from air attack by savvy utilization of Information Operations...

A functional overview of conservation biological control

DEFF Research Database (Denmark)

Begg, Graham S; Cook, Samantha M; Dye, Richard

2017-01-01

Conservation biological control (CBC) is a sustainable approach to pest management that can contribute to a reduction in pesticide use as part of an Integrated Pest Management (IPM) strategy. CBC is based on the premise that countering habitat loss and environmental disturbance associated...... CBC prescriptions have proved elusive. To tackle this, we consolidate existing knowledge of CBC using a simple conceptual model that organises the functional elements of CBC into a common, unifying framework. We identify and integrate the key biological processes affecting natural enemies...... and their biological control function across local and regional scales, and consider the interactions, interdependencies and constraints that determine the outcome of CBC strategies. Conservation measures are often effective in supporting natural enemy populations but their success cannot be guaranteed; the greatest...

Aquatic Plant Control Research Program

National Research Council Canada - National Science Library

Cofrancesco, Alfred

1998-01-01

.... This search for natural plant enemies (insects and fungal pathogens) has led researchers to the native ranges of noxious aquatic plants, located throughout the continents of Africa, Asia, Europe, and Australia...

Manhunting: A Methodology for Finding Persons of National Interest

National Research Council Canada - National Science Library

Marks, Steven M; Meer, Thomas M; Nilson, Matthew T

2005-01-01

.... The nature of today's threats call for the U.S. military to change from finding, fixing, and destroying the enemy's forces to identifying, locating and capturing rogue individuals to destroy networks...

Insecticide effects of Ruta graveolens, Copaifera langsdorffii and Chenopodium ambrosioides against pests and natural enemies in commercial tomato plantation = Ação inseticida de Ruta graveolens, Copaifera langsdorffii e Chenopodium ambrosioides sobre pragas de tomate

Directory of Open Access Journals (Sweden)

Flávia Silva Barbosa

2011-01-01

Full Text Available The aim of this study was to evaluate the insecticide effect of watery leaf extracts of Ruta graveolens (Rutaceae, alcoholic leaf extracts of Copaifera langsdorffii (Caesalpinaceae and Chenopodium ambrosioides (Chenopodiaceae in the concentration of 5% under field conditions. The experiment design was randomized blocks with six replications. The parcels treated with plant extracts showed reduction in the population of pests when compared with the controlparcels. The extract elaborated with C. langsdorffii presented greater insecticidal effect under Bemisia tabaci (Hemiptera: Aleyrodidae and sum of pests. It was verified that after 24 hours ofspraying, the parcels treated with the extract of C. ambrosioides presented minor numbers of adults of Tuta absoluta (Lepidoptera: Gelechiidae, followed by the parcels treated with extract of R.graveolens. There were smaller numbers of parasitoid eggs of epidopterans Trichogramma sp. (Hymenoptera: Trichogrammatidae and sum of natural enemies (predators + parasitoids in the parcels that had received spraying with extracts from the plants of C. langsdorffii and C. ambrosioides, followed by R. graveolens, compared to the control. There were a smaller number of parasitoids from the family Eulophidae (Hymenoptera attacking caterpillars of T. absoluta in plants treated with R. graveolens, followed by C. langsdorffii and C. ambrosioides than in the control.O objetivo deste trabalho foi avaliar o efeito inseticida dos extratos aquosos de folhas de Ruta graveolens (Rutaceae e alcoólicos de folhas de Copaifera langsdorffii (Caesalpinaceae e de folhas de Chenopodium ambrosioides (Chenopodiaceae a 5%. O experimento foi em blocos casualizados com seis repetições. As parcelas tratadas tiveram redução na população de pragas, quando comparadas às parcelas sem nenhum tratamento. O extrato elaborado com C. langsdorffii apresentou maior efeito inseticida em Bemisia tabaci (Hemiptera: Aleyrodidae e soma das pragas

Writing a love letter to your (perceived enemy: Thích Nhất Hạnh and the rhetoric of nonviolence

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Michael PHILLIPS-ANDERSON

2017-07-01

Full Text Available Vietnamese Buddhist monk and peace activist Thích Nhất Hạnh has been a leading figure in the promotion of nonviolent practice throughout the world. We examine his concept of engaged Buddhism, theories of nonviolence, and intersections with rhetorical and communication studies. His approach takes nonviolence beyond the realm of refusing to use physical violence to the recognition that language itself can be violent. In order to understand this approach we detail the concepts of interbeing, loving speech, and deep listening. We examine the role of love in Nhất Hạnh’s theory of nonviolence, comparing it with approaches taken by Mahatma Gandhi and Martin Luther King, Jr. Examples are given from many of Nhất Hạnh’s speeches and writings with particular attention paid to a love letter he wrote to US President George W. Bush during the Iraq War. Thích Nhất Hạnh offers the practice of writing a love letter to one’s perceived enemy as a means to persuade for a turn to nonviolence.

Biology and natural enemies of Peregrinus maidis (Ashmead in corn (Zea mays L., in systems of polycrops

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Marcos Tulio García González

2015-02-01

Full Text Available This research was done in Fomento municipality, Sancti Spíritus, in Cuba, from 2011 through 2013 in two ecosystems and in two sowing times (rainy and dry seasons. The objectives were to describe the life cycle of Peregrinus maidis (Ashmead and the damage caused to corn (Zea mays L., to identify the main pest bio-regulators naturally occurring in two agro-ecosystems, and to determine the predator-prey relationship. The experiment was arranged in a randomized block design. The data were collected through observation at weekly intervals. In order to estimate the number of pest insects and bio-regulators occurring on the plants, 25 plants per parcel were selected for a total of 100 plants per treatment (maize/squash, maize/beans, maize/ Sesame, maize/sunflower, and maize monoculture. Once the research was accomplished, it was concluded that P maidis had been present since the first week, and reached its population peak in week six. The lower indexes of affectation occurred in the pre-mountain agro-ecosystems, and with more frequency in the maize/sesame and maize/squash polyculture, which depended on the time of the year and the season. Fifteen species of P. maidis control insects of were identified, and Scymnus sp was found in all treatments. The life cycle of P maidis averaged 5.4 days more in the dry season than in rain season. The predator-prey relationship showed relatively superior indexes in the polyculture systems than in monocrops systems.

The functional response to prey density in an acarine system

NARCIS (Netherlands)

Fransz, H.G.

1974-01-01

Predacious mites are considered to be important natural enemies of phytophagous mites. Their efficiency in the natural control of prey populations depends on the relationships of the number of prey killed per predator per time unit and the oviposition rate on the one hand and prey density on the

Biological control of toxic cyanobacteria

CSIR Research Space (South Africa)

Ndlela, L

2016-04-01

Full Text Available harmful algal blooms and their impacts in over 30 countries. Biological control is a method of introducing natural enemies to control an organism and has been more successful using microorganisms....

Symbionts modify interactions between insects and natural enemies in the field

Czech Academy of Sciences Publication Activity Database

Hrček, Jan; McLean, A. H. C.; Godfray, H. C. J.

2016-01-01

Roč. 85, č. 6 (2016), s. 1605-1612 ISSN 0021-8790 Institutional support: RVO:60077344 Keywords : aphid * field experiment * host-parasite Subject RIV: EH - Ecology, Behaviour Impact factor: 4.474, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/1365-2656.12586/pdf

A comparison of the recruitment success of introduced and native species under natural conditions.

Directory of Open Access Journals (Sweden)

Habacuc Flores-Moreno

Full Text Available It is commonly accepted that introduced species have recruitment advantages over native species. However, this idea has not been widely tested, and those studies that have compared survival of introduced and native species have produced mixed results. We compiled data from the literature on survival through germination (seed to seedling survival, early seedling survival (survival through one week from seedling emergence and survival to adulthood (survival from germination to first reproduction under natural conditions for 285 native and 63 introduced species. Contrary to expectations, we found that introduced and native species do not significantly differ in survival through germination, early seedling survival, or survival from germination to first reproduction. These comparisons remained non-significant after accounting for seed mass, longevity and when including a random effect for site. Results remained consistent after excluding naturalized species from the introduced species data set, after performing phylogenetic independent contrasts, and after accounting for the effect of life form (woody/non-woody. Although introduced species sometimes do have advantages over native species (for example, through enemy release, or greater phenotypic plasticity, our findings suggest that the overall advantage conferred by these factors is either counterbalanced by advantages of native species (such as superior adaptation to local conditions or is simply too small to be detected at a broad scale.

Eucalypt pests and diseases: growing threats to plantation productivity

African Journals Online (AJOL)

Eucalypt pests and diseases: growing threats to plantation productivity. ... Southern Forests: a Journal of Forest Science ... plantations, it is clear that separation of the trees from their natural enemies has resulted in exceptional performance.

Intraguild predation by the generalist predator Orius majusculus on the parasitoid Encarsia formosa

DEFF Research Database (Denmark)

Sohrabi, Fariba; Enkegaard, Annie; Shishehbor, Parviz

2013-01-01

Intraguild predation of Orius majusculus (Reuter) (Heteroptera: Anthocoridae) on Encarsia formosa (Gahan) (Hymenoptera: Aphelinidae), both natural enemies of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), was studied under laboratory conditions. The experiments quantified prey consumption b...

Time Delayed Stage-Structured Predator-Prey Model with Birth Pulse and Pest Control Tactics

Directory of Open Access Journals (Sweden)

Mei Yan

2014-01-01

Full Text Available Normally, chemical pesticides kill not only pests but also their natural enemies. In order to better control the pests, two-time delayed stage-structured predator-prey models with birth pulse and pest control tactics are proposed and analyzed by using impulsive differential equations in present work. The stability threshold conditions for the mature prey-eradication periodic solutions of two models are derived, respectively. The effects of key parameters including killing efficiency rate, pulse period, the maximum birth effort per unit of time of natural enemy, and maturation time of prey on the threshold values are discussed in more detail. By comparing the two threshold values of mature prey-extinction, we provide the fact that the second control tactic is more effective than the first control method.

From war economies to peace economies in Africa | Broodryk ...

African Journals Online (AJOL)

One reason for the persistence and protracted nature of conflict on the. African continent is the phenomenon of war economies. These have transformed the nature of war itself where the object is not at neutralizing an enemy but to institutionalize violence at a profitable level of intensity. Transforming war economies into ...

Financial appraisal of efficiency investments. Why the good may be the worst enemy of the best

Energy Technology Data Exchange (ETDEWEB)

Verbruggen, A. [University of Antwerp, Prinsstraat 13, 2000 Antwerp (Belgium)

2012-11-15

This methodological paper has a didactic goal: improving our understanding of what 'cost optimal energy performance of buildings' means and how financial appraisal of efficiency investments must be set up. Three items merit improvement. First, focus on the endowment character of energy performance of long-living assets like buildings. Second, defining cost optimal requires more than a comparative static trade-off scheme; cost optimal refers to dynamic efficiency, which results from technology dynamics induced by changes in society and policy. Third, financial appraisal is a more complex issue than simple net present value and life cycle cost calculations. It must reflect the time sequential dynamics of real-life processes including real-life decision making. Financial appraisal is embedded in a complex framework made up by three dimensions: future time, doubt and irrevocability. The latter dimension connects with issues like lock-in and path dependency that are generally overlooked in net present value calculations. This may lead to very erroneous recommendations regarding efficiency investments, in particular regarding the energy performance endowment of buildings. Mostly irrevocability is used as an argument to 'wait and learn' what has, for example, blocked the pace of climate policy. But the opposite 'choose or lose' is the logical outcome when the methodology is fed with evidenced expectations. The latter boosts energy efficiency to its boundaries, saving it from the middle-of-the-river quagmire where incomplete appraisals are dropping it too often (making the good the worst enemy of the best)

Integration of Plant Defense Traits with Biological Control of Arthropod Pests: Challenges and Opportunities.

Science.gov (United States)

Peterson, Julie A; Ode, Paul J; Oliveira-Hofman, Camila; Harwood, James D

2016-01-01

Crop plants exhibit a wide diversity of defensive traits and strategies to protect themselves from damage by herbivorous pests and disease. These defensive traits may be naturally occurring or artificially selected through crop breeding, including introduction via genetic engineering. While these traits can have obvious and direct impacts on herbivorous pests, many have profound effects on higher trophic levels, including the natural enemies of herbivores. Multi-trophic effects of host plant resistance have the potential to influence, both positively and negatively, biological control. Plant defense traits can influence both the numerical and functional responses of natural enemies; these interactions can be semiochemically, plant toxin-, plant nutrient-, and/or physically mediated. Case studies involving predators, parasitoids, and pathogens of crop pests will be presented and discussed. These diverse groups of natural enemies may respond differently to crop plant traits based on their own unique biology and the ecological niches they fill. Genetically modified crop plants that have been engineered to express transgenic products affecting herbivorous pests are an additional consideration. For the most part, transgenic plant incorporated protectant (PIP) traits are compatible with biological control due to their selective toxicity to targeted pests and relatively low non-target impacts, although transgenic crops may have indirect effects on higher trophic levels and arthropod communities mediated by lower host or prey number and/or quality. Host plant resistance and biological control are two of the key pillars of integrated pest management; their potential interactions, whether they are synergistic, complementary, or disruptive, are key in understanding and achieving sustainable and effective pest management.

Integration of plant defense traits with biological control of arthropod pests: challenges and opportunities

Directory of Open Access Journals (Sweden)

Julie A Peterson

2016-11-01

Full Text Available Crop plants exhibit a wide diversity of defensive traits and strategies to protect themselves from damage by herbivorous pests and disease. These defensive traits may be naturally occurring or artificially selected through crop breeding, including introduction via genetic engineering. While these traits can have obvious and direct impacts on herbivorous pests, many have profound effects on higher trophic levels, including the natural enemies of herbivores. Multi-trophic effects of host plant resistance have the potential to influence, both positively and negatively, biological control. Plant defense traits can influence both the numerical and functional responses of natural enemies; these interactions can be semiochemically-, plant toxin-, plant nutrient-, and/or physically-mediated. Case studies involving predators, parasitoids, and pathogens of crop pests will be presented and discussed. These diverse groups of natural enemies may respond differently to crop plant traits based on their own unique biology and the ecological niches they fill. Genetically modified crop plants that have been engineered to express transgenic products affecting herbivorous pests are an additional consideration. For the most part, transgenic plant incorporated protectant (PIP traits are compatible with biological control due to their selective toxicity to targeted pests and relatively low non-target impacts, although transgenic crops may have indirect effects on higher trophic levels and arthropod communities mediated by lower host or prey number and/or quality. Host plant resistance and biological control are two of the key pillars of integrated pest management; their potential interactions, whether they are synergistic, complementary, or disruptive, are key in understanding and achieving sustainable and effective pest management.

Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowing behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz and Neiva) (Diptera: Psychodidae)

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Harvey, Jeffrey A. [Netherlands Institute of Ecology, Heteren (Netherlands). Dept. of Terrestrial Ecology; Hamilton, James G.C.; Ward, Richard D. [University of Keele, Staffordshire (United Kingdom). Centre for Applied Entomology and Parasitology. Dept. of Biological Sciences

2010-01-15

The sandfly Lutzomyia longipalpis (Lutz and Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L. longipalpis on a soil substrate when exposed to the fire ant Solenopsis invicata (Westwood). When ants were absent, most larvae tended to remain at or close to the soil surface, but when ants were present the larvae burrowed into the soil. Sandflies seek refuges in the presence of generalist predators, thus rendering them immune to attack from many potential enemies. (author)

Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowing behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz and Neiva) (Diptera: Psychodidae)

International Nuclear Information System (INIS)

Harvey, Jeffrey A.; Hamilton, James G.C.; Ward, Richard D.

2010-01-01

The sandfly Lutzomyia longipalpis (Lutz and Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L. longipalpis on a soil substrate when exposed to the fire ant Solenopsis invicata (Westwood). When ants were absent, most larvae tended to remain at or close to the soil surface, but when ants were present the larvae burrowed into the soil. Sandflies seek refuges in the presence of generalist predators, thus rendering them immune to attack from many potential enemies. (author)

Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowing behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae).

Science.gov (United States)

Harvey, Jeffrey A; Hamilton, James G C; Ward, Richard D

2010-01-01

The sandfly Lutzomyia longipalpis (Lutz & Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L.longipalpis on a soil substrate when exposed to the fire ant Solenopsis invicata (Westwood). When ants were absent, most larvae tended to remain at or close to the soil surface, but when ants were present the larvae burrowed into the soil. Sandflies seek refuges in the presence of generalist predators, thus rendering them immune to attack from many potential enemies.

Habitat eradication and cropland intensification may reduce parasitoid diversity and natural pest control services in annual crop fields

Directory of Open Access Journals (Sweden)

Deborah K. Letourneau

2015-10-01

Full Text Available Abstract California’s central coast differs from many agricultural areas in the U.S., which feature large tracts of monoculture production fields and relatively simple landscapes. Known as the nations salad bowl, and producing up to 90% of U.S. production of lettuces, broccoli and Brussels sprouts, this region is a mosaic of fresh vegetable fields, coastal meadow, chaparral shrubs, riparian and woodland habitat. We tested for relationships between the percent cover of crops, riparian and other natural landscape vegetation and the species richness of parasitic wasps and flies foraging in crops, such as broccoli, kale and cauliflower, and interpreted our results with respect to the decrease in natural habitat and increase in cropland cover prompted by a local microbial contamination event in 2006. Our key results are that: (1 as cropland cover in the landscape increased, fewer species of parasitoids were captured in the crop field, (2 parasitoid richness overall was positively associated with the amount of riparian and other natural vegetation in the surrounding 500m, (3 different groups of parasitoids were associated with unique types of natural vegetation, and (4 parasitism rates of sentinel cabbage aphid and cabbage looper pests were correlated with landscape vegetation features according to which parasitoids caused the mortality. Although individual species of parasitoids may thrive in landscapes that are predominantly short season crops, the robust associations found in this study across specialist and generalist parasitoids and different taxa (tachinid flies, ichneumon wasps, braconid wasps shows that recent food safety practices targeting removal of natural vegetation around vegetable fields in an attempt to eliminate wildlife may harm natural enemy communities and reduce ecosystem services. We argue that enhancing biological diversity is a key goal for transforming agroecosystems for future productivity, sustainability and public health.

Insecticidal, repellent, antimicrobial activity and phytotoxicity of essential oils: With special reference to limonene and its suitability for control of insect pests

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M.A. IBRAHIM

2008-12-01

Full Text Available The interest in the use of monoterpenes for insect pest and pathogen control originates from the need for pesticide products with less negative environmental and health impacts than highly effective synthetic pesticides. The expanding literature on the possibility of the use of these monoterpenes is reviewed and focused on the effects of limonene on various bioorganisms. Limonene is used as insecticide to control ectoparasites of pet animals, but it has activity against many insects, mites, and microorganisms. Possible attractive effects of limonene to natural enemies of pests may offer novel applications to use natural compounds for manipulation of beneficial animals in organic agriculture. However, in few cases limonene-treated plants have become attractive to plant damaging insects and phytotoxic effects on cultivated plants have been observed. As a plant-based natural product limonene and other monoterpenes might have use in pest and weed control in organic agriculture after phytotoxicity on crop plants and, effects on non-target soil animals and natural enemies of pest have been investigated

Effect of Neem Seed Kernel Extracts in the Management of Rice ...

African Journals Online (AJOL)

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conducted to determine the comparative efficacy of neem seed kernel ... sustainable production of rice and are generally not affordable to African peasant farmers. ... system where the use of natural enemies are being emphasized as a major ...

Phytophagous insects on native and non-native host plants: combining the community approach and the biogeographical approach.

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Kim Meijer

Full Text Available During the past centuries, humans have introduced many plant species in areas where they do not naturally occur. Some of these species establish populations and in some cases become invasive, causing economic and ecological damage. Which factors determine the success of non-native plants is still incompletely understood, but the absence of natural enemies in the invaded area (Enemy Release Hypothesis; ERH is one of the most popular explanations. One of the predictions of the ERH, a reduced herbivore load on non-native plants compared with native ones, has been repeatedly tested. However, many studies have either used a community approach (sampling from native and non-native species in the same community or a biogeographical approach (sampling from the same plant species in areas where it is native and where it is non-native. Either method can sometimes lead to inconclusive results. To resolve this, we here add to the small number of studies that combine both approaches. We do so in a single study of insect herbivory on 47 woody plant species (trees, shrubs, and vines in the Netherlands and Japan. We find higher herbivore diversity, higher herbivore load and more herbivory on native plants than on non-native plants, generating support for the enemy release hypothesis.

Residual Acute Toxicity of Some Modern Insecticides Toward Two Mirid Predators of Tomato Pests.

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Wanumen, Andrea C; Carvalho, Geraldo A; Medina, Pilar; Viñuela, Elisa; Adán, Ángeles

2016-03-31

The successful integration of chemical and biological control strategies for crop pests depends on a thorough evaluation of the effects of pesticides on the natural enemies of pests. A case-by-case review is difficult to achieve because of the many combinations of pests, natural enemies, and crops that need to be tested. Within this framework, we tested and compared seven insecticides representative of four different modes of action (MoAs) groups on closely related predators (Miridae): flubendiamide, spirotetramat, metaflumizone, and sulfoxaflor onNesidiocoris tenuisReuter and flubendiamide, spiromesifen, indoxacarb, and imidacloprid onMacrolophus basicornis(Stal). We follow the standardized methodology of the International Organization for Biological Control, a sequential testing exposure scheme. The lethal effect of each insecticide was evaluated in adults after three days of contact with treated surfaces in the laboratory, extended laboratory, and semifield tests (inert substrate, tomato leaves, and tomato plant as the treated surface, respectively). Flubendiamide, spiromesifen, and spirotetramat were classified as harmless (class 1), metaflumizone was slightly harmful (class 2) but persistent, indoxacarb was harmless (class 1), and sulfoxaflor and imidacloprid were toxic (class 4) and exhibited a long residual activity. Our results suggest similarities in the acute toxicities of insecticides from the same MoA group on related species of natural enemies. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Palmistichus elaeisis (Hymenoptera: Eulophidae as an indicator of toxicity of herbicides registered for corn in Brazil

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Claubert W.G de Menezes

2014-09-01

Full Text Available The diversity of plants in agricultural systems benefits natural enemies. Herbicides are used in weed management in corn (Zea mays L. to reduce competition and productivity losses, but they can impact natural enemies and contaminate the environment. The objective was to evaluate toxicity of herbicides on pupae parasitoid Palmistichus elaeisis Delvare and LaSalle, 1993 (Hymenoptera: Eulophidae. The treatments were represented by the host pupae Tenebrio molitor L., 1785 (Coleoptera: Tenebrionidae and herbicides atrazine, nicosulfuron, paraquat, and tembotrione in commercial doses compared to a control treatment with water. Pupae of T. molitor were immersed in the solution of herbicides and exposed to parasitism by six females of P. elaeisis each. The herbicides atrazine and paraquat were highly toxic and, therefore, not selective to P. elaeisis. Nicosulfuron reduced the sex ratio of P. elaeisis (0.20 ± 0.03, which may affect subsequent generations. Moreover, the herbicide tembotrione was selective to P. elaeisis, showing results comparable to the control. Floristic diversity of weeds can increase food source, habitat, shelter, breeding places and microclimates for insect parasitoids but herbicides formulations can be toxic and these products can affect P. elaeisis or its hosts by direct or indirect contact, showing the importance of selectivity studies for this natural enemy. However, the herbicide tembotrione was selective to P. elaeisis and it can be recommended for programs of sustainable management of weeds in corn crop with this parasitoid.

Comparative life tables of leek moth, Acrolepiopsis assectella (Zeller) (Lepidoptera: Acrolepiidae), in its native range.

Science.gov (United States)

Jenner, W H; Kuhlmann, U; Mason, P G; Cappuccino, N

2010-02-01

Leek moth, Acrolepiopsis assectella (Zeller) (Lepidoptera: Acrolepiidae), is an invasive alien species in eastern Canada, the larvae of which mine the green tissues of Allium spp. This study was designed to construct and analyse life tables for leek moth within its native range. Stage-specific mortality rates were estimated for the third leek moth generation at three sites in Switzerland from 2004 to 2006 to identify some of the principle factors that inhibit leek moth population growth in areas of low pest density. The contribution of natural enemies to leek moth mortality was measured by comparing mortality on caged and uncaged leeks. Total pre-imaginal mortality on uncaged plants was 99.6%, 99.1% and 96.4% in 2004, 2005 and 2006, respectively. Variation in mortality was greater among years than among sites. Total larval mortality was greater than that in the eggs and pupae. This was due largely to the high mortality (up to 83.3%) of neonates during the brief period between egg hatch and establishment of the feeding mine. Leek moth pupal mortality was significantly greater on uncaged than on caged leeks, indicating an impact by natural enemies, and this pattern was consistent over all three years of study. In contrast, the other life stages did not show consistently higher mortality rates on uncaged plants. This observation suggests that the pupal stage may be particularly vulnerable to natural enemies and, therefore, may be the best target for classical biological control in Canada.

The influence of insecticides and vegetation in structuring Formica mound ant communities (Hymenoptera: Formicidae) in Maine lowbush blueberry.

Science.gov (United States)

Choate, Beth; Drummond, Francis A

2013-04-01

Assessing the influence of new, reduced-risk insecticides on natural enemies within agroecosystems is essential to developing integrated pest management strategies. Three species of mound-building Formica ants are abundant throughout Maine lowbush blueberry fields (Formica exsectoides Forel, F. glacialis Wheeler, and F. ulkei Emery). All three species have been described in the literature as predaceous, with research demonstrating that F. exsectoides preys on major pest insects of lowbush blueberry. The objectives of this study were to determine the impact of common-use and newly introduced insecticides on Formica sp. ant communities in lowbush blueberry fields. Laboratory assays indicated that the commonly applied insecticide phosmet is toxic to F. exsectoides, even after 8 d of field weathering (P insecticides, such as acetamiprid, had little effect on survival of all three species. Abundance of each species in the field varied with lowbush blueberry pesticide-use strategy and amount of nonblueberry vegetation. Both F. exsectoides and F. glacialis were most abundant in organic fields; however, overall F. glacialis was the most abundant in fields of all management types. Field surveys support laboratory results suggesting that phosmet is highly toxic to these species and influences their spatial pattern. Manipulation of the crop to conserve natural enemies in lowbush blueberry is difficult because the crop is not planted; therefore, we must look closely at the incorporation of low toxicity insecticides with natural enemies to efficiently control pest insects.

Toxicity and sublethal effects of six insecticides to last instar larvae and adults of the biocontrol agents Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) and Adalia bipunctata (L.) (Coleoptera: Coccinellidae).

Science.gov (United States)

Garzón, A; Medina, P; Amor, F; Viñuela, E; Budia, F

2015-08-01

To further develop Integrated Pest Management (IPM) strategies against crop pests, it is important to evaluate the effects of insecticides on biological control agents. Therefore, we tested the toxicity and sublethal effects (fecundity and fertility) of flonicamid, flubendiamide, metaflumizone, spirotetramat, sulfoxaflor and deltamethrin on the natural enemies Chrysoperla carnea and Adalia bipunctata. The side effects of the active ingredients of the insecticides were evaluated with residual contact tests for the larvae and adults of these predators in the laboratory. Flonicamid, flubendiamide, metaflumizone and spirotetramat were innocuous to last instar larvae and adults of C. carnea and A. bipunctata. Sulfoxaflor was slightly toxic to adults of C. carnea and was highly toxic to the L4 larvae of A. bipunctata. For A. bipunctata, sulfoxaflor and deltamethrin were the most damaging compounds with a cumulative larval mortality of 100%. Deltamethrin was also the most toxic compound to larvae and adults of C. carnea. In accordance with the results obtained, the compounds flonicamid, flubendiamide, metaflumizone and spirotetramat might be incorporated into IPM programs in combination with these natural enemies for the control of particular greenhouse pests. Nevertheless, the use of sulfoxaflor and deltamethrin in IPM strategies should be taken into consideration when releasing either of these biological control agents, due to the toxic behavior observed under laboratory conditions. The need for developing sustainable approaches to combine the use of these insecticides and natural enemies within an IPM framework is discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

The enemy within: Power and politics in the transition to nurse practitioner

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Lorna MacLellan

Full Text Available Background: The period of transition from registered nurse to nurse practitioner is often challenging. While adjusting to their autonomous role, nurse practitioners need to create and define a distinct role for themselves within practice contexts that may be unfamiliar, sometimes unwelcoming and inhospitable. During this time of transition, nurses need well developed negotiation skills and personal attributes including resilience, tenacity, fortitude and determination. Purpose of the research: The purpose of the research reported in this paper was to explore the transition experiences of 10 newly endorsed nurse practitioners in Australia during their first year of practice. This paper focuses on power, control and political manoeuvring that negatively impacted the ׳nurse practitioners׳ transition. A qualitative approach using a modified version of Carspecken׳s five stage critical ethnography, informed by focused ethnography, was the methodology selected for this study. Methods included observations of practice, journaling, face to face and phone interviews which were recorded, transcribed and analysed thematically. Results: “The enemy within” emerged as a dominant theme highlighting issues of power, powerlessness and politics dominating the participant׳s experiences. Power struggles amongst nurses, both overt and covert, and the deliberate misuse of power were frequently encountered. Many of the participants felt powerless and ill-prepared to negotiate the challenging situations in which they found themselves. Many lacked the skills needed to address the negative behaviours they experienced. Conclusions: This paper reports on the experiences of 10 newly endorsed nurse practitioners during their transition to the nurse practitioner role. The impact of the political climate at the time of this study had an undeniable influence on many of the participants׳ transition experiences. Competition for the limited numbers of

Eliciting maize defense pathways aboveground attracts belowground biocontrol agents.

Science.gov (United States)

Filgueiras, Camila Cramer; Willett, Denis S; Pereira, Ramom Vasconcelos; Moino Junior, Alcides; Pareja, Martin; Duncan, Larry W

2016-11-04

Plant defense pathways mediate multitrophic interactions above and belowground. Understanding the effects of these pathways on pests and natural enemies above and belowground holds great potential for designing effective control strategies. Here we investigate the effects of aboveground stimulation of plant defense pathways on the interactions between corn, the aboveground herbivore adult Diabrotica speciosa, the belowground herbivore larval D. speciosa, and the subterranean ento-mopathogenic nematode natural enemy Heterorhabditis amazonensis. We show that adult D. speciosa recruit to aboveground herbivory and methyl salicylate treatment, that larval D. speciosa are relatively indiscriminate, and that H. amazonensis en-tomopathogenic nematodes recruit to corn fed upon by adult D. speciosa. These results suggest that entomopathogenicnematodes belowground can be highly attuned to changes in the aboveground parts of plants and that biological control can be enhanced with induced plant defense in this and similar systems.

Non-target effects of the entomopathogenic fungus Metarhizium brunneum (BIPESCO 5/F52) on predatory arthropods

DEFF Research Database (Denmark)

Campos de Azevedo, Ana Gorete

females in the presence of M. brunneum revealed that gravid A. aphidimyza are able to perceive the risk posed by M. brunneum and react to that by choosing a pathogen-free site for offspring. In conclusion, non-target effects of M. brunneum on predatory arthropods may be expected. However, knowledge......The overall objective of this PhD thesis was to investigate the interactions that may occur when combining natural enemies of an herbivore. This was done by assessing the non-target effects of the generalist entomopathogenic fungus Metarhizium brunneum on four different predatory arthropods...... of the life cycles of the predatory arthropods and the optimal timing for releasing the natural enemies can reduce the risk of antagonistic interactions. Findings confirm that A. aphidimyza females are able to change their oviposition behavior in the presence of the entomopathogen. It furthermore confirms...

Trophic Interactions between Generalist Predators and the Two Spotted Spide Mite, Tetranychus urticae in, Strawberry

DEFF Research Database (Denmark)

Jacobsen, Stine Kramer

The two spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is a major cause of pest damage worldwide. Its host range includes among many the strawberry crop, a high value crop in Denmark as well as in many other temperate and subtropical regions. Chemical control of T. urticae...... occurrence and diversity of predatory insects and predatory mites in Danish strawberry fields and surrounding vegetation is lacking, as is the knowledge of the potential of generalist insect predators to control T. urticae. The overall objective of this PhD thesis was to investigate the trophic interactions...... between natural enemies, in particular generalist predators and the two spotted spider mite, T. urticae, in strawberry. This was done by investigating interactions of T. urticae and its natural enemies as influenced by cropping practice and the surrounding vegetation (Manuscript I) as well as more...

Eliciting maize defense pathways aboveground attracts belowground biocontrol agents

Science.gov (United States)

Filgueiras, Camila Cramer; Willett, Denis S.; Pereira, Ramom Vasconcelos; Moino Junior, Alcides; Pareja, Martin; Duncan, Larry W.

2016-01-01

Plant defense pathways mediate multitrophic interactions above and belowground. Understanding the effects of these pathways on pests and natural enemies above and belowground holds great potential for designing effective control strategies. Here we investigate the effects of aboveground stimulation of plant defense pathways on the interactions between corn, the aboveground herbivore adult Diabrotica speciosa, the belowground herbivore larval D. speciosa, and the subterranean ento-mopathogenic nematode natural enemy Heterorhabditis amazonensis. We show that adult D. speciosa recruit to aboveground herbivory and methyl salicylate treatment, that larval D. speciosa are relatively indiscriminate, and that H. amazonensis en-tomopathogenic nematodes recruit to corn fed upon by adult D. speciosa. These results suggest that entomopathogenicnematodes belowground can be highly attuned to changes in the aboveground parts of plants and that biological control can be enhanced with induced plant defense in this and similar systems. PMID:27811992

Parasitism and olfactory responses of Dastarcus helophoroides (Coleoptera: Bothrideridae) to different Cerambycid hosts

Science.gov (United States)

Jian-Rong Wei; Zhong-Qi Yang; Therese M. Poland; Jia-Wei. Du

2009-01-01

Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae) is an important natural enemy of longhorned beetles (Coleoptera: Cerambycidae). It is distributed throughout most Provinces in China. We investigated whether there were differences among D. helophoroides populations collected from different hosts in different...

Effect of Parasitoid: Host Ratio and Parasitoid and Host Group Size on Fitness of Spathius galinae (Hymenoptera: Braconidae), a Parasitoid of Emerald Ash Borer (Coleoptera: Buprestidae): Implications for Mass-Rearing

Science.gov (United States)

Producing insect natural enemies in laboratories or insectaries for biological pest control is often expensive, and developing cost-effective rearing techniques is a goal of many biological control programs. Spathius galinae Belokobylskij and Strazenac (Hymenoptera: Braconidae), a recently described...

Biological control of tortricids and aphids in strawberries

DEFF Research Database (Denmark)

Sigsgaard, Lene; Enkegaard, Annie; Eilenberg, Jørgen

Cropping practice and biological control can contribute to reduced pesticide use in strawberries. Organic strawberries are less attacked by strawberry tortricid and buckwheat flower strips can augment its natural enemies. Against shallot aphid the two-spot ladybird is promising....

Complex tritrophic interactions in response to crop domestication: predictions from the wild

NARCIS (Netherlands)

Chen, Y.H.; Gols, R.; Stratton, C.A.; Brevik, K.A.; Benrey, B.

2015-01-01

Crop domestication is the process of artificially selecting plants to increase their suitability to human tastes and cultivated growing conditions. There is increasing evidence that crop domestication can profoundly alter interactions among plants, herbivores, and their natural enemies. However,

Why Fight the Enemy That You Can Reprogram

Science.gov (United States)

2010-02-17

and Autism , and in addition to natural causes of mental health difficulties, there are many man-made accidents that cause brain difficulties. The...learning, scientist were able to genetically create flies that had their “ dopamine -producing brain cells manufacture a membrane protein called P2X2 that

Signal transduction downstream of salicylic and jasmonic acid in herbivory-induced parasitoid attraction by Arabidopsis is independent of JAR1 and NPR1

NARCIS (Netherlands)

Poecke, van R.M.P.; Dicke, M.

2003-01-01

Plants can defend themselves indirectly against herbivores by emitting a volatile blend upon herbivory that attracts the natural enemies of these herbivores, either predators or parasitoids. Although signal transduction in plants from herbivory to induced volatile production depends on jasmonic acid

Complex of primary and secondary parasitoids (Hymenoptera: Encyrtidae and Signiphoridae) of Hypogeoccoccus spp. mealybugs (Hemiptera: Pseudococcidae) in the New World

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Parasitoids, both primary and secondary (hyperparasitoids), of Hypogeococcus spp. mealybugs (Hemiptera: Pseudococcidae) are reviewed to report results of the surveys in the New World conducted during 2009–2017 for perspective natural enemies of the Harrisia cactus mealybug, Hypogeococcus sp., which ...

Hunting for hiding hosts : the behavioral ecology of the stemborer parasitoid Cotesia flavipes

NARCIS (Netherlands)

Potting, R.P.J.

1996-01-01

Classical biological control involves the introduction of an exotic natural enemy to control an introduced pest species. In 1991 the department of Entomology of the Wageningen Agricultural University started a collaborative project with the International Centre for Insect Physiology and

Description and biology of Paectes longiformis Pogue, a new species from Brazil (Lepidoptera: Euteliidae) as a potential biological control agent of Brazilian peppertree in Florida

Science.gov (United States)

Brazilian peppertree, Schinus terebinthifolius Raddi (Anacardiaceae), a native weed from South America, has invaded different habitats throughout south and central Florida. In recent surveys of natural enemies conducted in Salvador, Brazil (native range), a new euteliid species in the genus Paectes ...

Microbial community of predatory bugs of the genus Macrolophus (Hemiptera: Miridae)

NARCIS (Netherlands)

Machtelinckx, T.; Van Leeuwen, T.; Van De Wiele, T.; Boon, N.; De Vos, W.H.; Sanchez, J.A.; Nannini, M.; Gheysen, G.; De Clercq, P.

2012-01-01

Background: The predatory mirids of the genus Macrolophus are key natural enemies of various economically important agricultural pests. Both M. caliginosus and M. pygmaeus are commercially available for the augmentative biological control of arthropod pests in European greenhouses. The latter

Landscape and host plant effects on reproduction by a mobile, polyphagous, multivoltine arthropod herbivore

Science.gov (United States)

Landscape factors can significantly influence arthropod natural enemy and herbivore pest populations. The economically important brown stink bug, Euschistus servus, is a native mobile, polyphagous and multivoltine pest of many crops in southeastern USA and understanding the relative influence of loc...

Lethality of the entomogenous fungus Beauveria bassiana strain NI8 on Lygus lineolaris (Hemiptera: Miridae) and its possible impact on beneficial arthropods

Science.gov (United States)

Bioassays were conducted to examine the pathogenicity of the fungus Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) strain NI8 against Lygus lineolaris (Palisot de Beauvois) and its impact on natural enemies including Apis mellifera L., Crysoperla rufrilabris Burmeister, Orius insid...

Olfactory responses of banana weevil predators to volatiles from banana pseudostem tissue and synthetic pheromone

NARCIS (Netherlands)

Tinzaara, W.; Gold, C.S.; Dicke, M.; Huis, van A.

2005-01-01

As a response to attack by herbivores, plants can emit a variety of volatile substances that attract natural enemies of these insect pests. Predators of the banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) such as Dactylosternum abdominale (Coleoptera: Hydrophilidae) and

Dangerous enemy in Estonian garden soil

International Nuclear Information System (INIS)

Petersell, V.; Mottus, V.; Taeht, K.

2005-01-01

Radon is thoroughly discussed in the article. Its generation and the heath risks it can cause. The distribution of radon in the soil is analysed (one soil lithotype at a time (kBq/m)). The measurements received on different surveyed sites are compared to the standards allowed for the construction works. There is also the link between lung cancer cases and radon's radiance and incense/smoking. The North of Estonia is the pearl of Estonia landscape. The sea being near, beautiful seaside views attract people and inspire them to build their houses in this kind of surroundings. However, these areas are natural danger sources, as the percentage of radon concentration in the soil is often high or very high. South Estonia also has a lot of spectacular places with high concentration of radon in the soil [et

Feeding status of the parasitoid Diadegma semiclausum affects biological control of Plutella xylostella: a simulation study

NARCIS (Netherlands)

Hemerik, L.

2007-01-01

Life history characteristics of the diamondback moth (DBM), Plutella xylostella, a worldwide pest on cruciferous crops, and its important natural enemy, the parasitoid Diadegma semiclausum have intensely been studied. In addition, the searching behaviour of the parasitoid and the role of foraging

Tritrophic choice experiments with Bt plants, the diamondback moth (Plutella xylostella) and the parasitoid Cotesia plutellae

NARCIS (Netherlands)

Schuler, T.H.; Potting, R.P.J.; Denholm, I.; Clark, S.J.; Clark, A.J.; Stewart, C.N.; Poppy, G.M.

2003-01-01

Parasitoids are important natural enemies of many pest species and are used extensively in biological and integrated control programmes. Crop plants transformed to express toxin genes derived from Bacillus thuringiensis (Bt) provide high levels of resistance to certain pest species, which is likely

Attraction of Three Mirid Predators to Tomato Infested by Both the Tomato Leaf Mining Moth Tuta absoluta and the Whitefly Bemisia tabaci

NARCIS (Netherlands)

Silva, Diego B.; Bueno, Vanda H.P.; Loon, van Joop J.A.; Peñaflor, Maria Fernanda G.V.; Bento, José Maurício S.; Lenteren, van Joop C.

2018-01-01

Plants emit volatile compounds in response to insect herbivory, which may play multiple roles as defensive compounds and mediators of interactions with other plants, microorganisms and animals. Herbivore-induced plant volatiles (HIPVs) may act as indirect plant defenses by attracting natural enemies

PCR-based identification of the pathogenic bacterium, Acaricomes phytoseiuli, in the biological control agent Phytoseiulus persimilis (Acari: Phytoseiidae)

NARCIS (Netherlands)

Gols, R.; Schütte, C.; Stouthamer, R.; Dicke, M.

2007-01-01

The predatory mite, Phytoseiulus persimilis is an important biological control agent of herbivorous spider mites. This species is also intensively used in the study of tritrophic effects of plant volatiles in interactions involving plants, herbivores, and their natural enemies. Recently, a novel

Plant responses to multiple herbivory

NARCIS (Netherlands)

Li, Yehua

2016-01-01

This thesis explores whether aphid-infestation interferes with the plant response to chewing herbivores and whether this impacts performance and behaviour of individual chewing insect herbivores and their natural enemies, as well as the entire insect community. I investigated this using three

Nectar production in oilseeds: Food for pollinators in an agriculture dominated landscape

Science.gov (United States)

Simplified agroecosystems have degraded habitats for beneficial insects throughout the Midwest and Northern Great Plains of the USA. Beneficial insects include pollinators and natural enemies of crop pests, and both rely heavily on floral resources and habitat diversity to maintain healthy populatio...

Marine air : shipping emissions in ports and their impact on local air quality. A case study on the ports of Delfzijl and Eemshaven.

NARCIS (Netherlands)

Meer van der, Ruurd

2012-01-01

Summary Ships translocate organisms across the world via on-board ballast water. When a ship releases its ballast water these organism are released as well. They might have the advantage of not having any natural enemies in their new environment and they

Evaluation of the host specificity of Spathius galinae (Hymenoptera: Braconidae), a larval parasitoid of the emerald ash borer (Coleoptera: Buprestidae) in Northeast Asia

Science.gov (United States)

Host-specificity determination prior to the introduction of non-native natural enemies (predators and parasitoids) is a critical component of the risk assessment for modern classical biological control programs. In the present study, we assessed the host specificity of a newly described parasitoid,...

Region, landscape, and host plant effects on reproduction by a mobile, multivoltine arthropod herbivore

Science.gov (United States)

Community structure, species abundance, and biotic interactions of invertebrate species in farmlands are influenced by larger-scale processes at region and landscape levels. While previous work makes clear the importance of landscape factors for natural enemy populations, relatively less is known ab...

Induced parasitoid attraction by Arabidopsis thaliana : involvement of the octadecanoid and the salicylic acid pathway

NARCIS (Netherlands)

Poecke, van M.P.; Dicke, M.

2002-01-01

Plants can use indirect defence mechanisms to protect themselves against herbivorous insects. An example of such an indirect defence mechanism is the emission of volatiles by plants induced by herbivore feeding. These volatiles can attract the natural enemies of these herbivores, for example,

Genetic engineering of plant volatile terpenoids: effects on a herbivore, a predator and a parasitoid

NARCIS (Netherlands)

Kos, M.; Houshyani, B.; Overeem, A.J.; Bouwmeester, H.J.; Weldegergis, B.T.; van Loon, J.J.A.; Dicke, M.; Vet, L.E.M.

2013-01-01

BACKGROUND: Most insect-resistant transgenic crops employ toxins to control pests. A novel approach is to enhance the effectiveness of natural enemies by genetic engineering of the biosynthesis of volatile organic compounds (VOCs). Before the commercialisation of such transgenic plants can be

Plant-mediated Interactions Among Insects within a Community Ecological Perspective

NARCIS (Netherlands)

Poelman, E.H.; Dicke, M.

2014-01-01

Plants may be visited by many species of insects during their life-time. These insects include harmful herbivores above and belowground as well as beneficial natural enemies of herbivores and pollinators. Moreover, these interactions may take place sequentially or simultaneously. Responses of plants

Discrimination of crop and weeds on visible and visible/near-infrared spectrums using support vector machines, artificial neural network and decision tree

Science.gov (United States)

Weeds are regarded as farmers' natural enemy. In order to avoid excessive pesticide residues, the destruction of ecological environment, and to guarantee the quality and safety of agricultural products, it is urgent to develop highly-efficient weed management methods. Amongst, weed discrimination is...

The effects of prey patchiness, predator aggregation, and mutual interference on the functional response of Phytoseiulus persimilis feeding on Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae)

DEFF Research Database (Denmark)

Nachman, Gösta

2006-01-01

The spatial distributions of two-spotted spider mites Tetranychus urticae and their natural enemy, the phytoseiid predator Phytoseiulus persimilis, were studied on six full-grown cucumber plants. Both mite species were very patchily distributed and P. persimilis tended to aggregate on leaves...

Relative importance of plant-mediated bottom-up and top-down forces on herbivore abundance on Brassica oleracea

NARCIS (Netherlands)

Kos, M.; Broekgaarden, C.; Kabouw, P.; Oude Lenferink, K.; Poelman, E.H.; Vet, L.E.M.; Dicke, M.; Loon, van J.J.A.

2011-01-01

1. Arthropod communities are structured by complex interactions between bottom-up (resource-based) and top-down (natural enemy-based) forces. Their relative importance in shaping arthropod communities, however, continues to be under debate. Bottom-up and top-down forces can be affected by

Side-effects of cowpea treatment with botanical insecticides on two parasitoids of Callosobruchus maculatus

NARCIS (Netherlands)

Boeke, S.J.; Sinzogan, A.A.C.; Almeida, de R.P.; Boer, de P.W.M.; Jeong, G.S.; Kossou, D.K.; Loon, van J.J.A.

2003-01-01

Studies on the protective effect of botanical products against pest insects have infrequently been extended to side-effects on natural enemies. Indirect effects of botanicals on the storability of seeds could occur through their possible negative impact on biological control agents. Four plant

Size of predatory mites and refuge entrance determine success of biological control of the coconut mite

NARCIS (Netherlands)

da Silva, F.R.; de Moraes, G.J.; Lesna, I.; Sato, Y.; Vasquez, C.; Hanna, R.; Sabelis, M.W.; Janssen, A.

2016-01-01

Predators face the challenge of accessing prey that live in sheltered habitats. The coconut mite Aceriaguerreronis Keifer (Acari: Eriophyidae) lives hidden beneath the perianth, which is appressed to the coconut fruit surface, where they feed on the meristematic tissue. Its natural enemy, the

The interaction of two-spotted spider mites, Tetranychus urticae Koch, with Cry protein production and predation by Amblyseius andersoni (Chant) in Cry1Ac/Cry2Ab cotton and Cry1F maize.

Science.gov (United States)

Crops producing insecticidal crystal (Cry) proteins from the bacterium, Bacillus thuringiensis (Bt), are an important tool for managing lepidopteran pests on cotton and maize. However, the effects of these Bt crops on non-target organisms, especially natural enemies that provide biological control s...

Experience with methyl salicylate affects behavioural responses of a predatory mite to blends of herbivore-induced plant volatiles

NARCIS (Netherlands)

Boer, de J.G.; Dicke, M.

2004-01-01

Many natural enemies of herbivorous arthropods use herbivore-induced plant volatiles to locate their prey. These foraging cues consist of mixtures of compounds that show a considerable variation within and among plantherbivore combinations, a situation that favours a flexible approach in the

The tri-trophic interactions hypothesis: interactive effects of host plant quality, diet breadth and natural enemies on herbivores.

Directory of Open Access Journals (Sweden)

Kailen A Mooney

Full Text Available Several influential hypotheses in plant-herbivore and herbivore-predator interactions consider the interactive effects of plant quality, herbivore diet breadth, and predation on herbivore performance. Yet individually and collectively, these hypotheses fail to address the simultaneous influence of all three factors. Here we review existing hypotheses, and propose the tri-trophic interactions (TTI hypothesis to consolidate and integrate their predictions. The TTI hypothesis predicts that dietary specialist herbivores (as compared to generalists should escape predators and be competitively dominant due to faster growth rates, and that such differences should be greater on low quality (as compared to high quality host plants. To provide a preliminary test of these predictions, we conducted an empirical study comparing the effects of plant (Baccharis salicifolia quality and predators between a specialist (Uroleucon macolai and a generalist (Aphis gossypii aphid herbivore. Consistent with predictions, these three factors interactively determine herbivore performance in ways not addressed by existing hypotheses. Compared to the specialist, the generalist was less fecund, competitively inferior, and more sensitive to low plant quality. Correspondingly, predator effects were contingent upon plant quality only for the generalist. Contrary to predictions, predator effects were weaker for the generalist and on low-quality plants, likely due to density-dependent benefits provided to the generalist by mutualist ants. Because the TTI hypothesis predicts the superior performance of specialists, mutualist ants may be critical to A. gossypii persistence under competition from U. macolai. In summary, the integrative nature of the TTI hypothesis offers novel insight into the determinants of plant-herbivore and herbivore-predator interactions and the coexistence of specialist and generalist herbivores.

Population biology of emerald ash borer and its natural enemies in China

Science.gov (United States)

Houping Liu; Leah S. Bauer; Tonghai Zhao; Ruitong Gao

2008-01-01

Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), also known as emerald ash borer (EAB), was first discovered in Michigan and Ontario, Canada, in 2002 following investigations of declining and dying ash trees (Fraxinus spp.). Agrilus planipennis has also spread to Ohio, Indiana, Maryland, Virginia,...

Potential contribution of natural enemies to patterns of local adaptation in plants

Czech Academy of Sciences Publication Activity Database

Crémieux, L.; Bischoff, A.; Šmilauerová, M.; Lawson, C.S.; Mortimer, S. R.; Doležal, Jiří; Lanta, Vojtěch; Edwards, A.R.; Brook, A.J.; Tscheulin, T.; Macel, M.; Lepš, Jan; Müller-Schärer, H.; Steinger, T.

2008-01-01

Roč. 180, č. 2 (2008), s. 524-533 ISSN 0028-646X Grant - others:EU(XE) EVK-2-CT-1999-00032 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z50070508 Keywords : local adaptation * plant-parasite interaction * pathogen Subject RIV: EF - Botanics Impact factor: 5.178, year: 2008

Handling of vegetable biodiversity and the biological control of insect-plague: Case of an organic vineyard

International Nuclear Information System (INIS)

Nicholls, Clara I

2000-01-01

In the handling of plagues it is feasible to increase natural enemies, populations diversifying the habitat. In the agro ecosystems the importance of the marginal vegetation is recognized for the parasitoids survival and predators. In commercial cultivations of vineyards, managed organically, was ahead this work, corridors of 65 different species from plants with flowers were settled down. The covering cultivations were sowed in array for half every year. The vineyards received 2 tons of compost on average for hectare. For the control of illnesses it was used sulfur preventively. It sought to be necessary if the corridor 200 meters long could increase the biological control of insect's plague in the vineyard. It was evaluated the contribution of the corridor like supplier of alternative nutritious resources, consistent, abundant and well distributed of natural enemies. It was proven the utility of the corridor to increase the populational levels of beneficent insects

Habitat Management to Suppress Pest Populations: Progress and Prospects.

Science.gov (United States)

Gurr, Geoff M; Wratten, Steve D; Landis, Douglas A; You, Minsheng

2017-01-31

Habitat management involving manipulation of farmland vegetation can exert direct suppressive effects on pests and promote natural enemies. Advances in theory and practical techniques have allowed habitat management to become an important subdiscipline of pest management. Improved understanding of biodiversity-ecosystem function relationships means that researchers now have a firmer theoretical foundation on which to design habitat management strategies for pest suppression in agricultural systems, including landscape-scale effects. Supporting natural enemies with shelter, nectar, alternative prey/hosts, and pollen (SNAP) has emerged as a major research topic and applied tactic with field tests and adoption often preceded by rigorous laboratory experimentation. As a result, the promise of habitat management is increasingly being realized in the form of practical worldwide implementation. Uptake is facilitated by farmer participation in research and is made more likely by the simultaneous delivery of ecosystem services other than pest suppression.

CONFIRMATION OF PRESENCE OF A PREDATORY GALL MIDGE, Feltiella acarisuga, (Vallot, 1827 AND STAPHYLINID PREDATOR Oligota oviformis Casey, 1893 OF A TWO SPOTTED SPIDER MITE (Tetranychus urticae, Koch, 1836 IN SLOVENIA

Directory of Open Access Journals (Sweden)

Katarina KOS

2018-04-01

Full Text Available The two spotted spider mite, Tetranychus urticae C. L. Koch, 1836 is one of the most important pests of greenhouse crops worldwide. Due to its polyphagic range of hosts and rapid development it forms great populations and as such represents a suitable host/prey for lots of natural enemies usable in biological control. Most commonly used predators of Tetranychid mites are predatory mites (Phytoseiulus persimilis Athias-Henriot, 1957, Amblyseius swirskii Athias-Henriot, 1962 ,…, but among most voracious predators is the larva of a predatory gall midge, Feltiella acarisuga (Vallot, 1827 that was found also in greenhouses of the Biotechnical Faculty in Ljubljana on eggplant leaves in 2017. Besides the predatory gall midge also another predator, staphylinid Oligota oviformis Casey, 1893 beetles and larvae were found in great numbers. After positive identification of F. acarisuga found naturally in Slovenia, it can be added to the list of indigenous species of natural enemies and thus can be used in biological control programs in greenhouse crop protection against spider mites.

Entomofauna associated to horticultural crops under organic and conventional practices in Cordoba, Argentina

International Nuclear Information System (INIS)

Zalazar, Laura; Salvo, Adriana

2007-01-01

Farming practices and the addition of chemical synthetic substances in conventional agroecosystems are detrimental mainly to natural enemies of phytophagous insects, diminishing the natural regulation of pest insects. On the other hand, in organic agriculture, biological processes and care of the environment are favoured, hence an increase in insect biodiversity is predicted in this type of systems. In this work, abundance, richness of insects and proportion of functional groups were compared through a single quantitative sampling of insects in horticultural crop fields, three under organic and three under conventional management practices. Insect species richness, total and for guilds (phytophagous and entomophagous insects) were significantly higher in organic orchards, and also was the abundance of entomophagous insects. Richness and abundance of all insect orders (with exception of Homoptera abundance), were higher in orchards under organic management, being significant the differences for richness of Coleoptera and richness and abundance of Hymenoptera. Similar tendencies were observed in data obtained through sweep net in weeds. These results suggest that organic practices increase the diversity of species, particularly that of natural enemies. (author)

Entomofauna associated to horticultural crops under organic and conventional practices in Cordoba, Argentina; Entomofauna asociada a cultivos horticolas organicos y convencionales en Cordoba, Argentina

Energy Technology Data Exchange (ETDEWEB)

Zalazar, Laura; Salvo, Adriana [Universidade Nacional de Cordoba (Argentina). Facultad de Ciencias Exactas Fisicas y Naturales. Centro de Investigaciones Entomologicas de Cordoba (CIEC)

2007-09-15

Farming practices and the addition of chemical synthetic substances in conventional agroecosystems are detrimental mainly to natural enemies of phytophagous insects, diminishing the natural regulation of pest insects. On the other hand, in organic agriculture, biological processes and care of the environment are favoured, hence an increase in insect biodiversity is predicted in this type of systems. In this work, abundance, richness of insects and proportion of functional groups were compared through a single quantitative sampling of insects in horticultural crop fields, three under organic and three under conventional management practices. Insect species richness, total and for guilds (phytophagous and entomophagous insects) were significantly higher in organic orchards, and also was the abundance of entomophagous insects. Richness and abundance of all insect orders (with exception of Homoptera abundance), were higher in orchards under organic management, being significant the differences for richness of Coleoptera and richness and abundance of Hymenoptera. Similar tendencies were observed in data obtained through sweep net in weeds. These results suggest that organic practices increase the diversity of species, particularly that of natural enemies. (author)

Compatibility of organic farming treatments against Monosteira unicostata with non-target arthropod fauna of almond trees canopy

Energy Technology Data Exchange (ETDEWEB)

Sánchez-Ramos, I.; Marcotegui, A.; Pascual, S.; Fernández, C.E.; Cobos, G.; González-Núñez, M.

2017-07-01

Field trials had shown that 1-2 applications of kaolin and potassium salts of fatty acids combined with thyme essential oil (PSTEO) reduced the abundance of the lace bug Monosteira unicostata (Mulsant & Rey) (Hemiptera: Tingidae), an important pest of almond trees in the Mediterranean region. These products could be useful for the control of this pest in organic production of almonds, but higher number of applications could be necessary. However, the possible detrimental effects on the almond orchard ecosystem should be evaluated. In the present work, the effects observed on the non-target arthropod fauna of the almond trees canopy in those field assays are shown. First, a comprehensive report of the non-target arthropod fauna of the almond tree is provided. Regarding natural enemies, most of the predatory arthropods captured were spiders belonging to different families like Salticidae, Thomisidae, Philodromidae, Theridiidae, Araneidae or Oxyopidae. Other predatory families that appeared in significant numbers were Chrysopidae, Anthocoridae, Aeolothripidae, Coccinellidae, Phytoseiidae, Erythraeidae or Forficulidae. Among parasitoids, the most abundant families were Eulophidae, Scelionidae and Dryinidae. Kaolin reduced the abundance of natural enemies and other non-target arthropods as well as their diversity and number of species. On the contrary, PSTEO only produced a slight reduction in the number of natural enemies, whereas no effect was found on the diversity and species richness. These effects were observed despite the reduced number of applications, so greater effect is expected if its frequency is increased in order to achieve an efficient control of M. unicostata.

Analysis and prediction of pest dynamics in an agroforestry context using Tiko'n, a generic tool to develop food web models

Science.gov (United States)

Rojas, Marcela; Malard, Julien; Adamowski, Jan; Carrera, Jaime Luis; Maas, Raúl

2017-04-01

While it is known that climate change will impact future plant-pest population dynamics, potentially affecting crop damage, agroforestry with its enhanced biodiversity is said to reduce the outbreaks of pest insects by providing natural enemies for the control of pest populations. This premise is known in the literature as the natural enemy hypothesis and has been widely studied qualitatively. However, disagreement still exists on whether biodiversity enhancement reduces pest outbreaks, showing the need of quantitatively understanding the mechanisms behind the interactions between pests and natural enemies, also known as trophic interactions. Crop pest models that study insect population dynamics in agroforestry contexts are very rare, and pest models that take trophic interactions into account are even rarer. This may be due to the difficulty of representing complex food webs in a quantifiable model. There is therefore a need for validated food web models that allow users to predict the response of these webs to changes in climate in agroforestry systems. In this study we present Tiko'n, a Python-based software whose API allows users to rapidly build and validate trophic web models; the program uses a Bayesian inference approach to calibrate the models according to field data, allowing for the reuse of literature data from various sources and reducing the need for extensive field data collection. Tiko'n was run using coffee leaf miner (Leucoptera coffeella) and associated parasitoid data from a shaded coffee plantation, showing the mechanisms of insect population dynamics within a tri-trophic food web in an agroforestry system.

Identification of Putative Coffee Rust Mycoparasites via Single-Molecule DNA Sequencing of Infected Pustules.

Science.gov (United States)

James, Timothy Y; Marino, John A; Perfecto, Ivette; Vandermeer, John

2016-01-15

The interaction of crop pests with their natural enemies is a fundament to their control. Natural enemies of fungal pathogens of crops are poorly known relative to those of insect pests, despite the diversity of fungal pathogens and their economic importance. Currently, many regions across Latin America are experiencing unprecedented epidemics of coffee rust (Hemileia vastatrix). Identification of natural enemies of coffee rust could aid in developing management strategies or in pinpointing species that could be used for biocontrol. In the present study, we characterized fungal communities associated with coffee rust lesions by single-molecule DNA sequencing of fungal rRNA gene bar codes from leaf discs (≈28 mm(2)) containing rust lesions and control discs with no rust lesions. The leaf disc communities were hyperdiverse in terms of fungi, with up to 69 operational taxonomic units (putative species) per control disc, and the diversity was only slightly reduced in rust-infected discs, with up to 63 putative species. However, geography had a greater influence on the fungal community than whether the disc was infected by coffee rust. Through comparisons between control and rust-infected leaf discs, as well as taxonomic criteria, we identified 15 putative mycoparasitic fungi. These fungi are concentrated in the fungal family Cordycipitaceae and the order Tremellales. These data emphasize the complexity of diverse fungi of unknown ecological function within a leaf that might influence plant disease epidemics or lead to the development of species for biocontrol of fungal disease. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Compatibility of organic farming treatments against Monosteira unicostata with non-target arthropod fauna of almond trees canopy

Directory of Open Access Journals (Sweden)

Ismael Sánchez-Ramos

2017-07-01

Full Text Available Field trials had shown that 1-2 applications of kaolin and potassium salts of fatty acids combined with thyme essential oil (PSTEO reduced the abundance of the lace bug Monosteira unicostata (Mulsant & Rey (Hemiptera: Tingidae, an important pest of almond trees in the Mediterranean region. These products could be useful for the control of this pest in organic production of almonds, but higher number of applications could be necessary. However, the possible detrimental effects on the almond orchard ecosystem should be evaluated. In the present work, the effects observed on the non-target arthropod fauna of the almond trees canopy in those field assays are shown. First, a comprehensive report of the non-target arthropod fauna of the almond tree is provided. Regarding natural enemies, most of the predatory arthropods captured were spiders belonging to different families like Salticidae, Thomisidae, Philodromidae, Theridiidae, Araneidae or Oxyopidae. Other predatory families that appeared in significant numbers were Chrysopidae, Anthocoridae, Aeolothripidae, Coccinellidae, Phytoseiidae, Erythraeidae or Forficulidae. Among parasitoids, the most abundant families were Eulophidae, Scelionidae and Dryinidae. Kaolin reduced the abundance of natural enemies and other non-target arthropods as well as their diversity and number of species. On the contrary, PSTEO only produced a slight reduction in the number of natural enemies, whereas no effect was found on the diversity and species richness. These effects were observed despite the reduced number of applications, so greater effect is expected if its frequency is increased in order to achieve an efficient control of M. unicostata.

Compatibility of organic farming treatments against Monosteira unicostata with non-target arthropod fauna of almond trees canopy

International Nuclear Information System (INIS)

Sánchez-Ramos, I.; Marcotegui, A.; Pascual, S.; Fernández, C.E.; Cobos, G.; González-Núñez, M.

2017-01-01

Field trials had shown that 1-2 applications of kaolin and potassium salts of fatty acids combined with thyme essential oil (PSTEO) reduced the abundance of the lace bug Monosteira unicostata (Mulsant & Rey) (Hemiptera: Tingidae), an important pest of almond trees in the Mediterranean region. These products could be useful for the control of this pest in organic production of almonds, but higher number of applications could be necessary. However, the possible detrimental effects on the almond orchard ecosystem should be evaluated. In the present work, the effects observed on the non-target arthropod fauna of the almond trees canopy in those field assays are shown. First, a comprehensive report of the non-target arthropod fauna of the almond tree is provided. Regarding natural enemies, most of the predatory arthropods captured were spiders belonging to different families like Salticidae, Thomisidae, Philodromidae, Theridiidae, Araneidae or Oxyopidae. Other predatory families that appeared in significant numbers were Chrysopidae, Anthocoridae, Aeolothripidae, Coccinellidae, Phytoseiidae, Erythraeidae or Forficulidae. Among parasitoids, the most abundant families were Eulophidae, Scelionidae and Dryinidae. Kaolin reduced the abundance of natural enemies and other non-target arthropods as well as their diversity and number of species. On the contrary, PSTEO only produced a slight reduction in the number of natural enemies, whereas no effect was found on the diversity and species richness. These effects were observed despite the reduced number of applications, so greater effect is expected if its frequency is increased in order to achieve an efficient control of M. unicostata.

Effect of methyl salicylate-based lures on beneficial and pest arthropods in strawberry.

Science.gov (United States)

Lee, Jana C

2010-04-01

Methyl salicylate (MeSA) is a common herbivore-induced plant volatile that, when applied to crops, has the potential to enhance natural enemy abundance and pest control. The impacts of MeSA in strawberry were unknown and examined in the spring and midsummer period. Strawberry plots contained no lures (control) or two 30-d MeSA lures (Predalure) in the center: one lure 0.61 m aboveground over a sticky trap, and one lure on a plant near the ground. Arthropod abundance was monitored at the point source, 5 m and 10 m away from lures over 31 d with white sticky traps, pitfall traps, and leaf inspection. Twenty-seven and nine comparisons were made among beneficial and pest arthropods, respectively. Overall positive responses were found among Chrysopidae in July-August 2008 and Orius tristicolor (White) in May-June 2009 to MeSA based on sticky traps. Chrysopidae showed attraction to the point source, but not at 5 m and 10 m. Ground-dwelling predators collected in pitfall traps such as Araneae, the carabid beetles, Pterostichus melanarius (Illiger), and Nebria brevicollis (Fabricius) did not respond. Increased abundance of six natural enemy groups appeared on various dates between 3 and 24 d after placement of lures in the field based on leaf inspection and sticky traps. Conversely, fewer Coccinellidae were captured on sticky traps on days 0-3, and fewer natural enemies were observed on leaves on day 28 in MeSA plots. MeSA did not increase nor decrease pest abundance.

Herbivore benefits from vectoring plant virus through reduction of period of vulnerability to predation

NARCIS (Netherlands)

Belliure, B.; Janssen, A.; Sabelis, M.W.

2008-01-01

Herbivores can profit from vectoring plant pathogens because the induced defence of plants against pathogens sometimes interferes with the induced defence of plants against herbivores. Plants can also defend themselves indirectly by the action of the natural enemies of the herbivores. It is unknown

Factitious prey and artificial diets for predatory lady beetles: current situation, obstacles, and approaches for improvement

Science.gov (United States)

Predatory lady beetles (Coleoptera: Coccinellidae) are important natural enemies of many pests in crop ecosystems throughout the world. Although several species are currently mass-reared and sold by biocontrol companies, there is an urgent need to reduce rearing costs. Cost effective mass rearing of...

Barcode haplotype variation in North American agroecosystem ladybird beetles (Coleoptera: Coccinellidae

Science.gov (United States)

DNA barcodes have proven invaluable in identifying and distinguishing insect pests, for example for determining the provenance of exotic invasives, but relatively few insect natural enemies have been barcoded. We used Folmer et al.’s universal invertebrate primers (1994), and those designed by Heber...

Implications of changes in land cover and landscape structure for the biocontrol potential of stemborers in Ethiopia

NARCIS (Netherlands)

Kebede, Yodit; Bianchi, Felix; Baudron, Frédéric; Abraham, Kristin; Valença, de Anne; Tittonell, Pablo

2018-01-01

The land cover and structure of agricultural landscapes may influence the abundance and diversity of natural enemies of crop pests. However, these landscapes are continuously evolving due to changing land uses and agricultural practices. Here we assess changes in land use and landscape structure in

Challenges of Integrated Pest Management in Sub-Saharan Africa

NARCIS (Netherlands)

Huis, van A.

2009-01-01

a response to the negative side effects of chemical control in the developed world, Integrated Pest Management (IPM) developed with an emphasis on reducing the role of pesticides. Later the role of natural enemies was recognized as being the cornerstone for sustainable pest management strategies.

A multitrophic perspective on functioning and evolution of facilitation in plant communities

NARCIS (Netherlands)

Putten, van der W.H.

2009-01-01

1. Plant facilitation has been studied mostly in the context of plant–plant interactions, whereas multitrophic interactions including those that occur below ground have not yet received much attention. Here, I will discuss how above-ground and below-ground natural enemies and their predators

Temporal dynamics of woodpecker predation on the invasive emerald ash borer (Agrilus planipennis) in North America

Science.gov (United States)

Woodpeckers (Picidae) are among the most prevalent natural enemies attacking the invasive emerald ash borer (EAB), Agrilus planipennis Fairmaire, in North America, but there can be considerable variation in the levels of EAB predation on ash trees (Oleaceae: Fraxinus) within and between sites as wel...

Stronger diversity effects with increased environmental stress : A study of multitrophic interactions between oak, powdery mildew and ladybirds

NARCIS (Netherlands)

Dillen, Mathias; Smit, Christian; Buyse, Martijn; Höfte, Monica; De Clercq, Patrick; Verheyen, Kris

2017-01-01

Recent research has suggested that increasing neighbourhood tree species diversity may mitigate the impact of pests or pathogens by supporting the activities of their natural enemies and/or reducing the density of available hosts. In this study, we attempted to assess these mechanisms in a

Prey and non-prey arthropods sharing a host plant : Effects on induced volatile emission and predator attraction

NARCIS (Netherlands)

de Boer, Jetske G.; Hordijk, Cornelis A.; Posthumus, Maarten A.; Dicke, Marcel

It is well established that plants infested with a single herbivore species can attract specific natural enemies through the emission of herbivore-induced volatiles. However, it is less clear what happens when plants are simultaneously attacked by more than one species. We analyzed volatile

Populations of Bactrocera oleae (Diptera: Tephritidae) and Its Parasitoids in Himalayan Asia

Science.gov (United States)

For a biological control program against olive fruit fly, Bactrocera oleae Rossi, olives were collected in the Himalayan foothills (China, Nepal, India, and Pakistan) to discover new natural enemies. Wild olives, Olea europaea ssp. cuspidata (Wall ex. G. Don), were sparsely distributed and fly-infes...

Save money the easy way with bio-control

Science.gov (United States)

Sweet potato whitefly is a key insect pests affecting cotton and many other agronomic and horticultural crops in the southwestern U.S. Prior research has shown that arthropod natural enemies, particularly predators, can have a significant impact on whitefly population dynamics and can regulate popul...

Fitness consequences of indirect plant defence in the annual weed, Sinapis arvensis

NARCIS (Netherlands)

Gols, R.; Wagenaar, R.; Poelman, E.H.; Kruidhof, H.M.; van Loon, J.J.A.; Harvey, J.A.

2015-01-01

Plant traits that enhance the attraction of the natural enemies of their herbivores have been postulated to function as an 'indirect defence'. An important underlying assumption is that this enhanced attraction results in increased plant fitness due to reduced herbivory. This assumption has been

Fitness consequences of indirect plant defence in the annual weed, Sinapis arvensis

NARCIS (Netherlands)

Gols, Rieta; Wagenaar, Roel; Poelman, Erik H.; Kruidhof, H. Marjolein; van Loon, Joop J.A.; Harvey, Jeffrey A.

2015-01-01

* Plant traits that enhance the attraction of the natural enemies of their herbivores have been postulated to function as an ‘indirect defence’. An important underlying assumption is that this enhanced attraction results in increased plant fitness due to reduced herbivory. This assumption has been

confidence in teaching integrated pest management (ipm)

African Journals Online (AJOL)

p2333147

The exploration for environmental friendly alternatives to pesticides use in agriculture has ... mechanical killing of pests; biological methods that include natural enemies; and ... Intervention through extension is especially important in furthering the ..... service providers to prioritize training and flow of information on advances ...

The herbivore-induced plant volatile methyl salicylate negatively affects attraction of the parasitoid Diadegma semiclausum

NARCIS (Netherlands)

Snoeren, T.A.L.; Mumm, R.; Poelman, E.H.; Yang, Y.; Pichersky, E.; Dicke, M.

2010-01-01

The indirect defense mechanisms of plants comprise the production of herbivore-induced plant volatiles that can attract natural enemies of plant attackers. One of the often emitted compounds after herbivory is methyl salicylate (MeSA). Here, we studied the importance of this caterpillar-induced

An amino acid substitution inhibits specialist herbivore production of a competitive antagonist effector and recovers insect-induced plant defenses

Science.gov (United States)

Plants respond to insect herbivory through the production of biochemicals that function as either direct defenses or indirect defenses via the attraction of natural enemies. Curiously, attack by even closely related insect pests can result in distinctive levels of induced plant defenses. Despite the...

An amino acid substitution inhibits specialist herbivore production of an antagonist effector and recovers insect-induced plant defenses

Science.gov (United States)

Plants respond to insect herbivory through the production of biochemicals that function as either direct defenses or indirect defenses via the attraction of natural enemies. Curiously, attack by even closely related insect pests can result in distinctive levels of induced plant defenses. Despite the...

The Nature and Functions of European Political Borders

Directory of Open Access Journals (Sweden)

Jernej Zupančič

2008-07-01

Full Text Available The political border limits a state’s territory and symbolizes the extent of a state’s power and ownership. Borders give integrity to the inner state territory which they enclose (the role of establishing national integrity and at the same time form an outer boundary segregating the state territory from the surrounding politicial entities (the segregation role. European borders are old and reflect the political history of an old continent. The last major border changes happened after World War II. Over the centuries borders were merely lines separating one territory from another. Such borders were understood as »frontiers«. Forming an effective barrier against enemies was the overriding function of borders. Many borders were fortified and further enhanced by means of various defensive systems. In the second half of the 20th century the character of political borders changed. They became a contact area between countries, nations and cultures. Contemporary European borders reflect the colourful history of an old continent. They are predominantely functional markers: they represent the political and juridical delimitation of territories, they mark economic barriers and show their defensive nature and reveal the extent of cultural contact. As a result of European integration processes, the nature of political borders has changed: instead of division, their integration role is brought to the fore. A united Europe is nevertheless still not a borderless Europe! The borders within the »Schengen-area« have retained their political and administrative functions, it is just that the customs and security checks at the borders have been removed. During the period of European integration, borderlines were stabilized in accordance with the 1974 Helsinki Agreement. But despite this we can still observe ongoing changes to state borders, particularly in areas of conflict such as the Balkan peninsula. It seems after all that the process of demarcation

Herbivory by an introduced Asian weevil negatively affects population growth of an invasive Brazilian shrub in Florida.

Science.gov (United States)

Stricker, Kerry Bohl; Stiling, Peter

2012-08-01

The enemy release hypothesis (ERH) is often cited to explain why some plants successfully invade natural communities while others do not. This hypothesis maintains that plant populations are regulated by coevolved enemies in their native range but are relieved of this pressure where their enemies have not been co-introduced. Some studies have shown that invasive plants sustain lower levels of herbivore damage when compared to native species, but how damage affects fitness and population dynamics remains unclear. We used a system of co-occurring native and invasive Eugenia congeners in south Florida (USA) to experimentally test the ERH, addressing deficiencies in our understanding of the role of natural enemies in plant invasion at the population level. Insecticide was used to experimentally exclude insect herbivores from invasive Eugenia uniflora and its native co-occurring congeners in the field for two years. Herbivore damage, plant growth, survival, and population growth rates for the three species were then compared for control and insecticide-treated plants. Our results contradict the ERH, indicating that E. uniflora sustains more herbivore damage than its native congeners and that this damage negatively impacts stem height, survival, and population growth. In addition, most damage to E. uniflora, a native of Brazil, is carried out by Myllocerus undatus, a recently introduced weevil from Sri Lanka, and M. undatus attacks a significantly greater proportion of E. uniflora leaves than those of its native congeners. This interaction is particularly interesting because M. undatus and E. uniflora share no coevolutionary history, having arisen on two separate continents and come into contact on a third. Our study is the first to document negative population-level effects for an invasive plant as a result of the introduction of a novel herbivore. Such inhibitory interactions are likely to become more prevalent as suites of previously noninteracting species continue to

The Bear’s Den: Russian Anti Access/Area Denial in the Maritime Domain

Science.gov (United States)

2016-05-01

quietly developing its capabilities. Russia’s territorial seizures and money from natural resources have helped the Russian military develop...an anti- access capability of its own. With their territorial seizures and an influx of money from natural resources, the Russian military has...Russia has also deployed its Bastion anti-ship missile system, designed to destroy enemy ships, to the area. The Bastion is coupled with the S

Interactions between natural enemies: Effect of a predatory mite on transmission of the fungus Neozygites floridana in two-spotted spider mite populations.

Science.gov (United States)

Trandem, Nina; Berdinesen, Ronny; Pell, Judith K; Klingen, Ingeborg

2016-02-01

Introducing the predatory mite Phytoseiulus persimilis into two-spotted spider mite, Tetranychus urticae, populations significantly increased the proportion of T. urticae infected with the spider mite pathogen Neozygites floridana in one of two experiments. By the final sampling occasion, the number of T. urticae in the treatment with both the predator and the pathogen had declined to zero in both experiments, while in the fungus-only treatment T. urticae populations still persisted (20-40 T. urticae/subsample). Releasing P. persimilis into crops in which N. floridana is naturally present has the potential to improve spider mite control more than through predation alone. Copyright © 2016 Elsevier Inc. All rights reserved.

Transformation means and forms of implementation of armed violence in the world today

Directory of Open Access Journals (Sweden)

A. V. Bader

2017-01-01

At present radically changed not only nature, but also the very essence of armed violence. Today is not the purpose of aggression capture national wealth and resources, the enslavement of the people or the occupation of foreign lands, and complete submission of the enemy at will. Along with how the purpose of armed violence did not become physical destruction of the enemy, and it complete submission to his will, in future military conflicts, the use of force may not even apply at all or not be the key. If you can impose its will on the opponent, make him willingly follow your interests, then the war aims can be achieved without the use of weapons.

Synergism in the effect of prior jasmonic acid application on herbivore-induced volatile emission by Lima bean plants: transcription of a monoterpene synthase gene and volatile emission

NARCIS (Netherlands)

Menzel, T.R.; Weldegergis, B.T.; David, A.; Boland, W.; Gols, R.; Loon, van J.J.A.; Dicke, M.

2014-01-01

Jasmonic acid (JA) plays a central role in induced plant defence e.g. by regulating the biosynthesis of herbivore-induced plant volatiles that mediate the attraction of natural enemies of herbivores. Moreover, exogenous application of JA can be used to elicit plant defence responses similar to those

Potential long-term storage of the predatory mite Phytoseiulus persimilis

Science.gov (United States)

Increasing the ability to store mass-reared natural enemies during periods or seasons of low demand is a critical need of the biocontrol industry. We tested the hypothesis that cryoprotectant or carbohydrate molecules can enhance long-term cold storage of a predatory mite Phytoseiulus persimilis At...

Insect-resistant transgenic plants in a multi-trophic context

NARCIS (Netherlands)

Groot, A.T.; Dicke, M.

2002-01-01

So far, genetic engineering of plants in the context of insect pest control has involved insertion of genes that code for toxins, and may be characterized as the incorporation of biopesticides into classical plant breeding. In the context of pesticide usage in pest control, natural enemies of

New record for the invasive Spotted Wing Drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae) in Anillaco, Argentina

Science.gov (United States)

The invasive Spotted Wing Drosophila (SWD), Drosophila suzukii Matsumura, is reported for the first time in La Rioja, Argentina. This represents a major range expansion for this species. The natural enemies of SWD, Leptopilina clavipes and Ganaspis hookeri were also collected with the SWD at the s...

In-transit temperature extremes could have negative effects on ladybird (Coleomegilla maculata) hatch rate

Science.gov (United States)

The shipment of mass-produced natural enemies for augmentative release is a standard procedure used by the biological control industry. Yet there has been insufficient research on the effects of temperature change, experienced during shipment, on the quality of predators as they arrive at release si...

Native grass ground covers in California vineyards provide multiple ecosystem services

Science.gov (United States)

The mechanisms responsible for the success or failure of agricultural diversification are often unknown. Most studies in this area have focused on enhancing the effectiveness of natural enemies, but non-crop plants can also improve pest suppression by changing the host quality of crop plants through...

Emerald Ash Borer (Coleoptera: Buprestidae)

Science.gov (United States)

The emerald ash borer, Agrilus planipennis Fairmaire, is an invasive beetle from Asia that has caused large scale ash (Fraxinus spp.) mortality in North America. This book chapter reviews the taxonomy, biology, life history of this invasive pest and its associated natural enemies in both its native ...

Exotic biological control agents

NARCIS (Netherlands)

Hajek, Ann E.; Hurley, Brett P.; Kenis, Marc; Garnas, Jeffrey R.; Bush, Samantha J.; Wingfield, Michael J.; Lenteren, van Joop C.; Cock, Matthew J.W.

2016-01-01

Biological control is a valuable and effective strategy for controlling arthropod pests and has been used extensively against invasive arthropods. As one approach for control of invasives, exotic natural enemies from the native range of a pest are introduced to areas where control is needed.

EPN Chemical ecology and new techniques for below ground sampling and analyses of volatile semiochemicals

Science.gov (United States)

It is well established that herbivory induced plant volatiles (HIPVs) attract natural enemies of the herbivores. Utilizing this plant response has become a fundamental part of above ground IPM programs. We now know that also roots can release HIPVs and that these compounds attract beneficial organis...

Augmentative biological control of arthropods in Latin America

NARCIS (Netherlands)

Lenteren, van J.C.; Bueno, V.H.P.

2003-01-01

Augmentative forms of biological control, where natural enemies are periodically introduced, are applied over large areas in various cropping systems in Latin America. About 25% of the world area under augmentative control is situated in this region. Well-known examples are the use of species of the

Biological control and sustainable food production

NARCIS (Netherlands)

Bale, J.S.; Lenteren, van J.C.; Bigler, F.

2008-01-01

The use of biological control for the management of pest insects pre-dates the modern pesticide era. The first major successes in biological control occurred with exotic pests controlled by natural enemy species collected from the country or area of origin of the pest (classical control).

Tritrophic interactions in wild and cultivated brassicaceous plant species

NARCIS (Netherlands)

Gols, R.

2008-01-01

Plants have evolved a range of defence traits that prevent or reduce attack by insect herbivores. Direct defence traits hamper or reduce the performance and behaviour of the herbivores, whereas indirect defence promote the efficiency of natural enemies to attack the herbivores. Here, I focused on

The northward shifting neophyte Tragopogon dubius is just as effective in forming mycorrhizal associations as the native T. pratensis.

NARCIS (Netherlands)

van Grunsven, R.; Yuwati, T.; Kowalchuk, George; van der Putten, W.H.; van Veenendaal, E.

2014-01-01

Background: As a consequence of climate warming, many organisms are shifting their range towards higher latitudes and altitudes. As not all do so at the same speed, this may disrupt biotic interaction. Release from natural enemies through range expansion can result in invasiveness, whereas loss of

Birds exploit herbivore-induced plant volatiles to locate herbivorous prey

NARCIS (Netherlands)

Amo, L.; Jansen, J.J.; Dam, van N.M.; Dicke, M.; Visser, M.E.

2013-01-01

Arthropod herbivory induces plant volatiles that can be used by natural enemies of the herbivores to find their prey. This has been studied mainly for arthropods that prey upon or parasitise herbivorous arthropods but rarely for insectivorous birds, one of the main groups of predators of herbivorous

Fitness consequences of indirect plant defence in the annual weed, Sinapis arvensis

NARCIS (Netherlands)

Gols, R.; Wagenaar, R.; Poelman, E.H.; Kruidhof, M.; Loon, van J.J.A.; Harvey, J.A.

2015-01-01

1. Plant traits that enhance the attraction of the natural enemies of their herbivores have been postulated to function as an ‘indirect defence’. An important underlying assumption is that this enhanced attraction results in increased plant fitness due to reduced herbivory. This assumption has been

Changes in plant defense chemistry (pyrrolizidine alkaloids) revealed through high-resolution spectroscopy

NARCIS (Netherlands)

Carvalho, S.; Macel, M.; Schlerf, M.; Eghbali Moghaddam, F.; Mulder, P.P.J.; Skidmore, A.K.; Van der Putten, W.H.

2013-01-01

Plant toxic biochemicals play an important role in defense against natural enemies and often are toxic to humans and livestock. Hyperspectral reflectance is an established method for primary chemical detection and could be further used to determine plant toxicity in the field. In order to make a

Predation of Halyomorpha halys (Hemiptera: Pentatomidae) from web-building spiders associated with anthropogenic dwellings

Science.gov (United States)

The brown marmorated stink bug or Halyomorpha halys is an invasive pest from Asia that causes severe agricultural damage and nuisance problems for homeowners. While the natural enemy community of H. halys has been evaluated in several agroecosystems, it has not been quantified where H. halys overwi...

Extended survival of spiders (Aranaeae) feeding on whitefly (Homoptera: Aleyrodidae) honeydew

Science.gov (United States)

Honeydew produced by homopteran insects such as aphids, whiteflies and mealybugs, can be abundant in some crops and may represent an important food resource for spiders and other honeydew feeding natural enemies. Woolly whiteflies are common in south Texas citrus, and spiders consistently make up a...

Invasive species in east Africa: current status for informed policy ...

African Journals Online (AJOL)

Invasive alien species are the second leading cause of biodiversity loss in the world today. A number of hypotheses have been advanced to explain the proliferation of invasive species. These hypotheses include deficiency of natural enemies in the introduced range, increased competitive ability, increased resource ...

Multisensory foraging by hymenopterous parasitoids

NARCIS (Netherlands)

Waeckers, F.L.

1994-01-01

The use of parasitoids as biological control agents is gaining interest as an environmentally sound alternative to the use of chemical insecticides. In order to extend and optimize biological control systems, it is essential to gain insight in the stimuli and mechanisms by which natural enemies

Evaluation of airborne methyl salicylate for improved conservation biological control of two-spotted spider mites and hop aphid in Oregon hop yards

Science.gov (United States)

The use of synthetic herbivore-induced plant volatiles (HIPV) to attract natural enemies has received interest as a tool to enhance conservation biological control (CBC). Methyl salicylate (MeSA) is a HIPV that is attractive to several key predators of two-spotted spider mite, Tetranychus urticae K...

Preferential Edge Habitat Colonization by a Specialist Weevil, Rhinoncomimus latipes (Coleoptera: Curculionidae)

Science.gov (United States)

Understanding the behavioral basis of dispersal and colonization is critical in biological control systems, where success of a natural enemy depends in part on its ability to find and move to new host patches. We studied behavior of the specialist weevil Rhinoncomimus latipes Korotyaev, a biological...

The Use of GIS Methodology in Jumping Plant Lice (Hemiptera: Psylloidae Studies in Serbia

Directory of Open Access Journals (Sweden)

Dušanka Jerinić-Prodanović

2012-01-01

Full Text Available Entomofaunistic studies contain a large number of data regarding the number ofcollected species, the number of individuals within species, time of collection, localities,species biology and morphology natural enemies and hosts. Besides thematic andtemporal components this kind of studies include spatial component which is crucialfor the use of GIS methodology and advanced possibilities of geospatial analysis. Duringour studies on jumping plant lice (Psylloidea fauna and their natural enemies on theterritory of Serbia which lasted for several years, a large number of spatially referenceddata related to this group of insects were collected. The process of collecting, archivingand classifying the data on each species was improved by applying the GIS methodologicalapproach after which the data were entered into database. The analysis of datausing thematic and spatial queries, as well as graphic, numeric and textual display of theresults from studies enabled simpler and more complete survey of horizontal and verticaldistribution of jumping plant lice, their biology and relationship with plants, predatorsand parasitoids.

Organochlorine insecticides in African agroecosystems. Report of a final research co-ordination meeting

International Nuclear Information System (INIS)

1997-03-01

Adverse effects also appear within the agroecosystem itself. Intensive use of broad spectrum insecticides can reduce populations of insect parasites and predators; as a result, pest populations may be inadequately controlled. This, in turn, can lead to the need of more frequent use of pesticides and to the appearance of secondary pests. We are slowly beginning to understand how natural enemies and the other non-target fauna are affected by pesticide use in a few agroecosystems in the developed countries. The knowledge about these matters in developing countries is very rudimentary. The objectives of this programme were to increase the knowledge of how pesticides affect the agroecosystem especially pest-natural enemy interactions and the non-target fauna within and outside African agroecosystem. Chlorinated hydrocarbon pesticides were used as representing the compounds most likely to produce undesirable consequences. This TECDOC reports the accomplishments of the programme which was financed by the Swedish International Development Authority (SIDA). Refs, figs, tabs

Response of native insect communities to invasive plants.

Science.gov (United States)

Bezemer, T Martijn; Harvey, Jeffrey A; Cronin, James T

2014-01-01

Invasive plants can disrupt a range of trophic interactions in native communities. As a novel resource they can affect the performance of native insect herbivores and their natural enemies such as parasitoids and predators, and this can lead to host shifts of these herbivores and natural enemies. Through the release of volatile compounds, and by changing the chemical complexity of the habitat, invasive plants can also affect the behavior of native insects such as herbivores, parasitoids, and pollinators. Studies that compare insects on related native and invasive plants in invaded habitats show that the abundance of insect herbivores is often lower on invasive plants, but that damage levels are similar. The impact of invasive plants on the population dynamics of resident insect species has been rarely examined, but invasive plants can influence the spatial and temporal dynamics of native insect (meta)populations and communities, ultimately leading to changes at the landscape level.

Extinction and permanence in delayed stage-structure predator-prey system with impulsive effects

International Nuclear Information System (INIS)

Pang Guoping; Wang Fengyan; Chen Lansun

2009-01-01

Based on the classical stage-structured model and Lotka-Volterra predator-prey model, an impulsive delayed differential equation to model the process of periodically releasing natural enemies at fixed times for pest control is proposed and investigated. We show that the conditions for global attractivity of the 'pest-extinction' ('prey-eradication') periodic solution and permanence of the population of the model depend on time delay. We also show that constant maturation time delay and impulsive releasing for the predator can bring great effects on the dynamics of system by numerical analysis. As a result, the pest maturation time delay is considered to establish a procedure to maintain the pests at an acceptably low level in the long term. In this paper, the main feature is that we introduce time delay and pulse into the predator-prey (natural enemy-pest) model with age structure, exhibit a new modelling method which is applied to investigate impulsive delay differential equations, and give some reasonable suggestions for pest management.

Environmental Engineering Approaches toward Sustainable Management of Spider Mites.

Science.gov (United States)

Suzuki, Takeshi

2012-10-26

Integrated pest management (IPM), which combines physical, biological, and chemical control measures to complementary effect, is one of the most important approaches to environmentally friendly sustainable agriculture. To expand IPM, we need to develop new pest control measures, reinforce existing measures, and investigate interactions between measures. Continued progress in the development of environmental control technologies and consequent price drops have facilitated their integration into plant production and pest control. Here I describe environmental control technologies for the IPM of spider mites through: (1) the disturbance of photoperiod-dependent diapause by artificial light, which may lead to death in seasonal environments; (2) the use of ultraviolet radiation to kill or repel mites; and (3) the use of water vapor control for the long-term cold storage of commercially available natural enemies. Such environmental control technologies have great potential for the efficient control of spider mites through direct physical effects and indirect effects via natural enemies.

Asteraceae Pollen Provisions Protect Osmia Mason Bees (Hymenoptera: Megachilidae) from Brood Parasitism.

Science.gov (United States)

Spear, Dakota M; Silverman, Sarah; Forrest, Jessica R K

2016-06-01

Many specialist herbivores eat foods that are apparently low quality. The compensatory benefits of a poor diet may include protection from natural enemies. Several bee lineages specialize on pollen of the plant family Asteraceae, which is known to be a poor-quality food. Here we tested the hypothesis that specialization on Asteraceae pollen protects bees from parasitism. We compared rates of brood parasitism by Sapyga wasps on Asteraceae-specialist, Fabeae-specialist, and other species of Osmia bees in the field over several years and sites and found that Asteraceae-specialist species were parasitized significantly less frequently than other species. We then tested the effect of Asteraceae pollen on parasites by raising Sapyga larvae on three pollen mixtures: Asteraceae, Fabeae, and generalist (a mix of primarily non-Asteraceae pollens). Survival of parasite larvae was significantly reduced on Asteraceae provisions. Our results suggest that specialization on low-quality pollen may evolve because it helps protect bees from natural enemies.

Dynamical System and Nonlinear Regression for Estimate Host-Parasitoid Relationship

Directory of Open Access Journals (Sweden)

Ileana Miranda Cabrera

2010-01-01

Full Text Available The complex relationships of a crop with the pest, its natural enemies, and the climate factors exist in all the ecosystems, but the mathematic models has studied only some components to know the relation cause-effect. The most studied system has been concerned with the relationship pest-natural enemies such as prey-predator or host-parasitoid. The present paper shows a dynamical system for studying the relationship host-parasitoid (Diaphorina citri, Tamarixia radiata and shows that a nonlinear model permits the estimation of the parasite nymphs using nymphs healthy as the known variable. The model showed the functional answer of the parasitoid, in which a point arrives that its density is not augmented although the number host increases, and it becomes necessary to intervene in the ecosystem. A simple algorithm is used to estimate the parasitoids level using the priori relationship between the host and the climate factors and then the nonlinear model.

[Love on enemy territory: Belgrade, Cetinje and Lublin under Austro-Hungarian occupation in World War I].

Science.gov (United States)

Scheer, Tamara

2015-01-01

During World War I, Serbia and Montenegro were under Austro-Hungarian occupation between late 1915/early 1916 and 1918. This article explores the attitude of the occupiers towards prostitution and venereal disease, among the indigenous population as well as among their own soldiers, officers and female support staff. The measures taken were primarily guided by military considerations. For the military, the occupied areas were zones that served particular purposes, such as preserving peace and order behind the front, making use of manpower and resources, and serving as cordon sanitaire. In spite of this, pseudo-peace-like structures evolved in the capitals Belgrade and Cetinje that facilitated the spread of prostitution and venereal disease. In my article, I will look at the scale of the debate and of the proposed countermeasures. It is noticeable that women were usually branded as the perpetrators, while the soldiers were seen as the ones in need of protection. In spite of this, it is apparent how candidly the royal-imperial army dealt with the topic even though it went against the current ideas of morality. The social differentiation that was customary in the imperial and royal army applied here, too. Officers suffering from venereal disease had their own hospitals and brothels and were permitted leave more often (a fact that went against the purpose of these institutions). The topic also received publicity because the military physicians, who were in fact civilians mobilized by the army, chose to publish continuously on the topic. Based on the microcosm of occupied enemy territory, my contribution shows how ideas of morality changed during the war despite traditional gender stereotypes, and the role played by the military in these developments.

The Genetics Underlying Natural Variation in the Biotic Interactions of Arabidopsis thaliana: The Challenges of Linking Evolutionary Genetics and Community Ecology.

Science.gov (United States)

Roux, F; Bergelson, J

2016-01-01

In the context of global change, predicting the responses of plant communities in an ever-changing biotic environment calls for a multipronged approach at the interface of evolutionary genetics and community ecology. However, our understanding of the genetic basis of natural variation involved in mediating biotic interactions, and associated adaptive dynamics of focal plants in their natural communities, is still in its infancy. Here, we review the genetic and molecular bases of natural variation in the response to biotic interactions (viruses, bacteria, fungi, oomycetes, herbivores, and plants) in the model plant Arabidopsis thaliana as well as the adaptive value of these bases. Among the 60 identified genes are a number that encode nucleotide-binding site leucine-rich repeat (NBS-LRR)-type proteins, consistent with early examples of plant defense genes. However, recent studies have revealed an extensive diversity in the molecular mechanisms of defense. Many types of genetic variants associate with phenotypic variation in biotic interactions, even among the genes of large effect that tend to be identified. In general, we found that (i) balancing selection rather than directional selection explains the observed patterns of genetic diversity within A. thaliana and (ii) the cost/benefit tradeoffs of adaptive alleles can be strongly dependent on both genomic and environmental contexts. Finally, because A. thaliana rarely interacts with only one biotic partner in nature, we highlight the benefit of exploring diffuse biotic interactions rather than tightly associated host-enemy pairs. This challenge would help to improve our understanding of coevolutionary quantitative genetics within the context of realistic community complexity. © 2016 Elsevier Inc. All rights reserved.

Predicting the potential establishment of two insect species using the simulation environment INSIM (INsect SIMulation)

NARCIS (Netherlands)

Hemerik, Lia; Nes, van Egbert H.

2016-01-01

Degree-day models have long been used to predict events in the life cycle of insects and therewith the timing of outbreaks of insect pests and their natural enemies. This approach assumes, however, that the effect of temperature is linear, whereas developmental rates of insects are non-linearly

Alternative food promotes broad mite control on chilli pepper plants

NARCIS (Netherlands)

Duarte, M.V.A.; Venzon, M.; de S. Bittencourt, M.C.; Rodríguez-Cruz, F.A.; Pallini, A.; Janssen, A.

2015-01-01

Many omnivorous arthropods are important natural enemies because they can feed on plant-provided pollen and several prey species, and thus persist in crops even in the absence of the target pest. Hence, populations of these predators can be established in a crop by providing alternative food, thus

Investigating Biological Controls to Suppress Spotted Wing Drosophila Populations

Science.gov (United States)

The spotted wing drosophila has become a major cherry pest in California. To develop sustainable management options for this highly mobile pest, we worked with cooperators at Oregon State University and the USDA to discover and import natural enemies of the fly from its native range in South Korea ...

Pupation behavior and larval and pupal biocontrol of Drosophila suzukii in the field

Science.gov (United States)

Drosophila suzukii is a worldwide pest of fruit crops. Biological control may play an important role in D. suzukii IPM, and suppressing populations in unmanaged areas. While predation has been observed in the field, nothing is known about the potential for natural enemies to reduce D. suzukii popula...

Jasmonate-deficient plants have reduced direct and indirect defences against herbivores

NARCIS (Netherlands)

Thaler, J.S.; Farag, M.A.; Paré, P.W.; Dicke, M.

2002-01-01

Plants employ a variety of defence mechanisms, some of which act directly by having a negative effect on herbivores and others that act indirectly by attracting natural enemies of herbivores. In this study we asked if a common jasmonate-signalling pathway links the regulation of direct and indirect

Big-Eyed Bugs Have Big Appetite for Pests

Science.gov (United States)

Many kinds of arthropod natural enemies (predators and parasitoids) inhabit crop fields in Arizona and can have a large negative impact on several pest insect species that also infest these crops. Geocoris spp., commonly known as big-eyed bugs, are among the most abundant insect predators in field c...

Direct and indirect chemical defence of pine against folivorous insects

NARCIS (Netherlands)

Mumm, R.; Hilker, M.

2006-01-01

The chemical defence of pine against herbivorous insects has been intensively studied with respect to its effects on the performance and behaviour of the herbivores as well as on the natural enemies of pine herbivores. The huge variety of terpenoid pine components play a major role in mediating

Errors in logic and statistics plague a meta-analysis

Science.gov (United States)

The non-target effects of transgenic insecticidal crops has been a topic of debate for over a decade and many laboratory and field studies have addressed the issue in numerous countries. In 2009 Lovei et al. (Transgenic Insecticidal Crops and Natural Enemies: A Detailed Review of Laboratory Studies)...

Efficacy of bio and synthetic pesticides against the American ...

African Journals Online (AJOL)

Management for the bollworm complex in Uganda is largely synthetic chemical use with little or no biopesticide use which reduces natural enemies population and resistance development to continuous use of a single synthetic pesticide product. Therefore this study aimed at determining the efficacy of bio and synthetic ...

Presence of the fire ant Solenopsis invicta (Westwood) (Hymenoptera: Formicidae) stimulates burrowiong behavior by larvae of the sandfly Lutzomyia longipalpis (Lutz & Neiva)(Diptera: Psychodidae)

NARCIS (Netherlands)

Harvey, J.A.; Hamilton, J.G.C.; Ward, R.D.

2010-01-01

The sandfly Lutzomyia longipalpis (Lutz & Neiva) vectors leishmaniasis in the neotropics. Although much is known about the biology of adult flies, little is known about interactions with its natural enemies. Here, we examined behavior of larvae of L4 L.longipalpis on a soil substrate when exposed to

Effects of symbiotic bacteria and tree chemistry on the growth and reproduction of bark beetle fungal symbionts

Science.gov (United States)

A.S. Adams; C.R. Currie; Y. Cardoza; K.D. Klepzig; K.F. Raffa

2009-01-01

Bark beetles are associated with diverse assemblages of microorganisms, many of which affect their interactions with host plants and natural enemies. We tested how bacterial associates of three bark beetles with various types of host relationships affect growth and reproduction of their symbiotic fungi. Fungi were exposed to volatiles...

Untangling the web...spiders in Arizona fields

Science.gov (United States)

Many kinds of arthropod natural enemies (predators and parasitoids) inhabit crop fields in Arizona and can have a large negative impact on several pest insect species that also infest these crops. Many different species of spiders are common in cotton, alfalfa and other crops in Arizona. Among the ...

Predicting the time to colonization of the parasitoid Diadegma semiclausum: the importance of the shape of spatial dispersal kernels for biological control

NARCIS (Netherlands)

Bianchi, F.J.J.A.; Schellhorn, N.A.; Werf, van der W.

2009-01-01

The time at which natural enemies colonize crop fields is an important determinant of their ability to suppress pest populations. This timing depends on the distance between source and sink habitats in the landscape. Here we estimate the time to colonization of sink habitats from a distant source

Seasonal variation in the populations of Polyphagotarsonemus latus and Tetranychus bastosi in physic nut (Jatropha curcas) plantations.

Science.gov (United States)

Rosado, Jander F; Picanço, Marcelo C; Sarmento, Renato A; da Silva, Ricardo Siqueira; Pedro-Neto, Marçal; Carvalho, Marcos Alberto; Erasmo, Eduardo A L; Silva, Laila Cristina Rezende

2015-07-01

Studies on the seasonal variation of agricultural pest species are important for the establishment of integrated pest control programs. The seasonality of pest attacks on crops is affected by biotic and abiotic factors, for example, climate and natural enemies. Besides that, characteristics of the host plant, crop management, location and the pests' bioecology also affect this seasonality. The mites Polyphagotarsonemus latus (Prostigmata: Tarsonemidae) and Tetranychus bastosi (Prostigmata: Tetranychidae) are the most important pests in the cultivation of physic nut, Jatropha curcas (Euphorbiaceae). All parts of J. curcas can be used for a wide range of purposes. In addition many researchers have studied its potential for use as neat oil, as transesterified oil (biodiesel), or as a blend with diesel. However studies about physic nut pests have been little known. The objective of this study was to assess the seasonal variation of P. latus and T. bastosi in physic nut. This study was conducted at three sites in the state of Tocantins, Brazil. We monitored climatic elements and the densities of the two mite species and of their natural enemies for a period of 2 years. Attack by P. latus occurred during rainy seasons, when the photoperiod was short and the physic nut had new leaves. In contrast, attack by T. bastosi occurred during warmer seasons with longer photoperiods and stronger winds. Populations of both mites and their natural enemies were greater in sites with greater plant diversity adjacent to the plantations. The predators found in association with P. latus and T. bastosi were Euseius concordis (Acari: Phytoseiidae), spiders, Stethorus sp. (Coleoptera: Coccinellidae) and Chrysoperla sp. (Neuroptera: Chrysopidae).

Response of predatory mites to a herbivore-induced plant volatile: genetic variation for context-dependent behaviour.

Science.gov (United States)

Sznajder, Beata; Sabelis, Maurice W; Egas, Martijn

2010-07-01

Plants infested with herbivores release specific volatile compounds that are known to recruit natural enemies. The response of natural enemies to these volatiles may be either learned or genetically determined. We asked whether there is genetic variation in the response of the predatory mite Phytoseiulus persimilis to methyl salicylate (MeSa). MeSa is a volatile compound consistently produced by plants being attacked by the two-spotted spider mite, the prey of P. persimilis. We predicted that predators express genetically determined responses during long-distance migration where previously learned associations may have less value. Additionally, we asked whether these responses depend on odors from uninfested plants as a background to MeSa. To infer a genetic basis, we analyzed the variation in response to MeSa among iso-female lines of P. persimilis by using choice-tests that involved either (1) MeSa presented as a single compound or (2) MeSa with background-odor from uninfested lima bean plants. These tests were conducted for starved and satiated predators, i.e., two physiological states, one that approximates migration and another that mimics local patch exploration. We found variation among iso-female lines in the responses to MeSa, thus showing genetic variation for this behavior. The variation was more pronounced in the starved predators, thus indicating that P. persimilis relies on innate preferences when migrating. Background volatiles of uninfested plants changed the predators' responses to MeSa in a manner that depended on physiological state and iso-female line. Thus, it is possible to select for context-dependent behavioral responses of natural enemies to plant volatiles.

EVALUATION OF FOUR INTEGRATED PEST MANAGEMENT PACKAGES FOR CONTROLLING MAIN PESTS OF COTTON IN RAINFED FIELDS

Directory of Open Access Journals (Sweden)

Nurindah Nurindah

2014-04-01

Full Text Available Cotton production nationally is low due to various constraints, including pests. Two main pests commonly found in cotton plantation in rain fed fields are cotton leafhopper (Amrasca biguttula and cotton bollworm (Helicoverpa armigera. The study aimed to evaluate four packages of integrated pest management (IPM techniques to control cotton leafhopper and cotton bollworm in rain fed fields. The experiment was conducted in farmers’ fields at Asembagus, East Java, between January and July 2012. Four packages of IPM evaluated were cotton varieties, i.e. Kanesia 10 or Kanesia 13, and seed treatment with synthetic insecticide (imidacloprid before sowing or spraying molasses (10 ml L-1 water as food for natural enemies. The cotton plants were intercropped with groundnut and sprayed with neem seed extract (NSE at the action threshold level for pest control. These packages were compared among themselves and also with the methods usually used by farmers, i.e. planting cotton variety Kanesia 8 intercropped with groundnut and pest control using synthetic chemical insecticides. Twenty five plants were sampled randomly per plot and measured for their growth, leafhopper and  bollworm populations, as well as cotton seed yield per plot. Observations were made weekly, starting at 30 days after planting (DAP until 120 DAP. The results showed that the use of Kanesia 10 or Kanesia 13 intercropped with groundnut and spraying molasses to conserve natural enemies was the best  pest management practice and superior to farmers’ practices. Conserving natural enemies is not only profitable (saving production cost of IDR1,150,000 to IDR1,500,000 ha-1 season-1, but also safe for the environment (no need to spray chemical insecticides.

Influence of Mortality Factors and Host Resistance on the Population Dynamics of Emerald Ash Borer (Coleoptera: Buprestidae) in Urban Forests.

Science.gov (United States)

Macquarrie, Chris J K; Scharbach, Roger

2015-02-01

The success of emerald ash borer (Agrilus planipennis Fairmaire) in North America is hypothesized to be due to both the lack of significant natural enemies permitting easy establishment and a population of trees that lack the ability to defend themselves, which allows populations to grow unchecked. Since its discovery in 2002, a number of studies have examined mortality factors of the insect in forests, but none have examined the role of natural enemies and other mortality agents in the urban forest. This is significant because it is in the urban forest where the emerald ash borer has had the most significant economic impacts. We studied populations in urban forests in three municipalities in Ontario, Canada, between 2010 and 2012 using life tables and stage-specific survivorship to analyze data from a split-rearing manipulative experiment. We found that there was little overall mortality caused by natural enemies; most mortality we did observe was caused by disease. Stage-specific survivorship was lowest in small and large larvae, supporting previous observations of high mortality in these two stages. We also used our data to test the hypothesis that mortality and density in emerald ash borer are linked. Our results support the prediction of a negative relationship between mortality and density. However, the relationship varies between insects developing in the crown and those in the trunk of the tree. This relationship was significant because when incorporated with previous findings, it suggests a mechanism and hypothesis to explain the outbreak dynamics of the emerald ash borer. © The Author 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

No correlation between the diversity and productivity of assemblages: evidence from the phytophage and predator assemblages in various cotton agroecosystems.

Science.gov (United States)

Gao, Feng; Men, XingYuan; Ge, Feng

2014-09-01

Biodiversity research has shown that primary productivity increases with plant species number, especially in many experimental grassland systems. Here, we assessed the correlation between productivity and diversity of phytophages and natural enemy assemblages associated with planting date and intercropping in four cotton agroecosystems. Twenty-one pairs of data were used to determine Pearson correlations between species richness, total number of individuals, diversity indices and productivity for each assemblage every five days from 5 June to 15 September 2012. At the same trophic level, the productivity exhibited a significant positive correlation with species richness of the phytophage or predator assemblage. A significant correlation was found between productivity and total number of individuals in most cotton fields. However, no significant correlations were observed between productivity and diversity indices (including indices of energy flow diversity and numerical diversity) in most cotton fields for either the phytophage or the predator assemblages. Species richness of phytophage assemblage and total individual numbers were significantly correlated with primary productivity. Also, species richness of natural enemy assemblage and total number of individuals correlated with phytophage assemblage productivity. A negative but not significant correlation occurred between the indices of numerical diversity and energy flow diversity and lower trophic-level productivity in the cotton-phytophage and phytophage-predator assemblages for most intercropped cotton agroecosystems. Our results clearly showed that there were no correlations between diversity indices and productivity within the same or lower trophic levels within the phytophage and predator assemblages in cotton agroecosystems, and inter-cropped cotton fields had a stronger ability to support the natural enemy assemblage and potentially to reduce phytophages.

Duality in Phase Space and Complex Dynamics of an Integrated Pest Management Network Model

Science.gov (United States)

Yuan, Baoyin; Tang, Sanyi; Cheke, Robert A.

Fragmented habitat patches between which plants and animals can disperse can be modeled as networks with varying degrees of connectivity. A predator-prey model with network structures is proposed for integrated pest management (IPM) with impulsive control actions. The model was analyzed using numerical methods to investigate how factors such as the impulsive period, the releasing constant of natural enemies and the mode of connections between the patches affect pest outbreak patterns and the success or failure of pest control. The concept of the cluster as defined by Holland and Hastings is used to describe variations in results ranging from global synchrony when all patches have identical fluctuations to n-cluster solutions with all patches having different dynamics. Heterogeneity in the initial densities of either pest or natural enemy generally resulted in a variety of cluster oscillations. Surprisingly, if n > 1, the clusters fall into two groups one with low amplitude fluctuations and the other with high amplitude fluctuations (i.e. duality in phase space), implying that control actions radically alter the system's characteristics by inducing duality and more complex dynamics. When the impulsive period is small enough, i.e. the control strategy is undertaken frequently, the pest can be eradicated. As the period increases, the pest's dynamics shift from a steady state to become chaotic with periodic windows and more multicluster oscillations arise for heterogenous initial density distributions. Period-doubling bifurcation and periodic halving cascades occur as the releasing constant of the natural enemy increases. For the same ecological system with five differently connected networks, as the randomness of the connectedness increases, the transient duration becomes smaller and the probability of multicluster oscillations appearing becomes higher.

Uptake and bioaccumulation of Cry toxins by an aphidophagous predator

International Nuclear Information System (INIS)

Paula, Débora P.; Andow, David A.

2016-01-01

Uptake of Cry toxins by insect natural enemies has rarely been considered and bioaccumulation has not yet been demonstrated. Uptake can be demonstrated by the continued presence of Cry toxin after exposure has stopped and gut contents eliminated. Bioaccumulation can be demonstrated by showing uptake and that the concentration of Cry toxin in the natural enemy exceeds that in its food. We exposed larvae of the aphidophagous predator, Harmonia axyridis, to Cry1Ac and Cry1F through uniform and constant tritrophic exposure via an aphid, Myzus persicae, and looked for toxin presence in the pupae. We repeated the experiment using only Cry1F and tested newly emerged adults. Both Cry toxins were detected in pupae, and Cry1F was detected in recently emerged, unfed adults. Cry1Ac was present 2.05 times and Cry1F 3.09 times higher in predator pupae than in the aphid prey. Uptake and bioaccumulation in the third trophic level might increase the persistence of Cry toxins in the food web and mediate new exposure routes to natural enemies. - Highlights: • Uptake and bioaccumulation of two Cry toxins by a larval coccinellid was tested. • Uptake was demonstrated by presence of the toxins in pupae and adults. • Bioaccumulation was shown by higher toxin concentration in pupae than prey. • Cry1Ac was present 2.05× and Cry1F 3.09× higher in predator pupae than prey. • This might increase persistence of Cry toxins in food webs with new exposure routes. - Immatures of the predaceous coccinellid Harmonia axyridis can uptake and bioaccumulate Cry toxins delivered via their aphid prey.

Use of nuclear techniques in biological control

International Nuclear Information System (INIS)

Greany, Patrick D.; Carpenter, James E.

2000-01-01

As pointed out by Benbrook (1996), pest management is at a crossroads, and there is a great need for new, biointensive pest management strategies. Among these approaches, biological control is a keystone. However, because of increasing concerns about the introduction of exotic natural enemies of insect pests and weeds (Howarth 1991, Delfosse 1997), the overall thrust of biological control has moved toward augmentative biological control, involving releases of established natural enemy species (Knipling 1992). This in turn has created a need to develop more cost-effective mass rearing technologies for beneficial insects. Nuclear techniques could play an especially important role in augmentative biological control, not only in facilitating mass rearing, but in several other ways, as indicated below. Recognising the potential value for use of nuclear techniques in biological control, the Insect and Pest Control Section of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, sponsored a Consultants' Group Meeting on this subject in April 1997. The Group produced a document entitled Use of Nuclear Techniques in Biological Control: Managing Pests, Facilitating Trade and Protecting the Environment. The consultants included the authors of this paper as well as Ernest Delfosse (at that time, with the USDA-APHIS National Biological Control Institute), Garry Hill (Intl. Institute for Biological Control), Sinthya Penn (Beneficial Insectary), and Felipe Jeronimo (USDA-APHIS PPQ, Guatemala). The remarks presented in this paper reflect the thoughts presented by these consultants and other participants at the IAEA-sponsored meeting. Several potential uses for nuclear techniques were identified by the Consultants' Group, including: 1) improvements in rearing media (either artificial diets or natural hosts/prey), 2) provision of sterilised natural prey to be used as food during shipment, to ameliorate concerns relating to the

Selective effects of natural and synthetic insecticides on mortality of Spodoptera frugiperda (Lepidoptera: Noctuidae) and its predator Eriopis connexa (Coleoptera: Coccinellidae).

Science.gov (United States)

Tavares, Wagner S; Costa, Mariana A; Cruz, Ivan; Silveira, Rodrigo D; Serrao, Jose E; Zanuncio, Jose C

2010-08-01

Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) is a serious pest of corn in several American countries. It is mainly controlled with synthetic insecticides. The objectives of this study were to evaluate the effects of the natural products, neem oil and pyroligneous extract, and the synthetic insecticide, lufenuron, at 2.50 mL water (0.25%) on the mortality of 2-, 4- and 6-day-old caterpillars of S. frugiperda, and their selectivities against fourth instar larvae of Eriopis connnexa Germar (Coleoptera: Coccinellidae). Four- and 6-day-old S. frugiperda caterpillars showed higher mortality after exposure to neem oil (83.33 +/- 0.83 and 89.58 +/- 0.90%, respectively) and lufenuron (95.83 +/- 0.96 and 85.41 +/- 0.83%), compared to pyroligneous extract (68.75 +/- 0.69 and 31.25 +/- 0.31%). The deleterious effect of pyroligneous extract was higher in 2- (83.33 +/- 0.83% mortality) and 4-day-old (68.75 +/- 0.69%) S. frugiperda caterpillars than in 6-day-old caterpillars (31.25 +/- 0.31%). Larval mortality of the predator E. connexa was lower with neem oil and pyroligneous extract (25.00 +/- 0.33%) than with lufenuron (91.66 +/- 1.22%). Neem oil is thus recommended for control of S. frugiperda because of its high toxicity, combined with its relatively low toxicity to larvae of the natural enemy E. connexa.

Evaluation naturelle de l'impact de Beauveria bassiana ...

African Journals Online (AJOL)

A study of finding out natural enemies of the coffee cherry borer beetle Coffea canephora, Hypothenemus hampei (Ferrari) (Coleoptera, Scolytidae) was carried out at two ecologically different sites of Cameroon: Nkoemvone in the South region of the country and Nkolbisson around Yaoundé in the central region. For six ...

Characterizing Specimens of Kudzu and Related Taxa with RAPD's

Science.gov (United States)

D.K. Jewett; C.J. Jiang; K.O. Britton; J.H. Sun; J. Tang

2003-01-01

Kudzu [Pueraria montana (Lour.) Merr. var. lobata (Willd.) Maesen and Almeidal is a perennial, semi-woody, climbing legume in the tribe Phaseoleae Benth., subtribe Glycininae Benth. (Maesen 1985, Maesen and Almeida 1988, Ward 1998). It is native to China, where an abundance of natural enemies (Pemberton 1988) and its cultivation...

Resistance: a threat to the insecticidal crystal proteins of Bacillus thuringiensis

Science.gov (United States)

Leah S. Bauer

1995-01-01

Insecticidal crystal proteins (also known as d-endotoxins) synthesized by the bacterium Bacillus thuringiensis Berliner (Bt) are the active ingredient of various environmentally friendly insecticides that are 1) highly compatible with natural enemies and other nontarget organisms due to narrow host specificity, 2) harmless to vertebrates, 3) biodegradable in the...

Status of biological control in vegetation management in forestry

Science.gov (United States)

George P. Markin; Donald E. Gardner

1993-01-01

Biological control traditionally depends upon importing the natural enemies of introduced weeds. Since vegetation management in forestry has primarily been aimed at protecting economic species of trees from competition from other native plants, biological control has been of little use in forestry. An alternative approach to controlling unwanted native plants,...

Discipline with Dignity: Oakland Classrooms Try Healing Instead of Punishment

Science.gov (United States)

Davis, Fania

2014-01-01

Nelson Mandela's adage, "I destroy my enemies when I make them my friends" captures the profoundly inclusive nature of restorative justice (RJ). The hallmark of RJ is intentionally bringing together people with seemingly diametrically opposed viewpoints--particularly people who have harmed with people who have been harmed--in a carefully…

Optimizing biocontrol using phenological day degree models: the European earwig in pipfruit orchards

NARCIS (Netherlands)

Moerkens, R.; Gobin, B.; Peusens, G.; Helsen, H.H.M.

2011-01-01

1 Phenological day degree models are often used as warning systems for the emergence of arthropod pests in agricultural crops or the occurrence of natural enemies of the pest species. In the present study, we report on a case study of the European earwig Forficula auricularia L., which is an

Influence of predators and parisitoids on bark beetle productivity

Science.gov (United States)

Jan Weslien

1991-01-01

In an earlier field experiment, natural enemies of the bark beetle, Ips typographus (L) were estimated to have reduced bark beetle productivity by more than 80 percent. To test this hypothesis, spruce logs (Picea abies) were placed in the forest in the spring, prior to commencement of flight by I. typographus....

Ecosystem services in the face of invasion: the persistence of native and nonnative spiders in an agricultural landscape.

Science.gov (United States)

Hogg, Brian N; Daane, Kent M

2011-03-01

The presence of intact natural ecosystems in agricultural landscapes can mitigate losses in the diversity of natural enemies and enhance ecosystem services. However, native natural enemies may fail to persist in agroecosystems if invaders dominate species interactions. In this study, native and nonnative spiders were sampled along transects that extended from oak woodland and riparian zones into surrounding California vineyards, to assess the role of natural habitat as a source for spider biodiversity in the vineyard landscape, and to compare the dominance of exotic Cheiracanthium spiders between habitats. Many spider species were more abundant in natural habitat than in vineyards, and numbers of spiders and spider species within vineyards were higher at the vineyard edge adjacent to oak woodland. These results suggest that natural habitat is a key source for spiders in vineyards. The positive effect of oak woodland on the vineyard spider community extended only to the vineyard edge, however. Proportions of Cheiracanthium spiders increased dramatically in the vineyard, while numbers of native wandering spiders (the native ecological homologues of Cheiracanthium spiders) decreased. Dispersal limitation and strong habitat preferences may have prevented native wandering spiders from establishing far from the vineyard edge. Exotic Cheiracanthium spiders, in contrast, may possess specific adaptations to vineyards or to a wide range of habitats. Results suggest that the ecosystem services provided by intact natural habitat may be limited in agricultural landscapes that are dominated by invasive species.

Management of Mango Hopper, Idioscopus clypealis, Using Chemical Insecticides and Neem Oil

Directory of Open Access Journals (Sweden)

S. M. Adnan

2014-01-01

Full Text Available An experiment was conducted in Field Laboratory, Department of Entomology at Bangladesh Agricultural University, Mymensingh, during 2013 to manage the mango hopper, Idioscopus clypealis L, using three chemical insecticides, Imidacloprid (0.3%, Endosulfan (0.5%, and Cypermethrin (0.4%, and natural Neem oil (3% with three replications of each. All the treatments were significantly effective in managing mango hopper in comparison to the control. Imidacloprid showed the highest efficacy in percentage of reduction of hopper population (92.50 ± 9.02 at 72 hours after treatment in case of 2nd spray. It also showed the highest overall percentage of reduction (88.59 ± 8.64 of hopper population and less toxicity to natural enemies including green ant, spider, and lacewing of mango hopper. In case of biopesticide, azadirachtin based Neem oil was found effective against mango hopper as 48.35, 60.15, and 56.54% reduction after 24, 72, and 168 hours of spraying, respectively, which was comparable with Cypermethrin as there was no statistically significant difference after 168 hours of spray. Natural enemies were also higher after 1st and 2nd spray in case of Neem oil.

Management of mango hopper, Idioscopus clypealis, using chemical insecticides and Neem oil.

Science.gov (United States)

Adnan, S M; Uddin, M M; Alam, M J; Islam, M S; Kashem, M A; Rafii, M Y; Latif, M A

2014-01-01

An experiment was conducted in Field Laboratory, Department of Entomology at Bangladesh Agricultural University, Mymensingh, during 2013 to manage the mango hopper, Idioscopus clypealis L, using three chemical insecticides, Imidacloprid (0.3%), Endosulfan (0.5%), and Cypermethrin (0.4%), and natural Neem oil (3%) with three replications of each. All the treatments were significantly effective in managing mango hopper in comparison to the control. Imidacloprid showed the highest efficacy in percentage of reduction of hopper population (92.50 ± 9.02) at 72 hours after treatment in case of 2nd spray. It also showed the highest overall percentage of reduction (88.59 ± 8.64) of hopper population and less toxicity to natural enemies including green ant, spider, and lacewing of mango hopper. In case of biopesticide, azadirachtin based Neem oil was found effective against mango hopper as 48.35, 60.15, and 56.54% reduction after 24, 72, and 168 hours of spraying, respectively, which was comparable with Cypermethrin as there was no statistically significant difference after 168 hours of spray. Natural enemies were also higher after 1st and 2nd spray in case of Neem oil.

Management of Mango Hopper, Idioscopus clypealis, Using Chemical Insecticides and Neem Oil

Science.gov (United States)

Adnan, S. M.; Uddin, M. M.; Alam, M. J.; Islam, M. S.; Kashem, M. A.; Rafii, M. Y.; Latif, M. A.

2014-01-01

An experiment was conducted in Field Laboratory, Department of Entomology at Bangladesh Agricultural University, Mymensingh, during 2013 to manage the mango hopper, Idioscopus clypealis L, using three chemical insecticides, Imidacloprid (0.3%), Endosulfan (0.5%), and Cypermethrin (0.4%), and natural Neem oil (3%) with three replications of each. All the treatments were significantly effective in managing mango hopper in comparison to the control. Imidacloprid showed the highest efficacy in percentage of reduction of hopper population (92.50 ± 9.02) at 72 hours after treatment in case of 2nd spray. It also showed the highest overall percentage of reduction (88.59 ± 8.64) of hopper population and less toxicity to natural enemies including green ant, spider, and lacewing of mango hopper. In case of biopesticide, azadirachtin based Neem oil was found effective against mango hopper as 48.35, 60.15, and 56.54% reduction after 24, 72, and 168 hours of spraying, respectively, which was comparable with Cypermethrin as there was no statistically significant difference after 168 hours of spray. Natural enemies were also higher after 1st and 2nd spray in case of Neem oil. PMID:25140344

Radiation technique for the destruction of plutella

International Nuclear Information System (INIS)

1980-01-01

Plutella can be destroyed by cultivation technique where cabbage is grown interchangebly with other plants, biological technique where the natural enemy of plutella is used, and chemical technique where insecticide is used. Those method do not better results than the sterile male technique which can be either nuclear or chemical in nature. Laboratory, semifield research, and research in a limited field have been carried out when applying the sterile male technique. (SMN)

Assessing the status of biological control as a management tool for suppression of invasive alien plants in South Africa

OpenAIRE

Zachariades, Costas; Paterson, Iain D.; Strathie, Lorraine W.; Hill, Martin P.; van Wilgen, Brian W.

2017-01-01

Background: Biological control of invasive alien plants (IAPs) using introduced natural enemies contributes significantly to sustained, cost-effective management of natural resources in South Africa. The status of, and prospects for, biological control is therefore integral to National Status Reports (NSRs) on Biological Invasions, the first of which is due in 2017. Objectives: Our aim was to evaluate the status of, and prospects for, biological control of IAPs in South Africa. We discuss...

Invasive alien species under attack: natural enemies of Harmonia axyridis in the Netherlands

NARCIS (Netherlands)

Raak-van den Berg, C.L.; Wielink, van P.; Jong, de P.W.; Gort, G.; Haelewaters, D.; Helder, J.; Lenteren, van J.C.

2014-01-01

The aphid predator Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is an invasive alien species in Europe and North America with negative effects on non-target species (including a decline of native ladybird populations), as well as fruit production, and human health. It is, therefore,

Responses to ammonium and nitrate additions by boreal plants and their natural enemies

Energy Technology Data Exchange (ETDEWEB)

Nordin, Annika [Umeaa Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83 Umeaa (Sweden)]. E-mail: annika.nordin@genfys.slu.se; Strengbom, Joachim [Department of Ecology and Environmental Sciences, Umeaa University, SE-901 87 Umeaa (Sweden)]. E-mail: joachim.strengbom@ebc.uu.se; Ericson, Lars [Department of Ecology and Environmental Sciences, Umeaa University, SE-901 87 Umeaa (Sweden)]. E-mail: lars.ericson@eg.umu.se

2006-05-15

Separate effects of ammonium (NH{sub 4} {sup +}) and nitrate (NO{sub 3} {sup -}) on boreal forest understorey vegetation were investigated in an experiment where 12.5 and 50.0 kg nitrogen (N) ha{sup -1} year{sup -1} was added to 2 m{sup 2} sized plots during 4 years. The dwarf-shrubs dominating the plant community, Vaccinium myrtillus and V. vitis-idaea, took up little of the added N independent of the chemical form, and their growth did not respond to the N treatments. The grass Deschampsia flexuosa increased from the N additions and most so in response to NO{sub 3} {sup -}. Bryophytes took up predominately NH{sub 4} {sup +} and there was a negative correlation between moss N concentration and abundance. Plant pathogenic fungi increased from the N additions, but showed no differences in response to the two N forms. Because the relative contribution of NH{sub 4} {sup +} and NO{sub 3} {sup -} to the total N deposition on a regional scale can vary substantially, the N load a habitat can sustain without substantial changes in the biota should be set considering specific vegetation responses to the predominant N form in deposition. - Biota will respond to nitrogen deposition depending on the form of nitrogen.

Enhancement of foreign collection and quarantine evaluation of hemlock woolly adelgid natural enemies

Science.gov (United States)

Mike Montgomery; Roy Van Driesche; Scott Salom; Wenhua Lu; Guoyue Yu; Jianhua Zhou; Li Li; Shigehiko Shiyake

2007-01-01

The objectives of this newly funded Forest Service activity are to promote the biological control of hemlock woolly adelgid (Adelges tsugae Annand) by (1) hiring an entomologist to work in Asia; (2) revisit known collecting sites and find promising new ones; (3) study the life history and phenology of HWA and its predators; (4) establish protocols...

Qualitative Research and the Radical Right: Cats and Dogs and Other Natural Enemies.

Science.gov (United States)

Lincoln, Yvonna S.; Cannella, Gaile S.

This investigation was conducted to explore contemporary critiques that challenge the growing body of scholarly research that would reveal and support diverse understandings of the world. Principal methods for this deconstruction of contemporary critiques include document analysis of writing that examines content and author location and context…

Responses to ammonium and nitrate additions by boreal plants and their natural enemies

International Nuclear Information System (INIS)

Nordin, Annika; Strengbom, Joachim; Ericson, Lars

2006-01-01

Separate effects of ammonium (NH 4 + ) and nitrate (NO 3 - ) on boreal forest understorey vegetation were investigated in an experiment where 12.5 and 50.0 kg nitrogen (N) ha -1 year -1 was added to 2 m 2 sized plots during 4 years. The dwarf-shrubs dominating the plant community, Vaccinium myrtillus and V. vitis-idaea, took up little of the added N independent of the chemical form, and their growth did not respond to the N treatments. The grass Deschampsia flexuosa increased from the N additions and most so in response to NO 3 - . Bryophytes took up predominately NH 4 + and there was a negative correlation between moss N concentration and abundance. Plant pathogenic fungi increased from the N additions, but showed no differences in response to the two N forms. Because the relative contribution of NH 4 + and NO 3 - to the total N deposition on a regional scale can vary substantially, the N load a habitat can sustain without substantial changes in the biota should be set considering specific vegetation responses to the predominant N form in deposition. - Biota will respond to nitrogen deposition depending on the form of nitrogen

Preferential edge habitat colonization by a specialist weevil, Rhinoncomimus latipes (Coleoptera: Curculionidae)

Science.gov (United States)

J.A. Hough-Goldstein; E. Lake; V. D' Amico; S.H. Berg

2012-01-01

Understanding the behavioral basis of dispersal and colonization is critical in biological control systems, where success of a natural enemy depends in part on its ability to find and move to new host patches. We studied behavior of the specialist weevil Rhinoncomimus latipes Korotyaev, a biological control agent of mile-a-minute weed, ...

Understanding Federal regulations as guidelines for classical biological control programs

Science.gov (United States)

Michael E. Montgomery

2011-01-01

This chapter reviews the legislation and rules that provide the foundation for federal regulation of the introduction of natural enemies of insects as biological control agents. It also outlines the steps for complying with regulatory requirements, using biological control of Adelges tsugae Annand, the hemlock woolly adelgid (HWA), as an example. The...

Population genetics and biological control of goldspotted oak borer, an invasive pest of California oaks

Science.gov (United States)

Vanessa Lopez; Paul F. Rugman-Jones; Tom W. Coleman; Richard Stouthamer; Mark Hoddle

2015-01-01

California’s oak woodlands are threatened by the recent introduction of goldspotted oak borer (Agrilus auroguttatus). This invasive wood-borer is indigenous to mountain ranges in southern Arizona where its low population densities may be due to the presence of co-evolved, host-specific natural enemies. Reuniting A. auroguttatus...

Future directions in EAB-affected forests

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Deborah G. McCullough; Roy Van Driesche; Therese M. Poland

2015-01-01

The ability of natural enemies to slow emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), population growth in a given area will play a major role in determining whether many native ash species can persist as functional components of forest ecosystems. Population growth of EAB, like that of any other organism, is...

The Role of Biocontrol of Emerald Ash Borer in Protecting Ash Regeneration after Invasion

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Emerald ash borer (EAB) is an invasive Asian beetle that is destroying ash in forests over much of eastern North America because of the high susceptibility of our native ash and a lack of effective natural enemies. To increase mortality of EAB larvae and eggs, the USDA (FS, ARS and APHIS) is carryin...

incidence and distribution of insect pests in rain-fed wheat in eastern ...

African Journals Online (AJOL)

ACSS

Insect pests are some of the major constraints limiting yield of wheat (Triticum aestivum L.) in East Africa. The objective of this study was to determine the species composition and distribution of insect pests, and their natural enemies associated with wheat in Eastern Africa. A survey was conducted in farmers' fields in ...

Author Details

African Journals Online (AJOL)

Umeh, EDN. Vol 3, No 2 (2005) - Articles Management of african rice gall midge Orseolia oryzivora Harris and Gagné with reference to time planting and natural enemies in southeastern Nigeria Abstract. ISSN: 1597-0906. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

Coastal Staphylinidae (Coleoptera: A worldwide checklist, biogeography and natural history

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Kee-Jeong Ahn

2011-06-01

Full Text Available We provide a list of the 392 described species of Staphylinidae confined to coastal habitats worldwide. The list is in taxonomic sequence by subfamily, tribe, and genus and includes 91 genera. We provide the page reference of the original description of every species and genus listed and of many synonyms. We note the existence of recent reviews, phylogenies and keys of each of the tribes and genera included. Coastal Staphylinidae contain eight subfamilies: Microsilphinae, Omaliinae, Pselaphinae, Aleocharinae, Oxytelinae, Scydmaeninae, Paederinae, and Staphylininae. By ‘coastal habitats’ we mean habitats existing on the sea coast and subject to inundation or at least splashing by the very highest tides. This includes rocky, boulder, coral, sandy, and muddy seashores, and at least portions of salt-marshes, estuaries, and mangrove swamps. We exclude the sand dune habitat and higher parts of sea-cliffs. The list notes distribution of all the species, first according to the ocean or sea on whose shores it has been recorded, and second by country (and for the larger countries by province or state. Although this distribution is undoubtedly incomplete, it provides a basis for future development of a dedicated database. The ‘Habitats, Habits, and Classificatory Notes’ section is designed to provide ecologists with further taxonomic and ecological information. It includes references to descriptions of the immature stages, behavior of adults and immatures, their food, natural enemies, and habitat. We would have preferred to separate these entities, but current knowledge of ecology is developed in few instances beyond natural history. The Pacific Ocean basin was the origin and contributed to the dispersal of the majority of specialist coastal Staphylinidae at the level of genus. However, at the level of species, species belonging to non-coastal-specialist genera are about as likely to occur on the shores of other oceans as on the shores of the

Biological characterization, habits, naturals enemy and populational fluctuation of Aconophora elongatiformis Dietrich in Tecoma Stans (L.) Juss. Ex Hbk

International Nuclear Information System (INIS)

Pinzon F, Olga Patricia; Quintero C, Paola Fernanda

2001-01-01

The ornamental trees complete a very important environmental function for the quality of the inhabitants' life in the urban areas, when offering momentous benefits as the subduing of the climate, regulation of CO 2 in the atmosphere and the scenic beauty. Thanks to the interest of the District Administration, in Bogota, in the last four years, the urban plantation of trees acquired a preponderant paper that became apparent during the biggest plantation of trees program and maintenance of green areas that it has been carried out in the history of the capital; day by day they get more importance, and they are recognized by the citizenship like fundamental values of its environment. Previously to this program, the attention received were minimum or were remembered soon after the surprising devastating consequences of phyto sanitary problems: the grooved cochineal of the acacia, the louse plant of the cypress and the bedbug of the Urapan in whose cases the ignorance of basic aspects of the biology, natural control and the harmful populations' behavior, it has forced to generally apply measured of chemical type to try to reduce the high levels population. The importance that have, the green areas in the city, it favors a continuous pursuit that allows to deepen in the knowledge of the main risk factors, current problems and potentials of the species, types and consequences of the damages and the intra and inter relationships of the arthropofauna of the urban vegetation, their relationship with the plants, as well as the incidence of biotic and abiotic in the tree phonologic behavior and in the fluctuation of the populations of this individuals in order to coming closer to the understanding of the dynamics of the populations of arthropods harmful, in such a way that is possible to design kind handling strategies with the environment, having in consideration in integrated form the conditions under the attack of arthropods harmful

Fuzzy logic and A* algorithm implementation on goat foraging games

Science.gov (United States)

Harsani, P.; Mulyana, I.; Zakaria, D.

2018-03-01

Goat foraging is one of the games that apply the search techniques within the scope of artificial intelligence. This game involves several actors including players and enemies. The method used in this research is fuzzy logic and Algorithm A*. Fuzzy logic is used to determine enemy behaviour. The A* algorithm is used to search for the shortest path. There are two input variables: the distance between the player and the enemy and the anger level of the goat. The output variable that has been defined is the enemy behaviour. The A* algorithm is used to determine the closest path between the player and the enemy and define the enemy's escape path to avoid the player. There are 4 types of enemies namely farmers, planters, farmers and sellers of plants. Players are goats that aims to find a meal that is a plant. In this game goats aim to spend grass in the garden in the form of a maze while avoiding the enemy. The game provides an application of artificial intelligence and is made in four difficulty levels.

Classical biological control of an invasive forest pest: a world perspective of the management of Sirex noctilio using the parasitoid Ibalia leucospoides (Hymenoptera: Ibaliidae).

Science.gov (United States)

Fischbein, D; Corley, J C

2015-02-01

Classical biological control is a key method for managing populations of pests in long-lived crops such as plantation forestry. The execution of biological control programmes in general, as the evaluation of potential natural enemies remains, to a large extent, an empirical endeavour. Thus, characterizing specific cases to determine patterns that may lead to more accurate predictions of success is an important goal of the much applied ecological research. We review the history of introduction, ecology and behaviour of the parasitoid Ibalia leucospoides. The species is a natural enemy of Sirex noctilio, one of the most important pests of pine afforestation worldwide. We use an invasion ecology perspective given the analogy between the main stages involved in classical biological control and the biological invasion processes. We conclude that success in the establishment, a common reason of failure in biocontrol, is not a limiting factor of success by I. leucospoides. A mismatch between the spread capacity of the parasitoid and that of its host could nevertheless affect control at a regional scale. In addition, we suggest that given its known life history traits, this natural enemy may be a better regulator than suppressor of the host population. Moreover, spatial and temporal refuges of the host population that may favour the local persistence of the interaction probably reduce the degree to which S. noctilio population is suppressed by the parasitoid. We emphasize the fact that some of the biological attributes that promote establishment may negatively affect suppression levels achieved. Studies on established non-native pest-parasitoid interactions may contribute to defining selection criteria for classical biological control which may prove especially useful in integrated pest management IPM programmes of invasive forest insects.

Ecological disequilibrium drives insect pest and pathogen accumulation in non-native trees.

Science.gov (United States)

Crous, Casparus J; Burgess, Treena I; Le Roux, Johannes J; Richardson, David M; Slippers, Bernard; Wingfield, Michael J

2016-12-23

Non-native trees have become dominant components of many landscapes, including urban ecosystems, commercial forestry plantations, fruit orchards, and as invasives in natural ecosystems. Often, these trees have been separated from their natural enemies (i.e. insects and pathogens) leading to ecological disequilibrium, that is, the immediate breakdown of historically co-evolved interactions once introduced into novel environments. Long-established, non-native tree plantations provide useful experiments to explore the dimensions of such ecological disequilibria. We quantify the status quo of non-native insect pests and pathogens catching up with their tree hosts (planted Acacia, Eucalyptus and Pinus species) in South Africa, and examine which native South African enemy species utilise these trees as hosts. Interestingly, pines, with no confamilial relatives in South Africa and the longest residence time (almost two centuries), have acquired only one highly polyphagous native pathogen. This is in contrast to acacias and eucalypts, both with many native and confamilial relatives in South Africa that have acquired more native pathogens. These patterns support the known role of phylogenetic relatedness of non-native and native floras in influencing the likelihood of pathogen shifts between them. This relationship, however, does not seem to hold for native insects. Native insects appear far more likely to expand their feeding habits onto non-native tree hosts than are native pathogens, although they are generally less damaging. The ecological disequilibrium conditions of non-native trees are deeply rooted in the eco-evolutionary experience of the host plant, co-evolved natural enemies, and native organisms from the introduced range. We should expect considerable spatial and temporal variation in ecological disequilibrium conditions among non-native taxa, which can be significantly influenced by biosecurity and management practices. Published by Oxford University Press on

Impacts of Rotation Schemes on Ground-Dwelling Beneficial Arthropods.

Science.gov (United States)

Dunbar, Mike W; Gassmann, Aaron J; O'Neal, Matthew E

2016-10-01

Crop rotation alters agroecosystem diversity temporally, and increasing the number of crops in rotation schemes can increase crop yields and reduce reliance on pesticides. We hypothesized that increasing the number of crops in annual rotation schemes would positively affect ground-dwelling beneficial arthropod communities. During 2012 and 2013, pitfall traps were used to measure activity-density and diversity of ground-dwelling communities within three previously established, long-term crop rotation studies located in Wisconsin and Illinois. Rotation schemes sampled included continuous corn, a 2-yr annual rotation of corn and soybean, and a 3-yr annual rotation of corn, soybean, and wheat. Insects captured were identified to family, and non-insect arthropods were identified to class, order, or family, depending upon the taxa. Beneficial arthropods captured included natural enemies, granivores, and detritivores. The beneficial community from continuous corn plots was significantly more diverse compared with the community in the 2-yr rotation, whereas the community in the 3-yr rotation did not differ from either rotation scheme. The activity-density of the total community and any individual taxa did not differ among rotation schemes in either corn or soybean. Crop species within all three rotation schemes were annual crops, and are associated with agricultural practices that make infield habitat subject to anthropogenic disturbances and temporally unstable. Habitat instability and disturbance can limit the effectiveness and retention of beneficial arthropods, including natural enemies, granivores, and detritivores. Increasing non-crop and perennial species within landscapes in conjunction with more diverse rotation schemes may increase the effect of biological control of pests by natural enemies. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Cucumber Plants Baited with Methyl Salicylate Accelerates Scymnus (Pullus) sodalis (Coleoptera: Coccinellidae) Visiting to Reduce Cotton Aphid (Hemiptera: Aphididae) Infestation.

Science.gov (United States)

Dong, Y J; Hwang, S Y

2017-10-01

The cotton aphid, Aphis gossypii (Glover) (Hemiptera: Aphididae), is a major pest of many crops worldwide and a major cucumber plant pest in Taiwan. Because cotton aphids rapidly develop insecticide resistance and because of the insecticide residue problem, a safe and sustainable method is required to replace conventional chemical control methods. Methyl salicylate (MeSA), a herbivore-induced plant volatile, has been shown to affect aphids' behavior and attract the natural enemies of aphids for reducing their population. Therefore, this study examined the direct effects of MeSA on cotton aphids' settling preference, population development, and attractiveness to natural enemies. The efficiency of using MeSA and the commercial insecticide pymetrozine for reducing the cotton aphid population in laboratory and outdoor cucumber plant pot was also examined. The results showed no difference in winged aphids' settling preference and population development between the MeSA and blank treatments. Cucumber plants infested with cotton aphids and baited with 0.1% or 10% MeSA contained significantly higher numbers of the natural enemy of cotton aphids, namely Scymnus (Pullus) sodalis (Weise) (Coleoptera: Coccinellidae), and MeSA-treated cucumber plants contained a lower number of aphids. Significantly lower cotton aphid numbers were found on cucumber plants within a 10-m range of MeSA application. In addition, fruit yield showed no difference between the MeSA and pymetrozine treatments. According to our findings, 0.1% MeSA application can replace insecticides as a cotton aphid control tool. However, large-scale experiments are necessary to confirm its efficiency and related conservation biological control strategies before further use. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Can entomophagous nematodes slow the spread of invasive pest populations? The case study of Beddingia siricidicola released for the management of Sirex noctilio

Science.gov (United States)

Juan C. Corley; José M. Villacide; Andrew M. Liebhold

2014-01-01

Though rarely used in this way, biological control could potentially be exploited for managing spread of invasive species. Because spread of invasive species emerges from the combined action of population growth and dispersal, natural enemies that affect either of these processes should also affect spread. Dispersal of parasitoid species plays a key role in determining...

Can Bt maize change the spatial distribution of predator Cycloneda ...

African Journals Online (AJOL)

Cultivation of Bt crops is an important tactic in integrated pest management. The effect of Bt maize on arthropod predators needs to be investigated because of the important role of these natural enemies in the absence of target pests. The objective of the present study was to generate information on the distribution model of ...

Susceptibility of Dalotia coriaria (Kraatz (Coleoptera: Staphylinidae to Entomopathogenic Nematodes (Rhabditida: Heterorhabditidae and Steinernematidae

Directory of Open Access Journals (Sweden)

Joseph Tourtois

2015-03-01

Full Text Available Dalotia coriaria (Kraatz (Coleoptera: Staphylinidae and entomopathogenic nematodes (Rhabditida: Heterorhabditidae and Steinernematidae are two soil-dwelling biological control agents used to manage western flower thrips, Frankliniella occidentalis (Pergande (Thysanoptera: Thripidae and fungus gnats Bradysis spp. (Diptera: Sciaridae in glasshouses. Growers often use multiple natural enemies to achieve economic control, but knowledge of interactions among natural enemies is lacking. We conducted a laboratory bioassay to test the pathogenicity of four commercially available nematode species—Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhbditidae, Steinernema carpocapsae (Weiser (Rhabditida: Steinernematidae, S. feltiae (Filipjev, and S. riobrave Cabanillas et al.—to third instar and adult D. coriaria. Third instars were three times more susceptible than the adults to the entomopathogenic nematodes. Mortality for D. coriaria adults and third instars treated with S. feltiae and H. bacteriophora was lower than the mortality for D. coriaria adults and third instars treated with S. carpocapsae and S. riobrave. Neither infective juvenile foraging behavior nor size correlates with D. coriaria mortality. Dalotia coriaria appears to be most likely compatible with applications of S. feltiae and H. bacteriophora.

Effects of pollutants on bottom-up and top-down processes in insect-plant interactions

International Nuclear Information System (INIS)

Butler, Casey D.; Trumble, John T.

2008-01-01

Bottom-up (host plant quality) and top-down (natural enemies) forces both influence the fitness and population dynamics of herbivores. However, the impact of pollutants acting on these forces has not been examined, which prompted us to review the literature to test hypotheses regarding this area of research. A comprehensive literature search found 126 references which examined fitness components and population dynamics of 203 insect herbivores. One hundred and fifty-three of the 203 herbivores (75.4%) had fitness impacted due to bottom-up factors in polluted environments. In contrast, only 20 of the 203 (9.9%) had fitness significantly impacted due to top-down factors in polluted environments. The paucity of results for top-down factors impacting fitness does not necessarily mean that top-down factors are less important, but rather that fewer studies include natural enemies. We provide a synthesis of available data by pollution type and herbivore guild, and suggest future research to address this issue. - Pollutants can affect insect herbivores through bottom-up and, possibly, top-down processes

Ozone exposure triggers the emission of herbivore-induced plant volatiles, but does not disturb tritrophic signalling

Energy Technology Data Exchange (ETDEWEB)

Vuorinen, Terhi; Nerg, Anne-Marja; Holopainen, Jarmo K

2004-09-01

We evaluated the similarities between ozone-induced and mite-induced emission of volatile organic compounds (VOCs) from lima beans, and tested the response of the natural enemies of herbivores to these emissions using trophic system of two-spotted spider mites and predatory mites. The acute ozone-exposure and spider mite-infestation induced the emission of two homoterpenes, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene, and (Z)-3-hexenyl acetate. Only plants with spider mite-infestation emitted the monoterpene (E)-{beta}-ocimene. Predatory mites were equally attracted to ozone-exposed and unexposed plants, but discriminated between spider mite-infested and uninfested plants, when both were exposed to ozone. The similarities between ozone and herbivore-induced VOCs suggest that plant defence against phytotoxic ozone and the production of VOCs for attraction of the natural enemies of herbivores may have adaptive coevolution. However, the expected elevated ozone concentrations in future may not disturb tritrophic signalling, unless herbivore-induced VOCs are lost in the process of aerosol formation.

METARHIZIUM ANISOPLIAE DAN ANDROGRAPHIS PANICULATA TERHADAP SERANGGA BUKAN HAMA SASARAN

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Dini Yuliani

2016-04-01

Full Text Available The objective of this study was to determine the effect of Metarhizium anisopliae and Andrographis paniculata to the natural enemies of Nephotettix virescens and non-target insect pests. This research was conducted in tungro endemic areas in Subang District, West Java in the wet season 2013/2014. The method of research used a split plot design with four replications. The main plot was IR66, Inpari 9, and Ciherang varieties. Subplot was the application of M. anisopliae, A. paniculata, and control. Observations were carried out five times started at nursery (2 weeks after seedling, 14, 28, 42, and 56 days after planting using insect nets, double swing 10 times on each plot observations. The results show M. anisopliae and A. paniculata not adversely affect on non-target insect pests such as Chironomid and natural enemies of N. virescens namely Lycosa pseudoannulata, Cyrtorhinus lividipennis, Sepedon sp., damselfly, Tipulidae sp., Telenomus sp., dragonfly, and Tetrastichus sp.. Efficacy of M. anisopliae and A. paniculata as one of the control strategies that are environmentally friendly and proved not harmful to non-target insect pests.

PENGARUH DOSIS SUBLETAL EKSTRAK SAMBILATA (ANDROGRAPHIS PANICULATA NEES TERHADAP AKTIVITAS MUSUH ALAMI DAN KEPERIDIAN WERENG HIJAU, NEPHOTETTIX VIRESCENS DISTANT

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I Nyoman Widiarta dan Dede Kusdiaman .

2011-11-01

Full Text Available Effect of sublethal doses of sambilata extract to the fecundity and natural enemies activity of the green leafhopper, Nepothettix virescens Distant. Sambilata (Andrographis paniculata is a tropical herb which has antifeeding property and could reduce rice tungro virus transmission by the rice green leafhopper (GLH, Nephotettix virescens.  Series of test were conducted to clarify the effect of sublethal doses of sambilata to the fecundity and natural enemies activity of the GLH. The objective of the test was to know wether sublethal dose of sambilata could cause physiological or ecological resurgence. The results of test showed that foliar spraying of sambilata extract at concentration of 100 and 1000 ppm to rice seedlings reduced the GLH females’s fecundity. Spraying sambilata extract up to dose of 100 ppm on rice seedlings and GLH did not reduce Lycosa preying activity. Egg parasitoid activity was not affected by sambilata application on rice seedlings bore GLH eggs. Thus  the probability of sublethal dose of sambilata to cause physiological or ecological resurgence was low.

Ozone exposure triggers the emission of herbivore-induced plant volatiles, but does not disturb tritrophic signalling

International Nuclear Information System (INIS)

Vuorinen, Terhi; Nerg, Anne-Marja; Holopainen, Jarmo K.

2004-01-01

We evaluated the similarities between ozone-induced and mite-induced emission of volatile organic compounds (VOCs) from lima beans, and tested the response of the natural enemies of herbivores to these emissions using trophic system of two-spotted spider mites and predatory mites. The acute ozone-exposure and spider mite-infestation induced the emission of two homoterpenes, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene, and (Z)-3-hexenyl acetate. Only plants with spider mite-infestation emitted the monoterpene (E)-β-ocimene. Predatory mites were equally attracted to ozone-exposed and unexposed plants, but discriminated between spider mite-infested and uninfested plants, when both were exposed to ozone. The similarities between ozone and herbivore-induced VOCs suggest that plant defence against phytotoxic ozone and the production of VOCs for attraction of the natural enemies of herbivores may have adaptive coevolution. However, the expected elevated ozone concentrations in future may not disturb tritrophic signalling, unless herbivore-induced VOCs are lost in the process of aerosol formation

Terpenoid biosynthesis in Arabidopsis attacked by caterpillars and aphids: effects of aphid density on the attraction of a caterpillar parasitoid.

Science.gov (United States)

Kroes, Anneke; Weldegergis, Berhane T; Cappai, Francesco; Dicke, Marcel; van Loon, Joop J A

2017-12-01

One of the responses of plants to insect attack is the production of volatile organic compounds that mediate indirect defence of plants by attracting natural enemies of the attacking herbivores. Herbivore-induced plant volatiles (HIPVs) include terpenoids that play key roles in the attraction of natural enemies. Crosstalk between phytohormonal signalling pathways is well known to affect the regulation of plant defences, including the emission of HIPVs. Thus, simultaneous feeding on the same plant by caterpillars and aphids, can affect the attraction of parasitoids by the plant compared to single insect attack. The role of aphid density in the regulation of HIPV emission by plants under dual attack has not been studied previously. Here, we investigated the attraction of Diadegma semiclausum, a parasitoid of the Diamondback moth Plutella xylostella, to volatiles emitted by Arabidopsis thaliana plants, simultaneously attacked by host caterpillars, and by the non-host aphid Brevicoryne brassicae. Our study shows that the effect of aphid infestation on parasitoid attraction is influenced by the density of the aphids. Biosynthesis and emission of (E,E)-α-farnesene could be linked to the observed preference of D. semiclausum parasitoids for the HIPV blend emitted by plants dually infested by caterpillars and aphids at a high density compared to dually infested plants with a low aphid density. Parasitoids such as D. semiclausum are important enemies of herbivorous insects and a better understanding of how plants express indirect defence mechanisms in response to multiple insect attack will provide important knowledge on plant-herbivore-parasitoid interactions under multiple stress conditions.

Natural vegetation cover in the landscape and edge effects: differential responses of insect orders in a fragmented forest.

Science.gov (United States)

González, Ezequiel; Salvo, Adriana; Valladares, Graciela

2017-10-01

Human activities have led to global simplification of ecosystems, among which Neotropical dry forests are some of the most threatened. Habitat loss as well as edge effects may affect insect communities. Here, we analyzed insects sampled with pan traps in 9 landscapes (at 5 scales, in 100-500 m diameter circles) comprising cultivated fields and Chaco Serrano forests, at overall community and taxonomic order level. In total 7043 specimens and 456 species of hexapods were captured, with abundance and richness being directly related to forest cover at 500 m and higher at edges in comparison with forest interior. Community composition also varied with forest cover and edge/interior location. Different responses were detected among the 8 dominant orders. Collembola, Hemiptera, and Orthoptera richness and/or abundance were positively related to forest cover at the larger scale, while Thysanoptera abundance increased with forest cover only at the edge. Hymenoptera abundance and richness were negatively related to forest cover at 100 m. Coleoptera, Diptera, and Hymenoptera were more diverse and abundant at the forest edge. The generally negative influence of forest loss on insect communities could have functional consequences for both natural and cultivated systems, and highlights the relevance of forest conservation. Higher diversity at the edges could result from the simultaneous presence of forest and matrix species, although "resource mapping" might be involved for orders that were richer and more abundant at edges. Adjacent crops could benefit from forest proximity since natural enemies and pollinators are well represented in the orders showing positive edge effects. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Genetic Relationships among Invasive Hydrilla (Hydrilla verticillata L.f. Royle) Biotypes in the US and Their Implications for Management

Science.gov (United States)

2014-02-01

throughout this large distribution, although they may be due to environmentally induced plasticity , rather than being indicative of taxonomic...Surveys of hydrilla herbivores have been undertaken in India, Pakistan, Malaysia , Korea, Japan, Thailand, Vietnam, Africa, and Australia (Bennett and... Malaysia (Steward 1993). US monoecious hydrilla plants likely originated in Korea (Madeira et al. 2007, Benoit 2011); therefore, natural enemy

Modelling mate-finding Allee effects and populations dynamics, with applications in pest control

Czech Academy of Sciences Publication Activity Database

Boukal S., David; Berec, Luděk

2009-01-01

Roč. 51, č. 3 (2009), s. 445-458 ISSN 1438-3896 R&D Projects: GA AV ČR KJB600070602 Grant - others:EU Research Training Network FishACE(BE) MRTN-CT-2004-005578 Institutional research plan: CEZ:AV0Z50070508 Keywords : culling * efficiency * natural enemies Subject RIV: EH - Ecology, Behaviour Impact factor: 1.539, year: 2009

Analysis of spatial density dependence in gypsy moth mortality

Science.gov (United States)

Andrew Liebhold; Joseph S. Elkinton

1991-01-01

The gypsy moth is perhaps the most widely studied forest insect in the world and much of this research has focused on various aspects of population dynamics. But despite this voluminous amount of research we still lack a good understanding of which, if any, natural enemy species regulate gypsy moth populations. The classical approach to analyzing insect population...

Nuclear techniques in plant pathology 1. Plant disease control and physiology of parasitism

International Nuclear Information System (INIS)

Menten, J.O.M.; Ando, A.; Tulmann Neto, A.

1986-01-01

Nuclear techniques are advantageously used in several areas of plant pathology. Among them are: induction of mutation for disease resistance, studies with pesticides, disease control through pathogen inactivation, induction of variability and stimulation in pathogens and natural enemies, studies of microorganism physiology and diseased plant physiology, effect of gamma radiation on pesticides, technology of pesticides application, etc. (Author) [pt

A web-based decision support system to enhance IPM programs in Washington tree fruit.

Science.gov (United States)

Jones, Vincent P; Brunner, Jay F; Grove, Gary G; Petit, Brad; Tangren, Gerald V; Jones, Wendy E

2010-06-01

Integrated pest management (IPM) decision-making has become more information intensive in Washington State tree crops in response to changes in pesticide availability, the development of new control tactics (such as mating disruption) and the development of new information on pest and natural enemy biology. The time-sensitive nature of the information means that growers must have constant access to a single source of verified information to guide management decisions. The authors developed a decision support system for Washington tree fruit growers that integrates environmental data [140 Washington State University (WSU) stations plus weather forecasts from NOAA], model predictions (ten insects, four diseases and a horticultural model), management recommendations triggered by model status and a pesticide database that provides information on non-target impacts on other pests and natural enemies. A user survey in 2008 found that the user base was providing recommendations for most of the orchards and acreage in the state, and that users estimated the value at $ 16 million per year. The design of the system facilitates education on a range of time-sensitive topics and will make it possible easily to incorporate other models, new management recommendations or information from new sensors as they are developed.

Understanding trophic interactions of Orius spp. (Hemiptera: Anthocoridae) in lettuce crops by molecular methods.

Science.gov (United States)

Gomez-Polo, Priscila; Alomar, Oscar; Castañé, Cristina; Aznar-Fernández, Thaïs; Lundgren, Jonathan G; Piñol, Josep; Agustí, Nuria

2016-02-01

The aphid Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae) and the thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) are common pests in Mediterranean lettuce crops, where Orius spp. are common generalist predators. Predation by Orius spp. was studied in a lettuce plot by conventional polymerase chain reaction (PCR) and real-time PCR analyses using specific primers of both main pests. Also, high-throughput sequencing was used to have a wider approach of the diet of these predators in natural field conditions. Molecular analyses indicated a higher predation on N. ribisnigri in spring and on F. occidentalis in summer. Predation on alternative prey, like Collembola, was also found in both seasons. Real-time PCR was more sensitive than conventional PCR in showing the target trophic links, whereas high-throughput sequencing revealed predation on other natural enemies - intraguild predation (IGP), showing other trophic interactions of Orius majusculus within the studied ecosystem. This study gives important information about the trophic relationships present in Mediterranean lettuce crops in different periods of the year. The detected predation by Orius spp. on alternative prey, as well as on other natural enemies, should be further investigated to clarify whether it adds or detracts to the biological control of N. ribisnigri and F. occidentalis. © 2015 Society of Chemical Industry.

Phages can constrain protist predation-driven attenuation of Pseudomonas aeruginosa virulence in multienemy communities

Science.gov (United States)

Friman, Ville-Petri; Buckling, Angus

2014-01-01

The coincidental theory of virulence predicts that bacterial pathogenicity could be a by-product of selection by natural enemies in environmental reservoirs. However, current results are ambiguous and the simultaneous impact of multiple ubiquitous enemies, protists and phages on virulence evolution has not been investigated previously. Here we tested experimentally how Tetrahymena thermophila protist predation and PNM phage parasitism (bacteria-specific virus) alone and together affect the evolution of Pseudomonas aeruginosa PAO1 virulence, measured in wax moth larvae. Protist predation selected for small colony types, both in the absence and presence of phage, which showed decreased edibility to protists, reduced growth in the absence of enemies and attenuated virulence. Although phage selection alone did not affect the bacterial phenotype, it weakened protist-driven antipredatory defence (biofilm formation), its associated pleiotropic growth cost and the correlated reduction in virulence. These results suggest that protist selection can be a strong coincidental driver of attenuated bacterial virulence, and that phages can constrain this effect owing to effects on population dynamics and conflicting selection pressures. Attempting to define causal links such as these might help us to predict the cold and hot spots of coincidental virulence evolution on the basis of microbial community composition of environmental reservoirs. PMID:24671085

Douglas-fir nutrients and terpenes as potential factors influencing western spruce budworm defoliation

Science.gov (United States)

Karen M. Clancy

1991-01-01

Variation in levels of herbivory within and among plants can be attributed to many mechanisms, such as differences in a) host nutritional quality, b) suitability of the physical environment, and c) abundance of competitor consumers or natural enemies (Mattson et al. 1982, Denno and McClure 1983, Mattson and Scriber 1987, Clancy et al. 1988a, 1988b, Mattson et al. 1988...

The Community of Rights

DEFF Research Database (Denmark)

Kjærgård, Jonas Ross

2012-01-01

be used in a particularistic and excluding way which was the case in the legislation of Maximilien de Robespierre’s Terror Regime. Situated somewhere between inclusion in and exclusion from the community of rights, the playwright and political activist Olympe de Gouges sought to propagate an understanding...... of the natural that could better accommodate women and nonmarital children. Her attempts were futile, however, and in 1793 she was sentenced to death according to a newly written law meant to prosecute enemies of the Republic’s natural community....

Do induced responses mediate the ecological interactions between the specialist herbivores and phytopathogens of an alpine plant?

Science.gov (United States)

Röder, Gregory; Rahier, Martine; Naisbit, Russell E

2011-05-04

Plants are not passive victims of the myriad attackers that rely on them for nutrition. They have a suite of physical and chemical defences, and are even able to take advantage of the enemies of their enemies. These strategies are often only deployed upon attack, so may lead to indirect interactions between herbivores and phytopathogens. In this study we test for induced responses in wild populations of an alpine plant (Adenostyles alliariae) that possesses constitutive chemical defence (pyrrolizidine alkaloids) and specialist natural enemies (two species of leaf beetle, Oreina elongata and Oreina cacaliae, and the phytopathogenic rust Uromyces cacaliae). Plants were induced in the field using chemical elicitors of the jasmonic acid (JA) and salicylic acid (SA) pathways and monitored for one month under natural conditions. There was evidence for induced resistance, with lower probability and later incidence of attack by beetles in JA-induced plants and of rust infection in SA-induced plants. We also demonstrate ecological cross-effects, with reduced fungal attack following JA-induction, and a cost of SA-induction arising from increased beetle attack. As a result, there is the potential for negative indirect effects of the beetles on the rust, while in the field the positive indirect effect of the rust on the beetles appears to be over-ridden by direct effects on plant nutritional quality. Such interactions resulting from induced susceptibility and resistance must be considered if we are to exploit plant defences for crop protection using hormone elicitors or constitutive expression. More generally, the fact that induced defences are even found in species that possess constitutively-expressed chemical defence suggests that they may be ubiquitous in higher plants.

Do induced responses mediate the ecological interactions between the specialist herbivores and phytopathogens of an alpine plant?

Directory of Open Access Journals (Sweden)

Gregory Röder

2011-05-01

Full Text Available Plants are not passive victims of the myriad attackers that rely on them for nutrition. They have a suite of physical and chemical defences, and are even able to take advantage of the enemies of their enemies. These strategies are often only deployed upon attack, so may lead to indirect interactions between herbivores and phytopathogens. In this study we test for induced responses in wild populations of an alpine plant (Adenostyles alliariae that possesses constitutive chemical defence (pyrrolizidine alkaloids and specialist natural enemies (two species of leaf beetle, Oreina elongata and Oreina cacaliae, and the phytopathogenic rust Uromyces cacaliae. Plants were induced in the field using chemical elicitors of the jasmonic acid (JA and salicylic acid (SA pathways and monitored for one month under natural conditions. There was evidence for induced resistance, with lower probability and later incidence of attack by beetles in JA-induced plants and of rust infection in SA-induced plants. We also demonstrate ecological cross-effects, with reduced fungal attack following JA-induction, and a cost of SA-induction arising from increased beetle attack. As a result, there is the potential for negative indirect effects of the beetles on the rust, while in the field the positive indirect effect of the rust on the beetles appears to be over-ridden by direct effects on plant nutritional quality. Such interactions resulting from induced susceptibility and resistance must be considered if we are to exploit plant defences for crop protection using hormone elicitors or constitutive expression. More generally, the fact that induced defences are even found in species that possess constitutively-expressed chemical defence suggests that they may be ubiquitous in higher plants.

The mitochondrial genome of Elodia flavipalpis Aldrich (Diptera: Tachinidae and the evolutionary timescale of Tachinid flies.

Directory of Open Access Journals (Sweden)

Zhe Zhao

Full Text Available Tachinid flies are natural enemies of many lepidopteran and coleopteran pests of forests, crops, and fruit trees. In order to address the lack of genetic data in this economically important group, we sequenced the complete mitochondrial genome of the Palaearctic tachinid fly Elodia flavipalpis Aldrich, 1933. Usually found in Northern China and Japan, this species is one of the primary natural enemies of the leaf-roller moths (Tortricidae, which are major pests of various fruit trees. The 14,932-bp mitochondrial genome was typical of Diptera, with 13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes. However, its control region is only 105 bp in length, which is the shortest found so far in flies. In order to estimate dipteran evolutionary relationships, we conducted a phylogenetic analysis of 58 mitochondrial genomes from 23 families. Maximum-likelihood and Bayesian methods supported the monophyly of both Tachinidae and superfamily Oestroidea. Within the subsection Calyptratae, Muscidae was inferred as the sister group to Oestroidea. Within Oestroidea, Calliphoridae and Sarcophagidae formed a sister clade to Oestridae and Tachinidae. Using a Bayesian relaxed clock calibrated with fossil data, we estimated that Tachinidae originated in the middle Eocene.

Conservation of Agroecosystem through Utilization of Parasitoid Diversity: Lesson for Promoting Sustainable Agriculture and Ecosystem Health

Directory of Open Access Journals (Sweden)

DAMAYANTI BUCHORI

2008-12-01

Full Text Available For many years, agricultural intensification and exploitation has resulted in biodiversity loss and threaten ecosystem functioning. Developing strategies to bridge human needs and ecosystem health for harmonization of ecosystem is a major concern for ecologist and agriculturist. The lack of information on species diversity of natural enemies and how to utilize them with integration of habitat management that can renovate ecological process was the main obstacle. Parasitoids, a group of natural enemies, play a very important role in regulating insect pest population. During the last ten years, we have been working on exploration of parasitoid species richness, how to use it to restore ecosystem functions, and identifying key factors influencing host-parasitoid interaction. Here, we propose a model of habitat management that is capable of maintaining agricultural biodiversity and ecosystem functions. We present data on parasitoid species richness and distribution in Java and Sumatera, their population structure and its impact toward biological control, relationship between habitat complexes and parasitoid community, spatial and temporal dynamic of parasitoid diversity, and food web in agricultural landscape. Implications of our findings toward conservation of agroecosystem are discussed.

Hymenopteran parasitoids associated with the banana-skipper Erionota thrax L. (Insecta: Lepidoptera, Hesperiidae in Java, Indonesia

Directory of Open Access Journals (Sweden)

ERNIWATI

2011-04-01

Full Text Available Erniwati, Ubaidillah R (2011 Hymenopteran parasitoids associated with the banana-skipper Erionota thrax L. (Insecta: Lepidoptera, Hesperiidae in Java, Indonesia. Biodiversitas 12: 76-85. Hymenopteran parasitoids of banana-skipper Erionota thrax L. (Insecta: Lepidoptera, Hesperiidae from Java, Indonesia are reviewed and an illustrated key to 12 species is presented to include Theronia zebra zebra, Xanthopimpla gamsura, Casinaria sp., Charops sp., Cotesia (Apanteles erionotae, Brachymeria lasus, B. thracis, Ooencyrtus pallidipes, Anastatus sp., Pediobius erionotae, Agiommatus sumatraensis and Sympiesis sp. The surveys of the natural enemies of the banana-skipper were conducted in 1990-2006 in several localities in Java. The aim of this study was to assess the native natural enemies of E. thrax, especially the parasitic Hymenoptera. Infested eggs, larvae and pupae of E. thrax were collected and reared in the laboratory. Emerging parasitoids were preserved in both dry mounting and in 80% alcohol for the species identification. Members of families Braconidae, Ichneumonidae, Encyrtidae, Pteromalidae, Chalcididae, Eupelmidae and Eulophidae were recorded as parasitoids of the banana skipper E. thrax from Java, Indonesia. Species distribution and alternative hosts of the parasitoids are presented.

Olfactory response of Phytoseiulus persimilis (Acari: Phytoseiidae) to untreated and Beauveria bassiana-treated Tetranychus urticae (Acari: Tetranychidae).

Science.gov (United States)

Seiedy, Marjan; Saboori, Alireza; Zahedi-Golpayegani, Azadeh

2013-06-01

Determination of attraction and avoidance behavior of predators is important in concomitant use of multiple natural enemies to control a pest. The olfactory response of the predatory mite Phytoseiulus persimilis was studied to odors related to Tetranychus urticae adults infected by Beauveria bassiana DEBI008 in 0, 24, 48 and 72 h intervals, both in absence and in presence of plants. In plant-present experiments, P. persimilis attraction was neither towards adults of T. urticae infected by 0.02 % Tween 80 (as control), nor to the ones infected by B. bassiana for 0 or 24 h, whereas significant attraction towards the control was observed when tested against T. urticae infected by B. bassiana for 48 or 72 h. In absence of plants, P. persimilis displayed significant avoidance of T. urticae infected by B. bassiana for 48 or 72 h, when their alternative option was 0.02 % Tween 80-infected T. urticae adults. These results indicate that P. persimilis can recognize the presence of B. bassiana and that the predator avoids the fungus. This suggests that the two natural enemy species can be used together in biological control programmes.

Biological control in agro-systems by means of the handling of entomophagous insects

International Nuclear Information System (INIS)

Nicholls, Clara Ines; Altieri, Miguel A

1998-01-01

From several decades ago the importance of natural enemies of the noxious organisms has been recognized. Unfortunately the introduction of the biological control has not had the desired dimension. The indiscriminate use of biocides products has altered the biodiversity of the agro-ecosystem. The parasitoids and predators have suffered the noxious effects of the plaguicides. These natural enemies of the plagues play a momentous paper in the regulation of noxious insects population. The predators of the insecta class register in diverse orders and the abundance of species is impressive. But the knowledge of their importance is only partial. In many countries the kindness of these organisms has not been specified and does not protect them. In the case of parasitoids something similar occurs. It is say that their biotic diversity is incalculable but very few species are exploited. In these two groups rest the classic biological control projects. The successes in projects of biological control are recognized and they are enlarging in several countries but more impulse is required. Due to demands of a sustainable agricultural production it should support the biological control of plagues. In this document general looks on the topic are expounded

Bagworm bags as portable armour against invertebrate predators

Directory of Open Access Journals (Sweden)

Shinji Sugiura

2016-02-01

Full Text Available Some animals have evolved the use of environmental materials as “portable armour” against natural enemies. Portable bags that bagworm larvae (Lepidoptera: Psychidae construct using their own silk and plant parts are generally believed to play an important role as a physical barrier against natural enemies. However, no experimental studies have tested the importance of bags as portable armour against predators. To clarify the defensive function, I studied the bagworm Eumeta minuscula and a potential predator Calosoma maximoviczi (Coleoptera: Carabidae. Under laboratory conditions, all bagworm larvae were attacked by carabid adults, but successfully defended themselves against the predators’ mandibles using their own bags. The portable bags, which are composed mainly of host plant twigs, may function as a physical barrier against predator mandibles. To test this hypothesis, I removed the twig bags and replaced some with herb leaf bags; all bag-removed larvae were easily caught and predated by carabids, while all bag-replaced larvae could successfully defend themselves against carabid attacks. Therefore, various types of portable bags can protect bagworm larvae from carabid attacks. This is the first study to test the defensive function of bagworm portable bags against invertebrate predators.

Bagworm bags as portable armour against invertebrate predators.

Science.gov (United States)

Sugiura, Shinji

2016-01-01

Some animals have evolved the use of environmental materials as "portable armour" against natural enemies. Portable bags that bagworm larvae (Lepidoptera: Psychidae) construct using their own silk and plant parts are generally believed to play an important role as a physical barrier against natural enemies. However, no experimental studies have tested the importance of bags as portable armour against predators. To clarify the defensive function, I studied the bagworm Eumeta minuscula and a potential predator Calosoma maximoviczi (Coleoptera: Carabidae). Under laboratory conditions, all bagworm larvae were attacked by carabid adults, but successfully defended themselves against the predators' mandibles using their own bags. The portable bags, which are composed mainly of host plant twigs, may function as a physical barrier against predator mandibles. To test this hypothesis, I removed the twig bags and replaced some with herb leaf bags; all bag-removed larvae were easily caught and predated by carabids, while all bag-replaced larvae could successfully defend themselves against carabid attacks. Therefore, various types of portable bags can protect bagworm larvae from carabid attacks. This is the first study to test the defensive function of bagworm portable bags against invertebrate predators.

New Approach to Evaluate the Antennal Response of an Adult Predator Insect to Different Volatile Chemical Compounds by using Electroantennogram Technique

Science.gov (United States)

Shonouda, Mourad L.

The antennal response of adult syrphid flies to selected plant volatile chemical compounds was investigated in the present study. The main chemical classes and their chemical compounds were aldehydes (nonanal and benzaldehyde), monoterpene-alcohols (linalool and alpha-terpineol), ketones (6-methyl-5-heptene-2-one and 2-undecanone), hydrocarbons (tetradecane) and benzoids (methyl salicylate). Electroantennogram (EAG) records showed that the syrphid antennae were strongly responded to linalool, 6-methyl-5-heptene-2-one and methyl salicylate even at low concentrations, in addition to the high dose concentration of nonanal comparably to the other chemical compounds. The antennae of old syrphid adults were more responsive and elicited higher levels of responses to all compounds rather than young syrphid adults. The antennal sensitivity may differ from one compound to another according to the sex. The difference in responses could be attributed to the sensitivity of olfactory receptors and/or the characterization of binding protein(s). The quality of biocontrol agent could be improved if the chemical interaction between beneficial natural enemies and the surrounding environment is intensively studied and we clearly understand the chemical ecology of each natural enemy.

De l'honorable ennemi au compagnon de fortune From the respectable enemy to the one who shares a common destiny

Directory of Open Access Journals (Sweden)

Györgyi Mate

2012-05-01

we shall study what it appears to be a subject that is fundamental as well as recurring, that of the question of honor and the word given. We shall further analyze these questions this along three axes: personal engagement - political and military - religious conversion, where we find al sorts of topics relating to religion and finally coexistence, which is more complex by itself. The texts illustrating those three different approaches are of a great diversity. Within such corpus we may find slave memoirs, epical songwriting, as well as the equally important XIXth century novels. The image of the Ottoman Empire has been through a considerable transformation over time in Hungary. In the fifteenth century one of the first existing European accounts of the country shows a well regulated regime, with moral values that constitute an example the whole Christian world should probably follow. Around the middle of the sixteenth century though, Hans Dernschwam finds that the empire is full of “ridiculous and vicious eccentricities". At the same time the epic poems of Tinódi show that sultan Suleiman was an enemy feared by the western forces. A century later, the poet Miklós Zrínyi makes a legend out of the same monarch. New voices appear during the XIXth century: Jókai’s romanticism depicts the deep oriental soul, while Tömörkény's realism portraits the little people in particular. In the XXth century, the ottoman element may be represented either as the incarnation of an age-long enemy, or as the people Hungarians are peacefully coexisting.

Effects of insecticides used in Bemisia tabaci (Gennadius biotype B control and their selectivity to natural enemies in soybean cropEfeitos dos inseticidas utilizados no controle de Bemisia tabaci (Gennadius biótipo B e sua seletividade aos inimigos naturais na cultura da soja

Directory of Open Access Journals (Sweden)

Simone Silva Vieira

2012-10-01

Full Text Available In recent crop seasons, the whitefly, Bemisia tabaci biotype B has become a serious pest in soybean crops due to high infestations and its control difficulties. Therefore, it is important to search control alternatives in the integrated pest management approach. Thus, it was evaluated in this study the efficacy of the whitefly control using different insecticides in greenhouse conditions and their selectivity to the parasitoids Encarsia formosa, Trichogramma pretiosum and Telenomus remus. Buprofezin 150 g. a.i.ha-1 + mineral oil 0.2% v/v and pyriproxyfen 100 g. a.i.ha-1 were considered the best options for the whitefly management due to combine good pest control efficacy with higher selectivity to the parasitoids except Encarsia formosa for which no treatment was classified as harmless. Betacyflutrin 9.375 + imidacloprid 75 g. i.a. ha-1 was efficient on controlling whiteflies nymphs but was not harmless to the studied natural enemies. In general, the treatments including pyretroids compounds (betacyflutrin 9.375 + imidacloprid 75 + spiromesifen 60, betacyflutrin 9.375 + imidacloprid 75 and lambda-cyhalothrin 26.5 + thiametoxan 35.25 g. a.i. ha-1 were the most harmful to the evaluated parasitoids and therefore it use should be avoid whenever possible. Nas últimas safras a mosca-branca, Bemisia tabaci biótipo B (Hemiptera: Aleyrodidae tornou-se praga de importância econômica para a cultura da soja devido à ocorrência de altas infestações e à dificuldade de controle desta praga. Sendo assim, é importante buscar alternativas de manejo com base em um programa de manejo integrado de pragas. Assim, avaliaram-se neste trabalho a eficiência de diferentes inseticidas no controle da mosca-branca em casa-de-vegetação e a seletividade destes aos parasitoides Encarsia formosa, Trichogramma pretiosum e Telenomus remus. Buprofezina 150 g i.a. ha-1 + óleo mineral 0,2% v/v e piriproxifem 100 g. i.a. ha-1 foram consideradas as melhores opções para

IO Sphere: The Professional Journal of Joint Information Operations. Special Edition 2008

Science.gov (United States)

2008-01-01

both the information and political levels; • The natural gas conflict between Ukraine and Russia,; a conflict over meat and milk products trade; as...of friendly forces. Deception is measures designed to mislead the enemy by manipulation, distortion, or falsification of information, to induce...categorizing new methods that are not criminalized in our legislation, such as computer crimes: • Falsif ication of electronic documents and credit cards

Dataset on the regulation of banana weevil abundance and corm damage associated with plant richness and the ground-dwelling arthropods’ food web

Directory of Open Access Journals (Sweden)

Charlotte Poeydebat

2017-12-01

Full Text Available The data presented in this article are related to the research article entitled ̎Plant richness enhances banana weevil regulation in a tropical agroecosystem by affecting a multitrophic food web ̎ [1]. It provides information about plant species richness, weevil corm damage and the abundance of different arthropod groups, including the banana weevil and its potential natural enemies and alternative preys.

Media and Military Relations during the Mexican War

Science.gov (United States)

2010-06-11

related to the war.97 Incidentally, when alliances failed to form, editors often turned to plagiarism , borrowing news from other papers and printing the...natural abilities included confidence, bravery, adaptability, organization, and command. He was an academic , a planner, ever seeking to control...considered an academic , Taylor used simplicity in planning and seized the initiative when facing the enemy in battle. His major flaw was tactical