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Sample records for aphidius colemani viereck

  1. Fitness Effects of Food Resources on the Polyphagous Aphid Parasitoid, Aphidius colemani Viereck (Hymenoptera: Braconidae: Aphidiinae).

    Science.gov (United States)

    Charles, Jennifer J; Paine, Timothy D

    2016-01-01

    Conservation biological control involving the polyphagous aphid parasitoid, Aphidius colemani Viereck, may include provisioning resources from a variety of plant sources. The fitness of adult A. colemani was enhanced with the provision of food resources such as floral nectar from a range of both native and introduced plant species and aphid honeydew under laboratory conditions. However, enhanced fitness appeared to be species specific rather than associated with the whether the plant was a native or an introduced species. Parasitoid survival and fecundity were enhanced significantly in response to the availability of floral nectar and honeydew compared to the response to available extrafloral nectar. These positive effects on the parasitoid's reproductive activity can improve the effectiveness of conservation biological control in nursery production systems because of the abundance and diversity of floral resources within typical production areas. Additionally, surrounding areas of invasive weeds and native vegetation could serve as both floral resources and honeydew food resources for A. colemani.

  2. Fitness Effects of Food Resources on the Polyphagous Aphid Parasitoid, Aphidius colemani Viereck (Hymenoptera: Braconidae: Aphidiinae)

    Science.gov (United States)

    Charles, Jennifer J.; Paine, Timothy D.

    2016-01-01

    Conservation biological control involving the polyphagous aphid parasitoid, Aphidius colemani Viereck, may include provisioning resources from a variety of plant sources. The fitness of adult A. colemani was enhanced with the provision of food resources such as floral nectar from a range of both native and introduced plant species and aphid honeydew under laboratory conditions. However, enhanced fitness appeared to be species specific rather than associated with the whether the plant was a native or an introduced species. Parasitoid survival and fecundity were enhanced significantly in response to the availability of floral nectar and honeydew compared to the response to available extrafloral nectar. These positive effects on the parasitoid’s reproductive activity can improve the effectiveness of conservation biological control in nursery production systems because of the abundance and diversity of floral resources within typical production areas. Additionally, surrounding areas of invasive weeds and native vegetation could serve as both floral resources and honeydew food resources for A. colemani. PMID:26808191

  3. Resource Provisioning as a Habitat Manipulation Tactic to Enhance the Aphid Parasitoid, Aphidius colemani Viereck (Hymenoptera: Braconidae: Aphidiinae), and the Plant-Mediated Effects of a Systemic Insecticide, Imidacloprid

    OpenAIRE

    Charles-Tollerup, Jennifer Jean

    2012-01-01

    Resource provisioning as a habitat manipulation tactic to control the melon aphid, Aphis gossypii, by the polyphagous aphid parasitoid, Aphidius colemani, was investigated in the ornamental, potted-plant nursery using the shrub Photinia x fraseri as a plant host. Floral food resources from an invasive, Conium maculatum, an ornamental, P. x fraseri, and a native, Salvia apiana considerably improved the longevity and fecundity of A. colemani in laboratory experiments. Additionally, floral nec...

  4. Ecological Interactions Affecting the Efficacy of Aphidius colemani in Greenhouse Crops

    Directory of Open Access Journals (Sweden)

    Sara G. Prado

    2015-06-01

    Full Text Available Aphidius colemani Viereck (Hymenoptera: Braconidae is a solitary endoparasitoid used for biological control of many economically important pest aphids. Given its widespread use, a vast array of literature on this natural enemy exists. Though often highly effective for aphid suppression, the literature reveals that A. colemani efficacy within greenhouse production systems can be reduced by many stressors, both biotic (plants, aphid hosts, other natural enemies and abiotic (climate and lighting. For example, effects from 3rd and 4th trophic levels (fungal-based control products, hyperparasitoids can suddenly decimate A. colemani populations. But, the most chronic negative effects (reduced parasitoid foraging efficiency, fitness seem to be from stressors at the first trophic level. Negative effects from the 1st trophic level are difficult to mediate since growers are usually constrained to particular plant varieties due to market demands. Major research gaps identified by our review include determining how plants, aphid hosts, and A. colemani interact to affect the net aphid population, and how production conditions such as temperature, humidity and lighting affect both the population growth rate of A. colemani and its target pest. Decades of research have made A. colemani an essential part of biological control programs in greenhouse crops. Future gains in A. colemani efficacy and aphid biological control will require an interdisciplinary, systems approach that considers plant production and climate effects at all trophic levels.

  5. Aphidius gifuensis: a promising parasitoid for biological control of two important aphid species in sweet pepper

    NARCIS (Netherlands)

    Messelink, G.J.; Bloemhard, C.M.J.; Hoogerbrugge, H.; Schelt, van J.

    2011-01-01

    The parasitoid Aphidius gifuensis is able to parasitize both the green peach aphid Myzus persicae and the foxglove aphid Aulacorthum solani in sweet pepper. In a greenhouse experiment we showed that rates of parasitism on green peach aphids alone were equal to the commonly used Aphidius colemani, bu

  6. The Palaearctic species of the genus Diachasmimorpha Viereck (Hymenoptera: Braconidae: Opiinae)

    NARCIS (Netherlands)

    Achterberg, van C.

    1999-01-01

    Two new species of the genus Diachasmimorpha Viereck, 1913 (Braconidae: Opiinae) are described: D. feijeni spec. nov. from Bhutan (reared from Bactrocera minax (Enderlein) (Diptera: Tephritidae) in fruits of Citrus reticulata Blanco (mandarin)) and D. budrysi spec. nov. from Far East Russia. A key t

  7. Asociaciones áfido-parasitoide (Hemiptera: Aphididae; Hymenoptera: Braconidae, Aphidiinae) en cultivos hortícolas orgánicos en Los Cardales, Buenos Aires, Argentina Aphid-parasitoid associations (Hemiptera: Aphididae; Hymenoptera: Braconidae, Aphidiinae) on organic vegetable crops in Los Cardales, Buenos Aires, Argentina

    OpenAIRE

    Andrea V. Andorno; Silvia N. López; Eduardo N. Botto

    2007-01-01

    Diez especies de áfidos (Hemiptera: Aphididae) se hallaron parasitados por siete especies de parasitoides (Hymenoptera: Braconidae, Aphidiinae) en cultivos hortícolas orgánicos. Myzus persicae (Sulzer) fue el áfido más frecuentemente encontrado sobre una amplia variedad de cultivos, y con mayor diversidad de parasitoides asociados. Aphidius colemani Viereck fue el afidiino más usual, que ataca varias especies de áfidos. Ocho asociaciones tritróficas, involucrando Aphidius matricariae Haliday,...

  8. Aphid parasitoids that occur on wheat crops of Northeast of the Parana State with recovery of Aphidius rhopalosiphi in BrazilParasitoides de pulgões-do-trigo que ocorrem no Norte do estado do Paraná e recaptura de Aphidius rhopalosiphi no Brasil

    Directory of Open Access Journals (Sweden)

    Adriano Thibes Hoshino

    2012-02-01

    Full Text Available Aphids (Hemiptera: Aphididae are the main pest of wheat (Hemiptera: Aphididae in several countries. In Brazil, the Biological Control of Wheat Aphids released millions of aphid parasitoids (Hymenoptera: Braconidae and Aphelinidae on wheat fields and in the present moment the chemical control is rarely necessary. However, since the 80’s few studies was carried out to evaluate the species established in Brazil. For this reason, the aim of this study was to record the species of aphid parasitoids that occur in wheat in the northern region of Parana state, Brazil. Four commercial wheat fields were investigated in the agricultural years of 2008 and 2009. The aphid parasitoids were captured with traps (Moericke and Malaise and aphid mummified were collected. In total, six species of parasitoids were found, Aphidius colemani, A. uzbekistanicus, A. ervi, Aphidius rhopalosiphi, Diaeretiella rapae e Lysiphlebus testaceipes. These results contribute with the register of three exotic species in Parana, and confirm the establishment of A. rhopalosiphi in the country. We emphasize the need for further studies in other regions of the country, as other species introduced also need to have their establishment confirmed.Os pulgões (Hemiptera: Aphididae são pragas de extrema importância em cereais de inverno no mundo todo. No Brasil, o programa Controle Biológico de Pulgões do Trigo liberou milhões de parasitoides (Hymenoptera: Braconidae e Aphelinidae nas áreas tritícolas, reduzindo expressivamente a população da praga, e atualmente raramente o controle químico se faz necessário. Entretanto, desde a década de 80 poucos trabalhos de campo tem sido realizados para verificar as espécies efetivamente estabelecidas no País. Por esta razão, este estudo objetivou registrar as espécies de parasitoides de pulgões ocorrentes em lavouras de trigo na região Norte no Paraná. O trabalho foi realizado em quatro áreas comerciais de trigo, durante as safras

  9. Asociaciones áfido-parasitoide (Hemiptera: Aphididae; Hymenoptera: Braconidae, Aphidiinae en cultivos hortícolas orgánicos en Los Cardales, Buenos Aires, Argentina Aphid-parasitoid associations (Hemiptera: Aphididae; Hymenoptera: Braconidae, Aphidiinae on organic vegetable crops in Los Cardales, Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Andrea V. Andorno

    2007-07-01

    Full Text Available Diez especies de áfidos (Hemiptera: Aphididae se hallaron parasitados por siete especies de parasitoides (Hymenoptera: Braconidae, Aphidiinae en cultivos hortícolas orgánicos. Myzus persicae (Sulzer fue el áfido más frecuentemente encontrado sobre una amplia variedad de cultivos, y con mayor diversidad de parasitoides asociados. Aphidius colemani Viereck fue el afidiino más usual, que ataca varias especies de áfidos. Ocho asociaciones tritróficas, involucrando Aphidius matricariae Haliday, han sido registradas por primera vez para la Argentina.Ten aphid species (Hemiptera: Aphididae were found parasitized by seven aphid parasitoid species (Hymenoptera: Braconidae, Aphidiinae on organic vegetable crops. Myzus persicae (Sulzer was the most frequent aphid found on a wide variety of crops, with the largest parasitoid diversity associated. Aphidius colemani Viereck was the most frequent aphidiine attacking several species of aphids. Eight tritrophic associations involving Aphidius matricariae Haliday are reported for the first time for Argentina.

  10. Fusion–fission experiments in Aphidius: evolutionary split without isolation in response to environmental bimodality

    OpenAIRE

    Emelianov, I; Hernandes-Lopez, A; Torrence, M; Watts, N

    2010-01-01

    Studying host-based divergence naturally maintained by a balance between selection and gene flow can provide valuable insights into genetic underpinnings of host adaptation and ecological speciation in parasites. Selection-gene flow balance is often postulated in sympatric host races, but direct experimental evidence is scarce. In this study, we present such evidence obtained in host races of Aphidius ervi, an important hymenopteran agent of biological control of aphids in agriculture, using ...

  11. Trade-Off Between Fitness Gain and Cost Determines Profitability of a Peach Aphid Parasitoid.

    Science.gov (United States)

    Khatri, Diwas; He, Xiong Z; Wang, Qiao

    2016-08-01

    Aphidius colemani (Viereck) (Hymenoptera: Aphidiidae) is commercially produced and utilized for biological control of peach aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) on greenhouse crops in many countries. To provide knowledge for the evaluation of parasitoid-host interactions and development of effective mass rearing programs, we investigated how and why host age or size affected fitness gain in A. colemani We show that the parasitoid was significantly more likely to encounter larger hosts and that an encounter almost always triggered an attack attempt. However, the attack attempt did not proportionally translate into oviposition because larger aphids had greater ability to defend themselves and the parasitoid spent more time in handling larger aphids. The host age at parasitization had no effect on emergence rates and sex ratio of parasitoid progeny, suggesting that pupae and larvae have similar survival rate in hosts of different ages and/or the parasitoid females do not adjust sex allocation based on host size. When parasitizing mid-aged hosts, the parasitoid gained maximum fitness for their progeny in developmental period, body size, and parasitism. Taking all findings together, we suggest that parasitizing mid-aged green peach aphid nymphs is most profitable for A. colemani. PMID:27289084

  12. Parasitoids and hyperparasitoids (Hymenoptera) on aphids (Hemiptera) infesting citrus in east Mediterranean region of Turkey.

    Science.gov (United States)

    Satar, Serdar; Satar, Gül; Karacaoğlu, Mehmet; Uygun, Nedim; Kavallieratos, Nickolas G; Starý, Petr; Athanassiou, Christos G

    2014-01-01

    The aphids, aphid parasitoids, and hyperparasitoids found in citrus orchards, the parasitoids' and hyperparasitoids' seasonal abundance, and the plant-aphid-parasitoid relationships in Hatay, Osmaniye, Adana, and Mersin provinces of the east Mediterranean region of Turkey are presented in the present 2-yr study. Aphidius colemani Viereck, Binodoxys angelicae (Haliday), and Lysiphlebus confusus Tremblay and Eady (Hymenoptera: Braconidae: Aphidiinae) were encountered as the most common parasitoids among 10 identified aphidiine and aphelinid taxa on different citrus species. Hyperparasitoids belonging to the genera Alloxysta, Phaenoglyphis, Asaphes, Pachyneuron, Syrphophagus, and Dendrocerus are reported for the first time emerging from aphids feeding on citrus in Turkey. Among them, Asaphes spp., Pachyneuron spp., and Syrphophagus spp. were recorded as the most common ones. Citrus reticulata Blanco and Citrus limon (L.) Burm. fil. were recorded as main hosts for the aphid parasitoids and their hyperparasitoids. PMID:25480969

  13. Olfactory responses of Aphidius gifuensis to odors of host plants and aphid-plant complexes

    Institute of Scientific and Technical Information of China (English)

    Song Yang; Rui Xu; Shuo-Yuan Yang; Rong-Ping Kuang

    2009-01-01

    The olfactory responses of Aphidius gifuensis to odors from two host plants (Nicotiana tabacum and Brassica napus ssp.) and their complexes with different infestation levels of two host aphids (Myzus persicae and Lipaphis erysimi) were respectively examined in an olfactometer. The results showed that female A. gifuensis did not respond to odors of undamaged or mechanically damaged host plants, but significantly responded to odors of aphid/plant complexes. Moreover, A. gifuensis responded significantly to odors of both M persicae and L. erysimi/plant complexes when host plants were infested by high levels of aphids, suggesting that quantity of aphid-induced volatiles could be important for attracting A. gifuensis. When tested between aphid/plant complexes, A. gifuensis did not show its preference for either complex. The efficiency of A. gifuensis against aphids in open fields potentially could be improved by using its olfactory response to aphid/plant complexes.

  14. Placenta-Like structure of the aphid endoparasitic wasp aphidius ervi : A strategy of optimal resources acquisition

    OpenAIRE

    Ahmed Sabri; Thierry Hance; Leroy, Pascal D.; Isabelle Frère; Eric Haubruge; Jacqueline Destain; Philippe Compère; Philippe Thonart

    2011-01-01

    Aphidius ervi (Hymenoptera: Braconidae) is an entomophagous parasitoid known to be an effective parasitoid of several aphid species of economic importance. A reduction of its production cost during mass rearing for inundative release is needed to improve its use in biological control of pests. In these contexts, a careful analysis of its entire development phases within its host is needed. This paper shows that this parasitoid has some characteristics in its embryological development rather c...

  15. A Method for Mass-rearing Aphidius gifuensis (Hymenoptera:Aphidiidae)

    Institute of Scientific and Technical Information of China (English)

    Xinzhong WANG; Jian ZHU; Junwei SUN; Yanxia HU; Dexun WANG

    2014-01-01

    Objective] This study presents a method for mass rearing of Aphidius gi-fuensis, a dominant endoparasitoid of Myzus persicae on tobacco in Southwest Chi-na. [Method] The tobacco cultivar Honghuadajinyuan (Nicotiana tabacum) was used as the host plant and M. persicae was the host insect. In a greenhouse, tobacco seedlings were reared in plastic trays. The seedlings at three-true-leaf stage were inoculated with two to three aphids per plant using aphid source with a parasitism rate of 47%±3.9%. [Result] By this inoculation method, the aphids and parasites were simultaneously inoculated on host plants. After approximately 25 d of rearing, we were able to produce 82.5±5.17 aphid mummies per tobacco seedling. A total of 445 500 aphid mummies were produced in one greenhouse (36 rearing trays per greenhouse) during an approximately 50-day rearing period. The emergence rate was 93.4%±2.76%, and 54% of the mummies were females. [Conclusion] The demonstrated technological feasibility of using tobacco seedlings for the mass rear-ing of A. gifuensis increases the potential for the biological control of M. persicae.

  16. Larval competition between Aphidius ervi and Praon volucre (Hymenoptera: Braconidae: Aphidiinae) in Macrosiphum euphorbiae (Hemiptera: Aphididae).

    Science.gov (United States)

    Sidney, Lívia Alvarenga; Bueno, Vanda Helena Paes; Lins, Juracy Caldeira; Sampaio, Marcus Vinicius; Silva, Diego Bastos

    2010-10-01

    Interspecific competition between parasitoid larvae may influence the size, structure, and stability of the population, leading to a reduction in total parasitism and thus restricting the pest control. Aphidius ervi (Haliday) and Praon volucre (Haliday) are endoparasitoids that possess a wide host range and present considerable potential for the biological control of the aphid Macrosiphum euphorbiae (Thomas). The larval competition between A. ervi and P. volucre, and the possible intrinsic competitive superiority of one of the parasitoids in M. euphorbiae, have been studied. In single parasitism experiments, mated parasitoid females (n=10) were maintained individually in contact with M. euphorbiae hosts (n=30) inside petri dishes containing lettuce leaf discs and maintained in environmental chamber at 22 ± 1°C, 70 ± 10% RH, and 12-h photophase. The multiple parasitism experiments consisted of exposing single parasitized aphids (n=120) to the second parasitoid species. Two oviposition events were performed with a 4-h interval between them, namely the following: sequence A (oviposition by A. ervi, followed by P. volucre) and sequence B (oviposition by P. volucre, followed by A. ervi). Oviposition sequence A generated 24 A. ervi and 55 P. volucre adults, whereas oviposition sequence B generated 23 and 49 adults. P. volucre is an intrinsically superior competitor compared with A. ervi, and the use of the two species simultaneously may result in competitive exclusion and influence the stability of the parasitoid population. PMID:22546445

  17. Parasitization of commercially available parasitoid species against the lettuce aphid, Nasonovia ribisnigri (Hemiptera: Aphididae).

    Science.gov (United States)

    Shrestha, G; Skovgård, H; Enkegaard, A

    2014-12-01

    The lettuce aphid, Nasonovia ribisnigri (Mosley), is an economically important pest of lettuce worldwide. Little documentation exists for the control efficacy of aphid parasitoids against N. ribisnigri. This laboratory study evaluated three commercially available parasitoid species: Aphidius colemani (Viereck), Lysiphlebus testaceipes (Cresson), and Aphelinus abdominalis (Dalman) for their mortality impact on N. ribisnigri. The green peach aphid Myzus persicae (Sulzer) was included as a reference aphid. The study showed that A. abdominalis successfully parasitized 39 and 13% of the offered N. ribisnigri and M. persicae, respectively, within a 24-h exposure period. In contrast, none of the lettuce aphids exposed to Ap. colemani or L. testaceipes were successfully parasitized, whereas 60 and 3.5% of M. persicae, respectively, were successfully parasitized within a 6-h exposure period. Lettuce aphid mortality due to incomplete parasitization was 26 and 31% when exposed to Ap. colemani and L. testaceipes, respectively, with corresponding values for M. persicae being 5 and 10%, respectively. Mortality as a result of incomplete parasitization when aphids were exposed to A. abdominalis was low for both aphid species. The total mortality inflicted by A. abdominalis within a 24-h exposure period was 51% for the lettuce aphids and significantly less (19%) for green peach aphids. In contrast, Ap. colemani inflicted a higher mortality in M. persicae (65%) compared with N. ribisnigri (26%) within a 6-h exposure period. L. testaceipes caused a greater mortality in N. ribisnigri as compared with M. persicae. This study concludes that A. abdominalis has the potential to be used against N. ribisnigri in inoculative biocontrol programs as compared with the other parasitoid species based on successful parasitization. PMID:25290653

  18. Dicty_cDB: Contig-U05449-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 8 ) oed16c01.b1 B.oleracea002 Brassica oleracea genom... 40 2.8 2 ( EU561659 ) Aphidius colemani isolate Aco... internal transcribe... 38 2.8 2 ( EJ949016 ) 1093018932160 Global-Ocean-Sampling_GS-30-02-01-1... 38 2.8 2 ( FJ495549 ) Aphidius col...emani clone Ac4 5.8S ribosomal RNA ge... 38 2.9 2 ( AC16

  19. Further contributions to the tritrophic plant-aphid-parasitoid associations in Malta with special reference to Aphis nerii (Hemiptera, Aphidoidea) as a prevalent refugium of Aphidiinae (Hymenoptera, Braconidae)

    OpenAIRE

    Mifsud, David; Zammit, Mark; Stary, Petr

    2013-01-01

    Four species of aphid parasitoids, namely Aphidius colemani, Binodoxys angelicae, Lysiphlebus fabarum and Lysiphlebus testaceipes were reared from Aphis nerii on Nerium oleander and/or Stephanotis floribunda in Malta. Aphidius colemani was the most abundant, occurring in different habitat types. Binodoxys angelicae represents a confirmation of a doubtful past record, while Lysiphlebus testaceipes is a new record for Malta. Aphis nerii is evaluated as a refugium of several aphid parasitoids in...

  20. Placenta-like structure of the aphid endoparasitic wasp Aphidius ervi: a strategy of optimal resources acquisition.

    Directory of Open Access Journals (Sweden)

    Ahmed Sabri

    Full Text Available Aphidius ervi (Hymenoptera: Braconidae is an entomophagous parasitoid known to be an effective parasitoid of several aphid species of economic importance. A reduction of its production cost during mass rearing for inundative release is needed to improve its use in biological control of pests. In these contexts, a careful analysis of its entire development phases within its host is needed. This paper shows that this parasitoid has some characteristics in its embryological development rather complex and different from most other reported insects, which can be phylogenetically very close. First, its yolkless egg allows a high fecundity of the female but force them to hatch from the egg shell rapidly to the host hemocoel. An early cellularisation allowing a rapid differentiation of a serosa membrane seems to confirm this hypothesis. The serosa wraps the developing embryo until the first instar larva stage and invades the host tissues by microvilli projections and form a placenta like structure able to divert host resources and allowing nutrition and respiration of embryo. Such interspecific invasion, at the cellular level, recalls mammal's trophoblasts that anchors maternal uterine wall and underlines the high adaptation of A. ervi to develop in the host body.

  1. Occurrence and parasitism of aphids (Hemiptera: Aphididae on cultivars of irrigated oat (Avena spp. in São Carlos, Brazil

    Directory of Open Access Journals (Sweden)

    Júlio Cesar Ronquim

    2004-06-01

    Full Text Available The interactions between aphids and their Hymenopteran parasitoids on irrigated oats as well as the response of different cultivars of cereals regarding the resistance to these aphids and the influence on the host/parasitoid relationships were studied during two years in São Carlos, Brazil. Rhopalosiphum padi (L. was the predominant aphid observed throughout the study, while the other species were rarely found. Five species of parasitic Hymenoptera were found: three primary parasitoids, Lysiphlebus testaceipes (Cresson, Aphidius colemani (Viereck and Diaeretiella rapae (M'Intosh and two hyperparasitoids, Syrphophagus aphidivorus (Myer and Alloxysta brassicae (Ashmead. The UPF 86081 cultivar presented significant results regarding lower Rhopalosiphum padi contamination and higher aphid parasitism rates than those observed on some other cultivars. No significant effect on the percentage variation of parasitoid emergence on the mummified aphids was observed throughout this study.Foram avaliadas as interações entre afídeos e seus himenópteros parasitóides em cultivares de aveia irrigada, como também a resposta de diferentes cultivares em relação resistência à estes afídeos e a influência nas relações hospedeiro/parasitóide durante dois anos em São Carlos, SP, Brasil. Rhopalosiphum padi (L. foi o afídeo predominante ao longo do estudo, enquanto as outras espécies raramente foram encontradas. Foram observadas cinco espécies de himenópteros parasitóides: três parasitóides primários, Lysiphlebus testaceipes (Cresson, Aphidius colemani (Viereck e Diaeretiella rapae (M'Intosh e dois hiperparasitóides, Syrphophagus aphidivorus (Myer and Alloxysta brassicae (Ashmead. A cultivar UPF 86081 apresentou resultados significativos quanto à baixa infestação por Rhopalosiphum padi e maiores taxas de parasitismo que a demais cultivares. Não foi observado efeito significativo na variação de porcentagem de emergência de parasit

  2. Effects of some Insecticides Applied in Sublethal Concentrations on the Survival and Longevity of Aphidius ervi (Haliday) (Hymenoptera: Aphidiidae) Adults Efecto de algunos Insecticidas Aplicados en Concentraciones Subletales en la Supervivencia y Longevidad de Adultos de Aphidius ervi (Haliday) (Hymenoptera: Aphidiidae)

    OpenAIRE

    Jaime E. Araya; Manuel Araya; María Angélica Guerrero

    2010-01-01

    The effects of four insecticides (dimethoate, pirimicarb, imidacloprid, and spinosad) applied in an ST4 Potter tower at sublethal concentrations (50% of those recommended commercially for aphid control) were studied in the laboratory on aphidiid Aphidius ervi (Haliday) adults, an important parasitoid of the pea aphid Acyrthosiphon pisum (Harris). The most selective treatment on the hymenopteran was imidacloprid, followed in decreasing order by spinosad, pirimicarb, and finally dimethoate, whi...

  3. The effect of larval and early adult experience on behavioural plasticity of the aphid parasitoid Aphidius ervi (Hymenoptera, Braconidae, Aphidiinae)

    Science.gov (United States)

    Villagra, Cristian A.; Pennacchio, Francesco; Niemeyer, Hermann M.

    2007-11-01

    The relevance of the integration of preimaginal and eclosion experiences on the subsequent habitat preferences and mate finding by the adult has been rarely tested in holometabolous insects. In this work, the effect of larval and early adult experiences on the behavioural responses of adult males of the aphid parasitoid, Aphidius ervi, towards volatiles from the host-plant complex (HPC) and from conspecific females were evaluated. Two experience factors were considered: host diet (normal diet=ND; artificial diet=AD), and eclosion, i.e. extraction or non-extraction of the parasitoid larva from the parasitised aphid (extracted=EX; non-extracted=NE). Thus, four treatments were set up: ND/NE, ND/EX, AD/NE and AD/EX. Glass Y-tube olfactometers were used to investigate the responses of adult A. ervi males to the odour sources used. Males from the ND/NE treatment showed a shorter latency to the first choice of olfactometer arms, displayed a marked preference towards the HPC olfactometer arm, and spent more time in the HPC arm than males from the other treatments. Only the interaction of host diet and eclosion experiences proved to be relevant in explaining the differences in latency to first choice, time spent in olfactometers arms, and behaviours displayed in the olfactometer arms. These results show the importance of the integration of larval and eclosion experiences in the development of stereotyped responses of the adults. This process may involve memory retention from the preimaginal and emergence period, but further research is needed to disentangle the contribution of each stage. The response to conspecific females was much less affected by the treatments in relation to first arm choice and times in olfactometer arms, suggesting a pheromone-mediated behaviour, even though a prompter and more intense wing fanning courtship behaviour was registered in the ND/NE males compared to males from the AD/NE treatment. These results show that sexual behaviours are less

  4. Survival of three commercially available natural enemies exposed to Michigan wildflowers.

    Science.gov (United States)

    Walton, Nathaniel J; Isaacs, Rufus

    2011-10-01

    Flowering plants are often used in habitat management programs to conserve the arthropod natural enemies of insect pests. In this study, nine species of flowering plants representing six families commonly found in North America east of the Rocky Mountains were evaluated based on how much they extended the lifespans of three commercially available natural enemy species in cages with cut flower stems compared with cages containing water only. The natural enemies used in the experiments were a lady beetle (Coleoptera: Coccinellidae: Hippodamia convergens Guérin-Méneville), a predatory bug (Heteroptera: Anthocoridae: Orius insidiosus (Say)), and an aphid parasitoid (Hymenoptera: Braconidae: Aphidius colemani Viereck). The plant species that most extended the lifespans of all three natural enemies were Monarda fistulosa L. (Lamiaceae), Solidago juncea Aiton (Asteraceae), and Daucus carota L. (Apiaceae). Agastache nepetoides (L.) Kuntze (Lamiaceae), Lobelia siphilitica L. (Campanulaceae), and Trifolium pratense L. (Fabaceae) were intermediate in their support of natural enemies. One plant species, Penstemon hirsutus (L.) Willdenow (Scrophulariaceae), did not contribute to the longevity of natural enemies any more than water alone. These results emphasize the need for multi-species evaluations of flowering plants for conservation biocontrol programs, and the variability in plant value for natural enemies.

  5. 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.

  6. 烟田常用杀虫剂对烟蚜茧蜂的毒力及其保护酶的影响%Effects of Conventional Insecticides onAphidius Gifuensis Ashmead and Its Protective Enzymes in Tobacco Fields

    Institute of Scientific and Technical Information of China (English)

    朱先志; 刘勇; 田雷; 刘莉; 宗浩; 高强; 徐蕊; 李兰芬; 张伟娜

    2015-01-01

    In order to screen for safer insecticides toAphidius gifuensis Ashmead and know about the effects of conventional insecticides on protective enzymes ofAphidius gifuensis Ashmead in tobacco fields, toxicity of three conventional insecticides to Aphidius gifuensis Ashmead was determined via the residual film method. Effects of different concentrations of imidacloprid on SOD, POD and CAT activities ofAphidius gifuensis Ashmead was also determined. The results showed that the order from high toxicity to low toxicity was: acetamiprid >lambda-cyhalothrin >imidacloprid. In terms of the effects of different concentrations of imidacloprid on the life activities ofAphidius gifuensis Ashmead and their defense mechanisms, all the treatments showed inhibition on enzyme activities except that the LC10 concentration of imidacloprid improved POD activities in adults and CAT activities increased significantly in adults after 12h treatment of three concentrations. This result provides theory basis for understanding the defense mechanisms ofAphidius gifuensis Ashmead against insecticides.%为了筛选对烟蚜茧蜂安全性高的药剂并明确烟田常用杀虫剂对烟蚜茧蜂保护酶的影响,测定了3种烟田常用杀虫剂对烟蚜茧蜂成虫的毒力以及不同浓度的吡虫啉对烟蚜茧蜂成虫体内超氧化物歧化酶、过氧化物酶和过氧化氢酶活性的影响。结果表明,杀虫剂对烟蚜茧蜂成虫的毒力大小顺序为:啶虫脒>高效氯氟氰菊酯>吡虫啉;从不同浓度的吡虫啉对烟蚜茧蜂生命活动和防御机制的影响来看,除LC10浓度吡虫啉促进烟蚜茧蜂成虫体内POD活性提高和3个浓度处理后12 h成虫CAT活性显著提高外,其余处理浓度和时间对3种酶的活性呈现抑制作用。此结果为探明烟蚜茧蜂对杀虫剂的防御机制提供了一定的理论依据。

  7. Effects of some Insecticides Applied in Sublethal Concentrations on the Survival and Longevity of Aphidius ervi (Haliday (Hymenoptera: Aphidiidae Adults Efecto de algunos Insecticidas Aplicados en Concentraciones Subletales en la Supervivencia y Longevidad de Adultos de Aphidius ervi (Haliday (Hymenoptera: Aphidiidae

    Directory of Open Access Journals (Sweden)

    Jaime E. Araya

    2010-06-01

    Full Text Available The effects of four insecticides (dimethoate, pirimicarb, imidacloprid, and spinosad applied in an ST4 Potter tower at sublethal concentrations (50% of those recommended commercially for aphid control were studied in the laboratory on aphidiid Aphidius ervi (Haliday adults, an important parasitoid of the pea aphid Acyrthosiphon pisum (Harris. The most selective treatment on the hymenopteran was imidacloprid, followed in decreasing order by spinosad, pirimicarb, and finally dimethoate, which quickly eliminated the parasitoid and thus its capacity to produce progeny. Three toxicity groups were distinguished in the study. The least damaging treatment to adults of A. ervi was imidacloprid, followed by a group of medium toxicity made up of spinosad and pirimicarb, and lastly dimethoate, which was extremely toxic to A. pisum.Se evaluaron en laboratorio los efectos de cuatro insecticidas (dimetoato, pirimicarb, imidacloprid, y spinosad aplicados en torre Potter ST4 en concentraciones subletales (50% de las dosis comerciales recomendadas para el control de áfidos sobre adultos del afídido Aphidius ervi Haliday, un importante parasitoide del pulgón de la arveja Acyrthosiphon pisum (Harris. El tratamiento más selectivo sobre el himenóptero fue imidacloprid, seguido en orden decreciente por spinosad, pirimicarb, y finalmente dimetoato, compuesto que eliminó rápidamente al parasitoide y su capacidad de producir descendencia. Se distinguieron tres grupos de toxicidad. El tratamiento menos dañino para los adultos de A. ervi fue imidacloprid; seguido por un grupo de selectividad media formado por spinosad y pirimicarb; y por último dimetoato, que fue extremadamente tóxico.

  8. Ocorrência e flutuação populacional de tripes, pulgões e inimigos naturais em crisântemo de corte em casa de vegetação Occurrence and population fluctuation of thrips, aphids and natural enemies in cut chrysanthemum in greenhouse

    Directory of Open Access Journals (Sweden)

    Lívia Mendes Carvalho

    2006-01-01

    Full Text Available Os pulgões e os tripes são importantes pragas em cultivo de crisântemo em casas de vegetação. O objetivo deste trabalho foi avaliar a ocorrência e flutuação populacional de tripes, pulgões e inimigos naturais em cultivares de crisântemo de corte ('White Reagan', 'Yellow Snowdon' e 'Sunny Reagan' em casa de vegetação comercial. A amostragem de tripes foi realizada através de batidas nas plantas ("tapping method" e a de pulgões a partir de coletas diretas nas plantas. Das espécies de tripes amostradas, mais de 90% foram identificadas como Frankliniella occidentalis (Pergande, e o restante incluíram F. gemina (Bagnall, Frankliniella sp., Caliothrips phaseoli (Hood e Haplothrips gowdeyi (Franklin. Foi observado maior número de tripes/planta no cultivar White Reagan se comparado com 'Yellow Snowdon'. Aphis gossypii Glover foi a espécie de pulgão mais comum (> 80%, sendo também coletados Myzus persicae (Sulzer e Dysaphis sp. Maior número de pulgões foi verificado na cultivar White Reagan, quando comparada com 'Sunny Reagan'. Orius insidiosus (Say foi o único predador encontrado associado aos tripes, sendo verificada uma correlação positiva significativa entre a população de tripes e a desse predador. Dentre os inimigos naturais relacionados aos pulgões, foram observados parasitóides (Aphidius colemani Viereck e Lysiphlebus testaceipes Cresson e predadores (Chrysoperla sp., Cycloneda sanguinea Linnaeus e Scymnus sp.. Houve uma correlação positiva significativa entre o crescimento populacional de pulgões e desses predadores e parasitóides nas cultivares White Reagan e Sunny Reagan. Inimigos naturais podem ocorrer naturalmente em casas de vegetação e influenciar as populações de pragas.Aphids and thrips play an important role on chrysanthemum crops in greenhouses. The objective of this work was to evaluate the occurrence and population densities of thrips, aphids and natural enemies in cut chrysanthemum cultivars

  9. Nonlinearities lead to qualitative differences in population dynamics of predator-prey systems.

    Directory of Open Access Journals (Sweden)

    Olga M C C Ameixa

    Full Text Available Since typically there are many predators feeding on most herbivores in natural communities, understanding multiple predator effects is critical for both community and applied ecology. Experiments of multiple predator effects on prey populations are extremely demanding, as the number of treatments and the amount of labour associated with these experiments increases exponentially with the number of species in question. Therefore, researchers tend to vary only presence/absence of the species and use only one (supposedly realistic combination of their numbers in experiments. However, nonlinearities in density dependence, functional responses, interactions between natural enemies etc. are typical for such systems, and nonlinear models of population dynamics generally predict qualitatively different results, if initial absolute densities of the species studied differ, even if their relative densities are maintained. Therefore, testing combinations of natural enemies without varying their densities may not be sufficient. Here we test this prediction experimentally. We show that the population dynamics of a system consisting of 2 natural enemies (aphid predator Adalia bipunctata (L., and aphid parasitoid, Aphidius colemani Viereck and their shared prey (peach aphid, Myzus persicae Sulzer are strongly affected by the absolute initial densities of the species in question. Even if their relative densities are kept constant, the natural enemy species or combination thereof that most effectively suppresses the prey may depend on the absolute initial densities used in the experiment. Future empirical studies of multiple predator - one prey interactions should therefore use a two-dimensional array of initial densities of the studied species. Varying only combinations of natural enemies without varying their densities is not sufficient and can lead to misleading results.

  10. Technical Obstacles and Solutions for Myzus persicae Control by Large-scale Reproduction of Aphidius gifuensis%规模化应用烟蚜茧蜂防治烟蚜的主要技术障碍及应对方法

    Institute of Scientific and Technical Information of China (English)

    周子方; 任伟; 周冀衡; 邓小刚; 李春明; 陈发荣; 沈晗; 孙耿

    2011-01-01

    烟蚜Myzus persicae(Sulzer)是危害烟草Nicotina tobaccum L.的一种主要害虫,烟蚜茧蜂是烟蚜的优势寄生天敌.对烟蚜茧蜂控制烟蚜能力、繁殖技术、保护应用及规模化应用中需要研究的主要技术问题进行了分析,并总结了一些可供规模化应用烟蚜茧蜂防治烟蚜的解决方案.%Myzus persicae ( Sulzer) is a major pest for Nicotina tobaccum L. , while Aphidius gifuensis Aphidiidae is the parasitic natural enemy of Myzus persicae (Sulzer). The paper analyzes gome technical problems, such as the control capacity, reproductive technology, protection and large-scale application of Aphidius gifuensis, and introduces some available solutions to the large-scale application of Aphidius gifuensis in controlling M. Persicae.

  11. Shallot aphids, Myzus ascalonicus, in strawberry: biocontrol potential of three predators and three parasitoids.

    Science.gov (United States)

    Enkegaard, Annie; Sigsgaard, Lene; Kristensen, Kristian

    2013-01-01

    The parasitization capacity of 3 parasitoids and the predation capacity of 3 predators towards the shallot aphid, Myzus ascalonicus Doncaster (Homoptera: Aphididae), on strawberry, Fragaria x ananassa Duchesne (Rosales: Rosaceae) cv. Honeoye, were examined in laboratory experiments. In Petri dish assays, both Aphidius colemani Viereck (Hymenoptera: Aphidiidae) and A. ervi Haliday readily stung shallot aphids, with no significant difference in stinging frequency between the two species. A. ervi induced a significantly higher mortality (79.0 ± 7.2%) in terms of stung aphids compared with A. colemani (55.3 ± 4.1%); however, only a minor fraction (2.7 ± 1.8% and 7.1 ± 3.1%, respectively) of the killed aphids resulted in formation of mummies, presumably due to a physiological response to parasitism. The low percentage of mummification precludes the use of either Aphidius species in anything but inundative biocontrol. In similar set-ups, Aphelinus abdominalis (Dalman) (Hymenoptera: Aphelinidae) killed almost half (49.6 ± 5.3%) of the exposed aphids through host feeding. In addition, 23.2 ± 7.3% of non-host-fed aphids developed into mummified aphids, and 38.1 ± 13.2% of non-host-fed aphids died from other parasitoid-induced causes. However, the host feeding rate was reduced to only 1.2 ± 0.8%, and no significant parasitization mortality was observed on strawberry plants, suggesting that host plants interfered with A. abdominalis activity. This parasitoid does not, therefore, seem to be suited to either inoculative or inundative biocontrol of shallot aphids in strawberry. The three predators studied were the green lacewing, Chrysoperla carnea Steph. (Neuroptera: Chrysopidae), the two-spotted lady beetle, Adalia bipunctata L. (Coleoptera: Coccinellidae), and the gall midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae). Third instars of all 3 predators readily preyed upon the shallot aphid in Petri dish set-ups with significant differences in daily

  12. Effects of volatiles from different trophic level on foraging behavior of Aphidius avenae.%不同营养层次挥发物对燕麦蚜茧蜂寄主搜寻行为的影响

    Institute of Scientific and Technical Information of China (English)

    刘勇; 胡萃; 倪汉祥; 孙京瑞

    2001-01-01

    "Y”型管嗅觉计及风洞测定试验表明,小麦植株、麦长管蚜(Sitobion avenae)、禾谷缢管蚜(Rhopalosiphum padi)对燕麦蚜茧蜂(Aphidius avenae)雌蜂的吸引作用较小,而有蚜植株及蚜害植株对其吸引作用较大,并以麦长管蚜有蚜植株的吸引作用最强.尽管该蜂对禾谷缢管蚜的寄生率极低,但由其危害诱导产生的挥发性信息化合物对该蜂仍具有较强的吸引作用.GC-MS鉴定结果表明,麦蚜取食诱导的挥发性信息化合物主要是2-莰烯、6-甲基-5-己烯-2-酮、6-甲基-5-己烯-2-醇、顺-3-己酰醋酸酯和水杨酸甲酯.其中6-甲基-5-己烯-2-酮和6-甲基-5-己烯-2-醇对燕麦蚜茧蜂的吸引作用最强,水杨酸甲酯无明显吸引作用.

  13. Health effects of predatory beneficial mites and wasps in greenhouses

    DEFF Research Database (Denmark)

    Bælum, Jesper; Enkegaard, Annie; Doekes, Gert;

    A three-year study of 579 greenhouse workers in 31 firms investigated the effect of four different beneficial arthropods. It was shown that the thrips mite Amblyseeius cucumeris and the spider mite predator Phytoseiulus persimilis may cause allergy measured by blood tests as well as eye and nose...... symptoms. No effect was seen by the predator wasp Aphidius colemani nor the predator mite Hypoaspis miles and no effect on lung diseases were seen....

  14. Aphidius Gifuensis Rearing and Its Effect of Aphids Control in the Filed in Northwest Plateau of Yunnan%滇西北高原烟蚜茧蜂繁育及田间防治蚜虫效果

    Institute of Scientific and Technical Information of China (English)

    崔宇翔; 胡小曼; 李佛琳; 方志存; 杨悦章; 陈茂建; 李成杰; 李学卫; 杨焕文

    2011-01-01

    为对丽江滇西高原烟蚜茧蜂繁殖技术作出评价和适合当地提供基础,采用蜂蚜同接技术,在18个简易温室塑料小棚大量繁殖烟蚜茧蜂,并进行田间释放烟蚜茧蜂防治烟蚜的试验.结果表明:(1)烟蚜繁殖较快,接蚜15 d后与20 d后,数量分别达到接蚜时的10倍与20倍,寄生率为7.83%与9.15%.在烟蚜繁殖的同时,寄生蚜数量也在增加,且寄生率控制在适合的范围内,为单株饲养烟蚜茧蜂创造条件.(2)接蚜15d,烟蚜数量达到994头/株,是接蚜时的8倍,僵蚜数量61头/株;接蚜20 d,烟蚜达到1 344头/株,是接蚜时的11倍,僵蚜数量284头/株.烟蚜的快速繁殖为烟蚜茧蜂的繁殖创造了条件,同时,烟蚜茧蜂的繁殖能力也相当快,能满足大田散放烟蚜茧蜂数量的需求.(3)放蜂烟田比对照烟田少使用农药3次,生物防治效果显著,达82%,农药施用金额平均减少4.12元.%In order to make evaluation on technology of Aphidius gifuensis rearing in western of Yunnan plateau and provide the basis for its localization, using the technology which A. Gifuensis and aphid inoculated on the same tobacco simultaneously to breed A. Gifuensis largely in 18 simple greenhouse plastic dometo, and test which releasing A. Gifuensis in field to prevent and cure aphid was carried out. The results showed that: (1) Aphid multiply faster, its quantity achieved 10 times and 20 times after 15 days and 20 days of inoculating aphid, parasitic ratio was 7. 83% and 9. 15% . Number of parasitic aphid was increasing when aphid bred, and parasitic rate was controlled in a suitable extent, which created conditions for feeding aphid on single tobacco plant. (2) After 15 days of inoculating aphid, aphid number reached 994 head/plant which was 8 times of aphid was inoculated, number of mummified aphid were 61 per plant; after 20 days of inoculating aphid, aphid number reached 1 344 per plantwhich was 11 times of aphid was inoculated, number of

  15. 不同漂浮烟苗密度对繁殖烟蚜及烟蚜茧蜂的影响研究%Density of Floating Tobacco Seedling to Reproduce Myzus periscae(Sulzer)and Aphidius gifuensis

    Institute of Scientific and Technical Information of China (English)

    吕娅维; 李宏光; 刘春明; 梁兵; 白崇禄; 王超; 吴伟

    2014-01-01

    为了筛选漂浮烟苗繁殖烟蚜及烟蚜茧蜂的最佳烟苗密度,采用漂浮育苗的方法,研究了4种烟苗密度处理(密度Ⅰ:162株/盘,密度Ⅱ:90株/盘,密度Ⅲ:81株/盘,密度Ⅳ:54株/盘)对烟蚜繁殖的影响。结果表明:密度Ⅱ处理的漂浮烟苗盘蚜量最大值显著高于密度Ⅲ处理和密度Ⅳ处理,与密度Ⅰ处理无显著差异;而密度Ⅱ处理的单株蚜量、有效繁蚜叶数量、有效繁蚜叶载蚜量以及僵蚜数量,均显著高于密度Ⅰ处理,且其患病烟蚜、死亡烟蚜数量低于密度Ⅰ处理。因此,以密度Ⅱ处理培育烟苗可获得最佳的繁蚜效益,进而为大量繁殖烟蚜茧蜂提供基础。%The effect of four density treatments of tobacco seedling (Density Ⅰ:transplanting 162 tobacco seedlings in per floating plate,Density Ⅱ:transplanting 90 tobacco seedlings in per floating plate,DensityⅢ:transplanting 81 tobacco seedlings in per floating plate,Density Ⅳ:transplanting 54 tobacco seedlings in per floating plate) on numbers of Myzus periscae(Sulzer) was studied using floating tobacco seedling technology in order to select the best density of tobacco seedling for reproducing M.periscae and Aphidius gifuensis. The results showed that there was no difference between the maximum per floating plate num-bers of aphid for Density Ⅰ treatment and Density Ⅱ treatment,and they were significantly higher than Density Ⅲ treatment and Density Ⅳ treatment.However,maximum per plant numbers of aphid,numbers of aphid mummies of A.gifuensis,numbers of leaf for effective reproducing aphid and numbers of aphid on leaf for effective reproducing aphid for Density Ⅱ treatment were significantly higher than Density Ⅰ treat-ment.Numbers of diseased aphid and numbers of dead aphid for Density Ⅱ treatment were lower than Den-sity Ⅰ treatment.In conclusion,we can achieve the best feeding quantities of aphid,when we used Density

  16. 以麦二叉蚜和麦长管蚜为寄主的烟蚜茧蜂生理生化特性比较研究%Comparative Studies of the Physiological and Biochemical Characteristics of Aphidius gifuensis Ashmead Parasitizing Schizaphis graminum and Macrosiphum avenae

    Institute of Scientific and Technical Information of China (English)

    宋修超; 郑方强; 戴凤宾; 墨铁路; 许永玉

    2012-01-01

    In the laboratory (22 ℃, RH 40%, a photoperiod of L : D=16h : 8h), the adult physiological and biochemical characteristics of Aphidius gifuensis Ashmead were compared after reared on the two species of wheat aphid, Schizaphis graminum and Macrosiphum avenae. The results showed that, compared with those reared on S. graminum, both female and male adult wasps had wider head width (0.67 mm, 0.62 mm), longer longevity (5.0 d, 4.6 d), lower supercooling points (-25.7 ℃, -25.3 ℃) and freezing points (-24.9 ℃, -24.8 ℃), and higher water, protein and carbohydrate contents when reared on M. avenae. However, there were no differences in fat content between those reared on two different host plants, and no differences in all previous parameters between female and males reared on the same host plants. There were no differences in activities of catalase, superoxide dismutase and peroxidase between those reared on two host plants, and between female and male adult wasps reared on the same host plants, with exceptions of that male adult wasps reared on M. avenae had higher activities of catalase than those reared on S. graminum and that female adult wasps reared on M. avenae had higher activities of peroxidase than those reared on S. graminum. The results indicated that A.gifuensis from M. avenae gets higher potential of anti-adversity than those from S. graminum.%在22 ℃,相对湿度 40%和光周期16L:8D条件下,对以麦二叉蚜Schizaphis graminum和麦长管蚜Macrosiphum avenae为寄主的烟蚜茧蜂Aphidius gifuensis Ashmead雌、雄成蜂生理生化特性进行了比较研究.结果发现,与以麦二叉蚜为寄主时相比,以麦长管蚜为寄主的烟蚜茧蜂雌、雄成蜂头壳更宽、寿命更长(雌蜂 5.0 d,雄蜂 4.6 d)、过冷却点(雌蜂 -25.7 ℃,雄蜂 -25.3 ℃)和结冰点(雌蜂 -24.9 ℃,雄蜂 -24.8 ℃)更低,体内水分、蛋白质和糖类含量更高,但脂肪含量无显著差异.在同一寄主上雌雄蜂间,前

  17. Consumption of snowdrop lectin (Galanthus nivalisagglutinin) causes direct effects on adult parasitic wasps.

    Science.gov (United States)

    Romeis, Jörg; Babendreier, Dirk; Wäckers, Felix L

    2003-03-01

    Honeydew is a common sugar-rich excretion of aphids and other phloem-feeding insects and represents the primary sugar in many agricultural systems. When honeydew-producing insects feed on genetically modified plants, the honeydew can contain amounts of the transgene product. Here we address whether this route of exposure poses a risk for non-target insects. Three species of parasitic wasps were selected: i.e. Aphidius colemani, Trichogramma brassicae and Cotesia glomerata, all of which are known to use honeydew as a carbohydrate source in the field. Wasps were fed sucrose solutions with varying concentrations of snowdrop lectin ( Galanthus nivalisagglutinin, GNA), a protein that has been engineered into crops to confer resistance against homopteran pests and that has been detected in honeydew. Parameters evaluated included gustatory response, longevity, fecundity, progeny emergence and sex ratio. While A. colemani and T. brassicae, but not C. glomerata, were able to detect GNA, this gustatory recognition had no effect on the acceptance of a GNA-sucrose solution. In all three species, GNA ingestion reduced parasitoid survival significantly. However, in respect to fecundity, negative effects were observed for T. brassicae but not for A. colemani. The results suggest that the effect of GNA consumption may depend on the specifics of a parasitoid's biology, especially its longevity and its mode of egg maturation.

  18. Bt crops benefit natural enemies to control non-target pests.

    Science.gov (United States)

    Tian, Jun-Ce; Yao, Ju; Long, Li-Ping; Romeis, Jörg; Shelton, Anthony M

    2015-11-12

    Crops producing insecticidal crystal (Cry) proteins from Bacillus thuringiensis (Bt) control important lepidopteran pests. However, pests such as aphids not susceptible to Cry proteins may require other integrated pest management (IPM) tactics, including biological control. We fed aphids on Bt and non-Bt plants and analyzed the Bt protein residue in aphids and compared the effects of Bt plants and a pyrethroid, lambda-cyhalothrin, on the performance of three natural enemies (predators: Coleomegilla maculata and Eupeodes americanus; parasitoid Aphidius colemani) of the green peach aphid, Myzus persicae. No Bt protein residues in aphids were detected and no significant differences were recorded in the performance of pyrethroid-resistant aphids that fed on Bt broccoli expressing Cry1Ab or Cry1C, or on non-Bt broccoli plants treated or not treated with the pyrethroid. This indicated the aphids were not affected by the Cry proteins or the pyrethroid, thus removing any effect of prey quality. Tri-trophic experiments demonstrated that no C. maculata and E. americanus survived consumption of pyrethroid-treated aphids and that ovipositional behavior of A. colemani was impaired when provided with pyrethroid-treated aphids. In contrast, natural enemies were not affected when fed aphids reared on Bt broccoli, thus demonstrating the safety of these Bt plants for IPM.

  19. Infestation and natural parasitism of aphids in single and mixed pastures of black oats and ryegrass

    Directory of Open Access Journals (Sweden)

    Vinícius Soares Sturza

    2012-09-01

    Full Text Available Some species of aphids are major pests on cereal crops and grass pastures. Usually these pests are not adequately controlled in pasture lands that become sources of aphid infestations to cereal crops. The dynamics of aphids and the incidence of natural enemies are less known in pasture systems than in cereal fields. The objective of this work was to assess the aphid infestation and natural aphid parasitism in different pasture composition. Three hypotheses were tested: 1- the aphid species composition in pastures may vary according to the cereal species in the field; 2- the mixture of two plant species can modify the amount and diversity of aphids; 3- the plant species composition of pasture fields influences the parasitism of aphids. Empirical data were obtained from three Poaceae fields: black oats (Avena strigosa L., ryegrass (Lolium multiflorum L., and a mixed field of black oats and ryegrass. The most abundant aphid species was Rhopalosiphum padi followed by Sitobion avenae. Plant species composition increases the amount and the parasitism rates of aphids. The mixture of heavily infested black oats with a poorly infested ryegrass resulted in reduction of aphid infestation in comparison with heavily-infested single plant species field. This is possible because the conditions are favorable for the development of parasitoid populations. Aphidius colemani was the main parasitoid found in these areas.

  20. Infestation and natural parasitism of aphids in single and mixed pastures of black oats and ryegrass Infestação e parasitismo natural de afídeos em pastagens com espécie única ou mistura de aveia preta e azevém

    Directory of Open Access Journals (Sweden)

    Vinícius Soares Sturza

    2012-09-01

    Full Text Available Some species of aphids are major pests on cereal crops and grass pastures. Usually these pests are not adequately controlled in pasture lands that become sources of aphid infestations to cereal crops. The dynamics of aphids and the incidence of natural enemies are less known in pasture systems than in cereal fields. The objective of this work was to assess the aphid infestation and natural aphid parasitism in different pasture composition. Three hypotheses were tested: 1- the aphid species composition in pastures may vary according to the cereal species in the field; 2- the mixture of two plant species can modify the amount and diversity of aphids; 3- the plant species composition of pasture fields influences the parasitism of aphids. Empirical data were obtained from three Poaceae fields: black oats (Avena strigosa L., ryegrass (Lolium multiflorum L., and a mixed field of black oats and ryegrass. The most abundant aphid species was Rhopalosiphum padi followed by Sitobion avenae. Plant species composition increases the amount and the parasitism rates of aphids. The mixture of heavily infested black oats with a poorly infested ryegrass resulted in reduction of aphid infestation in comparison with heavily-infested single plant species field. This is possible because the conditions are favorable for the development of parasitoid populations. Aphidius colemani was the main parasitoid found in these areas.Algumas espécies de pulgões são importantes pragas de cereais, atacando também pastagens de gramíneas. Normalmente, essas pragas não são controladas nas pastagens e podem tornar-se fontes de infestação dos afídeos para os cereais cultivados. A dinâmica dos afídeos e de seus inimigos naturais é pouco conhecida em sistemas de pastagem. O objetivo deste trabalho foi avaliar a infestação de pulgões e seu parasitismo natural em áreas com diferentes composições de pastagens. Três hipóteses foram testadas: 1 - a composição de esp

  1. A negative effect of a pathogen on its vector? A plant pathogen increases the vulnerability of its vector to attack by natural enemies.

    Science.gov (United States)

    de Oliveira, Camila F; Long, Elizabeth Y; Finke, Deborah L

    2014-04-01

    Plant pathogens that are dependent on arthropod vectors for transmission from host to host may enhance their own success by promoting vector survival and/or performance. The effect of pathogens on vectors may be direct or indirect, with indirect effects mediated by increases in host quality or reductions in the vulnerability of vectors to natural enemies. We investigated whether the bird cherry-oat aphid Rhopalosiphum padi, a vector of cereal yellow dwarf virus (CYDV) in wheat, experiences a reduction in rates of attack by the parasitoid wasp Aphidius colemani when actively harboring the plant pathogen. We manipulated the vector status of aphids (virus carrying or virus free) and evaluated the impact on the rate of attack by wasps. We found that vector status did not influence the survival or fecundity of aphids in the absence of parasitoids. However, virus-carrying aphids experienced higher rates of parasitism and greater overall population suppression by parasitoid wasps than virus-free aphids. Moreover, virus-carrying aphids were accepted as hosts by wasps more often than virus-free aphids, with a greater number of wasps stinging virus-carrying aphids following assessment by antennal palpations than virus-free aphids. Therefore, counter to the prevailing idea that persistent vector-borne pathogens enhance the performance of their vectors, we found that infectious aphids actively carrying a plant pathogen experience greater vulnerability to natural enemies. Our results suggest that parasitoids may contribute to the successful biological control of CYDV by disproportionately impacting virus-carrying vectors, and thus reducing the proportion of vectors in the population that are infectious. PMID:24322446

  2. A negative effect of a pathogen on its vector? A plant pathogen increases the vulnerability of its vector to attack by natural enemies.

    Science.gov (United States)

    de Oliveira, Camila F; Long, Elizabeth Y; Finke, Deborah L

    2014-04-01

    Plant pathogens that are dependent on arthropod vectors for transmission from host to host may enhance their own success by promoting vector survival and/or performance. The effect of pathogens on vectors may be direct or indirect, with indirect effects mediated by increases in host quality or reductions in the vulnerability of vectors to natural enemies. We investigated whether the bird cherry-oat aphid Rhopalosiphum padi, a vector of cereal yellow dwarf virus (CYDV) in wheat, experiences a reduction in rates of attack by the parasitoid wasp Aphidius colemani when actively harboring the plant pathogen. We manipulated the vector status of aphids (virus carrying or virus free) and evaluated the impact on the rate of attack by wasps. We found that vector status did not influence the survival or fecundity of aphids in the absence of parasitoids. However, virus-carrying aphids experienced higher rates of parasitism and greater overall population suppression by parasitoid wasps than virus-free aphids. Moreover, virus-carrying aphids were accepted as hosts by wasps more often than virus-free aphids, with a greater number of wasps stinging virus-carrying aphids following assessment by antennal palpations than virus-free aphids. Therefore, counter to the prevailing idea that persistent vector-borne pathogens enhance the performance of their vectors, we found that infectious aphids actively carrying a plant pathogen experience greater vulnerability to natural enemies. Our results suggest that parasitoids may contribute to the successful biological control of CYDV by disproportionately impacting virus-carrying vectors, and thus reducing the proportion of vectors in the population that are infectious.

  3. Summarize on the Using and Reproducing of Aphidius gifuensis(Aphidiidae)%烟蚜茧蜂繁殖利用概述

    Institute of Scientific and Technical Information of China (English)

    吴兴富

    2007-01-01

    烟蚜Myzus persicae(Sulzer)是为害烟草Nicotina tobaccum L.的一种主要害虫,目前生产上还是以化学杀虫剂为主控制该虫的为害.烟蚜茧蜂是烟蚜的优势寄生天敌,对烟蚜茧蜂寄主、繁殖技术和对烟蚜的控制作用及其规模化应用等方面的研究进展情况进行了概述,并对制约烟蚜茧蜂规模化繁殖利用的主要技术因素进行了探讨,以期为烟蚜茧蜂的规模化繁殖利用研究提供参考.

  4. Dicty_cDB: Contig-U04919-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 5 cytochrome oxidase subu... 44 3.3 1 ( AY427924 ) Aphidius ervi isolate Turkey10 cytochrome oxidase... 44 3...ondrial cytochro... 44 3.3 1 ( AY262764 ) Aphidius ervi clone Turkey mitochondria

  5. Dicty_cDB: Contig-U15499-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available l cytoch... 40 9.9 2 ( AY262769 ) Aphidius ervi clone Japan1 mitochondrial cytochro... 40 9.9 2 ( AY262768 ) Aphidius ervi clone Germ...any mitochondrial cytochr... 40 9.9 2 ( AY262767 ) Aphidius ervi clone Israel mitoc

  6. Effect of Maruca vitrata (Lepidoptera: Crambidae) host plants on life-history parameters of the parasitoid Apanteles taragamae (Hymenoptera: Braconidae)

    NARCIS (Netherlands)

    Dannon, A.E.; Tamo, M.; Agboton, C.; Huis, van A.; Dicke, M.

    2012-01-01

    The effect of four host plant species of the herbivore Maruca vitrata Fabricius (Lepidoptera: Crambidae) on development time, longevity, fecundity and sex ratio of the parasitoid Apanteles taragamae Viereck (Hymenoptera: Braconidae) was investigated under laboratory conditions. The larvae were paras

  7. Control potential of three hymenopteran parasitoid species against the bean weevil in stored beans: The effect of adult parasitoid nutrition on longevity and progeny production

    NARCIS (Netherlands)

    Schmale, I.; Wäckers, F.L.; Cardona, C.; Dorn, S.

    2001-01-01

    We evaluated the longevity and progeny production of three hymenopteran parasitoids of Acanthoscelides obtectus (Say) (Coleoptera: Bruchidae) when kept with or without food sources. In absence of adult food, Dinarmus basalis Ashm. (Pteromalidae) and Heterospilus prosopidis (Viereck) (Braconidae) liv

  8. Control potential of three hymenopteran parasitoid species against the bean weevil in stored beans: the effect of adult parasitoid nutrition on longevity and progeny production

    NARCIS (Netherlands)

    Schmale, I.; Wäckers, F.L.; Cardona, C.; Dorn, S.

    2001-01-01

    We evaluated the longevity and progeny production of three hymenopteran parasitoids of Acanthoscelides obtectus (Say) (Coleoptera: Bruchidae) when kept with or without food sources. In absence of adult food, Dinarmus basalis Ashm. (Pteromalidae) and Heterospilus prosopidis (Viereck) (Braconidae) liv

  9. Primera cita de Aleiodes laphygmae (Hymenoptera: Braconidae) para Argentina y de su asociación con larvas de Spodoptera eridania (Lepidoptera: Noctuidae) First record of Aleiodes laphygmae (Hymenoptera: Braconidae) for Argentina and its association with larvae of Spodoptera eridania (Lepidoptera: Noctuidae)

    OpenAIRE

    Liliana Valverde; D. Carolina Berta; Marcelo Geronimo Gomez

    2012-01-01

    Se reporta por primera vez para Argentina Aleiodes laphygmae (Viereck) (Hymenoptera: Braconidae) y como parasitoide de larvas de Spodoptera eridania (Stoll) (Lepidoptera: Noctuidae), en plantaciones de soja en la provincia de Tucumán (Argentina). Se provee información biológica como hábitos, hospedadores y distribución.Aleiodes laphygmae (Viereck) (Hymenoptera: Braconidae), is reported for the first time for Argentina. It is also reported parasitizing larvae of Spodoptera eridania (Stoll) (Le...

  10. Primera cita de Aleiodes laphygmae (Hymenoptera: Braconidae para Argentina y de su asociación con larvas de Spodoptera eridania (Lepidoptera: Noctuidae First record of Aleiodes laphygmae (Hymenoptera: Braconidae for Argentina and its association with larvae of Spodoptera eridania (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Liliana Valverde

    2012-06-01

    Full Text Available Se reporta por primera vez para Argentina Aleiodes laphygmae (Viereck (Hymenoptera: Braconidae y como parasitoide de larvas de Spodoptera eridania (Stoll (Lepidoptera: Noctuidae, en plantaciones de soja en la provincia de Tucumán (Argentina. Se provee información biológica como hábitos, hospedadores y distribución.Aleiodes laphygmae (Viereck (Hymenoptera: Braconidae, is reported for the first time for Argentina. It is also reported parasitizing larvae of Spodoptera eridania (Stoll (Lepidoptera: Noctuidae in soybeans crops in Tucumán province (Argentina. Biological information on habits, hosts and distribution is provided.

  11. Functional response and life history parameters of Apanteles taragamae, a larval parasitoid of Maruca vitrata

    NARCIS (Netherlands)

    Dannon, A.E.; Tamò, M.; Huis, van A.; Dicke, M.

    2010-01-01

    The legume pod borer Maruca vitrata Fabricius (Lepidoptera: Crambidae) is a serious pest of cowpea in West-Africa. The parasitoid Apanteles taragamae Viereck (Hymenoptera: Braconidae) that originates from Taiwan is a potential candidate for biological control of M. vitrata. We investigated under lab

  12. Assessing non-target effects and host feeding of the exotic parasitoid Apanteles taragamae, a potential biological control agent of the cowpea pod borer Maruca vitrata

    NARCIS (Netherlands)

    Dannon, A.E.; Tamo, M.; Huis, van A.; Dicke, M.

    2012-01-01

    Apanteles taragamae Viereck is a larval parasitoid introduced in Benin for classical biological control of the cowpea pod borer Maruca vitrata Fabricius. In the laboratory, we evaluated the effects of A. taragamae on non-target herbivore species, and on another parasitoid of M. vitrata, i.e. the egg

  13. Selectivity lists of pesticides to beneficial arthropods for IPM programs in carrot--first results.

    OpenAIRE

    Hautier, L.; Jansen, J.-P.; Mabon, N.; Schiffers, Bruno

    2005-01-01

    In order to improve IPM programs in carrot, 7 fungicides, 12 herbicides and 9 insecticides commonly used in Belgium were tested for their toxicity towards five beneficial arthropods representative of most important natural enemies encountered in carrot: parasitic wasps- Aphidius rhopalosiphi (De Stefani-Perez) (Hym., Aphidiidae), ladybirds - Adalia bipunctata (L.) (Col., Coccinellidae), hoverfly - Episyrphus balteatus (Dipt., Syrphidae), rove beetle - Aleochara bilineata (Col., Staphyllinida...

  14. Impact of change in winter strategy of one parasitoid species on the diversity and function of a guild of parasitoids.

    Science.gov (United States)

    Andrade, Thiago Oliveira; Krespi, Liliane; Bonnardot, Valérie; van Baaren, Joan; Outreman, Yannick

    2016-03-01

    The rise of temperatures may enable species to increase their activities during winter periods and to occupy new areas. In winter, resource density is low for most species and an increased number of active consumers during this season may produce heightened competitive pressure. In Western France, the aphid parasitoid species Aphidius avenae Haliday has been known to adopt a winter diapausing strategy adjacent to newly sown cereal crops, until recent reports of active winter populations in cereal crops. We investigate how the addition of this species to the winter guild of parasitoids may change the structure of the aphid-parasitoid food web and the host-exploitation strategies of previously occurring parasitoids. We showed that in winter, Aphidius avenae was mostly associated with two aphid species, Sitobion avenae Fabricius and Metopolophium dirhodum Walker, while the generalist species Aphidius rhopalosiphi was restricted to the aphid species Rhopalosiphum padi L. in the presence of Aphidius avenae. Due to this new competition, winter food webs present a higher degree of compartmentalization and lower proportional similarity index values than spring ones. Parasitoid and aphid abundances responded significantly to changes in daily high temperatures, suggesting that the host-parasitoid community structure can be partly predicted by climate. This study demonstrates how a change in the winter strategy of one species of a guild can modify complex interspecific relationships in host-parasitoid systems.

  15. The Braconidae (Hymenoptera) of Greenland

    NARCIS (Netherlands)

    Achterberg, van C.

    2006-01-01

    Thirty species belonging to 16 genera of the family Braconidae (Hymenoptera) are reported from Greenland. Seven are new species described and illustrated below: Dacnusa groenlandica spec. nov.; Aphidius tarsalis spec. nov.; Praon brevistigma spec. nov.; Blacus (B.) groenlandicus spec. nov.; Cotesia

  16. Checklist of Aphidiinae (Hymenoptera: Braconidae) and Aphelinus (Hymenoptera: Aphelinidae) species from Belgium with respectively four and three new records.

    Science.gov (United States)

    Lopes, Thomas; Libert, Pierre-Nicolas; Starý, Petr; Japoshvili, George; Hatt, Séverin; Francis, Frédéric

    2016-01-01

    Aphid parasitoids have good potential for crop protection. However, they have been poorly studied in Belgium, especially in terms of species diversity. Therefore, the aim of this work was to establish the first checklist for the country. To complete the list, aphid parasitoids were sampled in wheat and pea fields near Gembloux (Belgium), in 2013 and 2014. Among the identified species, Aphelinus asychis Walker, Aphelinus daucicola Kurdjumov, Aphelinus fusciscapus (Förster), Aphidius asteris Haliday, Aphidius eadyi Starý, Gonzalez & Hall, Praon barbatum Mackauer, and Trioxys auctus (Haliday) were recorded for the first time in Belgium. Thirty-two Aphidiinae and seven Aphelinus species were included in the checklist. It is hoped this study will stimulate further research, as species diversity is still low compared with neighbouring countries. PMID:27394473

  17. Effects of a commercial formulation of a plant resistance elicitor on non-target organisms

    OpenAIRE

    Jansen, Jean-Pierre; Buenotesta, Raphaël; Schiffers, Bruno

    2014-01-01

    The toxicity of Fyto11, a plant resistance elicitor commercial formulation used to increase the natural resistance of Cucurbitaceae (cucumber, zucchini and melon) and Solanaceae (tomato and sweet pepper) against powdery mildew under greenhouse conditions, has been assessed on several beneficial arthropods: the honeybee Apis mellifera, the predatory miteTyphlodromus pyri, the aphid parasitic wasp Aphidius rhopalosiphi and the aphid predator Episyrphus balteatus. Tested at 0.5% and 1.0% spra...

  18. 25. Sitzung des FAO/WHO Codex-Alimentarius-Komitees für Fische und Fischereierzeugnisse

    OpenAIRE

    Schubring, Reinhard

    2002-01-01

    Die 25. Sitzung des Komitees für Fische und Fischereierzeugnisse fand vom 3. bis 7. Juni 2002 in Aales und, Norwegen, statt. Die Tagung wurde von 131 Delegierten und Beobachtern aus 41 Mitgliedsstaaten und 2 internationalen Organisationen sowie FAO- und WHO-Personal (4)besucht. Die größten Delegationen stellten Frankreich (7), Thailand (7), USA (10) und Norwegen als Gastgeber (13).Die deutsche Delegation wurde von Dr. Achim Viereck(BMVEL) geleitet. Weitere Mitglieder waren Prof. Jörg Oehlensc...

  19. Parasitóides (Hymenoptera: Braconidae de Anastrepha Schiner (Diptera: Tephritidae no estado do Acre Parasitoids (Hymenoptera: Braconidae of Anastrepha Schiner (Diptera: Tephritidae in the state of Acre, Brazil

    Directory of Open Access Journals (Sweden)

    Marcílio José Thomazini

    2009-03-01

    Full Text Available Este trabalho relata a primeira ocorrência de parasitóides em moscas-das-frutas do gênero Anastrepha Schiner no estado do Acre. No município de Bujari foram encontrados os braconídeos Opius bellus Gahan (72,5%, Doryctobracon areolatus (Szépligeti (26,8% e Utetes anastrephae (Viereck (0,7% associados a A. obliqua (Macquart em frutos de taperebá (Spondias mombin L., com parasitismo de 29,5%. No município de Rio Branco, em frutos de goiaba (Psidium guajava L., ocorreu somente D. areolatus em A. obliqua com parasitismo de 2,7%.This paper records the first parasitoids occurrence on Anastrepha Schiner fruit flies in the state of Acre, Brazil. In the Bujari County there occurred the braconids Opius bellus Gahan (72.5%, Doryctobracon areolatus (Szépligeti (26.8% e Utetes anastrephae (Viereck (0.7% associated with A. obliqua (Macquart in tapereba fruits (Spondias mombin L., with parasitism of 29.5%. In guajava fruits (Psidium guajava L. at Rio Branco County, only D. areolatus on A. obliqua occurred, with parasitism of 2.7%.

  20. 早熟素对棉铃虫滞育的终止作用%TERMINATION OF PUPAL DIAPAUSE IN THE BOLLWORM HELICOVERPA ARMIGERA BY PRECOCENE Ⅱ

    Institute of Scientific and Technical Information of China (English)

    王方海; 龚和

    2001-01-01

    用外源激素和某些化合物处理棉铃虫的滞育蛹,结果发现早熟素与蜕皮素-样可终止棉铃虫蛹的滞育,使其进入到发育阶段.而保幼激素类似物ZR-515,环腺氨酸(cAMP)和色氨类化合物(5-HT)则完全不具有终止棉铃虫滞育的作用.结合早熟素还可终止蚜虫寄生蜂Aphidius matricariae Haliday和Praon volucre Haliday的预蛹滞育的报道,建议早熟素应具有终止多种类昆虫滞育的功能.%Precocene Ⅱ terminated pupal diapause in the bollworm Helicoverpa armigera as 20-hydroxyecdysterone did, whereas juvenile hormone analog ZR-515, cyclic adenosine monophosphate (cAMP), and 5-hydroxytryptamine (5-HT) did not. The results indicate that precocene Ⅱ affects diapausing pupae in the similar way as what was found in the prepupae of the aphid parasitoids, Aphidius matricariae Haliday and Praon volucre Haliday (Hymenoptera: Aphidiidae). It is suggested that precocene Ⅱ may affect different kinds of termination of diapause in insects.

  1. Determination of Opiinae parasitoids (Hymenoptera: Braconidae) associated with crop infesting Bactrocera spp. (Diptera: Tephritidae) using COI and Cyt b sequences

    Science.gov (United States)

    Shariff, Safiah; Yaakop, Salmah; Zain, Badrul Munir Md.

    2013-11-01

    Members of the Opiinae subfamily (Hymenoptera: Braconidae) are well known as important parasitoids of fruit fly larvae (Diptera: Tephritidae). They are widely used as biological control agents of fruit flies, especially the Bactrocera Macquart species that infest fruits. In this study, the larvae of fruit flies were collected from infested crops including star fruit, guava, wax apple and ridge gourd. The parasitized larvae were then reared under laboratory conditions until emergence of the adult parasitoids. Additionally, Malaise trap also was used to collect parasitoid species. The general concept of the multiplex PCR has been performed is to amplify two mitochondrial DNA markers, namely cytochrome oxidase subunit I (COI) and cytochrome b (Cyt b) simultaneously. Therefore, the lengthy process of reaction will be reduced. The status of the fruit fly species has also been confirmed by using COI marker on the early stage of the larvae. Maximum parsimony (MP) and Bayesian Inference (BI) were implemented to help and support the identification of Opiinae species. The result obtained from this study showed three parasitoid genera of the Opiinae viz. Fopius Wharton, Psyttalia Walker and Diachasmimorpha Viereck. Each genus has been determined by clustering together in a similar clade according to their infested crops. Therefore, accurate determination of parasitoids and the fruit fries species was highly useful and necessary for successful biological control of Bactrocera species.

  2. Larval endoparasitoids (Hymenoptera of frugivorous flies (Diptera, Tephritoidea reared from fruits of the cerrado of the State of Mato Grosso do Sul , Brazil

    Directory of Open Access Journals (Sweden)

    Uchôa-Fernandes Manoel A.

    2003-01-01

    Full Text Available This paper presents a five years survey of endoparasitoids obtained from the larvae of frugivorous Tephritidae and Lonchaeidae flies. The insects were reared from cultivated and wild fruits collected in areas of the cerrado in the State of Mato Grosso do Sul, Brazil. The flies obtained from 14 host fruit species were eight Anastrepha species, Ceratitis capitata (Wiedemann, 1824 (Tephritidae; Dasiops sp. and Neosilba spp. (Lonchaeidae. Eleven parasitoid species were collected: Braconidae - Asobara anastrephae (Muesebek, 1958, Doryctobracon areolatus (Szépligeti, 1911, D. fluminensis (Costa Lima, 1938, Opius bellus Gahan, 1930 and Utetes anastrephae (Viereck, 1913; Figitidae - Aganaspis nordlanderi Wharton, 1998, Lopheucoila anastrephae (Rhower, 1919, Odontosema anastrephae (Borgmeier, 1935 and Trybliographa infuscata Gallardo, Díaz & Uchôa-Fernandes, 2000 and, Pteromalidae - Spalangia gemina Boucek, 1963 and S. endius Walker, 1839. In all cases only one parasitoid emerged per puparium. D. areolatus was the most abundant and frequent parasitoid of fruit fly species, as was L. anastrephae in Neosilba spp. larvae. This is the first record of A. nordlanderi in the midwestern Brazilian region.

  3. Characterization of the natural enemy community attacking cotton aphid in the Bt cotton ecosystem in Northern China.

    Science.gov (United States)

    Ali, Abid; Desneux, Nicolas; Lu, Yanhui; Liu, Bing; Wu, Kongming

    2016-01-01

    Planting Bt cotton in China since 1997 has led to important changes in the natural enemy communities occurring in cotton, however their specific effect on suppressing the cotton aphids (being notorious in conventional cotton ecosystem) has not been fully documented yet. We observed strong evidence for top-down control of the aphid population, e.g. the control efficiency of natural enemies on cotton aphid increased significantly in open field cages compared to exclusion cages, accounted for 60.2, 87.2 and 76.7% in 2011, 2012 and 2013 season, respectively. The cotton aphid populations peaked in early June to late July (early and middle growth stages) in open field cotton survey from 2011 to 2013. The population densities of cotton aphids and natural enemies were highest on middle growth stage while lowest densities were recorded on late stage for aphids and on early plant stage for natural enemies. Aphid parasitoids (Trioxys spp., Aphidius gifuensis), coccinellids and spiders were key natural enemies of cotton aphid. Briefly, natural enemies can suppress aphid population increase from early to middle plant growth stages by providing biocontrol services in Chinese Bt cotton. PMID:27075171

  4. Partial aphid resistance in lettuce negatively affects parasitoids.

    Science.gov (United States)

    Lanteigne, Marie-Eve; Brodeur, Jacques; Jenni, Sylvie; Boivin, Guy

    2014-10-01

    This study investigated the effects of partial plant resistance on the lettuce aphid Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae), a major pest of cultivated lettuce (Lactuca sativa L.), and one of its parasitoids, Aphidius ervi Haliday (Hymenoptera: Braconidae). Aphids were reared on susceptible (L. sativa variety Estival; S) or partially resistant (Lactuca serriola L. PI 491093; PR) lettuce, and next parasitized by A. ervi females. Fitness proxies were measured for both aphids and parasitoids. Developmental time to adult stage took longer for alate and apterous aphids (an average of 3.5 and 1.5 additional days, respectively) on PR than on S lettuce, and fecundity of alate aphids reared on PR lettuce was reduced by 37.8% relative to those reared on S lettuce. Size (tibia length) and weight of aphids reared on PR lettuce were lower than for aphids reared on S lettuce from the third and second instar onward, respectively. Parasitism of aphids reared on PR plants resulted in lower parasitoid offspring emergence (-49.9%), lower adult female (-30.3%) and male (-27.5%) weight, smaller adult female (-17.5%) and male (-11.9%) size, and lower female fecundity (37.8% fewer eggs) than when parasitoids developed from aphids reared on S plants. Our results demonstrate that partial aphid resistance in lettuce negatively affects both the second and third trophic levels. Host plant resistance in cultivated lettuce may therefore create an ecological sink for aphid parasitoids. PMID:25197882

  5. 烟蚜茧蜂规模化繁殖和释放技术研究

    Institute of Scientific and Technical Information of China (English)

    王树会; 魏佳宁

    2006-01-01

    烟蚜(桃蚜)Myzus persicaeSulzer是危害云南省烟草Nicotina tobaccumL.的一种主要害虫.生产中还是以杀虫剂为主控制该虫危害.然而,近年来地方政府、科技人员和农户都在寻求以生物防治的方法控制烟蚜危害.烟蚜茧蜂是自然界控制烟蚜的一种优势天敌.作者在云南省玉溪烟区经过5 a的研究和推广,形成的烟蚜茧蜂(Aphidius gifuensisAshmead)大规模繁殖和释放技术.对大量繁蜂的设备和成本核算以及相关的一些技术问题进行了一定的探讨.

  6. Diversity and seasonality of fruit flies (Diptera: Tephritidae and Lonchaeidae) and their parasitoids (Hymenoptera: Braconidae and Figitidae) in orchards of guava, loquat and peach

    Energy Technology Data Exchange (ETDEWEB)

    Souza-Filho, M.F.; Raga, A. [Instituto Biologico, Campinas, SP (Brazil)], e-mail: miguelf@biologico.sp.gov.br; Azevedo-Filho, J.A. [Agencia Paulista de Tecnologia dos Agronegocios (APTA), Monte Alegre do Sul, SP (Brazil). Polo Regional do Leste Paulista; Strikis, P.C. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Biologia. Dept. de Parasitologia; Guimaraes, J.A. [EMBRAPA Agroindustria Tropical, Fortaleza, CE (Brazil); Zucchi, R.A. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Entomologia, Fitopatologia e Zoologia Agricola

    2009-02-15

    This work was carried out in orchards of guava progenies, and loquat and peach cultivars, in Monte Alegre do Sul, SP, Brazil, in 2002 and 2003. Guavas and loquats were bagged and unbagged bi-weekly and weekly, respectively, for assessment of the infestation period. Peach was only bagged weekly. The assays started when the fruits were at the beginning of development, but still green. Ripe fruits were taken to the laboratory and placed individually into plastic cups. McPhail plastic traps containing torula yeast were hung from January 2002 to January 2004 to assess the fruit fly population in each orchard, but only the Ceratitis capitata population is here discussed. Five tephritid species were reared from the fruits: Anastrepha bistrigata Bezzi, A. fraterculus (Wiedemann), A. obliqua (Macquart), A. sororcula Zucchi, and C. capitata, in addition to six lonchaeid species: Neosilba certa (Walker), N. glaberrima (Wiedemann), N. pendula (Bezzi), N. zadolicha McAlpine and Steyskal, Neosilba sp. 4, and Neosilba sp. 10 (both species are in the process of being described by P. C. Strikis), as well as some unidentified Neosilba species. Ten parasitoid species were obtained from fruit fly puparia, of which five were braconids: Asobara anastrephae (Muesebeck), Doryctobracon areolatus (Szepligeti), D. brasiliensis (Szepligeti), Opius bellus Gahan, and Utetes anastrephae (Viereck), and five figitids: Aganaspis pelleranoi (Brethes), Dicerataspis grenadensis Ashmead, Lopheucoila anastrephae (Rhower), Leptopilina boulardi (Barbotin, Carlton and Kelner-Pillaut), and Trybliographa infuscata Diaz, Gallardo and Uchoa. Ceratitis capitata showed a seasonal behavior with population density peaking at the second semester of each year. Anastrepha and Neosilba species remained in the orchards throughout both years. (author)

  7. Effect of Maruca vitrata (Lepidoptera: Crambidae) host plants on life-history parameters of the parasitoid Apanteles taragamae (Hymenoptera: Braconidae)

    Institute of Scientific and Technical Information of China (English)

    Elie A.Dannon; Manuele Tamò; Cyriaque Agboton; Arnold van Huis; Marcel Dicke

    2012-01-01

    The effect of four host plant species of the herbivore Maruca vitrata Fabricius (Lepidoptera:Crambidae) on development time,longevity,fecundity and sex ratio of the parasitoid Apanteles taragamae Viereck (Hymenoptera:Braconidae) was investigated under laboratory conditions.The larvae were parasitized when in the second instar.Maruca vitrata larvae were fed with flowers of four legumes,that is,Vigna unguiculata (cowpea),Sesbania rostrata,Lonchocarpus sericeus and Pterocarpus santalinoides,or an artificial diet both before and after parasitization.The parasitoid did not develop in hosts feeding on L.sericeus or V.unguiculata at 25℃,or on P.santalinoides at 25℃ or 29℃.Apanteles taragaraae had the shortest development time on artificial diet at both 25℃ and 29℃ while the longest development time was recorded on L.sericeus at 29℃.Female wasps took longer to develop compared to males at the two temperatures,regardless of the feeding substrate of their host.The longevity of the wasps at 25℃ varied among feeding substrates,but not at 29℃.Survival rate of parasitized larvae depends on the feeding substrate.Moreover,infection of host larvae with Maruca vitrata multi-nucleopolyhedrovirus (MaviMNPV) killed larger proportions of parasitized larvae at 25℃ than at 29℃,which was likely caused by the difference in parasitoid developmental rate.The proportion of female parasitoids was lowest on L.sericeus.The daily fecundity showed a nonlinear trend regardless of the feeding substrate,indicating that A.taragaraae is a pro-ovigenic species.The data support the slow growth-high mortality hypothesis.

  8. Nonhost diversity and density reduce the strength of parasitoid-host interactions.

    Science.gov (United States)

    Kehoe, Rachel; Frago, Enric; Barten, Catherin; Jecker, Flurin; van Veen, Frank; Sanders, Dirk

    2016-06-01

    The presence of nonprey or nonhosts is known to reduce the strength of consumer- resource interactions by increasing the consumer's effort needed to find its resource. These interference effects can have a stabilizing effect on consumer-resource dynamics, but have also been invoked to explain parasitoid extinctions. To understand how nonhosts affect parasitoids, we manipulated the density and diversity of nonhost aphids using experimental host-parasitoid communities and tested how this affects parasitation efficiency of two aphid parasitoid species. To further study the behavioral response of parasitoids to nonhosts, we tested for changes in parasitoid time allocation in relation to their host-finding strategies. The proportion of successful attacks (attack rate) in both parasitoid species was reduced by the presence of nonhosts. The parasitoid Aphidius megourae was strongly affected by increasing nonhost diversity with the attack rate dropping from 0.39 without nonhosts to 0.05 with high diversity of nonhosts, while Lysiphlebus fabarum responded less strongly, but in a more pronounced way to an increase in nonhost density. Our experiments further showed that increasing nonhost diversity caused host searching and attacking activity levels to fall in A. megourae, but not in L. fabarum, and that A. megourae changed its behavior after a period of time in the presence of nonhosts by increasing its time spent resting. This study shows that nonhost density and diversity in the environment are crucial determinants for the strength of consumer-resource interactions. Their impact upon a consumer's efficiency strongly depends on its host/prey finding strategy as demonstrated by the different responses for the two parasitoid species. We discuss that these trait-mediated indirect interactions between host and nonhost species are important for community stability, acting either stabilizing or destabilizing depending on the level of nonhost density or diversity present. PMID

  9. Influence of temperature on patch residence time in parasitoids: physiological and behavioural mechanisms

    Science.gov (United States)

    Moiroux, Joffrey; Abram, Paul K.; Louâpre, Philippe; Barrette, Maryse; Brodeur, Jacques; Boivin, Guy

    2016-04-01

    Patch time allocation has received much attention in the context of optimal foraging theory, including the effect of environmental variables. We investigated the direct role of temperature on patch time allocation by parasitoids through physiological and behavioural mechanisms and its indirect role via changes in sex allocation and behavioural defences of the hosts. We compared the influence of foraging temperature on patch residence time between an egg parasitoid, Trichogramma euproctidis, and an aphid parasitoid, Aphidius ervi. The latter attacks hosts that are able to actively defend themselves, and may thus indirectly influence patch time allocation of the parasitoid. Patch residence time decreased with an increase in temperature in both species. The increased activity levels with warming, as evidenced by the increase in walking speed, partially explained these variations, but other mechanisms were involved. In T. euproctidis, the ability to externally discriminate parasitised hosts decreased at low temperature, resulting in a longer patch residence time. Changes in sex allocation with temperature did not explain changes in patch time allocation in this species. For A. ervi, we observed that aphids frequently escaped at intermediate temperature and defended themselves aggressively at high temperature, but displayed few defence mechanisms at low temperature. These defensive behaviours resulted in a decreased patch residence time for the parasitoid and partly explained the fact that A. ervi remained for a shorter time at the intermediate and high temperatures than at the lowest temperature. Our results suggest that global warming may affect host-parasitoid interactions through complex mechanisms including both direct and indirect effects on parasitoid patch time allocation.

  10. Trans-generational effects of mild heat stress on the life history traits of an aphid parasitoid.

    Directory of Open Access Journals (Sweden)

    Ibrahim Ismaeil

    Full Text Available Temperature changes are common in nature and insects are particularly exposed and sensitive to such variations which can be potential stresses, ultimately affecting life history traits and overall fitness. Braconids have been widely used to study the effects of temperature on host-parasitoid interactions and the present work focused on the solitary endoparasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae Aphidiidae, an efficient biological control agent commercially used against aphids such as the potato aphid Macrosiphum euphorbiae Thomas (Sternorrhyncha: Aphididae. Contrary to previous studies using heat shocks at extreme temperatures, we evaluated the effects of mild heat stresses by transferring young parasitoid adults from the constant temperature of 20°C to either a warm (25°C or hot (28°C temperature, for either 1 h or 48 h. Such treatments are consistent with situations commonly experienced by parasitoids when moved from their rearing conditions to greenhouses or field conditions. The effects were evaluated both on the heat stressed A. ervi adults (G0 (immediate effects and on their first generation (G1 progeny (trans-generational effects. G0 wasps' mortality was significantly affected by the temperature in interaction with the duration of the stress. Longevity of G0 wasps surviving the heat stress was negatively affected by the temperature and females lived longer than males. Heat stress applied to A. ervi parents also had consequences on their G1 progeny whose developmental time, rates of mummification and percentage of parasitoid completing total development were negatively affected. Surprisingly, the egg load at emergence of the G1 female progeny was increased when their mothers had been submitted to a mild heat stress of 25°C or 28°C. These results clearly demonstrate trans-generational phenotypic plasticity, showing that adaptation to thermal stresses may be achieved via maternal effects. This study also sheds light on

  11. Study of two conditioning methods of parasitoids used in biological control prior to inundative releases in apple orchards

    Directory of Open Access Journals (Sweden)

    Valérie-Anne Dumont

    2011-12-01

    Full Text Available The rosy apple aphid, Dysaphis plantaginea Pass., is a major pest in apple orchards in Belgium. Two micro-hymenopteran parasitoids Aphidius matricariae Haliday and Ephedrus cerasicola Stary are potentially capable of controlling this pest. However, when released in orchards the adult parasitoids tend to disperse. Based on the results of previous work it is proposed that the reason is that the artificial diet in which they are raised does not contain the odors that enable the parasitoids to identify the habitat where there are suitable aphid hosts. To optimize the control and make it economically effective it is important to reduce dispersal. This might be done by conditioning parasitoids during rearing by exposing them to the odors associated with orchards. The odor used in this study was a hydrodistillate of apple leaves, the main host-plant of the targeted aphid. Two methods of conditioning were used: 1 soaking mummies of the parasitoid in p ure hydrodistillate, 2 including a defined concentration of hydrodistillate in the artificial diet used for rearing the parasitoid. They were exposed to either a dilution of 100×, 200× and 1000× in two consecutive generations. The response of adult parasitoids to odors was determined using a dual choice olfactometer. Of the E. cerasicola conditioned by soaking the mummies 70–75% of individuals were attracted to the odor of plants infested with D. plantaginea compared to the 55–60% in the controls. The A.matricariae that were conditioned by feeding them artificial diets containing different concentrations of apple odor for one or two generations, showed no preference for the odor of apple leaves. Second generation adults of E. cerasicola exposed to a 200 times dilution of pure hydrodistillate showed a more marked response to apple odor.

  12. Survival to parasitoids in an insect hosting defensive symbionts: a multivariate approach to polymorphic traits affecting host use by its natural enemy.

    Directory of Open Access Journals (Sweden)

    Emilie Bilodeau

    Full Text Available Insect parasitoids and their insect hosts represent a wide range of parasitic trophic relations that can be used to understand the evolution of biotic diversity on earth. Testing theories of coevolution between hosts and parasites is based on factors directly involved in host susceptibility and parasitoid virulence. We used controlled encounters with potential hosts of the Aphidius ervi wasp to elucidate behavioral and other phenotypic traits of host Acyrthosiphon pisum that most contribute to success or failure of parasitism. The host aphid is at an advanced stage of specialization on different crop plants, and exhibits intra-population polymorphism for traits of parasitoid avoidance and resistance based on clonal variation of color morph and anti-parasitoid bacterial symbionts. Randomly selected aphid clones from alfalfa and clover were matched in 5 minute encounters with wasps of two parasitoid lineages deriving from hosts of each plant biotype in a replicated transplant experimental design. In addition to crop plant affiliation (alfalfa, clover, aphid clones were characterized for color morph (green, pink, Hamiltonella defensa and Regiella insecticola symbionts, and frequently used behaviors in encounters with A. ervi wasps. A total of 12 explanatory variables were examined using redundancy analysis (RDA to predict host survival or failure to A. ervi parasitism. Aphid color was the best univariate predictor, but was poorly predictive in the RDA model. In contrast, aphid host plant and symbionts were not significant univariate predictors, but significant predictors in the multivariate model. Aphid susceptibility to wasp acceptance as reflected in host attacks and oviposition clearly differed from its suitability to parasitism and progeny development. Parasitoid progeny were three times more likely to survive on clover than alfalfa host aphids, which was compensated by behaviorally adjusting eggs invested per host. Strong variation of the

  13. Identification, activity and function determination of several salivary enzymes secreted by Macrosiphum avenae%麦长管蚜唾液中几种酶的鉴定、活力测定与功能分析

    Institute of Scientific and Technical Information of China (English)

    郭光喜; 刘勇; 杨景娟; 马向真

    2006-01-01

    用Parafilm膜夹营养液法,以两种食料介质饲喂麦长管蚜Macrosiphum avenae 3龄若蚜并收集其唾液,对唾液中的酶类进行了鉴定、活力测定和功能分析.结果表明,在20%蔗糖介质提取液中,鉴定有果胶酶、多酚氧化酶和纤维素酶;在水介质提取液中鉴定有纤维素酶;两种介质提取液中都未鉴定出过氧化物酶.酶活力测定结果表明,在20%蔗糖介质提取液中,每30头蚜虫分泌的果胶酶、多酚氧化酶和纤维素酶的酶活力分别为2.59×10-3U/g、7×10-3U/g和7.89×10-3U/g;在水介质提取液中,纤维素酶活力为3.68×10-3U/g.行为反应试验结果表明,果胶酶处理麦苗的挥发物组分能引起麦长管蚜寄生性天敌燕麦蚜茧蜂Aphidius avenae和捕食性天敌七星瓢虫Coccinellaseptempunctata的嗅觉偏好反应,因此,果胶酶在麦长管蚜取食诱导小麦植株的间接防御反应中具有重要作用.

  14. Altruistic defence behaviours in aphids

    Directory of Open Access Journals (Sweden)

    Brodeur Jacques

    2010-01-01

    Full Text Available Abstract Background Altruistic anti-predatory behaviours pose an evolutionary problem because they are costly to the actor and beneficial to the recipients. Altruistic behaviours can evolve through indirect fitness benefits when directed toward kin. The altruistic nature of anti-predatory behaviours is often difficult to establish because the actor can obtain direct fitness benefits, or the behaviour could result from selfish coercion by others, especially in eusocial animals. Non-eusocial parthenogenetically reproducing aphids form colonies of clone-mates, which are ideal to test the altruistic nature of anti-predatory defence behaviours. Many aphids release cornicle secretions when attacked by natural enemies such as parasitoids. These secretions contain an alarm pheromone that alerts neighbours (clone-mates of danger, thereby providing indirect fitness benefits to the actor. However, contact with cornicle secretions also hampers an attacker and could provide direct fitness to the actor. Results We tested the hypothesis that cornicle secretions are altruistic by assessing direct and indirect fitness consequences of smearing cornicle secretions onto an attacker, and by manipulating the number of clone-mates that could benefit from the behaviour. We observed parasitoids, Aphidius rhopalosiphi, foraging singly in patches of the cereal aphid Sitobion avenae of varied patch size (2, 6, and 12 aphids. Aphids that smeared parasitoids did not benefit from a reduced probability of parasitism, or increase the parasitoids' handling time. Smeared parasitoids, however, spent proportionately more time grooming and less time foraging, which resulted in a decreased host-encounter and oviposition rate within the host patch. In addition, individual smearing rate increased with the number of clone-mates in the colony. Conclusions Cornicle secretions of aphids were altruistic against parasitoids, as they provided no direct fitness benefits to secretion

  15. Seismic structure and dynamics of cratons: Stability and modification, continental collision and subduction

    Science.gov (United States)

    Lebedev, Sergei; Meier, Thomas; Schaeffer, Andrew J.; Agius, Matthew R.; Adam, Joanne M.-C.

    2014-05-01

    relatively low shear-wave speeds in the mantle lithosphere. This anomaly is present in regions of both Proterozoic and Archean crust, which suggests an alteration of the mantle lithosphere after the formation of the cratons. In orogenies, cratons generally resist deformation and subduction. Collisions of cratonic blocks, such as seen presently in the western part of the India-Asia convergence zone, can change the character of the orogeny, as well as the motions of the entire tectonic plates that are converging. Beneath western Tibet, cratonic Indian lithosphere has been stripped of its upper crust, pushed down underneath the thick Tibetan crust, and is now colliding with the Tarim Craton to the north. This recent deepening of the cold Indian lithosphere explains the exceptionally high shear speeds (up to 5.0 km/s) within it, higher than beneath any stable cratons with steady-state geotherms. High-velocity anomalies beneath central and eastern Tibet require negative thermal anomalies of hundreds of degrees at depths below 120-150 km, indicating, most likely, subducted Indian lithosphere. The active India-Asia convergence zone thus demonstrates different mechanisms of continental convergence, from craton-craton collision to underthrusting of a craton beneath thick orogenic crust and to shallow-angle subduction of cratonic lithosphere. References Agius, M. R., S. Lebedev. Tibetan and Indian lithospheres in the upper mantle beneath Tibet: Evidence from broadband surface-wave dispersion. Geochem. Geophys. Geosyst. 14, 4260-4281, doi:10.1002/ggge.20274, 2013. Legendre, C., T. Meier, S. Lebedev, W. Friederich, L. Viereck-Goette. A shear-wave velocity model of the European upper mantle from automated inversion of seismic shear and surface waveforms. Geophys. J. Int. 191, 282-304, 2012. Schaeffer, A. J., S. Lebedev. Global shear-speed structure of the upper mantle and transition zone. Geophys. J. Int. 194, 417-449, 2013.

  16. 江西省烟田主要害虫及其天敌种群动态%Population Dynamics of the Main Pests and Natural Enemies in Tobacco Fields in Jiangxi Province

    Institute of Scientific and Technical Information of China (English)

    徐昭焕; 罗妹; 喻敏; 张超群; 王建国

    2013-01-01

    通过采用5点调查法,对江西省南昌市烟田主要害虫及其天敌种群数量进行调查并对其进行动态分析。结果显示:烟蚜在烟草整个生长期均有发生,其种群数量动态变化呈双峰曲线,第1个蚜量高峰期出现在6月初,第2个蚜量高峰期出现在6月末至7月初,且蚜量雨后显著降低,雨后高温则又明显增加。烟青虫和斑须蝽在5月初开始发生,其种群数量动态变化均呈单峰曲线。烟青虫虫量高峰期出现在5月末至6月初,斑须蝽虫量高峰期则在6月中旬。烟田内主要天敌有烟蚜茧蜂、蜘蛛类、瓢虫和草蛉。天敌与烟蚜、烟青虫具一定的虫量跟随关系,其中烟蚜茧蜂和草蛉分别在烟草生长前后期与烟蚜跟随关系明显,蜘蛛则在烟青虫发生后与其跟随关系较为明显。%Based on the survey method of five points, we investigated into the population of the pests and natural enemies in tobacco fields in Nanchang, Jiangxi Province, and analyzed their dynamic changes. The experimental results indicated that the population of Myzus persicae had two peaks within a year, the first in early June, and the second from the end of June to early July. Also the population of M. persicae decreased significantly after the rain, and then increased significantly after high temperature. The population of Helicoverpa assulta and Dolycoris baccarum, respectively, had one peak within a year. The peak of H. assulta population occurred from the end of May to early June, and the peak of D. baccarum population occurred in the middle of June. The main natural enemies of the pests in tobacco fields included Aphidius gifuensis, spiders, lacewings and lady beetles. These natural enemies showed synchronization with M. persicae and H. assulta. Of the natural enemies, A. gifuensis and lady beetles, respectively, showed obvious synchronization with M. persicae at the early or later period of the tobacco growth, and

  17. Why does the Size of the Laacher See Magma Chamber and its Caldera Size not go together? - New Findings with regard to Active Tectonics in the East Eifel Volcanic Field

    Science.gov (United States)

    Schreiber, Ulrich; Berberich, Gabriele

    2013-04-01

    . 2002). Our research findings suggest that due to the slow movement rates of active tectonic faults, an estimated 18 km³ magma chamber within the brittle fracture section of the earth's crust beneath the Laacher See (v. d. Bogaard & Schmincke 1984) cannot be confirmed yet. Another discrepancy is given by a comparison of modeling of caldera evolution (Acocella 2007) with the Laacher See Caldera formation. The Laacher See caldera has a volume of 0.5 km³ with regard to the pre-eruptive surface (Viereck & v.d. Bogaard 1986). According to v. d. Bogaard & Schmincke (1984) a volume of 6.3 km³ dry rock equivalent of lava and basic rock was erupted. This magnitude is contradictory to the calculated 0.5 km³ volume of the Laacher See caldera. A volume compensation of approx. 6 km³ which could have prevented a further subsidence of the magma chamber cannot be a scientific possible explanation. This hypothesis is strengthened by performed sonar recordings of the post-eruptive Laacher See sediment layers which do not show any displacements that might indicate a doming caused by magma. Estimations of the erupted tephra volume provided the basis for the calculation of the size of the Laacher See magma chamber (v.d. Bogaard 1983), but there is no statistical significant data set with regard to spatial distribution of the erupted tephra amount. Our findings show an overestimation of the tephra thickness in published isopach maps of the Westerwald. Therefore, an order of magnitude smaller magma chamber stretched over a longer vertical crustal section can help to better match the given tectonic movement rates and the size of the caldera. To estimate the future development of the East Eifel volcanic field, a good knowledge of the active tectonics is an absolute prerequisite. Along the "Laacher See Strike-slip Fault", an area of intensive micro-seismicity and a new seismically active zone with local magnitudes up to 4 has developed over the last 40 years (Hinzen 2003). In the last