Do boll weevils really diapause?

Science.gov (United States)

Boll weevil, Anthonomus grandis grandis Boheman, diapause has been poorly understood since the term was first used 50 yrs ago to describe the pest’s winter dormancy in temperate regions. This literature-based study found that low temperature and changes in photoperiod are the boll weevil diapause-i...

Boll weevil (Anthonomus grandis) population genomics as a tool for monitoring and management

Science.gov (United States)

Despite the success of eradication efforts across most of the cotton-producing regions of the U.S., the cotton boll weevil (Anthonomus grandis grandis Boheman) remains a major pest of cotton in much of the New World. The area along the Texas border with northern Mexico has been a particularly troub...

Evaluation of bioassays for testing Bt sweetpotato events against ...

African Journals Online (AJOL)

Sweetpotato weevil (Cylas puncticollis) Boheman is a serious pest throughout Sub-Saharan Africa region and is a big threat to sweetpotato cultivation. Ten transgenic sweetpotato events expressing Cry7Aa1, Cry3Ca1, and ET33-34 proteins from Bacillus thuringiensis (Bt) were evaluated for resistance against C.

Effects of Temperature and Adult Diet on Development of Hypertrophied Fat Body in Prediapausing Boll Weevil (Coleoptera Curculionidae)

Science.gov (United States)

Terence L. Wagner; Eric J. Villavaso

1999-01-01

This study examines the effects of temperature and adult diet on the development of hypertrophied fat bodies in prediapausing adult boll weevils, Anthonomus grandis grandis Boheman. Simulation models derived from this work are used to estimate the minimal ages at which male and female boll weevils exhibit diapause morphology, based on conditions...

Irradiated boll weevils: pheromone production determined by GLC analysis

International Nuclear Information System (INIS)

McGovern, W.L.; McKibben, G.H.; Gueldner, R.C.; Cross, W.H.

1975-01-01

The production of pheromone by Anthonomus grandis Boheman when treated with 10,000 rad of 60 Co gamma irradiation compared favorably with that of control weevils for 5 days; however, feeding (determined by frass collection) was reduced from day one. No direct correlation was found between production of pheromone and elimination of frass

Epidemiology and Molecular Typing of Trypanosoma cruzi in Naturally-Infected Hound Dogs and Associated Triatomine Vectors in Texas, USA.

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Rachel Curtis-Robles

2017-01-01

Full Text Available Trypanosoma cruzi is the etiologic agent of Chagas disease throughout the Americas. Few population-level studies have examined the epidemiology of canine infection and strain types of T. cruzi that infect canines in the USA. We conducted a cross-sectional study of T. cruzi infection in working hound dogs in south central Texas, including analysis of triatomine vectors collected within kennel environments.Paired IFA and Chagas Stat-Pak serological testing showed an overall seroprevalence of 57.6% (n = 85, with significant variation across kennels. Dog age had a marginally significant effect on seropositivity, with one year of age increase associated with a 19.6% increase in odds of being seropositive (odds ratio 95% CI 0.996-1.435; p = 0.055. PCR analyses of blood revealed 17.4% of dogs harbored parasite DNA in their blood, including both seronegative and seropositive dogs. Molecular screening of organs from opportunistically sampled seropositive dogs revealed parasite DNA in heart, uterus, and mammary tissues. Strain-typing showed parasite discrete typing units (DTU TcI and TcIV present in dog samples, including a co-occurrence of both DTUs in two individual dogs. Bloodmeal analysis of Triatoma gerstaeckeri and Triatoma sanguisuga insects collected from the kennels revealed exclusively dog DNA. Vector infection with T. cruzi was 80.6% (n = 36, in which T. gerstaeckeri disproportionately harbored TcI (p = 0.045 and T. sanguisuga disproportionately harbored TcIV (p = 0.029. Tracing infection status across dog litters showed some seropositive offspring of seronegative dams, suggesting infection of pups from local triatomine vectors rather than congenital transmission.Canine kennels are high-risk environments for T. cruzi transmission, in which dogs likely serve as the predominant parasite reservoir. Disease and death of working dogs from Chagas disease is associated with unmeasured yet undoubtedly significant financial consequences because working

Projected future distributions of vectors of Trypanosoma cruzi in North America under climate change scenarios.

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Miroslava Garza

2014-05-01

Full Text Available Chagas disease kills approximately 45 thousand people annually and affects 10 million people in Latin America and the southern United States. The parasite that causes the disease, Trypanosoma cruzi, can be transmitted by insects of the family Reduviidae, subfamily Triatominae. Any study that attempts to evaluate risk for Chagas disease must focus on the ecology and biogeography of these vectors. Expected distributional shifts of vector species due to climate change are likely to alter spatial patterns of risk of Chagas disease, presumably through northward expansion of high risk areas in North America.We forecast the future (2050 distributions in North America of Triatoma gerstaeckeri and T. sanguisuga, two of the most common triatomine species and important vectors of Trypanosoma cruzi in the southern United States. Our aim was to analyze how climate change might affect the future shift of Chagas disease in North America using a maximum entropy algorithm to predict changes in suitable habitat based on vector occurrence points and predictive environmental variables. Projections based on three different general circulation models (CCCMA, CSIRO, and HADCM3 and two IPCC scenarios (A2 and B2 were analyzed. Twenty models were developed for each case and evaluated via cross-validation. The final model averages result from all twenty of these models. All models had AUC >0.90, which indicates that the models are robust. Our results predict a potential northern shift in the distribution of T. gerstaeckeri and a northern and southern distributional shift of T. sanguisuga from its current range due to climate change.The results of this study provide baseline information for monitoring the northward shift of potential risk from Chagas disease in the face of climate change.

Insecticidal activity of floral, foliar, and root extracts of Tagetes minuta (Asterales: Asteraceae) against adult mexican bean weevils (Coleoptera: Bruchidae)

Science.gov (United States)

David K. Weaver; Carl D. Wells; Florence V. Dunkel; Wolfgang Bertsch; Sharlene E. Sing; Shobha Sriharan

1994-01-01

Experiments were conducted to determine speed of action and toxicities of extracts of Tagetes minuta L., a source of naturally occurring insecticidal compounds. LC50 values for male and female Mexican bean weevils, Zabrotes subfasciatus (Boheman), were determined for floral, foliar, and root extracts of T. minuta. The 24-h LC50 values ranged from 138 μ g/cm2 for males...

Plagiometriona emarcida (Boheman, 1855) and Plagiometriona forcipata (Boheman, 1855) (Coleoptera: Chrysomelidae: Cassidinae), a single species differing in larval performace and adult phenotype

Czech Academy of Sciences Publication Activity Database

Flinte, V.; Windsor, D.; Sekerka, Lukáš; de Macedo, M. V.; Monteiro, R. F.

2010-01-01

Roč. 44, 15-16 (2010), s. 891-904 ISSN 0022-2933 Institutional research plan: CEZ:AV0Z50070508 Keywords : Cassidinae * Plagiometriona * synonymy Subject RIV: EG - Zoology Impact factor: 0.782, year: 2010

Residues of Malathion and Metabolites in and on the Cotton Leaf vs. Toxicity to the Boll Weevil

Science.gov (United States)

D.A. Wolfenbarger

2002-01-01

Malathion was applied at 12 and 16 oz [A.l.]/a to cotton near Mercedes, TX, in 1995 and sampled on 0, 2, 4 and 6 d posttreatment to determine residues of malathion, malaoxon, and iso-malathion. Residues were then compared to determine toxicity to boll weevil, Anthonomus grandis Boheman. Residues of malathion comprised 99% of the leaf washes and 100% of the leaf...

Boll weevils: field and laboratory assessment of mating ability and sperm content after irradiation with or without diflubenzuron treatment

International Nuclear Information System (INIS)

Villavaso, E.J.; Earle, N.W.; Hollier, D.D.

1977-01-01

Sperm depletion did not occur within the 1st week after irradiated males and females of Anthonomus grandis Boheman were released together into isolated field plots. Also, survival and mating ability did not differ as a result of treatment. The treatments were: irradiation of 4-day-old adults plus diflubenzuron (N-(4-chlorophenyl). N 1 -(2,6-difluorobenzoyl) urea)), fractionated irradiation of pupae, and fractionated irradiation of adults plus diflubenzuron

[Biological characteristics of the egg phase of citrus root weevils].

Science.gov (United States)

Guedes, Jerson V C; Parra, José R P

2007-01-01

The goal of this work was to study some characteristics of the egg phase of three species of citrus root weevils. The insects were collected from citrus plants in Itapetininga, SP, and brought to the Laboratório de Biologia de Insetos of ESALQ/USP, in Piracicaba, SP, where the species Naupactus cervinus (Boheman), Naupactus versatilis (Hustache) and Parapantomorus fluctuosus (Boheman) were kept. Duration and viability of the egg phase were evaluated, and the lower temperature threshold and thermal constant (K) were calculated for these species. The species of citrus root weevils showed different duration of egg phases. The egg phase ranged from 40.4 to 13.8 N. cervinus, from 38.7 to 20.0 days for N. versatilis, and from 35.0 to 13.8 days for P. fluctuosus, depending upon temperature. The temperature thresholds of this stage were 8.1, 8.3, and 9.9 masculineC at thermal constant was 385.7, 397.7 and 294.1 degree-days, for N. cervinus, N. versatilis and P. fluctuosus respectively. The duration of the egg phases of N. cervinus and N. versatilis were similar at the same temperatures and P. fluctuosus had a faster development than Naupactus spp. in all temperatures tested.

Epidemiology and Molecular Typing of Trypanosoma cruzi in Naturally-Infected Hound Dogs and Associated Triatomine Vectors in Texas, USA

Science.gov (United States)

Curtis-Robles, Rachel; Snowden, Karen F.; Dominguez, Brandon; Dinges, Lewis; Rodgers, Sandy; Mays, Glennon

2017-01-01

Background Trypanosoma cruzi is the etiologic agent of Chagas disease throughout the Americas. Few population-level studies have examined the epidemiology of canine infection and strain types of T. cruzi that infect canines in the USA. We conducted a cross-sectional study of T. cruzi infection in working hound dogs in south central Texas, including analysis of triatomine vectors collected within kennel environments. Methodology/Principle Findings Paired IFA and Chagas Stat-Pak serological testing showed an overall seroprevalence of 57.6% (n = 85), with significant variation across kennels. Dog age had a marginally significant effect on seropositivity, with one year of age increase associated with a 19.6% increase in odds of being seropositive (odds ratio 95% CI 0.996–1.435; p = 0.055). PCR analyses of blood revealed 17.4% of dogs harbored parasite DNA in their blood, including both seronegative and seropositive dogs. Molecular screening of organs from opportunistically sampled seropositive dogs revealed parasite DNA in heart, uterus, and mammary tissues. Strain-typing showed parasite discrete typing units (DTU) TcI and TcIV present in dog samples, including a co-occurrence of both DTUs in two individual dogs. Bloodmeal analysis of Triatoma gerstaeckeri and Triatoma sanguisuga insects collected from the kennels revealed exclusively dog DNA. Vector infection with T. cruzi was 80.6% (n = 36), in which T. gerstaeckeri disproportionately harbored TcI (p = 0.045) and T. sanguisuga disproportionately harbored TcIV (p = 0.029). Tracing infection status across dog litters showed some seropositive offspring of seronegative dams, suggesting infection of pups from local triatomine vectors rather than congenital transmission. Conclusions/Significance Canine kennels are high-risk environments for T. cruzi transmission, in which dogs likely serve as the predominant parasite reservoir. Disease and death of working dogs from Chagas disease is associated with unmeasured yet

Effect of diameter of the cotton squares in the development of boll weevil Efeito do diâmetro do botão floral no desenvolvimento do bicudo-do-algodoeiro

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Marcos Doniseti Michelotto

2007-01-01

Full Text Available The objective of this work was to study the effect of diameter of the cotton squares in the corporal mass of adults of boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae. The assay was carried out under field and laboratory conditions, in Jaboticabal, São Paulo State, Brazil. Six samplings obtained from a random harvesting of ten plants of each cultivar (Coodetec 405 and Fibermax 986. The number and diameter of squares were recorded for each plant. Squares with oviposition orifices were kept individually in a recipient and observed daily until adult emergence. The larger the diameter of the squares, the more corporal mass of boll weevil newly emerged adults in both cultivars.O objetivo deste trabalho foi estudar o efeito do diâmetro dos botões florais de algodoeiro na massa corporal de adultos do bicudo-do-algodoeiro, Anthonomus grandis Boheman (Coleoptera: Curculionidae. O experimento foi realizado em condições de campo e laboratório, em Jaboticabal (SP, Brasil. Foram realizadas seis amostragens, coletando-se ao acaso dez plantas nas cultivares Coodetec 405 e Fibermax 986, avaliando-se o número e o diâmetro de botões florais. Os botões florais com orifícios de oviposição foram individualizados em frascos e observados diariamente para a visualização da emergência dos adultos. Botões florais com maiores diâmetros proporcionam maior massa corporal de adultos de A. grandis recém-emergidos nas duas cultivares.

Estirpes de Bacillus thuringiensis efetivas contra insetos das ordens Lepidoptera, Coleoptera e Diptera Bacillus thuringiensis strains effective against insects of Lepidoptera, Coleoptera and Diptera orders

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Lílian Botelho Praça

2004-01-01

Full Text Available O objetivo deste trabalho foi selecionar entre 300 estirpes de Bacillus thuringiensis as efetivas simultaneamente contra larvas de Spodoptera frugiperda J.E. Smith e Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae, Anthonomus grandis Boheman (Coleoptera: Curculionidae, Aedes aegypti Linnaeus e Culex quinquefasciatus Say (Diptera: Culicidae. Foram selecionadas duas estirpes de B. thuringiensis, denominadas S234 e S997, que apresentaram atividade contra as três ordens de insetos. As estirpes foram caracterizadas por métodos morfológicos, bioquímicos e moleculares. As mesmas apresentaram duas proteínas principais de 130 e 65 kDa, produtos de reação em cadeia da polimerase de tamanho esperado para a detecção dos genes cry1Aa, cry1Ab, cry1Ac, cry1B e cry2 e cristais bipiramidais, cubóides e esféricos.The aim of this work was to select among 300 strains of Bacillus thuringiensis those which are simultaneously effective against larvae of Spodoptera frugiperda J.E. Smith and Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae, Anthonomus grandis Boheman (Coleoptera: Curculionidae, Aedes aegypti Linnaeus and Culex quinquefasciatus Say (Diptera: Culicidae. Two strains of B. thuringiensis were selected, S234 and S997, which presented activity against those three insect orders. Both strains were characterized by morphological, biochemical and molecular methods. They have presented two main proteins with 130 and 65 kDa, polimerase chain reaction products with expected sizes for detection of the genes cry1Aa, cry1Ab, cry1Ac, cry1B and cry2 and bipiramidal, cubical and spherical crystals.

Mechanical damage in cotton buds caused by the boll weevil

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Santos Roseane Cavalcanti

2003-01-01

Full Text Available The boll weevil (Anthonomus grandis Boheman causes high levels of bud abscission in cotton plants due to feeding or oviposition punctures. It has been reported that abscission is mainly due to enzymes present in the insect's saliva, but mechanical damage could also contribute to square abscission. The objective of this paper was to undertake an analysis of the morphological damages caused by the insect in cotton squares using microscopy. Anthers and ovules are the main target of boll weevil feeding. The process initiates by perforation of young sepal and petal tissues and proceeds with subsequent alimentation on stamen and ovary leading to abscission of floral structures.

Eradication of the cotton boll weevil (Anthonomus grandis) in the United States - A successful multi-regional approach

International Nuclear Information System (INIS)

Cunningham, Gary L.; Grefenstette, William J.

2000-01-01

The cotton boll weevil, Anthonomus grandis Boheman, is believed to have entered the US from Mexico and was first detected in South Texas in 1892. Since that time, the pest has spread throughout most of the nation's cotton-producing areas and has become the industry's number one nemesis. More than US$13 billion in economic losses have occurred since its introduction, with recent annual expenditures of more than US$300 million for control costs alone. Although the weevil has been eradicated from over 4 million acres, its presence in non-programme areas continues to dictate production practices within the mid-south, Texas and Oklahoma

Fractionated vs acute irradiation: the effects of treating adult boll weevils (Coleoptera: Curculionidae) at different ages

International Nuclear Information System (INIS)

Haynes, J.W.; Wright, J.E.; Mattix, E.

1979-01-01

When 6-7 days old mass-reared ebony boll weevils, Anthonomus grandis Boheman, were given 25 doses of γ-irradiation totaling 6625 rads, mortality was 14%-15% less 1 week later than when young weevils (1-2 day-old) were similarly treated. However, giving older weevils an acute dose of 6625 rads did not reduce mortality. Seven-day-old weevils receiving the acute treatment mated 10% more than weevils that were 3 days old at the time of treatment. Seven-day-old male weevils exposed to the fractionated treatment transferred sperm to 12% more females than 7-day-old males exposed to the acute treatment. (Auth.)

Boll weevil (Coleoptera: Curculionidae) response to and volatilization rates of grandlure when combined with varying doses of eugenol in the extended-life pheromone lure.

Science.gov (United States)

Armstrong, J S

2010-04-01

Boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), trapping and pheromone quantitative analysis of extended-life pheromone lures manufactured with 0, 10, 20, and 30 mg of eugenol was conducted in the Rio Grande Valley of Texas under spring and summer conditions. Boll weevils responded positively to eugenol on one of 12 trapping weeks when densities were high, but when densities were low (30 degrees C, accumulative grandlure loss per week may be too high, leaving too little residual grandlure to effectively attract boll weevils at the end of 3 wk of trapping. Eugenol plays no role in reserving or encouraging the release of grandlure, or in increasing boll weevil captures when boll weevil densities are low.

Description of the immature stages of the weevil Anthonomus vis Clark (Coleoptera, Curculionidae, inquiline into the gall of Leandra aurea (Melastomataceae

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Daniela de Cassia Bená

2013-12-01

Full Text Available Description of the immature stages of the weevil Anthonomus vis Clark (Coleoptera, Curculionidae, inquiline into the gall of Leandra aurea (Melastomataceae. The third instar larva and the pupa of Anthonomus vis Clark, 1992 are described and illustrated, based upon specimens collected in the Serra de São José, Tiradentes, in Minas Gerais, southeastern Brazil. The species was previously known from the type series collected in the states of Amapá and Pará. Comparisons with the larva and pupa of A. grandis Boheman, 1843 and A. monostigma Champion, 1903 are included. The larvae of A. vis live as inquilines in the galls induced by a species of momphid moths (Lepidoptera, Momphidae in the stems of Leandra aurea (Cham. Cogn. (Melastomataceae.

A revision of thirteen species of Triatominae (Hemiptera: Reduviidae vectors of Chagas disease in Mexico

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Salazar-Schettino Paz Maria

2010-10-01

Full Text Available Vectors of Trypanosoma cruzi, parasite responsible for Chagas disease, are divided in intradomestic, peridomestic and sylvatic. The intradomestic are Triatoma barberi and Triatoma dimidiata, two species that represent the highest health risk among the Mexican population. Triatoma dimidiata is a species found mainly inside human habitats, but in Yucatan, it corresponds to the peridomicile vectors. Also in the peridomicile most of Chagas disease vectors are found: Meccus bassolsae, M. longipennis, M. mazzottii, M pallidipennis, M. phyllosomus, M picturata, Triatoma gerstaeckeri, T mexicana, T rubida, Dipetalogaster máxima (the last two are in the process of becoming adapted to the domicile, Panstrongylus rufotuberculatus which occasionally enters the domicile in its adult stage, and Rhodnius prolixus, which is practically controlled in the country. Peridomestic vectors are of lower risk in the transmission dynamics, as compared to the intradomestic ones. For the control of the intradomestic vectors, health education programs, improvements of housing, and the use of pesticides are essential To control the peridomestic vectors, health education programs are required, as well as the use of mosquito nets on doors and windows and around beds, aside from cementing the stone wall fences.

Lufenuron impact upon Anthonomus grandis Boheman (Coleoptera: Curculionidae) midgut and its reflection in gametogenesis.

Science.gov (United States)

Costa, Hilton Nobre; da Cunha, Franklin Magliano; Cruz, Glaucilane Santos; D'assunção, Carolline Guimarães; Rolim, Guilherme Gomes; Barros, Maria Edna Gomes; Breda, Mariana Oliveira; Teixeira, Alvaro Aguiar Coelho; Teixeira, Valéria Wanderley

2017-04-01

The insecticide Match® (lufenuron), one of the main insect growth regulators used in pest control, has been presented as a viable alternative against the boll weevil, Anthonomus grandis (Coleoptera: Curculionidae), by inhibiting chitin synthesis. Thus, this study aimed to examine whether Match® interferes in the synthesis of the peritrophic matrix, leading to changes in the midgut epithelium, resulting in nutritional deficiency and reflecting, thereby, in the gametogenesis process of A. grandis. Floral cotton buds were immersed in the insecticide solution (800μL of Match®+200mL of distilled water) and offered to the adult insects. The midguts of the insects were evaluated after 24 and 120h after feeding. The gonads were evaluated after 120h. The results showed that Match®, in both evaluation periods, induced histopathological alterations such as disorganization, vacuolization and desquamation of the midgut epithelium; histochemical modifications in the distribution patterns of carbohydrates, although without quantitative changes; and a strong decrease in protein levels. No apoptosis were observed, however, there was an increase in the number of regenerative cell nests. In the testicles, a reduction in the amount of spermatozoids and reduced carbohydrate levels were observed, but no difference in protein levels. The ovarioles presented structural disorganization of follicular cells, yolk reduction and decrease in protein levels, however, no change in carbohydrates levels was noted. Therefore, it is concluded that Match® performs histopathologic and histochemical alterations in the midgut epithelium and the gonads of A. grandis adults, reflecting in the gametogenesis process, presenting itself as a promising tool in the management of this pest on cotton crops. Copyright © 2016 Elsevier Inc. All rights reserved.

Mutantes morfológicos de algodoeiro herbáceo como fonte de resistência ao bicudo Morphological mutants of upland cotton as source of boll weevil resistance

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Francisco das Chagas Vidal Neto

2005-02-01

Full Text Available Este trabalho teve como objetivo avaliar os efeitos de três características morfológicas mutantes de linhagens de algodoeiro herbáceo (Gossypium hirsutum L. r. latifolium Hutch., isoladas ou combinadas no mesmo genótipo, como fonte de resistência ao bicudo, Anthonomus grandis Boheman, 1843 (Coleoptera, Curculionidae. O experimento foi conduzido em campo, sob infestação natural, com delineamento de blocos ao acaso e arranjo fatorial 2´3 com um tratamento adicional, com quatro repetições. Em teste com chance de escolha, a característica bráctea frego foi a que apresentou maior redução no dano de oviposição pelo bicudo (34,71%, em relação ao equivalente normal. A folha "okra" reduziu o dano apenas quando associada à bráctea frego (40%. A combinação das três características mutantes na mesma planta proporcionou a menor porcentagem de botões com dano de oviposição (23,13%.This work aimed to evaluate the effects of three morphological mutants of upland cotton lines (Gossypium hirsutm L. r. latifolium Hutch., isolated or in combination in the same cotton genotype, as a source of resistance to boll weevil, Anthonomus grandis Boheman, 1843 (Coleoptera, Curculionidae. The experiment was carried out in the field, under natural infestation, with a completely randomized block design arranged in a factorial 2´3 plus an additional treatment, with four replications. In a multiple choice test, the character mutant frego bract presented the higher reduction on boll weevil oviposition damage (34.71%, in relation to the normal equivalent. The okra leaf reduced the boll weevil damage only when associated with frego bract (40%. The combination of the three mutant characters in the same plant presented the least square percent with oviposition damage (23.13%.

First records of Chrysomelidae (Insecta, Coleoptera on blueberries in Argentina: new associations between native chrysomelids and an exotic crop Primeros registros de Chrysomelidae (Insecta, Coleoptera sobre arándanos en Argentina: nuevas asociaciones entre crisomélidos nativos y un cultivo exótico

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Nora Cabrera

2012-06-01

Full Text Available The blueberry, Vaccinium corymbosum L. (Ericaceae, is a shrub native to the northern Hemisphere introduced in Argentina, where it occupies small cultivated areas mainly in the provinces of Buenos Aires, Entre Ríos and Tucumán. At present, little is known about insects associated with this crop in Argentina. The aim of this study was to identify the species of Chrysomelidae present in blueberry crops in different regions of Argentina, and to present new chrysomelids-blueberry associations. Identification diagnosis, geographical distribution, association with other plants and aspects of their biology is given for each species. Seven species of crop-damaging Chrysomelidae were recorded in blueberry crops of Buenos Aires and Entre Rios. They belong to the subfamilies Galerucinae: Diabrotica speciosa (Germar, Disonychodes exclamationis (Boheman, Caeporis stigmula Germar, and Cacoscelis melanoptera Germar; Eumolpinae: Percolaspis varia (Lefèvre, and Spintherophyta semiaurata (Klug; and Cryptocephalinae: Lexiphanes coenobita Suffrian.El arándano, Vaccinium corymbosum L. (Ericaceae, es un arbusto nativo del hemisferio Norte, que fue introducido en la Argentina donde ocupa pequeñas áreas cultivadas, principalmente en las provincias de Buenos Aires, Entre Ríos y Tucumán. Hasta la actualidad, se conoce poco sobre los insectos asociados con este cultivo. El objetivo de este trabajo es relevar las especies de crisomélidos presentes en los cultivos de arándano de diferentes regiones, y aportar nuevas asociaciones crisomélidos-arándano para la Argentina. Para cada especie registrada, se brinda la diagnosis para su reconocimiento, su distribución geográfica, la asociación con otras plantas y algunos aspectos de su biología. Se registraron siete especies de Chrysomelidae que utilizan el arándano como recurso alimenticio en las provincias de Buenos Aires y Entre Ríos: subfamilia Galerucinae: Diabrotica speciosa (Germar, Disonychodes

Expression and Chloroplast Targeting of Cholesterol Oxidase in Transgenic Tobacco Plants

Science.gov (United States)

Corbin, David R.; Grebenok, Robert J.; Ohnmeiss, Thomas E.; Greenplate, John T.; Purcell, John P.

2001-01-01

Cholesterol oxidase represents a novel type of insecticidal protein with potent activity against the cotton boll weevil (Anthonomus grandis grandis Boheman). We transformed tobacco (Nicotiana tabacum) plants with the cholesterol oxidase choM gene and expressed cytosolic and chloroplast-targeted versions of the ChoM protein. Transgenic leaf tissues expressing cholesterol oxidase exerted insecticidal activity against boll weevil larvae. Our results indicate that cholesterol oxidase can metabolize phytosterols in vivo when produced cytosolically or when targeted to chloroplasts. The transgenic plants exhibiting cytosolic expression accumulated low levels of saturated sterols known as stanols, and displayed severe developmental aberrations. In contrast, the transgenic plants expressing chloroplast-targeted cholesterol oxidase maintained a greater accumulation of stanols, and appeared phenotypically and developmentally normal. These results are discussed within the context of plant sterol distribution and metabolism. PMID:11457962

Remote sensing techniques for monitoring the Rio Grande Valley cotton stalk destruction program

Energy Technology Data Exchange (ETDEWEB)

Richardson, A.J.; Gerbermann, A.H.; Summy, K.R.; Anderson, G.L. (Department of Agriculture, Weslaco, TX (United States))

1993-09-01

Post harvest cotton (Gossypium hirsutum L.) stalk destruction is a cultural practice used in the Rio Grande Valley to suppress over wintering populations of boll weevils (Anthonomus grandis Boheman) without using chemicals. Consistent application of this practice could substantially reduce insecticide usage, thereby minimizing environmental hazards and increasing cotton production profits. Satellite imagery registered within a geographic information system was used to monitor the cotton stalk destruction program in the Rio Grande Valley. We found that cotton stalk screening procedures based on standard multispectral classification techniques could not reliably distinguish cotton from sorghum. Greenness screening for cotton plant stalks after the stalk destruction deadline was possible only where ground observations locating cotton fields were available. These findings indicate that a successful cotton stalk destruction monitoring program will require satellite images and earth referenced data bases showing cotton field locations.

Immature stages of giants: morphology and growth characteristics of Goliathus Lamarck, 1801 larvae indicate a predatory way of life (Coleoptera, Scarabaeidae, Cetoniinae

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Tomáš Vendl

2016-09-01

Full Text Available The third larval instar of Goliathus goliatus (Drury, 1770, G. orientalis Moser, 1909 and G. albosignatus Boheman, 1857 are described and illustrated for the first time and compared with the immature stages of other Cetoniinae. Larval development of G. goliatus is investigated under laboratory conditions, with particular emphasis on food requirements. These results support the obligatory requirement of proteins in the larval diet. The association between larval morphological traits (e. g., the shape of the mandibles and pretarsus, presence of well-developed stemmata and larval biology is discussed. Based on observations and the data from captive breeds it is concluded that a possible shift from pure saprophagy to an obligatory predaceous way of larval life occurred within the larvae of this genus, which may explain why these beetles achieve such an enormous size.

Cholesterol oxidase interference on the emergence and viability of cotton boll weevil larvae

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Santos Roseane Cavalcanti

2002-01-01

Full Text Available The aim of this work was to evaluate the influence of the enzyme cholesterol oxidase (Coase on emergence and viability of larvae of the cotton boll weevil (Anthonomus grandis Boheman, 1843. A series of bioassays was performed with eggs and neonate larvae exposed to different enzyme concentrations in artificial diet. Larval survival was affected at all enzyme concentrations tested, and the six-day LD50 was 53 mug/mL (CI 95%: 43-59. Coase also interfered with hatching of larvae after eggs were floated for 15 min in Coase solution at different concentrations. Observations at the light and electronic microscopic level of midguts from larvae fed on artificial diet containing 53 mug/mL of Coase and collected at six days revealed highly vacuolated regions in the epithelial cells as well as partial degradation of the basal membrane and microvilli.

Natural and synthetic oviposition stimulants forCatolaccus grandis (Burks) females.

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Guerra, A A; Martinez, S; Sonia Del Rio, H

1994-07-01

Oviposition behavior was elicited fromCatolaccus grandis (Burks) (Hymenoptera: Pteromalidae) females, an ectoparasitoid of the boll weevil,Anthonomus grandis Boheman (Coleoptera: Curculionidae), by smears of freshly cut cotton bolls or smears of extracts prepared with boll weevil damaged or undamaged cotton boll tissues. Oviposition behavior was also elicited fromC. grandis females by smears made withn-pentane,n-hexane,n-heptane, and isooctane. This is the first report of oviposition behavior elicited for any parasitoid by these short-chain saturated hydrocarbons (alkanes), introducing a new concept on the chemical mediation of parasitoid behavior during host selection. Oviposition behavior was also elicited fromC. grandis females by volatiles emanating from an artificial diet devoid of insect components that was specifically developed for the in vitro rearing of ectoparasitoids. The possible use of a synergistic combination ofn-hexane and diet to optimize the mechanized production of noncontaminated eggs is also discussed.

Selective breeding for increased pheromone production in the boll weevil (Coleoptera: Curculionidae)

International Nuclear Information System (INIS)

McCoy, J.R.; Wright, J.E.

1990-01-01

The male boll weevil, Anthonomus grandis grandis Boheman, uses an aggregating pheromone to attract females, after which mating often occurs. Sterile boll weevil release programs depend upon this phenomenon to produce sterile matings with feral females. In an effort to increase the effectiveness of the individual sterile male and thereby reduce the number of sterile males required per hectare, a selective-breeding system was used to increase the total pheromone produced by individual male boll weevils. This breeding program increased the total pheromone production by individual male boll weevils to 4.5 times that of the parent population. After irradiation-induced sterilization, there remained 2.2 times more pheromone produced by the selected strain. Therefore, these sterile weevils should be about 2.2 times more attractive to feral females than the parent weevils now in use, and they have the potential to reduce the number of sterile males required in a sterile release program

Lethal and sublethal effects of selected insecticides and an insect growth regulator on the boll weevil (Coleoptera: Curculionidae) ectoparasitoid Catolaccus grandis (Hymenoptera: Pteromalidae).

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Elzen, G W; Maldonado, S N; Rojas, M G

2000-04-01

A laboratory culture of Catolaccus grandis (Burks), an ectoparasitoid of the boll weevil, Anthonomus grandis grandis Boheman, was exposed to lethal and sublethal doses of insecticides and an insect growth regulator using a spray chamber bioassay. Materials tested were azinphos-methyl, endosulfan, fipronil, malathion, cyfluthrin, dimethoate, spinosad, methyl parathion, acephate, oxamyl, and tebufenozide. At full rates, spinosad was significantly less toxic to female C. grandis than other treatments except endosulfan. Fipronil and malathion were significantly more toxic to females than other treatments. Most of the chemicals tested were highly toxic to male C. grandis; spinosad was least toxic. At reduced rates, most of 4 selected chemicals tested were low in toxicity to C. grandis; however, a reduced rate of malathion was significantly more toxic to females than other treatments. No C. grandis pupae developed from parasitism during a 24-h treatment period with malathion or spinosad. The sex ratio of progeny from sprayed adults appeared to be unaffected by the treatments.

Laboratory and field evaluation of sterile male boll weevil competitiveness

International Nuclear Information System (INIS)

McGovern, W.L.

1976-01-01

The production of pheromone by boll weevils, Anthonomus grandis Boheman, treated with 10,000 rad of CO-60 gamma irradiation compared favorably with that of control weevils for 5 days; however, feeding (determined by frass collection) was reduced from the first day post-treatment. No direct correlation was found between production of pheromone and elimination of frass. Overwintered male boll weevils were found to produce small quantities of pheromone and the ratio of components was less attractive at the same concentration as the standard laboratory formulation of grandlure. Most healthy sterilized male weevils should be more attractive than overwintered males. Laboratory-reared sterilized male boll weevils can be as attractive to female weevils as overwintered field males. Weevils treated with busulfan (1,4-butanediol dimethanesulfonate) alone were more attractive than those treated with combinations of busulfan and hempa. In general, sterilization reduced the attractiveness of laboratory males by about 50 percent. Evidence is presented for the existence of ''super-males.''

The genus Ruteria roudier, 1954 (Curculionidae in Serbia

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Pešić Snežana

2008-01-01

Full Text Available The presence of Ruteria graeca (Caldara, 1973 and R. hypocrita (Boheman, 1837 (93 and 215 specimens respectively was confirmed among other adult soil weevil material collected at 24 localities on the territory of Serbia between 1995 and 2003 for the most part using pitfall traps. Ruteria hypocrita was much more frequent. In both species, males were dominant (36.55 and 37.21%, respectively. Biogeographically, the new Ruteria graeca findings are an impor- tant supplement completing the picture of the mosaic distribution of this species, endemic to the Balkan Peninsula. Until now, the given species was completely unknown in Serbia, i.e., in the central part of the Balkan Peninsula. Our data show a new northern boundary of its distribution. In addition, we provide ecological details about the finding places of both species. Briefly, different deciduous and mixed deciduous-coniferous woods at various altitudes and on different geological substrates are host ecosystems for Ruteria.

Feeding deterrent compounds to the boll weevil,Anthonomus grandis Boheman in Rose-of-Sharon,Hibiscus syriacus L.

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Bird, T G; Hedin, P A; Burks, M L

1987-05-01

The Rose-of-Sharon,Hibiscus syriacus (L.), can be a significant alternate host plant for the boll weevil,Anthonomus gradis (Boh.). Boll weevils are known to be deterred from feeding and ovipositing in the buds unless the calyx is removed. This investigation was initiated to identify calyx allelochemicals that deter feeding with the eventual strategy of breeding for cotton lines high in these allelochemicals in the appropriate tissues. The feeding deterrency of calyx tissue from the buds of Rose-of-Sharon for the boll weevil was confirmed. The most active deterrent fraction was found to contain mostly fatty acids and their methyl esters. Saturated fatty acids and their methyl esters were generally found to be stimulatory, while the unsaturated species were found to be deterrent. Higher quantities of the fatty acids, particularly the unsaturated species, were found in Rose-of-Sharon calyx tissue than in the buds without calyx. This supports the hypothesis developed through the isolational work and testing of standards that the unsaturated fatty acids are significant deterrents of boll weevil feeding.

Stable isotope tracer marking of individual boll weevils

International Nuclear Information System (INIS)

James, W.D.; Showler, A.T.; Armstrong, J.S.; Westbrook, J.K.

2006-01-01

Stable isotope markers have been used to study animal nutrition for several decades and more recently to study the foraging and cultural habits of imported fire ants. In this work, we have extended that effort to evaluate the potential for marking boll weevils, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), with the rare earth element samarium to aid in studies of insect invasion and pest eradication protocols. Neutron activation analysis (NAA) was performed on the marked boll weevils as well as plant material from the cotton squares on which the insects were fed. Samarium levels in non-dosed insects average about 20 ng/g or about 100 pg total element per insect. Our computed average determination limit was 36 pg samarium/weevil. The determination limit for cotton plant squares and leaves averaged 3.5 ng/g and 8.2 ng/g, respectively. These initial results indicate the NAA method is capable of identifying individual marked insects which have assimilated 1 ng of samarium, a ten-fold increase in content over average blank values. (author)

Sunning as a technique for disinfecting stored beans

International Nuclear Information System (INIS)

Chinwada, P.; Giga, D.P.

1996-01-01

The effectiveness of sunning (solar heating) as a small farm technique for controlling the bean bruchids Zabrotes subfasciatus (Boheman) and Acanthoscelides obtectus (Say) was investigated. Bean seeds infested with mixed-stage larvae were placed on clear or black polyethylene sheets or inside polyethylene pouches with clear upper and black lower surfaces and exposed to the sun for five hours each day for 0, 3 and 5 successive days. No live insects emerged from seeds heated in the pouches while the few that emerged from seeds on the black sheets resulted in damage to less than 1% of the seeds. Of the three polyethylene systems used, the clear sheet was the least useful, while the pouches even for only 3 days, were the most effective in eliminating infestations. These studies demonstrated that effective bruchid control can be achieved with daily 5-h exposure periods of seeds for a successive 5-day duration. However, the success of the method of control may be influenced by the time of the year and prevailing environmental conditions

On the identity of some weevil species described by Johann Christian Fabricius (1745-1808) in the Museum of Zoology of Copenhagen (Coleoptera, Cucujoidea, Curculionoidea, Tenebrionoidea).

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Alonso-Zarazaga, Miguel A

2014-01-01

) (from Attelabus), Nerthopssticticus (Fabricius, 1777) (from Curculio), Piezotracheluscrotalariae (Fabricius, 1802) (from Attelabus), and Poropterusgranulatus (Fabricius, 1802) (from Curculio). The junior homonym Brachycerusuva Fabricius, 1792 (non Sparrman, 1785) is replaced by Brachycerusfabricii nom. n. The following new synonymies are established: Brachycerusobesus (Fabricius, 1775) = Curculioscalaris Fabricius, 1777, syn. n., Brachydereslusitanicus (Fabricius, 1781) = Curculiomoratus Fabricius, 1798, syn. n., Brachypera (Brachypera) crinita (Boheman, 1834) = Curculiostriatus Fabricius, 1787, syn. n., Brachysomuserinaceus (Fabricius, 1802) = Brachysomusvillosulus (Germar, 1824), syn. n., Bronchusabruptecostatus (Gyllenhal, 1833) = Curculiospectrum Fabricius, 1802, syn. n., Bronchusnivosus (Sparrman, 1785) = Curculiorecurvus Fabricius, 1802, syn. n., Camptorhinustibialis (Sparrman, 1785) = Rhynchaenusalienatus Fabricius, 1802, syn. n., Coelocephalapionatrirostre (Fabricius, 1802) = Coelocephalapionluteirostre (Gerstäcker, 1854), syn. n., Cyrtoderescristatus (DeGeer, 1778) (Tenebrionidae) = Brachyceruscristatus Fabricius, 1798, syn. n., Desmidophorushebes (Fabricius, 1781) = Curculiotuberculatus Fabricius, 1792, syn. n., Donussalviae (Schrank, 1789) = Curculiodenticornis Fabricius, 1798, syn. n., Exomiasholosericeus (Fabricius, 1802) = Exomiaschevrolati (Boheman, 1842), syn. n., Nerthopssticticus (Fabricius, 1777) = Nerthopsguttatus (Olivier, 1807), syn. n., Phyllobiusoblongus (Linnaeus, 1758) = Curculiomali Fabricius, 1782, syn. n., and Rhinocyllusconicus (Froelich, 1792) = Bruchuspunctatus Fabricius, 1798, syn. n. Bronchussynthesys sp. n. is described to represent the concept of Hipporhinusspectrum sensu Marshall, 1904, a misidentification.

Efficacy of fipronil aerially applied in oil adjuvants and drift retardants against boll weevils, Anthonomus Grandis Boheman (Coleoptera:Curculionidae)

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Joseph E. Mulrooney

2002-01-01

Results of aerial application tests in the field and insecticide transfer tests in the laboratory showed that cottonseed oil was the most effective oil adjuvant to use with fipronil for controlling boll weevils under field conditions and for transferring fipronil from cotton leaf surfaces to boll weevils. The mineral oil and mineral oil + drift retardant more...

Molecular diagnosis of populational variants of Anthonomus grandis (Coleoptera: Curculionidae) in North America.

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Barr, Norman; Ruiz-Arce, Raul; Obregón, Oscar; De Leon, Rosita; Foster, Nelson; Reuter, Chris; Boratynski, Theodore; Vacek, Don

2013-02-01

The utility of the cytochrome oxidase I (COI) DNA sequence used for DNA barcoding and a Sequence Characterized Amplified Region for diagnosing boll weevil, Anthonomus grandis Boheman, variants was evaluated. Maximum likelihood analysis of COI DNA sequences from 154 weevils collected from the United States and Mexico supports previous evidence for limited gene flow between weevil populations on wild cotton and commercial cotton in northern Mexico and southern United States. The wild cotton populations represent a variant of the species called the thurberia weevil, which is not regarded as a significant pest. The 31 boll weevil COI haplotypes observed in the study form two distinct haplogroups (A and B) that are supported by five fixed nucleotide differences and a phylogenetic analysis. Although wild and commercial cotton populations are closely associated with specific haplogroups, there is not a fixed difference between the thurberia weevil variant and other populations. The Sequence Characterized Amplified Region marker generated a larger number of inconclusive results than the COI gene but also supported evidence of shared genotypes between wild and commercial cotton weevil populations. These methods provide additional markers that can assist in the identification of pest weevil populations but not definitively diagnose samples.

First records of Chrysomelidae (Insecta, Coleoptera on blueberries in Argentina: new associations between native chrysomelids and an exotic crop

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Nora CABRERA

2012-01-01

Full Text Available El arándano, Vaccinium corymbosum L. (Ericaceae, es un arbusto nativo del hemisferio Norte, que fue introducido en la Argentina donde ocupa pequeñas áreas cultivadas, principalmente en las provincias de Buenos Aires, Entre Ríos y Tucumán. Hasta la actualidad, se conoce poco sobre los insectos asociados con este cultivo. El objetivo de este trabajo es relevar las especies de crisomélidos presentes en los cultivos de arándano de diferentes regiones, y aportar nuevas asociaciones crisomélidos-arándano para la Argentina. Para cada especie registrada, se brinda la diagnosis para su reconocimiento, su distribución geográfica, la asociación con otras plantas y algunos aspectos de su biología. Se registraron siete especies de Chrysomelidae que utilizan el arándano como recurso alimenticio en las provincias de Buenos Aires y Entre Ríos: subfamilia Galerucinae: Diabrotica speciosa (Germar, Disonychodes exclamationis (Boheman, Caeporis stigmula Germar, Cacoscelis melanoptera Germar; subfamilia Eumolpinae: Percolaspis varia (Lefèvre y Spintherophyta semiaurata (Klug; y subfamilia Cryptocephalinae: Lexiphanes coenobita Suffrian.

FONTES ALTERNATIVAS DE PÓLEN UTILIZADAS PELO BICUDO-DOALGODOEIRO EM DUAS REGIÕES PRODUTORAS DE ALGODÃO NA BAHIA

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JULIANA ALVES DE MACÊDO

2015-01-01

Full Text Available Cotton boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae, is one of the most limiting factors for cotton crop expansion. It presents different biological and behavioral aspects that ensure its success on this agroecosystem. This research aimed to identify pollen sources used by this insect during harvest and intercrop periods of cotton cultivations in Iuiu and Correntina – BA, Brazil; moreover, evaluating Caatinga and Cerrado neighboring areas. Adult insect samplings were made from February to September of 2013, through pheromone traps. Samples were analyzed to identify the pollen types inside the digestive system of insects. The results indicated that the pest explores 22 botanical families as nourishment source, from which 16 in Caatinga and five in Cerrado. Regarding crop samples, eight genera were found in Iuiu and Correntina, being three found in both areas (Angelonia, Mimosa and Myrcia sp.1. Pollen from 26 genera were identified for Caatinga and six for Cerrado, with three genera in common for both (Myrcia sp.2, Eucalyptus, and Mimosa. The boll weevil uses alternative sources of food within the main cotton growing regions in Bahia State, highlighting the Caatinga with most of the botanical families and genera explored by the pest.

Recombinant Cry1Ia protein is highly toxic to cotton boll weevil (Anthonomus grandis Boheman) and fall armyworm (Spodoptera frugiperda).

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Martins, E S; Aguiar, R W D S; Martins, N F; Melatti, V M; Falcão, R; Gomes, A C M M; Ribeiro, B M; Monnerat, R G

2008-05-01

To evaluate the activity of cry1Ia gene against cotton pests, Spodoptera frugiperda and Anthonomus grandis. Had isolated and characterized a toxin gene from the Bacillus thuringiensis S1451 strain which have been previously shown to be toxic to S. frugiperda and A. grandis. The toxin gene (cry1Ia) was amplified by PCR, sequenced, and cloned into the genome of a baculovirus. The Cry1Ia protein was expressed in baculovirus infected insect cells, producing protein inclusions in infected cells. The Cry1Ia protein has used in bioassays against to S. frugiperda and A. grandis. Bioassays using the purified recombinant protein showed high toxicity to S. frugiperda and A. grandis larvae. Molecular modelling of the Cry1Ia protein translated from the DNA sequence obtained in this work, showed that this protein possibly posses a similar structure to the Cry3A protein. Ultrastructural analysis of midgut cells from A. grandis incubated with the Cry1Ia toxin, showed loss of microvilli integrity. The results indicate that the cry1Ia is a good candidate for the construction of transgenic plants resistant to these important cotton pests.

Genetic diversity of Brazilian natural populations of Anthonomus grandis Boheman (Coleoptera: Curculionidae), the major cotton pest in the New World.

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Martins, W F S; Ayres, C F J; Lucena, W A

2007-01-27

Twenty-five RAPD loci and 6 isozyme loci were studied to characterize the genetic variability of natural populations of Anthonomus grandis from two agroecosystems of Brazil. The random-amplified polymorphic DNA data disclosed a polymorphism that varied from 52 to 84% and a heterozygosity of 0.189 to 0.347. The index of genetic differentiation (GST) among the six populations was 0.258. The analysis of isozymes showed a polymorphism and a heterozygosity ranging from 25 to 100% and 0.174 to 0.277, respectively. The genetic differentiation (FST) among the populations obtained by isozyme data was 0.544. It was possible to observe rare alleles in the populations from the Northeast region. The markers examined allowed us to distinguish populations from large-scale, intensive farming region (cotton belts) versus populations from areas of small-scale farming

Repelência e atividade inseticida de pós vegetais sobre Zabrotes subfasciatus Boheman em feijão-fava armazenado

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J.E. Girão Filho

2014-09-01

Full Text Available O objetivo desta pesquisa foi avaliar o potencial inseticida de Piper nigrum L. (pimenta do reino, Ruta graveolens L. (arruda, Laurus nobilis L. (louro, Syzygium aromaticum (L. Merr. & L.M.Perry (cravo da índia, Chenopodium ambrosioides L. (mastruz, Piper tuberculatum Jaqc. (pimenta de macaco, Tagetes erecta L. (cravo de defunto, Cymbopogon nardus L. (citronela e Melissa officinalis L. (erva cidreira sobre Z. subfasciatus Boh. através dos testes de confinamento, onde os insetos foram confinados durante cinco dias em um recipiente contendo dez grãos de feijão-fava com 0,3 g do pó da planta a ser testada, e, com chance de escolha por meio de uma arena circular, os insetos tiveram a possibilidade de escolha entre grãos com os pós e a testemunha, grãos sem pó das plantas. Observou-se que houve plantas que atuaram como inseticida, outras que repeliram o inseto e não causaram a morte, e outras, que além de repelir também mataram os insetos quando em contato (cravo da índia e matruz. Concluímos que: P. nigrum, P. tuberculatum, S. aromaticum e C. ambrosioides são tóxicas à Z. subfasciatus causando-lhes a morte, L. nobilis, T. erecta, e C. nardus não apresentaram efeito tóxico sobre Z. subfasciatus, C. ambrosioides, S. aromaticum, e C. nardus são repelentes à Z. subfasciatus; P. nigrum, P. tuberculatum, e T. erecta são neutras, e que M. officinalis não apresentou nenhum efeito sobre Z. subfasciatus em relação aos parâmetros avaliados.

The Prevalence of Trypanosoma cruzi, the Causal Agent of Chagas Disease, in Texas Rodent Populations.

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Aleman, Adriana; Guerra, Trina; Maikis, Troy J; Milholland, Matthew T; Castro-Arellano, Ivan; Forstner, Michael R J; Hahn, Dittmar

2017-03-01

Rodent species were assessed as potential hosts of Trypanosoma cruzi, the etiologic agent of Chagas disease, from five sites throughout Texas in sylvan and disturbed habitats. A total of 592 rodents were captured, resulting in a wide taxonomic representation of 11 genera and 15 species. Heart samples of 543 individuals were successfully analyzed by SybrGreen-based quantitative PCR (qPCR) targeting a 166 bp fragment of satellite DNA of T. cruzi. Eight rodents representing six species from six genera and two families were infected with T. cruzi. This is the first report of T. cruzi in the pygmy mouse (Baiomys taylori) and the white-footed mouse (Peromyscus leucopus) for the USA. All infected rodents were from the southernmost site (Las Palomas Wildlife Management Area). No differences in pathogen prevalence existed between disturbed habitats (5 of 131 tested; 3.8%) and sylvan habitats (3 of 40 tested; 7.5%). Most positives (n = 6, 16% prevalence) were detected in late winter with single positives in both spring (3% prevalence) and fall (1% prevalence). Additionally, 30 Triatoma insects were collected opportunistically from sites in central Texas. Fifty percent of these insects, i.e., 13 T. gerstaeckeri (68%), and two T. lecticularia (100%) were positive for T. cruzi. Comparative sequence analyses of 18S rRNA of samples provided identical results with respect to detection of the presence or absence of T. cruzi and assigned T. cruzi from rodents collected in late winter to lineage TcI. T. cruzi from Triatoma sp. and rodents from subsequent collections in spring and fall were different, however, and could not be assigned to other lineages with certainty.

Combining Public Health Education and Disease Ecology Research: Using Citizen Science to Assess Chagas Disease Entomological Risk in Texas.

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Rachel Curtis-Robles

2015-12-01

Full Text Available Chagas disease is a zoonotic parasitic disease well-documented throughout the Americas and transmitted primarily by triatomine 'kissing bug' vectors. In acknowledgment of the successful history of vector control programs based on community participation across Latin America, we used a citizen science approach to gain novel insight into the geographic distribution, seasonal activity, and Trypanosoma cruzi infection prevalence of kissing bugs in Texas while empowering the public with information about Chagas disease.We accepted submissions of kissing bugs encountered by the public in Texas and other states from 2013-2014 while providing educational literature about Chagas disease. In the laboratory, kissing bugs were identified to species, dissected, and tested for T. cruzi infection. A total of 1,980 triatomines were submitted to the program comprised of at least seven species, of which T. gerstaeckeri and T. sanguisuga were the most abundant (85.7% of submissions. Triatomines were most commonly collected from dog kennels and outdoor patios; Overall, 10.5% of triatomines were collected from inside the home. Triatomines were submitted from across Texas, including many counties which were not previously known to harbor kissing bugs. Kissing bugs were captured primarily throughout April-October, and peak activity occurred in June-July. Emails to our dedicated account regarding kissing bugs were more frequent in the summer months (June-August than the rest of the year. We detected T. cruzi in 63.3% of tested bugs.Citizen science is an efficient approach for generating data on the distribution, phenology, and infection prevalence of kissing bugs-vectors of the Chagas disease parasite-while educating the public and medical community.

Preferência alimentar do bicudo-do-algodoeiro por frutos de diferentes cultivares e idades

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Busoli Antonio Carlos

2004-01-01

Full Text Available O objetivo deste trabalho foi avaliar a preferência alimentar de adultos do bicudo-do-algodoeiro, Anthonomus grandis Boheman, 1843 (Coleoptera: Curculionidae, por duas cultivares de algodão (Gossypium hirsutum L. com frutos de diferentes idades. Foram realizados quatro experimentos em laboratório, avaliando-se o número de orifícios de alimentação. Maçãs de 2, 8 e 12 dias de idade, das cultivares IAC-20 e Reba P288, foram oferecidas aos insetos, confinados em recipientes, com opção de escolha quanto à idade e cultivar (primeiro experimento, sem opção de escolha quanto à idade e cultivar (segundo experimento, sem opção de escolha quanto à cultivar e com opção quanto a idade (terceiro experimento e sem opção quanto à idade e com opção de escolha quanto à cultivar (quarto experimento. Observou-se preferência por maçãs da cultivar IAC-20 com dois dias de idade, com uma redução de danos de 23,53% e 78,43%, respectivamente, aos oito e aos doze dias de idade.

Replication of Chilo iridescent virus in the cotton boll weevil, Anthonomus grandis, and development of an infectivity assay.

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Henderson, C W; Johnson, C L; Lodhi, S A; Bilimoria, S L

2001-01-01

The boll weevil, Anthonomus grandis Boheman, is a devastating pest of cotton. Chemical pesticides are problematic due to relative lack of target specificity and resistance. Microbial pesticides may provide viable alternatives because of their narrow host range. Chilo iridescent virus (CIV) is the type species for genus Iridovirus, family Iridoviridae: large, icosahedral cytoplasmic viruses containing a double-stranded DNA genome. Earlier work suggested that CIV replicated in the boll weevil; however, efficiency or production of infectious virus was not established. We showed that CIV undergoes a productive cycle in A. grandis. CIV DNA levels in boll weevil pupae increased significantly from 0 to 3 days post infection. Moreover, virogenic stromata and complete virus particles were observed in the cytoplasm by 7 days. An endpoint dilution assay using viral DNA replication as indicator suggested a 10(5)-fold increase in infectious virus titer over 7 days. This is the first such demonstration in larval infections with genus Iridovirus. Our study establishes that CIV undergoes a productive cycle in the boll weevil and provides an important and useful model system for replication at the organismal level. These results have important implications for the potential of CIV and its components in boll weevil control.

Effects of insecticides and defoliants applied alone and in combination for control of overwintering boll weevil (Anthonomus grandis; Coleoptera: Curculionidae)--laboratory and field studies.

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Greenberg, Shoil M; Sappington, Thomas W; Elzen, Gary W; Norman, John W; Sparks, Alton N

2004-09-01

In laboratory, greenhouse and field tests, we determined the effects of combining full rates of the defoliants tribufos and thidiazuron and the herbicide thifensulfuron-methyl with half rates of the insecticides lambda-cyhalothrin or azinphos-methyl, and the combination of tribufos and thidiazuron, both in half rates, on mortality of the boll weevil, Anthonomus grandis grandis Boheman and on the quality of defoliation. Tribufos, 0.47 kg ha(-1) and tribufos, 0.235 kg ha(-1) + thidiazuron, 0.125 kg ha(-1) exhibited a slightly toxic effect to boll weevil, while tribufos, 0.47 kg ha(-1) + lambda-cyhalothrin, 0.019 kg ha(-1), tribufos, 0.47 kg ha(-1) + azinphos-methyl, 0.14 kg ha(-1), and tribufos, 0.235 kg ha(-1) + thidiazuron, 0.125 kg ha(-1) + azinphos-methyl, 0.14 kg ha(-l), provided control of boll weevil as good as or better than full-rate azinphos-methyl or lambda-cyhalothrin alone owing to synergistic effects. Thidiazuron or thifensulfuron-methyl alone or in combination with insecticides did not affect boll weevil mortality. Treatment with tribufos + thidiazuron, both at half rate, significantly increased defoliation compared to full rates of tribufos or thidiazuron alone, and provided adequate defoliation for approximately the same cost per hectare.

Vitellogenin knockdown strongly affects cotton boll weevil egg viability but not the number of eggs laid by females.

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Coelho, Roberta R; de Souza Júnior, José Dijair Antonino; Firmino, Alexandre A P; de Macedo, Leonardo L P; Fonseca, Fernando C A; Terra, Walter R; Engler, Gilbert; de Almeida Engler, Janice; da Silva, Maria Cristina M; Grossi-de-Sa, Maria Fatima

2016-09-01

Vitellogenin (Vg), a yolk protein precursor, is the primary egg nutrient source involved in insect reproduction and embryo development. The Cotton Boll weevil (CBW) Anthonomus grandis Boheman, the most important cotton pest in Americas, accumulates large amounts of Vg during reproduction. However, the precise role of this protein during embryo development in this insect remains unknown. Herein, we investigated the effects of vitellogenin (AgraVg) knockdown on the egg-laying and egg viability in A. grandis females, and also characterized morphologically the unviable eggs. AgraVg transcripts were found during all developmental stages of A. grandis, with highest abundance in females. Silencing of AgraVg culminated in a significant reduction in transcript amount, around 90%. Despite this transcriptional reduction, egg-laying was not affected in dsRNA-treated females but almost 100% of the eggs lost their viability. Eggs from dsRNA-treated females showed aberrant embryos phenotype suggesting interference at different stages of embryonic development. Unlike for other insects, the AgraVg knockdown did not affect the egg-laying ability of A. grandis, but hampered A. grandis reproduction by perturbing embryo development. We concluded that the Vg protein is essential for A. grandis reproduction and a good candidate to bio-engineer the resistance against this devastating cotton pest.

Association of Trypanosoma cruzi infection with risk factors and electrocardiographic abnormalities in northeast Mexico

Science.gov (United States)

2014-01-01

Background American trypanosomiasis is a major disease and public health issue, caused by the protozoan parasite Trypanosoma cruzi. The prevalence of T. cruzi has not been fully documented, and there are few reports of this issue in Nuevo Leon. The aim of this study was to update the seroprevalence rate of T. cruzi infection, including an epidemiological analysis of the risk factors associated with this infection and an electrocardiographic (ECG) evaluation of those infected. Methods Sera from 2,688 individuals from 10 municipalities in the state of Nuevo Leon, Mexico, were evaluated using an enzyme-linked immunosorbent assay and an indirect hemagglutination assay. An ECG case–control study was performed in subjects seropositive for T. cruzi and the results were matched by sex and age to seronegative residents of the same localities. A univariate analysis with χ2 and Fisher’s exact tests was used to determine the association between seropositivity and age (years), sex, and ECG changes. A multivariate analysis was then performed to calculate the odd ratios between T. cruzi seropositivity and the risk factors. Results The seropositive rate was 1.93% (52/2,688). In the ECG study, 22.85% (8/35) of the infected individuals exhibited ECG abnormalities. Triatoma gerstaeckeri was the only vector reported. The main risk factors were ceiling construction material (P ≤ 0.0024), domestic animals (P ≤ 0.0001), and living in rural municipalities (P ≤ 0.0025). Conclusions These findings demonstrate a 10-fold higher prevalence of Chagas disease than previously reported (0.2%), which implies a serious public health threat in northeastern Mexico. The epidemiological profile established in this study differs from that found in the rest of Mexico, where human populations live in close proximity to domiciliary triatomines. PMID:24580840

Trypanosoma cruzi I genotypes in different geographic regions and transmission cycles based on a microsatellite motif of the intergenic spacer of spliced leader genes✯

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Cura, Carolina I.; Mejía-Jaramillo, Ana M.; Duffy, Tomás; Burgos, Juan M.; Rodriguero, Marcela; Cardinal, Marta V.; Kjos, Sonia; Gurgel-Gonçalves, Rodrigo; Blanchet, Denis; De Pablos, Luis M.; Tomasini, Nicolás; Silva, Alex Da; Russomando, Graciela; Cuba Cuba, Cesar A.; Aznar, Christine; Abate, Teresa; Levin, Mariano J.; Osuna, Antonio; Gürtler, Ricardo E.; Diosque, Patricio; Solari, Aldo; Triana-Chávez, Omar; Schijman, Alejandro G.

2011-01-01

The intergenic region of spliced-leader (SL-IR) genes from 105 Trypanosoma cruzi I (Tc I) infected biological samples, culture isolates and stocks from 11 endemic countries, from Argentina to the USA were characterised, allowing identification of 76 genotypes with 54 polymorphic sites from 123 aligned sequences. On the basis of the microsatellite motif proposed by Herrera et al. (2007) to define four haplotypes in Colombia, we could classify these genotypes into four distinct Tc I SL-IR groups, three corresponding to the former haplotypes Ia (11 genotypes), Ib (11 genotypes) and Id (35 genotypes); and one novel group, Ie (19 genotypes). Genotypes harboring the Tc Ic motif were not detected in our study. Tc Ia was associated with domestic cycles in southern and northern South America and sylvatic cycles in Central and North America. Tc Ib was found in all transmission cycles from Colombia. Tc Id was identified in all transmission cycles from Argentina and Colombia, including Chagas cardiomyopathy patients, sylvatic Brazilian samples and human cases from French Guiana, Panama and Venezuela. Tc Ie gathered five samples from domestic Triatoma infestans from northern Argentina, nine samples from wild Mepraia spinolai and Mepraia gajardoi and two chagasic patients from Chile and one from a Bolivian patient with chagasic reactivation. Mixed infections by Tc Ia + Tc Id, Tc Ia + Tc Ie and Tc Id + Tc Ie were detected in vector faeces and isolates from human and vector samples. In addition, Tc Ia and Tc Id were identified in different tissues from a heart transplanted Chagas cardiomyopathy patient with reactivation, denoting histotropism. Trypanosoma cruzi I SL-IR genotypes from parasites infecting Triatoma gerstaeckeri and Didelphis virginiana from USA, T. infestans from Paraguay, Rhodnius nasutus and Rhodnius neglectus from Brazil and M. spinolai and M. gajardoi from Chile are to our knowledge described for the first time. PMID:20670628

Posición taxonómica de Acrotomopus atropunctellus (Coleoptera: Curculionidae y descripción del daño producido en el cultivo de caña de azúcar en la Argentina Taxonomic position of Acrotomopus atropunctellus (Coleoptera: Curculionidae and description of damages to sugar cane crops in Argentina

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M. L. Pilar Pérez

2012-12-01

Full Text Available Acrotomopus atropunctellus (Boheman (Curculionidae: Molytinae: Cholini es una especie de picudo, endémica de la Argentina, que habita principalmente en la provincia biogeográfica de las Yungas; citada como perjudicial para la caña de azúcar en 1929. Hasta hace una década, no se habían producido nuevos reportes de daños, sin embargo, el aumento de la superficie cultivada con caña ha provocado el resurgimiento de la plaga. Morfológicamente, esta especie se asemeja a Acrotomopus wagneri Hustache, distribuida en la provincia biogeográfica del Chaco. Su biología es similar a la de otras especies de la tribu Cholini con larvas minadoras de cañas. Las hembras oviponen en las porciones basal y media de los plantines. Las larvas cavan galerías descendentes hasta alcanzar la cepa para pasar allí el invierno y reducen paulatinamente el rebrote de la caña en las siguientes temporadas. Los adultos producen perforaciones de pequeño diámetro y bordes ásperos en los brotes, macollos, tallos y nervadura central de las hojas. Se brinda una clave dicotómica para separar A. atropunctellus de las otras tres especies del género, todas presentes en la Argentina (A. wagneri, A. microspilotus (Pascoe y A. obtusus (Hustache y se describen los rasgos principales de su ciclo biológico y de los daños ocasionados en cultivos de caña de la provincia de Tucumán. El trabajo incluye fotografías de hábito de las cuatro especies de Acrotomopus, y de la larva y los daños ocasionados por A. atropunctellus.Acrotomopus atropunctellus (Boheman (Curculionidae: Molytinae: Cholini is a weevil species endemic to Argentina, mainly inhabiting the biogeographic province of the Yungas. It was first reported as harmful to sugar cane in 1929. Damages were not cited again until a decade ago, when the species became a serious pest due to the increased sugar cane production. This species is morphologically similar to A. wagneri Hustache that occurs in the Chacoan

Comportamento de progênies oriundas de raças primitivas de algodão herbáceo frente ao ataque do bicudo Behavior of lines from cotton primitive race stocks to attack of the boll weevil

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Francisco José Correia Farias

1999-12-01

Full Text Available Com o objetivo de obter linhagens resistentes ao bicudo-do-algodoeiro (Anthonomus grandis Boheman, a Embrapa-Centro Nacional de Pesquisa de Algodão vem testando progênies oriundas de raças primitivas de algodoeiro herbáceo (Gossypium hirsutum L. originárias do México e da América Central, que apresentam níveis aceitáveis de resistência ao bicudo. Em 1991 e 1992, as progênies em BC1F5 e BC1F6 oriundas das linhagens Texas 277, Texas 326 e Texas 1180, Texas 297, Texas 339, Texas 766 e Texas 1134, foram avaliadas com relação à resistência ao bicudo. O delineamento experimental utilizado foi o de blocos ao acaso, com seis repetições. A unidade experimental foi constituída por duas fileiras de 5 m, sob um espaçamento de 0,75 m x 0,20 m. As parcelas foram infestadas com adultos do bicudo recém-emergidos, a uma taxa de 10.000 adultos/ha. Aos seis dias após a liberação dos adultos, as parcelas foram pulverizadas com Cipermethrim, sendo realizadas em intervalos semanais. Foram procedidas cinco avaliações através da coleta de 33 botões florais ao acaso, por parcela. Os maiores níveis de resistência ao bicudo foram obtidos pelas progênies Texas 326-95-1, Texas 277-87-5, Texas 1180-99-2, Texas 297 e Texas 339, com redução de ataque de 44,0, 41,2, 32,0, 40,4 e 36,4%, respectivamente, em relação à testemunha CNPA 6H.The goal of the boll weevil (Anthonomus grandis Boheman resistance program of Embrapa-Centro Nacional de Pesquisa de Algodão is to obtain cultivars that give 80% suppression when compared to commercial cultivars. The primitive cottons (Gossypium hirsutum L. from Mexico and Central America have been known to show measurable levels of resistance to the boll weevil. In 1991 and 1992, the lines in BC1F5 and BC1F6 from Texas 277, Texas 326, Texas 1180, Texas 297, Texas 339, Texas 766 and Texas 1134 were evaluated to boll weevil resistance. The experiment was carried out at Campina Grande, PB, Brazil. The trial

Spatial distribution of adult Anthonomus grandis Boheman (Coleoptera: Curculionidae and buds with feeding punctures on conventional and Bt cottonDistribuição espacial de adultos e botões com orifício de alimentação de Anthonomus grandis Boheman (Coleoptera: Curculionidae em algodoeiro convencional e Bt

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Paulo Rogerio Beltramin da Fonseca

2013-06-01

Full Text Available O conhecimento dos arranjos de dispersão para adultos e botões com orifício de alimentação de Anthonomus grandis em cultivares de algodoeiro é necessário para aperfeiçoar o monitoramento e controle da praga. Esta pesquisa teve por objetivo realizar análises probabilísticas dos padrões de distribuição espacial dos adultos e botões com orifícios de alimentação de A. grandis em duas cultivares de algodão Bt e não Bt. O estudo foi conduzido a campo em duas áreas experimentais, cada uma composta por 100 parcelas de sete linhas de sete metros de comprimento. Em 16 amostragens avaliaram-se cinco plantas por parcela através da contagem dos adultos e dos botões com orifício de alimentaçãoentre janeiro e maio de 2010. Foram calculados os índices de dispersão (razão variância/média, índice de Morisita e Expoente k da Distribuição Binomial Negativa e as distribuições teóricas de freqüência (Poisson, Binomial Negativa e Binomial Positiva. Não houve diferença estatística entre as cultivares avaliadas. A distribuição espacial dos adultos de A. grandis, nas cultivares Bt e não Bt, ajustou-se nos arranjos probabilísticos de distribuição binomial negativa (agregado e distribuição binomial positiva (uniforme, conforme os dias após a emergência do algodoeiro. As análises de dispersão para os botões com orifícios de alimentação nas culturas Bt e convencional mostraram os modelos espaciais de Poisson (aleatório, distribuição binomial negativa (agregado e distribuição binomial positiva (uniforme, em seqüência, durante o ciclo da cultura.Dispersion patterns of Anthonomus grandis adults and damaged squares with their feeding punctures are important to enhance pest monitoring and control on cotton. In this research we performed probabilistic analyses of the distribution patterns of adults and squares with feeding punctures of A. grandis on two cotton genotypes, Bt and non-Bt near isogenic lines. We conducted the field experiment in two experimental areas; each area had 100 plots composed of seven rows, each seven metros long. Between Jan and May 2010, 16 samplings were made, in each, five plants were evaluated per plot by counting the adults and damaged squares. The dispersion indexes (ratio of the variance/mean, the Morisita index, and Exponent k of the Binomial Negative Distribution and the theoretical distribution of frequencies (Poisson, Negative Binomial and Positive Binomial were calculated. No differences between cotton genotypes were found. The spatial distribution of A. grandis adults fit the Negative Binominal (aggregate and Positive Binominal (uniform distributions, depending on the number of days after cotton emergence. The dispersion analyses of the feeding damaged squares on the Bt and conventional cotton revealed Poisson (random, Negative Binominal (aggregate and Positive Binominal (uniform distribution patterns in sequence during the crop cycle.

Population Development of Zabrotes subfasciatus (Coleoptera: Chrysomelidae) in Landrace Bean Varieties Occurring in Southwestern Amazonia.

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Lopes, L M; Araújo, A E F; Santos, A C V; Santos, V B; Sousa, A H

2016-02-01

The common bean, Phaseolus vulgaris (L.), is one of the most important sources of protein worldwide, and Latin America is one of the recognized centers of diversity of this species. However, storage of this product after harvest is not feasible because of bruchid attacks. This study determined the accumulated normalized rate of emergence and the daily emergence rate of Zabrotes subfasciatus (Boheman) (Coleoptera: Chrysomelidae:Bruchinae) in five landrace varieties of common bean (BRL 01, SNA 01, RDR 01, RBC 01, and RBC 13) that occurin southwestern Amazonia. These varieties were selected for this study because they are well-distributed throughout the Amazonian communities. Beans of each variety were infested with 50 unsexed adults, and the insects were removed 13 d after beginning the bioassays. The adult progeny obtained from the feeding substrate were counted and removed every other day after the first emergence, until the end of the emergence period. Differences were observed in the calculated rates of development; however, the time required for development and emergence of the insects was independent. Of the five varieties of bean investigated, we observed that the RDR 01, BRL 01, and SNA 01 cultivars are resistant to Z. subfasciatus; the results indicate that the use of these three varieties can reduce problems associated with bruchid attacks and enable storage of the product after harvesting.

Boll weevil: experimental sterilization of large numbers by fractionated irradiation

International Nuclear Information System (INIS)

Haynes, J.W.; Wright, J.E.; Davich, T.B.; Roberson, J.; Griffin, J.G.; Darden, E.

1978-01-01

Boll weevils, Anthonomus grandis grandis Boheman, 9 days after egg implantation in the larval diet were transported from the Boll Weevil Research Laboratory, Mississippi State, MS, to the Comparative Animal Research Laboratory, Oak Ridge, TN, and irradiated with 6.9 krad (test 1) or 7.2 krad (test 2) of 60 Co gamma rays delivered in 25 equal doses over 100 h. In test 1, from 600 individual pairs of T (treated) males x N (normal) females, only 114 eggs hatched from a sample of 950 eggs, and 47 adults emerged from a sample of 1042 eggs. Also, from 600 pairs of T females x N males, 6 eggs hatched of a sample of 6 eggs and 12 adults emerged from a sample of 20 eggs. In test 2, from 700 individual pairs of T males x N females, 54 eggs hatched from a sample of 1510, and 10 adults emerged from a sample of 1703 eggs. Also, in T females x N males matings, 1 egg hatched of a sample of 3, and no adults emerged from a sample of 4. Transportation and handling in the 2nd test reduced adult emergence an avg of 49%. Thus the 2 replicates in test 2 resulted in 3.4 x 10 5 and 4.3 x 10 5 irradiated weevils emerging/day for 7 days. Bacterial contamination of weevils was low

Digestion of Starch Granules from Maize, Potato and Wheat by Larvae of the the Yellow Mealworm, Tenebrio molitor and the Mexican Bean Weevil, Zabrotes subfasciatus

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Meireles, Elaine A.; Carneiro, Cíntia N. B.; DaMatta, Renato A.; Samuels, Richard I.; Silva, Carlos P.

2009-01-01

Scanning electron microscopy images were taken of starch granules from different sources following exposure in vivo and in vitro to gut α-amylases isolated from Tenebrio molitor L. (Coleoptera: Tenebrionidae) and Zabrotes subfasciatus Boheman (Coleoptera: Bruchidae). One α-amylase was isolated from whole larval midguts of T. molitor using non-denaturing SDS-PAGE, while two other α-amylase fractions were isolated from whole larval midguts of Z. subfasciatus using hydrophobic interaction chromatography., Digested starch granules from larvae fed on maize, potato or wheat were isolated from midgut contents. Combinations of starch granules with isolated α-amylases from both species showed similar patterns of granule degradation. In vitro enzymatic degradation of maize starch granules by the three different α-amylase fractions began by creating small holes and crater-like areas on the surface of the granules. Over time, these holes increased in number and area resulting in extensive degradation of the granule structure. Granules from potato did not show formation of pits and craters on their surface, but presented extensive erosion in their interior. For all types of starch, as soon as the interior of the starch granule was reached, the inner layers of amylose and amylopectin were differentially hydrolyzed, resulting in a striated pattern. These data support the hypothesis that the pattern of starch degradation depends more on the granule type than on the α-amylase involved. PMID:19619014

Effect of garlic extraction on injury by cowpea, Curculio Chalcodermes aenus Boheman (Coleoptera: Cucurlionidae), and other pests, to cowpea, Vigna unguiculata L. Walp

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Garlic-based oils and extract formulations have been used as insecticides against various insects on numerous crops, but there are contradictions among findings on the insecticidal or repellent properties of garlic-based products. In a field plot test, the effects of garlic extract on control of th...

Alternative food sources and overwintering feeding behavior of the boll weevil, Anthonomus grandis boheman (Coleoptera: Curculionidae) under the tropical conditions of Central Brazil.

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Ribeiro, Paulina de A; Sujii, Edison R; Diniz, Ivone R; Medeiros, Maria A de; Salgado-Labouriau, Maria L; Branco, Marina C; Pires, Carmen S S; Fontes, Eliana M G

2010-01-01

The boll weevil causes serious damage to the cotton crop in South America. Several studies have been published on this pest, but its phenology and behavior under the tropical conditions prevailing in Brazil are not well-known. In this study the feeding behavior and main food sources of adult boll weevils throughout the year in Central Brazil was investigated. The digestive tract contents of insects captured in pheromone traps in two cotton fields and two areas of native vegetation (gallery forest and cerrado sensu stricto) were analyzed. The insect was captured all through the year only in the cerrado. It fed on pollen of 19 different plant families, on Pteridophyta and fungi spores and algae cysts. Simpson Index test showed that the cerrado provided greater diversity of pollen sources. In the beginning of the cotton cycle, the plant families used for pollen feeding were varied: in cotton area 1, the weevil fed on Poaceae(50%), Malvaceae and Smilacaceae (25% each); in cotton area 2 the pollen sources were Malvaceae (50%), Asteraceae (25%) and Fabaceae and Clusiaceae (25% each); in the cerrado they were Chenopodiaceae (67%) and Scheuchzeriaceae (33%). No weevils were collected in the gallery forest in this period. After cotton was harvested, the family Smilacaceae was predominant among the food plants exploited in all the study areas. These results help to explain the survivorship of adult boll weevil during cotton fallow season in Central Brazil and they are discussed in the context of behavioral adaptations to the prevailing tropical environmental conditions.

Effect of temperature on the reproduction of Bracon vulgaris Ashmead (Hymenoptera: Braconidae, a parasitoid of the cotton boll weevil

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Francisco S. Ramalho

2011-09-01

Full Text Available This research studied the effect of temperature on the reproduction of Bracon vulgaris Ashmead, an ectoparasitoid of cotton boll weevil ( Anthonomus grandis Boheman at constant temperatures of 20, 25 and 30ºC, 70 ± 10% RH and a photophase of 14 h. Females of the parasitoid produced a greater number of eggs when exposed to 25ºC (124.65 eggs in relation to those exposed to 20 (43.40 eggs and 30ºC (49.60 eggs. The number of parasitized larvae per female of B. vulgaris at 25ºC (71.75 was greater than at 20ºC (31.40 and 30ºC (25.15. The daily intrinsic rates of increase (r m were - 0.007 at 20ºC, 0.07 at 25ºC and 0.03 at 30ºC, revealing that the temperature of 25ºC produced increases of 1,100 and 133% in the value r m in relation to temperatures of 20 and 30ºC, respectively. In programs of biological control of the boll weevil using innoculative releases, adult females of B. vulgaris with approximately five (at 25 or 30ºC or 20 day old (at 20ºC should be used; when using innundative releases, adult females of B. vulgaris , with ages between 11 and 31; 9 and 29 or 3 and 14 days, respectively, at 20, 25 or 30ºC should be used.Estudamos os efeitos da temperatura na reprodução de Bracon vulgaris Ashmead, ectoparasitóide do bicudo-do-algodoeiro, Anthonomus grandis Boheman, em câmaras climatizadas, em temperaturas constantes de 20, 25 and 30ºC, umidade relativa do ar de 70 ± 10% e fotofase de 14 h. As fêmeas do parasitóide produziram mais ovos a 25ºC (124,65 ovos do que aquelas expostas a 20 (43,40 ovos e a 30ºC (49,60 ovos. O número médio de larvas parasitadas por fêmea de B. vulgaris a 25ºC(71,75 larvas foi maior do que a 20ºC (31,40 larvas e 30ºC (25,15 larvas. As taxas diárias de aumento (r m foram -0,007 a 20ºC, 0,07 a 25ºC e 0,03 a 30ºC, indicando que a temperatura de 25ºC produziu aumento de 1100 e 133% no valor de r m em relação às temperaturas de 20 e 30ºC, respectivamente. Nos programas de controle biol

Widespread Trypanosoma cruzi infection in government working dogs along the Texas-Mexico border: Discordant serology, parasite genotyping and associated vectors.

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Alyssa C Meyers

2017-08-01

Full Text Available Chagas disease, caused by the vector-borne protozoan Trypanosoma cruzi, is increasingly recognized in the southern U.S. Government-owned working dogs along the Texas-Mexico border could be at heightened risk due to prolonged exposure outdoors in habitats with high densities of vectors. We quantified working dog exposure to T. cruzi, characterized parasite strains, and analyzed associated triatomine vectors along the Texas-Mexico border.In 2015-2016, we sampled government working dogs in five management areas plus a training center in Texas and collected triatomine vectors from canine environments. Canine serum was tested for anti-T. cruzi antibodies with up to three serological tests including two immunochromatographic assays (Stat-Pak and Trypanosoma Detect and indirect fluorescent antibody (IFA test. The buffy coat fraction of blood and vector hindguts were tested for T. cruzi DNA and parasite discrete typing unit was determined. Overall seroprevalence was 7.4 and 18.9% (n = 528 in a conservative versus inclusive analysis, respectively, based on classifying weakly reactive samples as negative versus positive. Canines in two western management areas had 2.6-2.8 (95% CI: 1.0-6.8 p = 0.02-0.04 times greater odds of seropositivity compared to the training center. Parasite DNA was detected in three dogs (0.6%, including TcI and TcI/TcIV mix. Nine of 20 (45% T. gerstaeckeri and T. rubida were infected with TcI and TcIV; insects analyzed for bloodmeals (n = 11 fed primarily on canine (54.5%.Government working dogs have widespread exposure to T. cruzi across the Texas-Mexico border. Interpretation of sample serostatus was challenged by discordant results across testing platforms and very faint serological bands. In the absence of gold standard methodologies, epidemiological studies will benefit from presenting a range of results based on different tests/interpretation criteria to encompass uncertainty. Working dogs are highly trained in security

A REVISION OF THE PACHNEPHORUS FROM THE AFROTROPICAL REGION (COLEOPTERA, CHRYSOMELIDAE

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Stefano Zoia

2007-04-01

Full Text Available A revision of the genus Pachnephorus Chevrolat, 1837 from the Afrotropical Region is given and a key to the species is provided. Types of all the previously known taxa have been studied and redescribed; 40 new taxa are described and illustrated: P. achardi n. sp. (Mali, P. aequatorianus n. sp. (Rep. Pop. Congo, P. aethiopicus n. sp. (Etiopia, P. baehri n. sp. (Namibia, P. balyi n. sp. (Angola, P. beharui n. sp. (Etiopia, P. bertiae n. sp. (Madagascar, P. bezdeki n. sp. (Rep. Pop. Congo, P. bracarumvestitus n. sp. (Rep. Pop. Congo, P. bryanti n. sp. (Mali, P. burgeoni n. sp. (Natal, P. camerun­ensis n. sp. (Camerun, P. cristiani n. sp. (Namibia, P. crocodilinus n. sp. (Zambia, P. daccordii n. sp. (Yemen, P. danielssoni n. sp. (Sierra Leone, P. danielssoni congoanus n. ssp. (Rep. Pop. Congo, P. demeyeri n. sp. (Rep. Pop. Congo, P. episternalis n. sp. (Madagascar, P. fabianae n. sp. (Congo, P. fasciatus occidentalis n. ssp. (Nigeria, P. gardinii n. sp. (Etiopia, P. gerstaeckeri n. sp. (Namibia, P. grobbelaarae n. sp. (South Africa, P. hajeki n. sp. (Madagascar, P. lopatini n. sp. (Senegal, P. malicus n. sp. (Mali, P. maroantsetranus n. sp. (Madagascar, P. medvedevi n. sp. (Zambia, P. mo­seykoi n. sp. (Chad, P. pacificus n. sp. (Central Afr. Rep., P. parentorum n. sp. (Ghana, P. poggii n. sp. (Somalia, P. regalini n. sp. (Zambia, P. rigatoi n. sp. (Kenya, P. sas­sii n. sp. (Guinea Bissau, P. shuteae n. sp. (Rep. South Africa, P. sprecherae n. sp. (Madagascar, P. uhligi n. sp. (Namibia, P. willersi n. sp. (Namibia. The lectoypes of P. conspersus Gerstaecker, 1871, P. senegalensis Achard, 1914, P. latior Pic, 1921 and P. testaceipes Fairmaire, 1880 are designated. A new synonymy (P. costatus Achard, 1914 n. syn. of P. torridus Baly, 1878 and a nomenclatural change (Mecistes lineatus (Pic, 1921 n. comb. for Pachnephorus lineatus Pic, 1921 are proposed; the Lectotypes of M. lineatus and of M. flavipes (Gerstaecker, 1855 are designated.

Effect of temperature on the reproduction of Bracon vulgaris Ashmead (Hymenoptera: Braconidae), a parasitoid of the cotton boll weevil.

Science.gov (United States)

Ramalho, Francisco S; Wanderley, Paulo A; Malaquias, José B; Fernandes, Francisco S; Nascimento, Antônio R B; Zanuncio, José C

2011-09-01

This research studied the effect of temperature on the reproduction of Bracon vulgaris Ashmead, an ectoparasitoid of cotton boll weevil ( Anthonomus grandis Boheman) at constant temperatures of 20, 25 and 30ºC, 70 ± 10% RH and a photophase of 14 h. Females of the parasitoid produced a greater number of eggs when exposed to 25ºC (124.65 eggs) in relation to those exposed to 20 (43.40 eggs) and 30ºC (49.60 eggs). The number of parasitized larvae per female of B. vulgaris at 25ºC (71.75) was greater than at 20ºC (31.40) and 30ºC (25.15). The daily intrinsic rates of increase (r m) were - 0.007 at 20ºC, 0.07 at 25ºC and 0.03 at 30ºC, revealing that the temperature of 25ºC produced increases of 1,100 and 133% in the value r m in relation to temperatures of 20 and 30ºC, respectively. In programs of biological control of the boll weevil using innoculative releases, adult females of B. vulgaris with approximately five (at 25 or 30ºC) or 20 day old (at 20ºC) should be used; when using innundative releases, adult females of B. vulgaris , with ages between 11 and 31; 9 and 29 or 3 and 14 days, respectively, at 20, 25 or 30ºC should be used.

Effects of black-eyed pea trypsin/chymotrypsin inhibitor on proteolytic activity and on development of Anthonomus grandis.

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Franco, Octávio L; dos Santos, Roseane C; Batista, João A N; Mendes, Ana Cristina M; de Araújo, Marcus Aurélio M; Monnerat, Rose G; Grossi-de-Sá, Maria Fátima; de Freitas, Sonia M

2003-06-01

The cotton boll weevil Anthonomus grandis (Boheman) is one of the major pests of cotton (Gossypium hirsutum L.) in tropical and sub-tropical areas of the New World. This feeds on cotton floral fruits and buds causing severe crop losses. Digestion in the boll weevil is facilitated by high levels of serine proteinases, which are responsible for the almost all proteolytic activity. Aiming to reduce the proteolytic activity, the inhibitory effects of black-eyed pea trypsin/chymotrypsin inhibitor (BTCI), towards trypsin and chymotrypsin from bovine pancreas and from midguts of A. grandis larvae and adult insects were analyzed. BTCI, purified from Vigna unguiculata (L.) seeds, was highly active against different trypsin-like proteinases studied and moderately active against the digestive chymotrypsin of adult insects. Nevertheless, no inhibitory activity was observed against chymotrypsin from A. grandis larval guts. To test the BTCI efficiency in vivo, neonate larvae were reared on artificial diet containing BTCI at 10, 50 and 100 microM. A reduction of larval weight of up to approximately 54% at the highest BTCI concentration was observed. At this concentration, the insect mortality was 65%. This work constitutes the first observation of a Bowman-Birk type inhibitor active in vitro and in vivo toward the cotton boll weevil A. grandis. The results of bioassays strongly suggest that BTCI may have potential as a transgene protein for use in engineered crop plants modified for heightened resistance to the cotton boll weevil.

Determination of Attributes in Cotton (Gossypium hirsutum L. Genotypes in Corn-Soybean Rotation Associated with Acid Amended Soils in the Colombian Eastern Plains

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Luis Fernando Campuzano Duque

2015-07-01

Full Text Available For the last 15 years, Colombia has developed a research process leading to the expansion of its agricultural frontier at the flat well drained savannas of the Eastern Plains, by improving predominantly acid soils with liming to increase base saturation with depth, vertical liming —as its referred locally—, crop rotation with rice, corn, soybeans, and with the potential to include other crops like cotton in the rotation system. To achieve this, a pioneering research in Colombia was conducted to determine the adaptation of cotton in the acid conditions of the high plains improved sheets. An Agronomic evaluation test was developed using five elite genotypes of cotton in a design of a randomized complete block at four locations in soils with base saturation above 80 %. The results identified a genotype (LC-156, which presented an adaptation to the high plains, associated with an average yield of 2.2 t/ha of cottonseed, 1.5 t/ha of cotton fiber type medium-long, a percentage of fiber extraction above 36.0 %. The comparative advantage of this region for sustainable cotton production is given by the yield of cotton fiber —which ishigher than the national average—, to the 33.2 % reduction in production costs, the quality of long/medium-fiber destined for export and the absence of the pest insect of greatest economic impact in Colombia: the weevil (Anthonomus grandis Boheman.

Collection of pheromone from atmosphere surrounding boll weevils,Anthonomus grandis.

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Chang, J F; Benedict, J H; Payne, T L; Camp, B J; Vinson, S B

1989-02-01

An effluvial method was developed to collect the pheromone, grandlure from actively calling male boll weevils,Anthonomus grandis Boheman. The adsorbant, Porapak Q (ethylvinylbenzene-divinylbenzene), was utilized to trap and concentrate the pheromone. Captured pheromone was desorbed from columns packed with Porapak Q by elution withn-pentane and quantified by capillary column gas-liquid chromatography. In recovery studies with known amounts of synthetic grandlure, we found that the amount of each pheromone component collected was a function of collection duration, elution volume, and initial concentration. This effluvial method was capable of recovering as much as 94.9% of a known quantity (80 μg) of grandlure. The chromatograms were free of extraneous peaks. In studies of insect-produced pheromone, the effluvial method was used to collect pheromone from the air space surrounding male boll weevils as they fed on flower buds from CAMD-E cotton. The quantity and quality of boll-weevil-produced pheromone was determined for days 6, 8, 10, 11, 12, 13, and 14 of boll weevil adulthood. The maximum quantity of natural pheromone was produced on day 13 (4.2 μg/weevil) with a pheromone component ratio of 2.41∶2.29∶0.95∶1 for components I, II, III, and IV, respectively. The effluvial method described in this report is an efficient method to collect and quantify boll weevil pheromone from the atmosphere surrounding actively calling insects. Other applications of this method are suggested.

Efficacy of the organic-certified insecticide Diatect II against the boll weevil (Anthonomus grandis) in cotton.

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Sappington, Thomas W

2002-10-01

The efficacy of the organic insecticide Diatect II against boll weevil (Anthonomus grandis Boheman) in cotton (Gossypium hirsutum L) in the Lower Rio Grande Valley of Texas were assessed in small-plot field trials and greenhouse cage tests using azinphos-methyl treatments as a standard for comparison. Plastic sheets were placed in the furrows of the treated plots to retrieve boll weevils which dropped from the plants after being killed by the insecticides. Samples of live weevils taken by a tractor-mounted vacuum sampler revealed a modest, but significant, reduction in boll weevil populations in Diatect II plots. However, samples of dead weevils indicated that this reduction was due to movement of weevils out of the plots rather than to mortality. This interpretation is supported by greenhouse cage studies, where mortality in Diatect II treated cages was no greater than that in untreated control cages. The effects of insecticide treatments in small plots can be confounded easily and quickly by interplot movement of target insects. Although the relative effects of various compounds can usually be assessed by sampling the populations in plots soon after treatment, the best measure of efficacy is obtained by directly sampling insects that have died in the plot. This parameter is insulated from the effects of interplot movement, unless the toxicant is slow to immobilize the target insect. Taken together, our results indicate little efficacy by Diatect II against boll weevil under our test conditions.

Reproductive dormancy in boll-weevil from populations of the midwest of Brazil.

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Paula, D P; Claudino, D; Timbó, R V; Miranda, J E; Bemquerer, M P; Ribeiro, A C J; Sujii, E R; Fontes, E M G; Pires, C S S

2013-02-01

The boll weevil (Anthonomus grandis Boheman) (Coleoptera: Curculionidae) is an introduced pest in Brazil, which in 30 yr has successfully expanded to various eco-regions and became the most important pest of cotton (Gossypium hirsutum, Malvaceae). Given the limited knowledge about the adaptive mechanisms that allowed successful establishment of the pest population in a tropical region, in this work we studied the potential of the Midwest population of boll weevils to enter a reproductive dormancy and identified the importance of the feeding source for induction of dormancy. We investigated morphological and physiological characters as indicators of the dormancy. We also investigated the occurrence of reproductive dormancy in boll weevils populations from cotton farms of the Midwestern region of Brazil during the cotton and noncotton seasons of 2009 and 2010. The studies revealed that boll weevils entered facultative reproductive dormancy; however, unlike what has been observed for boll weevils from temperate and subtropical regions, the hypertrophy of fat body and hexamerin levels did not straightly correlated to reproductive dormancy. The food source and field conditions during early adult development were decisive factor for the induction of reproductive dormancy. The incidence of reproductive dormancy increased progressively as the phenology of cotton plant advanced, reaching approximately 90% at the end of the crop season. During the noncotton season, the boll weevil was predominantly found in reproductive dormancy, especially females; however, there is evidence of use of multiple adaptive strategies to colonize the next harvest.

An experiment using neutron activation analysis and a rare earth element to mark cotton plants and two insects that feed on them

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Showler, Allan T. [USDA-ARS IFNRRU, Kika de la Garza Subtropical Agricultural Research Center, 2413 East Highway 83, Weslaco, TX 78596 (United States)]. E-mail: ashowler@weslaco.ars.usda.gov; James, William D. [Elemental Analysis Laboratory, 3144 Texas A and M University, College Station, TX 77843-3144 (United States); Armstrong, John S. [USDA-ARS BIRU, Kika de la Garza Subtropical Agricultural Research Center, 2413 East Highway 83, Weslaco, TX 78596 (United States); Westbrook, John K. [USDA-ARS APMRU, 2771 F and B Road, College Station, TX 77845-4966 (United States)

2006-08-15

Studies on insect dispersal and other behaviors can benefit from using markers that will not alter flight and fitness. Rare earth elements, such as samarium (Sm), have been used as ingested markers of some insects and detected using neutron activation analysis (NAA). In this study, samarium nitrate hexahydrate was mixed into artificial diet for boll weevils, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), at different dosages and in water used to irrigate cotton, Gossypium hirsutum L. Samarium was detected in adult boll weevils fed on the samarium-labeled diet, but not after 5 or 10 days of being switched to non-labeled diet, even if the insects were given labeled diet for as long as 7 consecutive days. Introduced in irrigation water, 1% samarium (m/m) was detectable in cotton squares and leaf tissue. However, boll weevil adults fed samarium-labeled squares did not retain detectable levels of samarium, nor did boll weevil adults reared to adulthood from samarium-labeled squares. Fourth instar beet armyworms, Spodoptera exigua (Huebner) (Noctuidae: Lepidoptera), fed on samarium-labeled cotton leaves obtained enough samarium for NAA detection, but adult moths reared from them did not have detectable amounts of samarium. Although samarium can be useful as a marker when insects are presented with a continuous pulse of the label, elements that are assimilated by the insect would be more useful if a continuous infusion of the marker cannot be provided.

Genetic profiling to determine potential origins of boll weevils (Coleoptera: Curculionidae) captured in a Texas eradication zone: endemicity, immigration, or sabotage?

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Kim, Kyung Seok; Sappington, Thomas W; Allen, Charles T

2008-12-01

Thirty-seven boll weevils, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), were captured in pheromone traps near Lubbock, TX, in the Southern High Plains/Caprock eradication zone during August-October 2006. No boll weevils had been captured in this zone or neighboring zones to the north earlier in the year, and only very low numbers had been captured in neighboring zones to the south and east. Therefore, the captures near Lubbock were unexpected. Five of the weevils captured the last week of August were preserved and genotyped at 10 microsatellite loci for comparison with a database of genotypes for 22 boll weevil populations sampled from eight U.S. states and four locations in Mexico. The Lubbock population itself is an unlikely source, suggesting that the captured weevils probably did not originate from a low-level endemic population. Populations from eastern states, Mexico, and Big Spring, TX, can be confidently excluded as potential source regions. Although the Weslaco and Kingsville, TX, areas cannot be statistically excluded, they are unlikely sources. The most likely sources are nearby areas in New Mexico, TX, or southwest Oklahoma, or from areas of eastern Texas represented by Waxahachie and El Campo populations. Together, genetic and circumstantial evidence suggest either that the trapped boll weevils are the offspring of alone mated female that immigrated from eastern Texas earlier in the summer or that weevils originally captured near Waxahachie but now long-dead were planted in the traps by a disgruntled employee of the eradication program.

Temporal variation in seed predation by insects in a population of Syagrus romanzoffiana (Arecaceae) in Santa Catarina Island, SC, Brazil.

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da Silva, F R; Begnini, R M; Lopes, B C; Castellani, T T

2012-02-01

Insect seed predation may vary depending on seed production. The present study considers the hypothesis that the rates of seed predation tend to be smaller in years of higher fruit production. Thus, we monitored the production of fruits and predation of seeds of the palm Syagrus romanzoffiana over 2 years in the Atlantic Forest (Parque Municipal da Lagoa do Peri, Florianópolis, SC, Brazil), between July 2006 and June 2008. Plots of 0.25 m(2) were fitted under 20 mother plants and fruits were monthly collected for assessment of abundance and seed predation. There was variation in fruit production between the 2 years and among reproductive plants. Predation rates were high and occurred in the predispersal phase by the Curculionidae Revena rubiginosa Boheman, Anchylorhynchus aegrotus Fahraeus, and Anchylorhynchus variabilis Gyllenhal. Seed predation by these species of Anchylorhynchus is first registered in the present study. In average, about 60% of the seeds monthly produced in the population tend to escape insect predation in year of high or low production, becoming available for recruitment. The predation rate was not related to the amount of fruits produced per reproductive plant. Also, different than expected, there was a positive relation between the rates of seed predation and the total of fruits produced monthly on the plots. Thus, no evidence for the satiation of insect seed predators was found in this study with S. romanzoffiana.

Alternative food sources and over wintering feeding behavior of the boll weevil, Anthonomus grandis boheman (coleoptera: curculionidae) under the tropical conditions of central Brazil

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Ribeiro, Paulina de A.; Sujii, Edison R.; Pires, Carmen S.S.; Fontes, Eliana M.G.; Diniz, Ivone R.; Salgado-Labouriau, Maria L.

2010-01-01

The boll weevil causes serious damage to the cotton crop in South America. Several studies have been published on this pest, but its phenology and behavior under the tropical conditions prevailing in Brazil are not well-known. In this study the feeding behavior and main food sources of adult boll weevils throughout the year in Central Brazil was investigated. The digestive tract contents of insects captured in pheromone traps in two cotton fields and two areas of native vegetation (gallery forest and cerrado sensu stricto) were analyzed. The insect was captured all through the year only in the cerrado. It fed on pollen of 19 different plant families, on Pteridophyta and fungi spores and algae cysts. Simpson Index test showed that the cerrado provided greater diversity of pollen sources. In the beginning of the cotton cycle, the plant families used for pollen feeding were varied: in cotton area 1, the weevil fed on Poaceae (50%), Malvaceae and Smilacaceae (25% each); in cotton area 2 the pollen sources were Malvaceae (50%), Asteraceae (25%) and Fabaceae and Clusiaceae (25% each); in the cerrado they were Chenopodiaceae (67%) and Scheuchzeriaceae (33%). No weevils were collected in the gallery forest in this period. After cotton was harvested, the family Smilacaceae was predominant among the food plants exploited in all the study areas. These results help to explain the survivorship of adult boll weevil during cotton fallow season in Central Brazil and they are discussed in the context of behavioral adaptations to the prevailing tropical environmental conditions. (author)

Alternative food sources and over wintering feeding behavior of the boll weevil, Anthonomus grandis boheman (coleoptera: curculionidae) under the tropical conditions of central Brazil

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, Paulina de A.; Sujii, Edison R.; Pires, Carmen S.S.; Fontes, Eliana M.G. [EMBRAPA Recursos Geneticos e Biotecnologia (CENARGEN), Brasilia, DF (Brazil)], e-mail: paulina723@hotmail.com, e-mail: sujii@cenargen.embrapa.br, e-mail: cpires@cenargen.embrapa.br, e-mail: eliana@cenargen.embrapa.br; Diniz, Ivone R. [Universidade de Brasilia (UnB), DF (Brazil). Dept. de Zoologia], e-mail: irdiniz@unb.br; Medeiros, Maria A. de; Branco, Marina C. [EMBRAPA Hortalicas, Brasilia, DF (Brazil)], e-mail: medeiros@cnph.embrapa.br, e-mail: marina@cnph.embrapa.br; Salgado-Labouriau, Maria L. [Universidade de Brasilia (UnB), DF (Brazil). Dept. de Geologia], e-mail: mlea@unb.br

2010-01-15

The boll weevil causes serious damage to the cotton crop in South America. Several studies have been published on this pest, but its phenology and behavior under the tropical conditions prevailing in Brazil are not well-known. In this study the feeding behavior and main food sources of adult boll weevils throughout the year in Central Brazil was investigated. The digestive tract contents of insects captured in pheromone traps in two cotton fields and two areas of native vegetation (gallery forest and cerrado sensu stricto) were analyzed. The insect was captured all through the year only in the cerrado. It fed on pollen of 19 different plant families, on Pteridophyta and fungi spores and algae cysts. Simpson Index test showed that the cerrado provided greater diversity of pollen sources. In the beginning of the cotton cycle, the plant families used for pollen feeding were varied: in cotton area 1, the weevil fed on Poaceae (50%), Malvaceae and Smilacaceae (25% each); in cotton area 2 the pollen sources were Malvaceae (50%), Asteraceae (25%) and Fabaceae and Clusiaceae (25% each); in the cerrado they were Chenopodiaceae (67%) and Scheuchzeriaceae (33%). No weevils were collected in the gallery forest in this period. After cotton was harvested, the family Smilacaceae was predominant among the food plants exploited in all the study areas. These results help to explain the survivorship of adult boll weevil during cotton fallow season in Central Brazil and they are discussed in the context of behavioral adaptations to the prevailing tropical environmental conditions. (author)

El picudo del algodonero en la Argentina: Principales resultados e implicancias de los estudios moleculares The cotton boll weevil in Argentina: Main results and implications of the molecular studies

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Analía A. Lanteri

2003-12-01

Full Text Available Después de diez años del primer registro del picudo del algodonero, Anthonomus grandis Boheman (Coleoptera, Curculionidae, en la Argentina, el insecto ha llegado a la zona algodonera del Chaco. Los estudios moleculares realizados sobre poblaciones de la Argentina, Brasil y Paraguay, y posibles poblaciones fuente de EE.UU y México, han aportado información relevante para el control de la plaga. Se aplicaron las técnicas de RAPD (Polimorfismos del ADN Amplificados al Azar y de secuenciación de los genes mitocondriales de la Citocromo Oxidasa I y II, las cuales permitieron identificar dos linajes principales de picudos: a linajes con escasa o nula variabilidad medida en términos de heterocigosis y diversidad haplotípica, considerados colonizadores recientes, y asociados con ambientes xerófilos y cultivos de algodón (provincia de Formosa; b linajes con una elevada variabilidad y diversidad haplotípica, considerados ancestrales, y asociados con áreas de vegetación nativa de la selva misionera (Parque Nacional Iguazú. Se supone que ambos linajes tendrían diferentes orígenes, adaptaciones y preferencias de huéspedes, y que en este momento se estarían hidridando en zonas de ecotono. Se postula que el picudo se hallaría presente en América del Sur como consecuencia de una dispersión natural asociada principalmente con sus huéspedes silvestres de los géneros Gossypium y Cienfuegosia, probablemente desde el Pleistoceno. Por otra parte no se descarta la posibilidad de una o más introducciones desde EE.UU. hacia Brasil, mediante el comercio del algodón. Se destaca la importancia del cultivo extensivo del algodón, y de la deforestación y formación de corredores entre fragmentos de selva, para explicar la dispersión rápida de la plaga durante los últimos 20 años, en áreas algodoneras y/o no algodoneras pero afectadas por serios disturbios ambientales, como por ejemplo la provincia de Misiones.Ten years after the first record of

Método de diagnóstico para el monitoreo de resistencia a insecticidas en poblaciones de "picudo del algodonero", Anthonomus grandis (Coleoptera: Curculionidae A diagnostic test for insecticide resistance monitoring in "cotton boll weevil" Anthonomus grandis (Coleoptera: Curculionidae populations

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Teodoro Stadler

2009-06-01

Full Text Available El control de las poblaciones de Anthonomus grandis Boheman, por debajo de su umbral de daño económico durante el ciclo del cultivo del algodón, se realiza en forma efectiva hasta el momento, a través de insecticidas de síntesis. La presión selectiva de las aplicaciones extensivas e intensivas de insecticidas hace imperativa la detección temprana de focos de resistencia a los mismos, en función de un correcto manejo del fenómeno. Se desarrolló un método de diagnóstico de resistencia para A. grandis a partir de la técnica "vial test", que fue adaptada en forma de "kit" para el monitoreo rápido y sencillo de los focos de resistencia en el campo. La toxicidad (CL99, para calcular la concentración discriminante (CD del insecticida y la preparación del "kit", se obtiene a partir de bioensayos de laboratorio con una cepa normal susceptible de A. grandis. Se determinó la vida media de los insecticidas dentro de los viales por CIPAC MT 46, para establecer una fecha de vencimiento del "kit". La CD y el método en su conjunto fueron validados a través de ensayos a campo. El "kit", usado en el monitoreo de resistencia en el campo, fue especialmente diseñado para ser utilizado en las condiciones geográficas, económicas y socio-culturales presentes en la región algodonera argentina. La implementación de esta técnica permitirá conseguir la información necesaria, y así obtener una apropiada alternancia de insecticidas. Como consecuencia, se prevé una reducción de impacto ambiental de las prácticas agronómicas en el control de plagas en algodón.The in-season control of the cotton boll weevil Anthonomus grandis Boheman is done by insecticide application, which so far is the only effective way to reduce boll weevil populations to levels below economic significance. The extensive and intensive control actions with insecticides cause selective pressure on pest populations. Thus, to achieve an accurate insecticide resistance

Field evaluation of Bt cotton crop impact on nontarget pests: cotton aphid and boll weevil.

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Sujii, E R; Togni, P H B; de A Ribeiro, P; de A Bernardes, T; Milane, P V G N; Paula, D P; Pires, C S S; Fontes, E M G

2013-02-01

Bt cotton plants expressing Cry1Ac protein have high specificity for the control of lepidopteran larvae. However, studies conducted in several countries have shown these plants have a differential impact on nontarget herbivores. The aim of this study was to compare the colonization rates and population abundance of the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae) and the boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae), in plots of Bt (Nuopal) and non-Bt cotton (Delta Opal) in an experimental field in Brasilia, DF, Brazil. No difference was observed in the preference and colonization by winged aphids to plants from the two treatments. There was no significant difference in abundance of wingless aphids or in the production of winged aphids between treatments. Apparently, the parameters that control factors such as fecundity, survival, and dispersal were similar on both Bt and non-Bt plants. Monitoring of plants for coccinellids, a specialist predator of aphids, and ants that act on the dispersal of aphids among plants showed no significant difference between Bt and non-Bt plants, supporting the inference above. Regarding the effect on boll weevil, there was also no significant difference between treatments in the total number of fruiting structures attacked in each plot, the percentage of fruiting structures attacked per plant or on the number of weevils emerging from fruits with boll weevil damage from egg-laying, when damaged fruit samples were held in the laboratory. Based on these results, we conclude that there is no impact of Bt cotton crop expressing Cry1Ac on the nontarget herbivores tested under field conditions.

Captures of Boll Weevils (Coleoptera: Curculionidae) in Relation to Trap Orientation and Distance From Brush Lines.

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Spurgeon, Dale W

2016-04-01

Eradication programs for the boll weevil (Anthonomus grandis grandis Boheman) rely on pheromone-baited traps to trigger insecticide treatments and monitor program progress. A key objective of monitoring in these programs is the timely detection of incipient weevil populations to limit or prevent re-infestation. Therefore, improvements in the effectiveness of trapping would enhance efforts to achieve and maintain eradication. Association of pheromone traps with woodlots and other prominent vegetation are reported to increase captures of weevils, but the spatial scale over which this effect occurs is unknown. The influences of trap distance (0, 10, and 20 m) and orientation (leeward or windward) to brush lines on boll weevil captures were examined during three noncropping seasons (October to February) in the Rio Grande Valley of Texas. Differences in numbers of captured weevils and in the probability of capture between traps at 10 or 20 m from brush, although often statistically significant, were generally small and variable. Variations in boll weevil population levels, wind directions, and wind speeds apparently contributed to this variability. In contrast, traps closely associated with brush (0 m) generally captured larger numbers of weevils, and offered a higher probability of weevil capture compared with traps away from brush. These increases in the probability of weevil capture were as high as 30%. Such increases in the ability of traps to detect low-level boll weevil populations indicate trap placement with respect to prominent vegetation is an important consideration in maximizing the effectiveness of trap-based monitoring for the boll weevil.

Development of a meridic diet for Hylobius transversovittatus (Coleoptera: Curculionidae) and the role of carbohydrates in feeding, growth, and survival of larvae.

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Tomic-Carruthers, Nada

2007-08-01

The root-feeding weevil Hylobius transversovittatus Goeze (Coleoptera: Curculionidae) is used for biological control of the invasive plant purple loosestrife, Luthrum salicaria L. (Lythraceae). A simple rearing system for this weevil was developed with the goals of improving production techniques and increasing the availability of insects for field introduction. Additionally, the dietary effects of digestible and indigestible carbohydrates were explored. A meridic diet for rearing H. transversovittatus was formulated through nutritional alterations of a boll weevil, Anthonomus grandis grandis Boheman, diet. Diet attractiveness was evaluated on two levels: first, by recording the incidence of initial tunneling, and second, by estimating the larval establishment rate. The performance of test diet formulations was further assessed by measuring developmental and survival rates of H. transversovittatus. Sucrose, starch, and three types of indigestible carbohydrates were tested as components to improve diet performance. Physical properties of the diet, modified by fillers in test formulations, produced major effects on the initial tunneling of hatchlings. The establishment of hatchlings was affected by chemical properties of the diet. Increases in sucrose concentration decreased larval establishment, decreased the rate of larval development, and decreased larval survival. However, omitting sucrose from the diet, or replacing it with starch, increased mortality of first instars. In advanced stages of larval development, omitting sucrose from the diet did not significantly affect larval survival. The developmental rate of larvae was increased when the amount of digestible carbohydrate was reduced. To date, seven generations of the univoltine H. transversovittatus have been successfully produced on this new meridic diet.

Comparisons of boll weevil (Coleoptera: Curculionidae) pheromone traps with and without kill strips.

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Suh, C P C; Armstrong, J S; Spurgeon, D W; Duke, S

2009-02-01

Boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), eradication programs typically equip pheromone traps with an insecticide-impregnated kill strip. These strips are intended to kill captured insects, thereby simplifying trap servicing and reducing the loss of weevils from predation and escape. However, the effectiveness of kill strips has not been extensively evaluated. We examined the influences of kill strips on weevil captures, trap servicing, and the incidences of weevil predation and trap obstruction (e.g., by spider webs). Evaluations were conducted weekly during three different production periods (pre- to early-, late-, and postseason) of cotton, Gossypium hirsutum L., to represent different environmental conditions and weevil population levels. Within each period, mean weekly captures of weevils in traps with and without kill strips were statistically similar. On average, traps with kill strips took 9 s longer to service than traps without kill strips, but statistical differences were only detected during the late-season period. Overall, the mean weekly proportion of traps with evidence of weevil predation or trap obstruction was significantly lower for traps with kill strips (0.25) than for traps without kill strips (0.37). However, this reduction in the frequency of weevil predation or trap obstruction was too small to produce a corresponding increase in the numbers of weevils captured. In light of these findings, the use of kill strips is likely unnecessary in eradication programs, but may be a consideration in situations when the numbers of deployed traps are reduced and chronic problems with weevil predation or trap obstruction exist.

Molecular diagnostic for boll weevil (Coleoptera: Curculionidae) based on amplification of three species-specific microsatellites.

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Kim, Kyung Seok; Szendrei, Zsofia; Rodriguez-Saona, Cesar; Mulder, Phillip G; Sappington, Thomas W

2009-04-01

The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is a serious pest of cultivated cotton, Gossypium hirsutum L., in the Americas, and reinfestation of zones from which they have been eradicated is of perpetual concern. Extensive arrays of pheromone traps monitor for reintroductions, but occasionally the traps collect nontarget weevils that can be misidentified by scouts. For example, the congeneric pepper weevil, Anthonomus eugenii Cano, and other superficially similar weevils are attracted to components of the boll weevil lure or trap color. Although morphologically distinguishable by trained personnel, the potential for misidentification is compounded when captured weevils are dismembered or partially consumed by ants or ground beetles that sometimes feed on them in the traps. Because misidentification can have expensive consequences, a molecular diagnostic tool would be of great value to eradication managers. We demonstrate that a cocktail of three primer pairs in a single polymerase chain reaction (PCR) amplify species-specific microsatellites that unambiguously distinguish the boll weevil from three other weevil species tested, including pepper weevil; cranberry weevil, Anthonomus eugenii musculus Say; and pecan weevil, Curculio caryae Horn. However, it does not distinguish the boll weevil from the subspecific "thurberia" weevil. A universal internal transcribed spacer primer pair included in the cocktail cross-amplifies DNA from all species, serving as a positive control. Furthermore, the diagnostic primers amplified the target microsatellites from various boll weevil adult body parts, indicating that the PCR technology using the primer cocktail is sensitive enough to positively identify a boll weevil even when the body is partly degraded.

Host plants of the tarnished plant bug (Heteroptera: Miridae) in Central Texas.

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Esquivel, J F; Mowery, S V

2007-08-01

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), has taken on added importance as a pest of cotton in the Cotton Belt after successful eradication efforts for the boll weevil (Anthonomus grandis grandis Boheman). Because the Southern Blacklands region of Central Texas is in advanced stages of boll weevil eradication, blooming weeds and selected row crops were sampled during a 3-yr study to determine lygus species composition and associated temporal host plants. L. lineolaris was the sole lygus species in the region. Thirteen previously unreported host plants were identified for L. lineolaris, of which 69% supported reproduction. Rapistrum rugosum L. Allioni and Ratibida columnifera (Nuttall) Wooton and Standley were primary weed hosts during the early season (17 March to 31 May). Conyza canadensis L. Cronquist variety canadensis and Ambrosia trifida L. were primary weed hosts during the midseason (1 June to 14 August) and late-season (15 August to 30 November), respectively. Sisymbrium irio L. and Lamium amplexicaule L. sustained L. lineolaris populations during the overwintering period (1 December to 16 March). The proportion of females and numbers of nymphs found in R. rugosum, C. canadensis, A. trifida, and S. irio suggests these weeds supported reproductive adults during the early, mid-, and late season and overwintering period, respectively. Medicago sativa L. was the leading crop host for L. lineolaris; Glycine max L. Merrill did not yield L. lineolaris. Few L. lineolaris were collected in Gossypium hirsutum L. These results provide a more comprehensive assessment of host plants contributing to L. lineolaris populations in central Texas.

Proteolytic processing of the vitellogenin precursor in the boll weevil, Anthonomus grandis.

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Heilmann, L J; Trewitt, P M; Kumaran, A K

1993-01-01

The soluble proteins of the eggs of the coleopteran insect Anthonomus grandis Boheman, the cotton boll weevil, consist almost entirely of two vitellin types with M(r)s of 160,000 and 47,000. We sequenced their N-terminal ends and one internal cyanogen bromide fragment of the large vitellin and compared these sequences with the deduced amino acid sequence from the vitellogenin gene. The results suggest that both the boll weevil vitellin proteins are products of the proteolytic cleavage of a single precursor protein. The smaller 47,000 M(r) vitellin protein is derived from the N-terminal portion of the precursor adjacent to an 18 amino acid signal peptide. The cleavage site between the large and small vitellins at amino acid 362 is adjacent to a pentapeptide sequence containing two pairs of arginine residues. Comparison of the boll weevil sequences with limited known sequences from the single 180,000 M(r) honey bee protein show that the honey bee vitellin N-terminal exhibits sequence homology to the N-terminal of the 47,000 M(r) boll weevil vitellin. Treatment of the vitellins with an N-glycosidase results in a decrease in molecular weight of both proteins, from 47,000 to 39,000 and from 160,000 to 145,000, indicating that about 10-15% of the molecular weight of each vitellin consists of N-linked carbohydrate. The molecular weight of the deglycosylated large vitellin is smaller than that predicted from the gene sequence, indicating possible further proteolytic processing at the C-terminal of that protein.

Evaluation of extended-life pheromone formulations used with and without dichlorvos for boll weevil (Coleoptera: Curculionidae) trapping.

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Armstrong, J Scott; Greenberg, Shoil M

2008-04-01

Boll weevil traps baited with a ComboLure (25 of mg grandlure + 30 mg of eugenol + 90 of mg dichlorvos [DDVP]), an extended-release lure (25 mg of grandlure + 30 mg of eugenol + 60 of mg DDVP kill-strip), and extended-release lure with no DDVP were evaluated for boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), captures in South Texas cotton, Gossypium hirsutum L., fields during February-March 2005 and March-April 2006. The traps were serviced once a week for five consecutive weeks by using the same methodology as active boll weevil eradication programs. Mean captured boll weevils from extended-release lures with no DDVP were significantly higher in five of 10 trapping weeks compared with captures of the ComboLure and extended lure. Weekly mortality of boll weevils captured was similar for the ComboLure (72.6 +/- 4.7%) and extended lure + DDVP (73.5 +/- 4.0%), and both were significantly higher than the extended lure (32.8 +/- 5.0%) with no DDVP. The presence or absence of DDVP did not significantly affect the sex ratio of field-captured boll weevils. We found no functional reasoning for using DDVP in large scale trapping of boll weevils regardless of the formulation or presentation in the trap. We conducted two additional trapping evaluations after the 2005 and 2006 studies, but the numbers of boll weevils captured were too low for statistical comparisons, indicating that boll weevil eradication is reducing populations in the Rio Grande Valley of Texas.

Effects of photoperiod on boll weevil (Coleoptera: Curculionidae) development, survival, and reproduction.

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Greenberg, S M; Sappington, T W; Adamczyk, J J; Liu, T-X; Setamou, M

2008-12-01

Effects of photoperiod on development, survival, feeding, and oviposition of boll weevils, Anthonomus grandis grandis Boheman, were assessed under five different photophases (24, 14, 12, 10, and 0 h) at a constant 27 degrees C temperature and 65% RH in the laboratory. Analyses of our results detected positive relationships between photoperiod and puncturing (mean numbers of oviposition and feeding punctures per day), and oviposition (oviposition punctures/oviposition+feeding punctures) activities, and the proportion of squares attacked by boll weevil females. When boll weevil females developed in light:darkness cycles, they produced a significantly higher percentage of eggs developing to adulthood than those developed in 24-h light or dark conditions. In long photoperiod (24:0 and 14:10 h), the number of female progeny was significantly higher and their development time was significantly shorter than those developed in short photoperiod (0:24 and 10:14 h). Lifetime oviposition was significantly highest at 12- and 14-h photophase, lowest at 0- and 10-h photophase, and intermediate at 24 h of light. Life table calculations indicated that boll weevil populations developed in a photoperiod of 14:10 and 12:12 (L:D) h will increase an average of two-fold each generation (Ro) compared with boll weevils developed in 24:0- and 10:14-h photoperiods and 15-fold compared with those at 0:24 h. Knowledge of the photoperiod-dependent population growth potential is critical for understanding population dynamics to better develop sampling protocols and timing insecticide applications.

Ecology and phenology of the boll weevil (Coleoptera: Curculionidae) on an unusual wild host, Hibiscus pernambucensis, in southeastern Mexico.

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Arzaluz, I O; Jones, R W

2001-12-01

The phenology and ecology of Hibiscus pernambucensis Arruda and its interaction and importance in maintaining populations of the boll weevil, Anthonomus grandis Boheman, were studied over a period of 3 yr in the Soconusco Region of the state of Chiapas, Mexico. H. pernambucensis is a small tree of Neotropical distribution, restricted to lowland areas, and generally associated with halophytic vegetation. This species is found exclusively along the shores of brackish estuaries, in or near mangrove swamps in southeastern Mexico. In this region, H. pernambucensis has a highly seasonal flowering pattern in which the greatest bud production occurs shortly after the start of the rainy season in May and the highest fruit production occurs in July and August. Boll weevil larvae were found in buds of H. pernambucensis during all months but February and densities of buds and weevils were highest from May through September. The percentage of buds infested with boll weevil larvae rarely exceeded 30%. Because plant densities and reproductive output of H. pernambucensis is relatively low and, consequently, the number of oviposition and larval development sites for boll weevils is limited, the importance of this plant as a source of boll weevils with potential of attacking commercial cotton is minimal in comparison with the quantity produced in cultivated cotton. However, the plant could be important as a reservoir of boll weevils in areas of boll weevil quarantine and eradication programs. The factors and circumstances that may have led to this apparent recent host shift of the boll weevil in this region are discussed.

Azadirachtin-induced hormesis mediating shift in fecundity-longevity trade-off in the Mexican bean weevil (Chrysomelidae: Bruchinae).

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Mallqui, K S Vilca; Vieira, J L; Guedes, R N C; Gontijo, L M

2014-04-01

Insecticides can have lethal or sublethal effects upon targeted pest species, and sublethal effects may even favor pest outbreaks if insecticide-induced hormesis occurs. Hormesis is a biphasic dose-response of a given chemical compound that is stimulatory at low doses and toxic at high doses. The former response may result from the disruption of animal homeostasis leading to trade-off shifts between basic ecophysiological processes. A growing interest in the use of biorational insecticides, such as azadirachtin to control stored-product pests, raises concerns about potential sublethal effects. In this study, we explored the hypothesis that azadirachtin can negatively impact the reproductive capacity of the Mexican bean weevil, Zabrotes subfasciatus (Boheman) (Chrysomelidae: Bruchinae), a key pest of stored beans. In addition, we investigated whether adults of this species could compensate for any sublethal effect that might have affected any of their reproductive parameters by adjusting the allocation of its reproductive efforts. The results showed that females of Z. subfasciatus increased fecundity daily to compensate for azadirachtin-induced decreased longevity. In addition, a stage-structured matrix study revealed that populations of Z. subfasciatus engendered from females exposed to azadirachtin exhibited a higher rate of population increase (r) and a higher net reproductive rate (R(o)). Finally, a projection matrix analysis showed notably higher densities along the generations for azadirachtin-exposed Z. subfasciatus populations. Thus, our study provides empirical evidence for the capacity of Z. subfasciatus to adapt to sublethal effects caused by biorational insecticides; consequently, this study highlights the importance of understanding this phenomenon when devising pest management strategies.

Transcriptomic survey of the midgut of Anthonomus grandis (Coleoptera: Curculionidae).

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Salvador, Ricardo; Príncipi, Darío; Berretta, Marcelo; Fernández, Paula; Paniego, Norma; Sciocco-Cap, Alicia; Hopp, Esteban

2014-01-01

Anthonomus grandis Boheman is a key pest in cotton crops in the New World. Its larval stage develops within the flower bud using it as food and as protection against its predators. This behavior limits the effectiveness of its control using conventional insecticide applications and biocontrol techniques. In spite of its importance, little is known about its genome sequence and, more important, its specific expression in key organs like the midgut. Total mRNA isolated from larval midguts was used for pyrosequencing. Sequence reads were assembled and annotated to generate a unigene data set. In total, 400,000 reads from A. grandis midgut with an average length of 237 bp were assembled and combined into 20,915 contigs. The assembled reads fell into 6,621 genes models. BlastX search using the NCBI-NR database showed that 3,006 unigenes had significant matches to known sequences. Gene Ontology (GO) mapping analysis evidenced that A. grandis is able to transcripts coding for proteins involved in catalytic processing of macromolecules that allows its adaptation to very different feeding source scenarios. Furthermore, transcripts encoding for proteins involved in detoxification mechanisms such as p450 genes, glutathione-S-transferase, and carboxylesterases are also expressed. This is the first report of a transcriptomic study in A. grandis and the largest set of sequence data reported for this species. These data are valuable resources to expand the knowledge of this insect group and could be used in the design of new control strategies based in molecular information. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Components of competitiveness in sterile male boll weevils (Coleoptera: Curculionidae)

International Nuclear Information System (INIS)

Villavaso, E.J.; McGovern, W.L.; Wagner, T.L.; Willers, J.L.

1998-01-01

This study examines the relative importance of age at the time of irradiation on attractiveness, mating ability, sperm transfer, prior mating, and longevity as factors of competitiveness in sterile male boll weevil, Anthonomus grandis grandis Boheman. The amount of sperm transferred by irradiated males appeared to be the most important factor in competitiveness. More sperm was transferred by virgin males irradiated on day 5 than by virgin males irradiated on day 2, and males irradiated on day 5 had greater impact on egg hatch than those irradiated on day 2. The amount of sperm in spermathecae of females mated to virgin mates irradiated on day 5 was indistinguishable from that in females mated to virgin control males. Mating ability of males of all treatments was similar. Comparable numbers of boll weevils were captured in traps baited with males irradiated at 2 or 5 d during the first 4-5 d after irradiation, but thereafter, generally more weevils were captured in traps baited with males irradiated at 2 d or with control males. Attractiveness of males irradiated at 2 d was generally comparable to that of control males. More than 91% of irradiated males individually caged on cotton, Gossypium hirsutum L., plants lived for 10 d in the field, and 40% lived for 14 d; all individually caged control males lived 14 d. When released into cotton fields, however, the numbers of both irradiated and control males declined sharply over 14 d. Thus, the potential for an effective 2-wk life span in the field suggested by the caged study did not appear to apply to laboratory-reared weevils released into cotton fields

Relationships of abscised cotton fruit to boll weevil (Coleoptera: Curculionidae) feeding, oviposition, and development.

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Showler, Allan T

2008-02-01

Abscised cotton, Gossypium hirsutum L., fruit in field plots planted at different times were examined to assess adult boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), use of squares and bolls during 2002 and 2003 in the Lower Rio Grande Valley of Texas. Although boll abscission is not necessarily related to infestation, generally more bolls abscised than squares and abundances of fallen bolls were not related to the planting date treatments. During 2003, fallen squares were most abundant in the late-planted treatment. Although large squares (5.5-8-mm-diameter) on the plant are preferred for boll weevil oviposition, diameter of abscised squares is not a reliable measurement because of shrinkage resulting from desiccation and larval feeding. Fallen feeding-punctured squares and bolls were most abundant in late plantings but differences between fallen feeding-punctured squares versus fallen feeding-punctured bolls were found in only one treatment in 2003. During the same year, fallen oviposition-punctured squares were more numerous in the late-planted treatment than in the earlier treatments. Treatment effects were not found on numbers of oviposition-punctured bolls, but fallen oviposition-punctured squares were more common than bolls in the late-planted treatment compared with earlier treatments each year. Dead weevil eggs, larvae, and pupae inside fallen fruit were few and planting date treatment effects were not detected. Living third instars and pupae were more abundant in fallen squares of the late-planted treatment than in the earlier treatments and bolls of all three treatments. This study shows that fallen squares in late-planted cotton contribute more to adult boll weevil populations than bolls, or squares of earlier plantings.

A model for long-distance dispersal of boll weevils (Coleoptera: Curculionidae)

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Westbrook, John K.; Eyster, Ritchie S.; Allen, Charles T.

2011-07-01

The boll weevil, Anthonomus grandis (Boheman), has been a major insect pest of cotton production in the US, accounting for yield losses and control costs on the order of several billion US dollars since the introduction of the pest in 1892. Boll weevil eradication programs have eliminated reproducing populations in nearly 94%, and progressed toward eradication within the remaining 6%, of cotton production areas. However, the ability of weevils to disperse and reinfest eradicated zones threatens to undermine the previous investment toward eradication of this pest. In this study, the HYSPLIT atmospheric dispersion model was used to simulate daily wind-aided dispersal of weevils from the Lower Rio Grande Valley (LRGV) of southern Texas and northeastern Mexico. Simulated weevil dispersal was compared with weekly capture of weevils in pheromone traps along highway trap lines between the LRGV and the South Texas / Winter Garden zone of the Texas Boll Weevil Eradication Program. A logistic regression model was fit to the probability of capturing at least one weevil in individual pheromone traps relative to specific values of simulated weevil dispersal, which resulted in 60.4% concordance, 21.3% discordance, and 18.3% ties in estimating captures and non-captures. During the first full year of active eradication with widespread insecticide applications in 2006, the dispersal model accurately estimated 71.8%, erroneously estimated 12.5%, and tied 15.7% of capture and non-capture events. Model simulations provide a temporal risk assessment over large areas of weevil reinfestation resulting from dispersal by prevailing winds. Eradication program managers can use the model risk assessment information to effectively schedule and target enhanced trapping, crop scouting, and insecticide applications.

Migration and dispersal of Anthonomus grandis (Coleoptera: Curculionidae in South America Migración y dispersión de Anthonomus grandis (Coleoptera: Curculionidae en América del Sur

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Teodoro Stadler

2007-12-01

Full Text Available This study discusses the dispersal of Anthonomus grandis Boheman, the cotton boll weevil, in Argentina, Brazil, Paraguay and Bolivia, exploring the ecological and physiological factors that have made the dispersal and establishment of this insect in South America so successful. The boll weevil's phenotypic plasticity is represented by its flexible developmental time, its multivoltine life cycle with several overlapping generations, its capacity to feed on pollen from diverse botanical families as well as from non pollen food sources and its ability to migrate and disperse aided by winds. These characteristics make it a key pest for cotton. Probable overwintering «hot spots» for the boll weevil were identified in Misiones-Argentina, where large numbers of prediapausing weevils concentrate after arrival from newly harvested cotton fields in Paraguay, probably attracted by citrus orchards volatiles. The boll weevil's facultative quiescence is always relative to environmental adverse conditions. This suggests that overwintering in the boll weevil can be defined as «oligopause», an intermediate form of diapause. Since its introduction to Brazil in 1983, until 2006, it has spread southwest at an average of 61 km year-1 towards Argentina. However, it took the boll weevil approximately ten years to move 250 km between Paraguay and the main cotton growing area in Argentina. This slower progress is probably due to the actions taken by the Argentine government through the boll weevil eradication program. The arrival of the boll weevil at the cotton cropping areas in Paraguay and Argentina reinforces the fact that the boll weevil should finally be included in an integrated cotton pest management program jointly with other major cotton pests.El presente estudio sobre la dispersión de Anthonomus grandis Boheman, el picudo del algodonero, en Argentina, Brasil, Paraguay y Bolivia, explora las características ecológicas y fisiológicas que han permitido a

Competition between Catolaccus grandis (Hymenoptera: Pteromalidae and Bracon vulgaris (Hymenoptera: Braconidae, parasitoids of the Boll Weevil

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Francisco de Sousa Ramalho

2007-05-01

Full Text Available The competition between populations of the parasitoids C. grandis and B. vulgaris was studied using larvae of Euscepes postfasciatus (Fairmaire as an alternative host. A series of biological parameters was observed and related to the competitive abilities of both parasitoid species. They were capable of colonizing and maintaining their populations regardless of host location. The population growth of C. grandis and B. vulgaris, based on fecundity was not affected by the competition. The parasitism and survivorship to the adult stage were affected by competition, except when the host was located at the bottom of the rearing cage. C. grandis performed better than B. vulgaris independently of the competition and host location, but it did not exclude the other species.Catolaccus grandis (Burks e Bracon vulgaris Ashmead são os principais parasitóides do bicudo-do-algodoeiro Anthonomus grandis Boheman no Nordeste do Brasil. É importante que se determinem as interações entre esses parasitóides e o seu efeito em programas de controle biológico dessa praga com os mesmos. A competição entre os parasitóides C. grandis e B. vulgaris foi estudada, utilizando-se larvas de Euscepes postfasciatus Fairmaire como hospedeiro alternativo. A fecundidade de C. grandis e B. vulgaris baseada na produção de ovos, não foi afetada pela competição, mas o parasitismo e a produção de adultos desses parasitóides foram afetados pela competição, exceto quando o hospedeiro se encontrava na base da caixa de criação. Independentemente da competição e da localização do hospedeiro, C. grandis apresentou melhor desempenho que B. vulgaris, mas não excluiu as populações da outra espécie de parasitóide.

Captures of Boll Weevils (Coleoptera: Curculionidae) in Relation to Trap Distance From Cotton Fields.

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Spurgeon, Dale W

2016-12-01

The boll weevil (Anthonomus grandis grandis Boheman) has been eradicated from much of the United States, but remains an important pest of cotton (Gossypium spp.) in other parts of the Americas. Where the weevil occurs, the pheromone trap is a key tool for population monitoring or detection. Traditional monitoring programs have placed traps in or near the outermost cotton rows where damage by farm equipment can cause loss of trapping data. Recently, some programs have adopted a trap placement adjacent to but outside monitored fields. The effects of these changes have not been previously reported. Captures of early-season boll weevils by traps near (≤1 m) or far (7-10 m) from the outermost cotton row were evaluated. In 2005, during renewed efforts to eradicate the boll weevil from the Lower Rio Grande Valley of Texas, far traps consistently captured more weevils than traps near cotton. Traps at both placements indicated similar patterns of early-season weevil captures, which were consistent with those previously reported. In 2006, no distinction between trap placements was detected. Early-season patterns of captures in 2006 were again similar for both trap placements, but captures were much lower and less regular compared with those observed in 2005. These results suggest magnitude and likelihood of weevil capture in traps placed away from cotton are at least as high as for traps adjacent to cotton. Therefore, relocation of traps away from the outer rows of cotton should not negatively impact ability to monitor or detect the boll weevil. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by a US Government employee and is in the public domain in the US.

Cotton harvest at 40% versus 75% boll-splitting on yield and economic return under standard and proactive boll weevil (Coleoptera: Curculionidae) spray regimes.

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Showler, A T; Robinson, J R C

2008-10-01

The standard practice of two or three preemptive insecticide applications at the start of pinhead (1-2-mm-diameter) squaring followed by threshold-triggered (when 10% of randomly selected squares have oviposition punctures) insecticide applications for boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), control does not provide reliable protection of cotton, Gossypium hirsutum L., lint production. This study, conducted during 2004 and 2005, showed that three to six fewer spray applications in a "proactive" approach, in which spraying began at the start of large (5.5-8-mm-diameter) square formation and continued at approximately 7-d intervals while large squares were abundant, resulted in fewer infested squares and 1.4- to 1.7-fold more lint than the standard treatment. Fewer sprays and increased yield made proactive spraying significantly more profitable than the standard approach, which resulted in relatively low or negative economic returns. Harvest at 75% boll-split in the proactive spray regime of 2005 resulted in four-fold greater economic return than cotton harvested at 40% boll-split because of improved protection of large squares and the elimination of late-season sprays inherent to standard spray regime despite the cost of an extra irrigation in the 75% boll-split treatments. The earlier, 40% harvest trigger does not avoid high late-season boll weevil pressure, which exerts less impact on bolls, the predominant form of fruiting body at that time, than on squares. Proactive spraying and harvest timing are based on an important relationship between nutrition, boll weevil reproduction, and economic inputs; therefore, the tactic of combining proaction with harvest at 75% boll-split is applicable where boll weevils are problematic regardless of climate or region, or whether an eradication program is ongoing.

Sequential Sampling Plan of Anthonomus grandis (Coleoptera: Curculionidae) in Cotton Plants.

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Grigolli, J F J; Souza, L A; Mota, T A; Fernandes, M G; Busoli, A C

2017-04-01

The boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is one of the most important pests of cotton production worldwide. The objective of this work was to develop a sequential sampling plan for the boll weevil. The studies were conducted in Maracaju, MS, Brazil, in two seasons with cotton cultivar FM 993. A 10,000-m2 area of cotton was subdivided into 100 of 10- by 10-m plots, and five plants per plot were evaluated weekly, recording the number of squares with feeding + oviposition punctures of A. grandis in each plant. A sequential sampling plan by the maximum likelihood ratio test was developed, using a 10% threshold level of squares attacked. A 5% security level was adopted for the elaboration of the sequential sampling plan. The type I and type II error used was 0.05, recommended for studies with insects. The adjustment of the frequency distributions used were divided into two phases, so that the model that best fit to the data was the negative binomial distribution up to 85 DAE (Phase I), and from there the best fit was Poisson distribution (Phase II). The equations that define the decision-making for Phase I are S0 = -5.1743 + 0.5730N and S1 = 5.1743 + 0.5730N, and for the Phase II are S0 = -4.2479 + 0.5771N and S1 = 4.2479 + 0.5771N. The sequential sampling plan developed indicated the maximum number of sample units expected for decision-making is ∼39 and 31 samples for Phases I and II, respectively. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A taxonomic monograph of the genus Tylodinus Champion (Coleoptera: Curculionidae: Cryptorhynchinae: Tylodina) of Chiapas, Mexico.

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Luna-Cozar, Jesús; Anderson, Robert S; Jones, Robert W; León-Corté, Jorge L

2014-04-15

nodulosus species group (3) T. andersoni new species (Chiapas, Ángel Albino Corzo, Reserva El Triunfo, Polígono 1), T. nodulosus (Boheman), T. zilchi Kuschel; Tylodinus pusillus species group (2) T. porvenirensis new species (type locality: Chiapas, El Porvenir, El Porvenir (2 km NE)), T. pusillus new species (type locality: Chiapas, 4 km SE Custepec); Tylodinus spiniventris species group (2) T. lum new species (Chiapas, San Cristóbal de las Casas, Cerro Huitepec), and T. spiniventris new species (type locality: Chiapas, San Cristóbal de las Casas, Reserva Huitepec); Incertae sedis (13) T. pinguis new species (type locality: Chiapas, Ángel Albino Corzo, Reserva El Triunfo, Polígono 1) , T. kissingeri new species (type locality: Chiapas, Tapalapa, ca. 14 km NE Coapilla), T. complicatus new species (type locality: Chiapas, Pueblo Nuevo Solistahuacán, La Yerbabuena), T. dominicus new species (type locality: Chiapas, Villa Corzo, Reserva de la Biósfera La Sepultura), T. noctis new species (type locality: Chiapas, Coapilla, ca. 10.5 km NE Coapilla), T. rufus new species (type locality: Chiapas, San Cristóbal de las Casas, Cerro Huitepec); T. branstetteri new species (type locality: Chiapas, La Concordia, 4 km SE Custepec), T. kuscheli new species (type locality: Chiapas, Villa Flores, Ejido Sierra Morena), T. pappi new species (type locality: Chiapas, Unión Juárez, Volcán Tacan), T. gibbosus new species (type locality: Chiapas, Pueblo Nuevo Solistahuacán, Yerbabuena Reserve), T. immundus new species (type locality: Chiapas, San Cristóbal de las Casas Cerro Huitepec), T. intzin new species (type locality: Chiapas, Tenejapa, Yashanal), T. elongatus new species (type locality: Chiapas, Ángel Albino Corzo, Reserva El Triunfo, Polígono 1). Three species (T. nodulosus (Boheman), T. zilchi Kuschel and T. cavicrus Champion) are not known to occur in Chiapas but were included in this study to be more representative of inter- and intraspecific variation and to provide a

Método de diagnóstico para el monitoreo de resistencia a insecticidas en poblaciones de “picudo del algodonero”, Anthonomus grandis (Coleoptera: Curculionidae

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Teodoro STADLER

2009-01-01

Full Text Available El control de las poblaciones de Anthonomus grandis Boheman, por debajo de su umbral de daño económico durante el ciclo del cultivo del algodón, se realiza en forma efectiva hasta el momento, a través de insecticidas de síntesis. La presión selectiva de las aplicaciones extensivas e intensivas de insecticidas hace imperativa la detección temprana de focos de resistencia a los mismos, en función de un correcto manejo del fenómeno. Se desarrolló un método de diagnóstico de resistencia para A. grandis a partir de la técnica “vial test”, que fue adaptada en forma de “kit” para el monitoreo rápido y sencillo de los focos de resistencia en el campo. La toxicidad (CL99, para calcular la concentración discriminante (CD del insecticida y la preparación del “kit”, se obtiene a partir de bioensayos de laboratorio con una cepa normal susceptible de A. grandis. Se determinó la vida media de los insecticidas dentro de los viales por CIPAC MT 46, para establecer una fecha de vencimiento del “kit”. La CD y el método en su conjunto fueron validados a través de ensayos a campo. El “kit”, usado en el monitoreo de resistencia en el campo, fue especialmente diseñado para ser utilizado en las condiciones geográficas, económicas y socio-culturales presentes en la región algodonera argentina. La implementación de esta técnica permitirá conseguir la información necesaria, y así obtener una apropiada alternancia de insecticidas. Como consecuencia, se prevé una reducción de impactoambiental de las prácticas agronómicas en el control de plagas en algodón.

Bioecologia de Euborellia annulipes (Dermaptera: Anisolabididae

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Aldeni Barbosa da Silva

2015-03-01

Full Text Available 800x600 Dentre os agentes biológicos com boa capacidade predatória, os dermápteros têm despertado grande atenção, pois são predadores vorazes, isto é, com alta capacidade de ataque e que se alimentam de diversas presas, particularmente, de ovos e fases imaturas de insetos das ordens Lepidoptera, Hemiptera, Coleoptera e Diptera. São insetos terrestres, predadores, de hábitos noturnos, e às vezes vistos durante o dia. Os dermápteros têm se destacado no controle de insetos-praga, principalmente de ovos e formas jovens. Euborellia annulipes (Lucas é um agente controlador de Hyadaphis foeniculi (Passerini e Brevicoryne brassicae (Linnaeus, no Brasil; Cosmopolites sordidus (Germar, na Jamaica; lagartas de Sesamia inferens (Walker, no Japão, e alguns insetos-praga de grãos armazenados, da lagarta Crambus bonifatellus (Hulst, lagartas e pupas de Diatraea saccharalis (Fabricius, de ovos, larvas, ninfas e adultos de Dermanyssus gallinae (De Geer, Carpocapsa pomonella (Linné na França, de Icerya purchasi (Maskell na Califórnia e larvas e pupas de Anthonomus grandis (Boheman em nível de campo. Este trabalho teve o objetivo de fazer uma abordagem sobre a bioecologia de Euborellia annulipes, assim como, traçar considerações a respeito da sua classificação, de sua associação a pragas agrícolas e de seu uso em programas de controle biológico. Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";}

History of the sterile insect technique

International Nuclear Information System (INIS)

Klassen, W.; Curtis, C.F.

2005-01-01

During the 1930s and 1940s the idea of releasing insects of pest species to introduce sterility (sterile insect technique or SIT) into wild populations, and thus control them, was independently conceived in three extremely diverse intellectual environments. The key researchers were A. S. Serebrovskii at Moscow State University, F. L. Vanderplank at a tsetse field research station in rural Tanganyika (now Tanzania), and E. F. Knipling of the United States Department of Agriculture. Serebrovskii's work on chromosomal translocations for pest population suppression could not succeed in the catastrophic conditions in the USSR during World War II, after which he died. Vanderplank used hybrid sterility to suppress a tsetse population in a large field experiment, but lacked the resources to develop this method further. Knipling and his team exploited H. J. Muller's discovery that ionizing radiation can induce dominant lethal mutations, and after World War II this approach was applied on an area-wide basis to eradicate the New World screwworm Cochliomyia hominivorax (Coquerel) in the USA, Mexico, and Central America. Since then very effective programmes integrating the SIT have been mounted against tropical fruit flies, some species of tsetse flies Glossina spp., the pink bollworm Pectinophora gossypiella (Saunders), and the codling moth Cydia pomonella (L.). In non-isolated onion fields in the Netherlands, the onion maggot Delia antiqua (Meigen) has since 1981 been suppressed by the SIT. In the 1970s there was much research conducted on mosquito SIT, which then went into 'eclipse', but now appears to be reviving. Development of the SIT for use against the boll weevil Anthonomus grandis grandis Boheman and the gypsy moth Lymantria dispar (L.) has ended, but it is in progress for two sweetpotato weevil species, Cylas formicarius (F.) and Euscepes postfasciatus (Fairmaire), the false codling moth Cryptophlebia leucotreta (Meyrick), the carob moth Ectomyelois ceratoniae

Survival and behavioural responses of the predatory ladybird beetle, Eriopis connexa populations susceptible and resistant to a pyrethroid insecticide.

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Spíndola, A F; Silva-Torres, C S A; Rodrigues, A R S; Torres, J B

2013-08-01

The ladybird beetle, Eriopis connexa (Germar) (Coleoptera: Coccinellidae), is one of the commonest predators of aphids (Hemiptera: Aphididae) in the cotton agroecosystem and in many other row and fruit crops in Brazil, and has been introduced into other countries such as the USA for purposes of aphid control. In addition, the boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae) is the most serious cotton pest where it occurs, including Brazil. Controlling boll weevils and other pests such as cotton defoliators still tends to involve the intense application of insecticides to secure cotton production. The pyrethroid insecticide lambda-cyhalothrin (LCT) is commonly used, but this compound is not effective against aphids; hence, a desirable strategy would be to maintain E. connexa populations in cotton fields where LCT is applied. Using populations of E. connexa resistant (Res) and susceptible (Sus) to LCT, we compared behavioural responses on treated cotton plants and under confinement on partially and fully treated surfaces, and assessed the insects' survival on treated plants compared with that of the boll weevil. The E. connexa resistant population caged on treated plants with 15 and 75 g a.i. ha-1 exhibited ≫82% survival for both insecticide concentrations compared with ≪3% and ≪17% survival for susceptible E. connexa populations and boll weevils, respectively. The response of E. connexa Res and Sus populations when released, either on the soil or on the plant canopy, indicated avoidance towards treated plants, as measured by elapsed time to assess the plant. When compared with susceptible individuals, resistant ones took longer time to suffer insecticide knockdown, had a higher recovery rate after suffering knockdown, and spent more time in the plant canopy. Based on behavioural parameters evaluated in treated arenas, no ladybird beetles exhibited repellency. However, irritability was evident, with the susceptible population exhibiting

Migration and dispersal of Anthonomus grandis (Coleoptera: Curculionidae in South America

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Teodoro STADLER

2007-01-01

Full Text Available El presente estudio sobre la dispersión de Anthonomus grandis Boheman, el picudo del algodonero, en Argentina, Brasil, Paraguay y Bolivia, explora las características ecológicas y fisiológicas que han permitido a este insecto dispersarse y establecerse exitosamente en América del Sur. La plasticidad fenotípica de A. grandis se caracteriza por un tiempo de desarrollo flexible, ciclo de vida multivoltino con generaciones superpuestas, la capacidad de alimentarse con polen de diversas familias botánicas así como de otras fuentes de alimento y por su habilidad para migrar y dispersarse con la ayuda del viento. Todo esto hace de esta especie una plaga clave para el cultivo del algodón. Los cultivos de cítricos en Misiones, Argentina, son posibles sitios para la hibernación de esta especie. En esta región fueron capturadas grandes cantidades de individuos prediapausantes, provenientes de algodonales en post-cosecha en Paraguay, atraídos probablemente por compuestos volátiles de cítricos cultivados en la zona. La quiescencia facultativa que atraviesan los adultos ante condiciones adversas, conlleva a un retraso en el desarrollo que se relaciona con las condiciones desfavorables. Esto sugiere que la hibernación en A. grandis puede ser definida como «oligopausa», una forma intermedia de diapausa. Desde su introducción en Brasil en 1983 y hasta el 2006, el picudo se ha dispersado en dirección sudoeste hacia Argentina, a una velocidad promedio de 61 km año-1. Sin embargo, le ha insumido aproximadamente diez años cruzar 250 km, desde Paraguay hacia el centro de la zona algodonera de Argentina. Este progreso más lento se debe probablemente a las acciones llevadas a cabo en el marco del programa de erradicación del picudo del algodonero, por parte del gobierno de Argentina. La llegada del picudo al área central de cultivo de algodón en la Argentina, así como a otras áreas de cultivo en Paraguay y Argentina, confirma el hecho de que

Aspectos biológicos de adultos de um parasitóide do bicudo do algodoeiro Biological aspects of a parasitoid of the cotton boll weevil

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Lúcia Helena Avelino Araújo

1999-10-01

Full Text Available Bracon sp. é um importante agente de controle biológico de Anthonomus grandis (Boheman. Estudaram-se em laboratório, aspectos biológicos de Bracon sp., utilizando-se como hospedeiro larva do bicudo do algodoeiro, a temperatura de 26 ± 2oC, 70 ± 5% UR e fotofase de 12 horas. O ciclo biológico de Bracon sp. teve duração média de 11,7 dias, o período de incubação de 1 dia, o período médio larval de 3,9 dias, com 4 estádios; a viabilidade larval de 98,7%, o período pré-pupal de 0,6 dia, o período pupal de 6,2 dias, o tempo de pré-oviposição de 4,0 dias. A fêmea colocou, em média, 74 ovos em um período de 27,2 dias, a oviposição média diária de 2,7 ovos/fêmea/dia, o período de pós-oviposição de 3,7 dias e a longevidade de Bracon sp. foi de 34 dias para as fêmeas. A informação da biologia deste braconídeo é necessária para desenvolver estratégias de propagação e colonização do parasitóide.Bracon sp. is an important biological control agent of Anthonomus grandis, the cotton Boll weevil. The objective of this work was to evaluate biological aspects of Bracon sp. using cotton Boll weevil larvae as host, at conditions of 26 ± 2oC, with 70 ± 5% RH and 12h photoperiod. The complete life cycle of Bracon sp. was 11.7 days. The incubation period lasted 1.0 day and the larval period 3.9 days with four stages; the viability of the larvae was 98.7%; prepupal period lasted 0.6 day; and the pupal period lasted 6.2 days. Preoviposition period was 4.0 days, and the females laid an average of 74.0 eggs with in an oviposition period of 27.2 days, while the average daily oviposition rate was 2.7 eggs per female per day, posovipositional lasted 3.7 days, and the longevity of Bracon sp. was 34.0 days in females. The information of the biology of this Braconid is needed to develop parasitoid propagation and colonization strategies.

Chagas disease risk in Texas.

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Sarkar, Sahotra; Strutz, Stavana E; Frank, David M; Rivaldi, Chissa-Louise; Sissel, Blake; Sánchez-Cordero, Victor

2010-10-05

Chagas disease, caused by Trypanosoma cruzi, remains a serious public health concern in many areas of Latin America, including México. It is also endemic in Texas with an autochthonous canine cycle, abundant vectors (Triatoma species) in many counties, and established domestic and peridomestic cycles which make competent reservoirs available throughout the state. Yet, Chagas disease is not reportable in Texas, blood donor screening is not mandatory, and the serological profiles of human and canine populations remain unknown. The purpose of this analysis was to provide a formal risk assessment, including risk maps, which recommends the removal of these lacunae. The spatial relative risk of the establishment of autochthonous Chagas disease cycles in Texas was assessed using a five-stage analysis. 1. Ecological risk for Chagas disease was established at a fine spatial resolution using a maximum entropy algorithm that takes as input occurrence points of vectors and environmental layers. The analysis was restricted to triatomine vector species for which new data were generated through field collection and through collation of post-1960 museum records in both México and the United States with sufficiently low georeferenced error to be admissible given the spatial resolution of the analysis (1 arc-minute). The new data extended the distribution of vector species to 10 new Texas counties. The models predicted that Triatoma gerstaeckeri has a large region of contiguous suitable habitat in the southern United States and México, T. lecticularia has a diffuse suitable habitat distribution along both coasts of the same region, and T. sanguisuga has a disjoint suitable habitat distribution along the coasts of the United States. The ecological risk is highest in south Texas. 2. Incidence-based relative risk was computed at the county level using the Bayesian Besag-York-Mollié model and post-1960 T. cruzi incidence data. This risk is concentrated in south Texas. 3. The

Chagas disease risk in Texas.

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Sahotra Sarkar

Full Text Available BACKGROUND: Chagas disease, caused by Trypanosoma cruzi, remains a serious public health concern in many areas of Latin America, including México. It is also endemic in Texas with an autochthonous canine cycle, abundant vectors (Triatoma species in many counties, and established domestic and peridomestic cycles which make competent reservoirs available throughout the state. Yet, Chagas disease is not reportable in Texas, blood donor screening is not mandatory, and the serological profiles of human and canine populations remain unknown. The purpose of this analysis was to provide a formal risk assessment, including risk maps, which recommends the removal of these lacunae. METHODS AND FINDINGS: The spatial relative risk of the establishment of autochthonous Chagas disease cycles in Texas was assessed using a five-stage analysis. 1. Ecological risk for Chagas disease was established at a fine spatial resolution using a maximum entropy algorithm that takes as input occurrence points of vectors and environmental layers. The analysis was restricted to triatomine vector species for which new data were generated through field collection and through collation of post-1960 museum records in both México and the United States with sufficiently low georeferenced error to be admissible given the spatial resolution of the analysis (1 arc-minute. The new data extended the distribution of vector species to 10 new Texas counties. The models predicted that Triatoma gerstaeckeri has a large region of contiguous suitable habitat in the southern United States and México, T. lecticularia has a diffuse suitable habitat distribution along both coasts of the same region, and T. sanguisuga has a disjoint suitable habitat distribution along the coasts of the United States. The ecological risk is highest in south Texas. 2. Incidence-based relative risk was computed at the county level using the Bayesian Besag-York-Mollié model and post-1960 T. cruzi incidence data. This

North-Western Palaearctic species of Pristiphora (Hymenoptera, Tenthredinidae

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Marko Prous

2017-09-01

Full Text Available North-Western Palaearctic species of Pristiphora Latreille, 1810 are revised. Altogether, 90 species are treated, two of which are described as new: P. caraganae Vikberg & Prous, sp. n. from Finland and P. dedeara Liston & Prous, sp. n. from Germany. Host plant of P. caraganae is Caragana arborescens Lam. Pristiphora dasiphorae (Zinovjev, 1993 (previously known from East Palaearctic and P. cadma Wong & Ross, 1960 (previously known from North America are recorded for the first time from Europe. Nematus nigricans Eversmann, 1847 [= Pristiphora nigricans (Eversmann, 1847, comb. n.], N. breviusculus Eversmann, 1847 [= Euura melanocephalus (Hartig, 1837], and N. caudalis Eversmann, 1847 [= E. caudalis (Eversmann, 1847, comb. n.] are removed from synonymy with P. pallidiventris (Fallén, 1808, N. paralellus Hartig, 1840 [= P. paralella (Hartig, 1840, comb. n.] is removed from synonymy with P. bufo (Brischke, 1883, and P. mesatlantica Lacourt, 1976 is removed from synonymy with P. insularis Rohwer, 1910. The following 29 new synonymies are proposed: P. nigropuncticeps Haris, 2002, syn. n. with P. albitibia (Costa, 1859; Lygaeonematus karvoneni Lindqvist, 1952, syn. n. with P. alpestris (Konow, 1903; P. (P. anivskiensis Haris, 2006, syn. n. with P. appendiculata (Hartig, 1837; Nematus canaliculatus Hartig, 1840, syn. n with P. carinata (Hartig, 1837; P. nigrogroenblomi Haris, 2002, syn. n. with P. cincta Newman, 1837; Tenthredo flavipes Zetterstedt, 1838, syn. n., Nematus congener W.F. Kirby, 1882, syn. n., and P. thomsoni Lindqvist, 1953, syn. n. with P. dochmocera (Thomson, 1871; P. atrata Lindqvist, 1975, syn. n. with P. friesei (Konow, 1904; P. gelida Wong, 1968, syn. n. with P. frigida (Boheman, 1865; Pachynematus nigricorpus Takagi, 1931, syn. n. with P. laricis (Hartig, 1837; Nematus (Pikonema piceae Zhelochovtsev in Zhelochovtsev and Zinovjev, 1988, syn. n. and P. (P. hoverlaensis Haris, 2001, syn. n. with P. leucopodia (Hartig, 1837; Mesoneura

Dez anos de sucessivas adubações com boro no algodoeiro Ten years of cotton fertilization with boron

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Nelson Machado da Silva

1995-01-01

Canajus indicus was cultivated, in crop rotation, to control the increasing incidence of nemathodes. After the eighth year, there was intense attack of Anthonomus grandis Boheman. Thus, cotton yield diminished from the first period, of three years, to the last, while the effect of boron accumulation increased in this sense. In the first period, there was an enchance of yield at rate of 0.4 kg/ha of B, but after lime reaction the best responses were obtained with 0.8 kg/ha of B. The plants were more sensitives to fertilization in terms of boron concentration in the leaf blade, specially after liming. Rates of 1.6 and 3.2 kg/ha of B were injurious starting from the beginning of the study. After liming, yield decreases were related with B concentration higher than 50 mg/kg in leaf blades. Results of soil analysis in the nineth year, indicated a great residual effect of boron accumulation in the 0-20 cm soil layer, as well as leaching of the micronutrient at least down to 40-60 cm deep, in proportion to the rates applied.