The neotropical brown stink bug, Euschistus heros (F.), is a phytophagous pentatomid that causes considerable economic losses in soybean crop, but it has been recently reported using cotton as a new host plant. Nymphs and adults of E. heros were raised on six different food sources composed of the reproductive structures of cotton and soybean plants: a standard diet (green-bean pods + raw peanuts + privet fruits), soybean seeds, soybean pods, cotton seeds, cotton bolls, and cotton floral buds. The following biological parameters were evaluated: nymph developmental time, instar duration, and survivorship; adult weight at emergence; male and female longevity; duration of pre-oviposition and oviposition periods; and female fecundity and fertility. Nymphal development time and survival, as well as the adult weight and fecundity of E. heros fed on cotton bolls and seeds were reduced if compared to those fed on soybean pods. The cotton floral buds did not support the immature development nor the reproduction of adults of E. heros. Most of the cotton plant structures fed to E. heros caused high nymph mortality and low adult fertility. Cotton, therefore, appeared to be an unsuitable host for the development and reproduction of E. heros. Therefore, our data may allow us to suggest that the occurrence of E. heros on cotton may be due to occasional dispersion in search for shelter.

Este texto é uma revisáo bibliográfica que abrange 30 anos de ocorrência do bicudo-do-algodoeiro, Anthonomus grandisBoheman, 1843 (Coleoptera: Curculionidae), no Brasil. O bicudo é considerado uma das pragas mais prejudiciais à agricultura pelos danos que causa e pelas dificuldades de seu controle. Originário do México, esse inseto foi constatado pela primeira vez no Brasil em 1983 e duas safras após seu surgimento já estava disseminado nas principais áreas produtoras de algodão no país, onde se mantém até a atualidade. Quando não controlado, esse inseto pode destruir completamente a produção de um algodoal, já quando controlado os prejuízos variam de 3 a 75% da produtividade esperada. Os principais danos causados pelo bicudo são resultantes de orifícios promovidos nas estruturas reprodutivas da planta durante a alimentação e oviposição dos adultos, sendo os botões florais as estruturas preferencialmente atacadas pelo inseto. O período de ataque do bicudo às plantas de algodoeiro se inicia por volta dos 30 dias após a emergência, no estabelecimento vegetativo da cultura, passando pelo florescimento e frutificação e chegando até a fase de maturação, sendo que durante esse período vários métodos podem ser adotados visando ao seu controle. Para controle de A. grandis, no Brasil, são citados métodos de controle comportamental, controle cultural, resistência de plantas, controle biológico (predadores, parasitoides e patógenos), produtos naturais, controle legislativo e manejo integrado, além de iniciativas de programas de supressão populacional do inseto. O controle químico não é discutido neste artigo.

Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) causes economically significant damage to soybeans Glycine max (L.) Merrill (Fabaceae: Phaseoleae). The genetically modified soybean expressing the Cry1Ac protein of Bacillus thuringiensis Berliner, which is toxic to lepidopterans, is a potential alternative tool to manage this pest. Bioassays with H. armigera larval instars were conducted with Bt (Cry1Ac) and non-Bt soybean plants in order to evaluate the efficacy of control with the modified cultivar. Bt soybean affected the mean time of mortality in each larval instar, but its efficacy was not affected by the larval stage. Mortality was 100% in all six instars, indicating that the Bt soybean expressing the Cry 1Ac protein is an efficient control tactic for this pest.

Recently, the Neotropical brown stink bug, Euschistus heros (Pentatomidae: Hemiptera), has been detected in cotton in the Brazilian Cerrado. Several reliable surveys have been conducted on the spatial distribution of stink bugs in soybean; however, few studies have examined the behavior of this insect in cotton in Brazil. Thus, this study examined the spatial distribution of E. heros in cotton using aggregation indices based on the variance-to-mean ratio, Morisita index, exponent k, Poisson and negative binomial distributions. Inverse Distance Weighting interpolation maps were also used to represent insect density. The study was conducted in a 1.1 hectare experimental cotton field in which 64 equally-sized plots were sampled on a weekly basis. Our findings revealed that stink bugs presented an aggregate distribution in 2 sampling weeks based on aggregation indices, and this pattern was best described by a negative binomial distribution. Maps showing the density of pests can be an important tool for sampling pests in crops and control measures in early stages of infestation, when there is an edge effect on the distribution of E. heros, can be an efficient strategy in cotton.

A reprodução de parasitóides apresenta etapas interligadas e a idade de hospedeiros e parasitóides pode afetar o desenvolvimento desses últimos. Características biológicas de fêmeas de Trichospilus diatraeae Cherian & Margabandhu (Hymenoptera: Eulophidae), com até 96 horas de idade, foram estudadas em pupas do hospedeiro alternativo Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae). Cada pupa de A. gemmatalis com 0-24, 24-48, 48-72 ou 72-96 horas de idade, foi oferecida ao parasitismo por 10 fêmeas de T. diatraeae com 0-24, 24-48, 48-72 ou 72-96 horas de idade, por 24 horas à 25 ± 2oC, umidade relativa de 70 ± 10% e fotofase de 14 horas. A emergência, o número de descendentes, a duração do ciclo, a razão sexual, a longevidade e largura da cápsula cefálica de machos e de fêmeas de T. diatraeae apresentaram resposta semelhante para o efeito idade das pupas desse hospedeiro e fêmeas desse parasitóide em conjunto. No entanto, houve redução da emergência, número de descendentes e longevidade das fêmeas de T. diatraeae com duração do ciclo se ajustando a uma função quadrática quando se avaliou apenas o efeito da idade do parasitóide. Pupas de A. gemmatalis, com até 96 horas de idade, podem ser usadas para criação massal de T. diatraeae utilizando-se fêmeas desse parasitóide com até 96 horas de idade.Reproduction of Trichospilus diatraeae Cherian & Margabandhu (Hymenoptera: Eulophidae) on Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) Pupae in Relation to  Age of the Parasitoid and HostAbstract. Reproduction of parasitoids presents interconnected steps and the ages of hosts and parasitoids can affect the development of parasitoids. Biological parameters of Trichospilus diatraeae Cherian & Margabandhu (Hymenoptera: Eulophidae), at up to 96 hours of age were studied on pupae of the alternative host Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) pupae. Each A. gemmatalis pupae from 0-24, 24-48, 48-72 or 72-96 hours of age, was offered to parasitism to 10 females of T. diatraeae at 0-24, 24-48, 48-72 or 72-96 hours of age for 24 hours at 25 ± 2°C, relative humidity of 70 ± 10% and photophase of 14 hours. Emergency, number of offspring, length of cycle, sex ratio, longevity and width of cephalic capsule of males and females of T. diatraeae showed similar response when effect of age of pupae and females of parasitoid were evaluate jointly. However, emergency, number of offspring and longevity of females of T. diatraeae were reduced as length of cycle was being adjusted to a quadratic function when only effect of age of parasitoid was evaluated. Pupae of A. gemmatalis with up to 96 hours of age can be used for mass rearing of T. diatraeae using females at up to 96 hours of age.

RESUMOO percevejo-asa-preta-da-soja Edessa meditabunda (Fabricius) (Hemiptera: Pentatomidae) dispersa para o algodoeiro e utiliza essa planta como hospedeiro alternativo, após colonizar e multiplicar-se nas áreas de soja circunvizinhas. Visando conhecer o potencial desta espécie como praga em algodoais e auxiliar na tomada decisão quanto ao manejo deste inseto, hipotetizou-se nesse trabalho que o algodoeiro é nutricionalmente adequado para a reprodução e desenvolvimento de E. meditabunda. Os tratamentos testados foram: 1) folhas e maçã de algodoeiro e 2) dieta padrão, recomendada para criação de pentatomídeos fitófagos em laboratório, utilizada como testemunha. As características biológicas avaliadas foram: período de desenvolvimento ninfal, duração de cada ínstar, porcentagem de sobrevivência, peso dos adultos na emergência, longevidade de machos e de fêmeas, período de pré-oviposição e de oviposição, número total de ovos por fêmea e fecundidade das fêmeas. Observou-se que, apesar do prolongamento do período de desenvolvimento ninfal, as ninfas alimentadas com algodoeiro sobreviveram, atingiram a fase adulta e os adultos se reproduziram, o que nos permite sugerir que o algodoeiro seja uma planta nutricionalmente adequada para o desenvolvimento e reprodução de E. meditabunda, permitindo a manutenção do inseto em campo após as colheitas da soja.Palavras-chave: ecologia nutricional, Gossypium hirsutum L., percevejo-asa-preta, planta-hospedeira alternativa. ABSTRACTAt the end of soybean crop cycle, the Brown-winged stink bug Edessa meditabunda (Fabricius) (Hemiptera: Pentatomidae) scatter to cotton fields using this plant as an alternative host. In order to know if this specie has potential as a cotton pest and to help its management it was hypothesized that cotton is nutritionally adequate for reproduction and development of E. meditabunda. The tested food sources were: 1) cotton bolls and leaves, and 2) standard diet recommended for laboratory rearing of phytophagous pentatomids, used as control treatment. The following biological parameters were evaluated: nymph developmental time, instar duration, survivorship percentage, adult weight at emergence, male and female longevity, duration of pre-oviposition and oviposition periods, total amount of eggs laid by each female, and female fecundity and fertility. Even with an extended nymphal development time, we observed that nymphs fed on cotton structures survived and reached adulthood and the adults reproduced. The results allow us to suggest that cotton is a plant nutritionally suitable for development and reproduction of E. meditabunda, and it allows the insect maintenance in the field after soybean harvests.

Apis mellifera bees that forage in agricultural fields may be exposed to pesticides through many routes. One of them is the collection of pollen contaminated with insecticides. In this study, we evaluate the mortality of adult honeybees exposed to pollen from cotton plants whose seeds were treated with insecticides thiamethoxam, clothianidin, imidacloprid and fipronil, and the pollen collection capacity of adult honeybees in cotton fields. Bee mortality based on linear regression analysis showed significant differences, but no differences were noted among treatments. According to the contrast analysis of the mean groups of insecticides against the mean of the control group, no significant differences were found, indicating a natural mortality for all treatments including the control. Quantitative analysis of the pollen revealed the presence of only cotton pollen grains on bees, indicating floral fidelity of Africanized honeybees. Pearson's correlation coefficient was positive, but statistically insignificant, for increase in pollen collection with time.

Insecticide-treated cotton seeds can pose risks to Apis mellifera Linnaeus, 1758 populations during crop establishment if chemical residues reach these insects near agricultural fields via dust drift produced during planting. However, the treatment of seeds with insecticides is essential to protect cotton plants from damage caused by pests, including thrips and aphids. Thus, the aim of this study was to evaluate the toxic effects (acute toxicity) of soil dust from cotton fields planted with insecticide-treated seeds on A. mellifera adults using a toxicity assay developed in the laboratory. Forager honeybees were maintained in 700-ml plastic cages with 7 g of surface soil where insecticide-treated cotton seeds were sown (270 g a.i. clothianidin, 270 g a.i. imidacloprid, 210 g a.i. thiamethoxam, and 75 g a.i. fipronil/100 kg of seeds, and an untreated group). Ten bees were placed in each cage. The experimental design was randomized, with five treatments and twelve replicates. The mortality rate was evaluated during the entire assay. Data were transformed to x + 0.5  and compared with a regression analysis and contrast test. The linear regression model revealed a significant relationship between bee mortality and exposure time. The mortality rate gradually increased as time progressed in all treatments and the control group. The contrast test did not reveal significant differences between the insecticide and control groups. Thus, residues of the products tested, thiamethoxam, clothianidin, imidacloprid, and fipronil, did not influence the mortality of A. mellifera adults as a result of exposure to soil contaminated with insecticide-treated seeds.