The intracellular bacterium Wolbachia is one of the most common symbionts in arthropods and, because of its manipulative effects on host reproduction, is assumed to be an important factor in several evolutionary processes. These bacteria are mainly vertically transmitted from mother to daughter through the egg cytoplasm, and horizontal transmission is generally assumed to be rare. Here, we show natural inter-and intraspecific horizontal transfer of parthenogenesis-inducing Wolbachia between parasitoid wasps of the genus Trichogramma. Horizontal transfer was observed when infected and uninfected larvae shared the same host egg. This is the first report, to our knowledge, on interspecific horizontal transfer of Wolbachia between closely related sympatric species. Some originally uninfected immature wasps acquired Wolbachia while inside the host egg, but not all of these newly infected females exhibited the parthenogenesis phenotype. In general, intraspecific horizontal transfer was more successful than interspecific transfer. Wolbachia underwent vertical transmission in the new species but the infection tended to be lost within several generations. Our results have important implications for understanding the evolution of Wolbachia-host associations.

The side-effects of pesticides (insecticides, fungicides, herbicides and plant growth regulators) used on cotton were tested on adults and pupae of Trichogramma pretiosum Riley reared in the laboratory on two different hosts, the Angoumois grain moth (Sitotroga cerealella Olivier) and the Mediterranean flour moth (Ephestia kuehniella (Zeller)). The eggs of the host enclosing the parasitoid pupae received direct pesticide sprays, while the adults of the parasitoid were exposed to the pesticides through contact with residues on sprayed eggs offered to parasitism. Alpha-cypermethrin, carbosulfan, deltamethrin, endosulfan, profenofos and zeta-cypermethrin were highly noxious to the parasitoid, significantly reducing the percentage of emergence and parasitism of T. pretiosum developing in E. kuehniella or S. cerealella eggs. However, the pupal stage of the parasitoid developing in S. cerealella eggs was less susceptible to alpha-cypermethrin and deltamethrin. Lufenuron and metamidophos greatly reduced the percentage of adult emergence from eggs of both hosts, while novaluron only interfered on this variable when the wasps were developing in E. kuehniella eggs. However, lufenuron and monocrotophos had no effect on the parasitoid pupae of T. pretiosum developing in E. kuehniella eggs. Chlorfluazuron, diafenthiuron, diflubenzuron, fentin hydroxide, mepiquat chloride, novaluron, thiacloprid and triflumuron did not affect T. pretiosum emergence when eggs of S. cerealella enclosing pupae of the wasps were surface treated. The pesticides azoxystrobin, carbendazin + thiram, mepiquat chloride and novaluron had no effect on the ability of the wasps to parasitise E. kuehniella eggs. However, only mepiquat chloride did not affect the percentage of F1 wasps emerging from E. kuehniella eggs. The remaining pesticides moderately reduced the percentage of emergence and parasitism of the wasps when they had contact with the chemicals during their pupal or adult stage. Thus there were differences in pesticide toxicity according to the host used for parasitoid development. These differences were hypothesised to occur because of differences in egg morphology and parasitoid performance.

RESUMO -Estudou-se a distribuição da produção, a qualidade da semente e o peso de frutos em relação às diferentes posições do fruto na planta de algodão. Os dados foram oriundos do mapeamento de 360 plantas da cultivar CNPA 7H, em área irrigada no município de Bom Sucesso, PB. Mais de 80% da produção da cultivar é proveniente do baixeiro e terço médio e da primeira e segunda posição frutífera da planta. A qualidade das sementes é afetada à medida que os frutos se afastam da primeira posição para as demais.Termos para indexação: Gossypium hirsutum, algodão, regiões frutíferas, posições frutíferas. INFLUENCE OF FRUITING POSITION ON COTTON PRODUCTIONABSTRACT -Cotton production distribution within the plant, seed quality and fruit weight were studied in relation to fruiting position. Data were produced by mapping 360 cotton plants cultivar CNPA 7H which were grown under irrigation in Bom Sucesso, PB. According to the results more than 80% of the total plant yield comes from the botton and middle of the plant and from the first and second fruiting position. Seed quality was affected as the boll position distanced from the first position.Index terms: Gossypium hirsutum, cotton, fruiting regions, fruiting positions. niente dos frutos da primeira posição frutífera, e os restantes 25% e 2%, oriundos da segunda e terceira posição, respectivamente.Trabalhos mais recentes têm evidenciado que a chance de um botão tornar-se capulho é de 60%, 30% e 11% na primeira, segunda e terceira posição no ramo frutífero ou simpodial, respectivamente, até o sexto nó do eixo principal (baixeiro da planta). Tais porcentagens caíram para 30%, 15% e 7% do 7 o ao 12 o nó do eixo principal (terço médio da planta); do 13 o ao 18 o nó, última porção da planta, estes índices caíram para 12%, 7% e 3% na primeira, segunda e terceira posição frutífera, respectivamente.Outros autores (Beltrão et al., 1992, procuraram estudar a distribuição da produção do algodoeiro por posições-chaves de frutificação, bem como suas características agronômicas e tecnológicas de fibras.Considerando-se que a distribuição da produção do algodoeiro é 73%, 25% e 2% para a primeira, 1 Aceito para publicação em 5 de outubro de 1998.

-The parasitoid Trichogramma has been used worldwide as biological control agent due to its wide geographic distribution, high specialization and effi cacy against many lepidopteran pests. Biological and behavioral traits of Trichogramma pretiosum Riley parasitizing Sitotroga cerealella (Oliver) eggs were studied aiming to a better understanding of the results from parasitism and superparasitism. The variables investigated were: host acceptance and contact time by T. pretiosum on parasitized host, percentage of parasitoid emergence, number of deformed individuals produced, egg-adult period, sex ratio, offspring female body size and longevity, and number of S. cerealella eggs parasitized/female. Parasitism rejection was observed on parasitized host eggs after 24, 72 and 120h of parasitism. The rejection was higher for eggs parasitized after 72h and 120h of parasitism as compared to the eggs after 24h of parasitism. T. pretiosum contact time on eggs after 24h of parasitism was greater than on 72 and 120h. The offspring produced from hosts from which a single parasitoid emerged were larger, exhibited no deformities and greater capacity of parasitism, different from those produced from eggs where two parasitoids emerged. Offspring longevity, however, was similar for females emerged from hosts from which one or two adults emerged. In conclusion, T. pretiosum was able to recognize previously parasitized eggs and the superparasitism reduced the parasitoid.reproductive success.KEY WORDS: Biological control, egg parasitoid, host compatibility RESUMO -Parasitóides Trichogramma vêm sendo utilizados em todo o mundo como agentes de controle biológico devido à sua ampla distribuição geográfi ca, alta especialização e efi ciência no controle de muitas espécies-praga de lepidópteros. Para o entendimento dos resultados do parasitismo e superparasitismo de Trichogramma pretiosum Riley, estudaram-se os aspectos comportamentais e biológicos desse parasitóide sobre ovos de Sitotroga cerealella (Oliver). As variáveis investigadas foram: aceitação hospedeira e tempo de contato de T. pretiosum com o hospedeiro parasitado, porcentagem de emergência, porcentagem de indivíduos deformados, duração ovo-adulto, razão sexual, tamanho e longevidade de T. pretiosum e número de ovos de S. cerealella parasitados por fêmea descendente. Observou-se rejeição de parasitismo em ovos de S. cerealella previamente parasitados com 24, 72 e 120h de idade. A rejeição foi superior para ovos com 72h e 120h após o parasitismo em comparação com aqueles com 24h. Ovos previamente parasitados com 24h apresentaram maior tempo de contato por T. pretiosum comparados aos de 72h e 120h. Os descendentes oriundos de hospedeiros dos quais apenas um parasitóide se desenvolveu apresentaram-se todos maiores, sem deformidades e com maior capacidade de parasitismo, ao contrário dos indivíduos descendentes de hospedeiros em que dois parasitóides se desenvolveram. Entretanto, a longevidade de fêmeas descendentes não diferiu entre parasitóides oriundos de hospedeiros em ...

Studies on the protective effect of botanical products against pest insects have infrequently been extended to side‐effects on natural enemies. Indirect effects of botanicals on the storability of seeds could occur through their possible negative impact on biological control agents. Four plant powders and six plant oils with a known effect on the cowpea beetle Callosobruchus maculatus (Fabr.) (Coleoptera: Bruchidae) were investigated for their effect on the beetles’ egg parasitoid Uscana lariophaga (Steffan) (Hymenoptera: Trichogrammatidae) and the larval parasitoid Dinarmus basalis (Rondani) (Hymenoptera: Pteromalidae). All treatments caused a decrease in parasitisation by U. lariophaga, and developing parasitoids of this species were affected by powders of Nicotiana tabacum (L.) and Tephrosia vogelii (Hook. f). In a two‐choice situation using a linear olfactometer, U. lariophaga was repelled by most of the oils. In a no‐choice situation, parasitisation by D. basalis was hampered by treatment with plant powders, but eggs that were laid developed normally. In a Y‐tube olfactometer, this parasitoid did not discriminate between odours of untreated and plant‐powder‐treated beans. The powders of N. tabacum and T. vogelii had stronger negative effects on the two parasitoids than the powders of Azadirachta indica (Juss.) or Blumea aurita (DC). In samples collected from untreated traditional storage facilities, subsequently treated with plant powders in the laboratory, none of the treatments could prevent the increase in beetle numbers. At 24 days after treatment, most beetles had emerged from beans treated with powders of N. tabacum and T. vogelii. Parasitoids were affected by the botanical insecticides tested here, but the powders of A. indica and B. aurita may be compatible with biological control by D. basalis.

Unisexual Trichogramma forms have attracted much attention due to their potential advantages as biocontrol agents. Fitness studies have been performed and understanding the cost that Wolbachia may inflict on their hosts will help in deciding if Wolbachia infected (unisexual) forms are indeed better than sexual forms when used in biological control programmes. The influence of Wolbachia on the foraging behaviour (including walking activity and speed) of T. atopovirilia is reported in this paper. Temperature strongly affected T. atopovirilia female walking activity, but Wolbachia infected and uninfected females differed in none of the behavioural components that were measured such as walking activity and walking speed. Walking activity was highest at 25 °C and differed significantly from that at 20 and 15 °C. Trichogramma wasps were highly affected at 15 °C. Behaviour analysis with females showed that female wasps spend most of the time on drilling + ovipositing on host eggs followed by host drumming and walking while drumming. The parasitism rate and number of offspring did not differ significantly between infected and cured Trichogramma females. Biological control implications of these findings are discussed.Keywords: Hymenoptera, Parasitoid, thelytoky, alpha-Proteobacteria, foraging behaviour. A infecção por Wolbachia afeta o comportamento de Trichogramma atopovirilia? ResumoFormas unissexuais de Trichogramma têm despertado a atenção de pesquisadores devido as potenciais vantagens deste parasitóide como agente de controle biológico. O estudo do "Fitness" tem sido avaliado e entender o custo de ser infectado por Wolbachia ajudará em determinar se formas infectadas por Wolbachia (unisexuais) são realmente melhores que as sexuadas quando utilizadas em programas de controle biológico. A influência de Wolbachia no comportamento de procura (incluindo a atividade e a velocidade de caminhamento) de T. atopovirilia é relatada neste artigo. A temperatura afetou grandemente a atividade de caminhamento de fêmeas de T. atopovirilia, entretanto os componentes de comportamento tais como a atividade e a velocidade de caminhamento não diferiram em relação às fêmeas infectadas e não infectadas. A atividade de caminhamento foi maior a 25 °C e diferiu significativamente de 20 e 15 °C. Fêmeas de Trichogramma foram altamente afetados a 15 °C. Em função da análise do comportamento com fêmeas, pode-se verificar que houve maior tempo gasto no processo de oviposição, seguido pelo toque com as antenas sobre os ovos dos hospedeiros e do caminhamento ao mesmo tempo que toca os ovos com as antenas. A taxa de parasitismo e o número de descendentes não diferiram significativamente entre fêmeas de Trichogramma infectadas e curadas da infecção por Wolbachia. As implicações dos resultados obtidos sobre o controle biológico são discutidas.Palavras-chave: Hymenoptera, Parasitóide, telitoquia, alpha-Proteobacteria, comportamento de procura.

-The mealybug Planococcus minorMaskell is a significant pest of more than 250 cultivated plants belonging to at least 80 families. Among the host plants several Malvaceae species are attacked, including the genera Gossypium. In 2005 and 2006 the mealybug P. minor was observed infesting cotton fields in the arid area of northeast region of Brazil. The occurrence was registered in high densities and in several farms resulting in mortality of plants in some cases. This species is not cited as a cotton pest in any region of Brazil where cotton grows, although it is enlisted in the Global Pest and Disease Database. Hence, there is a lack of studies what makes this pest of great deal to control.KEY WORDS: Mealybug, Gossypium, sesame, alternative host RESUMO -A cochonilha Planococcus minor (Maskell) é uma praga importante de mais de 250 culturas pertencentes a cerca de 80 famílias. Entre as plantas hospedeiras, várias espécies de Malvaceae são atacadas, incluindo o gênero Gossypium. Durante as safras de 2005 e 2006 constatou-se o ataque de P. minor em lavouras de algodão localizadas no semi-árido nordestino do Brasil. A constatação foi feita em diferentes localidades, onde altas densidades populacionais da cochonilha chegaram a ocasionar mortalidade de plantas. Esse inseto não é citado como praga do algodoeiro em nenhuma região onde se cultiva o algodoeiro no Brasil, apesar de constar na lista de Pragas e Doenças Globais. Conseqüentemente, não existem estudos sobre essa cochonilha como praga do algodoeiro o que torna o seu manejo difícil no momento.

RESUMOPropôs-se, neste trabalho, avaliar a bioatividade do óleo de nim sobre Alphitobius diaperinus, em sementes armazenadas. Sementes de amendoim cultivar BRS Havana foram tratadas com óleo de nim nas concentrações de 0,0; 1,0; 2,0; 3,0 e 4,0% (volume/massa de sementes) e mantidas em bandejas durante 24 h. Cinquenta gramas de sementes foram colocados em recipientes plásticos e infestados com 20 insetos adultos de A. diaperinus. Avaliaram-se, aos 30, 60, 90 e 120 dias de armazenamento, a mortalidade, o número de descendentes (larvas, pupas e adultos) e o número de sementes perfuradas. Para análise de variância dos dados utilizou-se o teste de Friedman (p ≤ 0,05), sendo a comparação das médias realizada pelo teste de Student Newman Keuls (p ≤ 0,05). Calculou-se, também, a eficiência do produto pelo método de Henderson & Tilton (1955). Eficiência do óleo de nim sobre a mortalidade de A. diaperinus acima de 74,92% foi observada a partir dos 90 dias do armazenamento, para as concentrações de 3 e 4%; entretanto, o produto conferiu proteção às sementes de amendoim, em todas as concentrações, nos períodos estudados, visto que afetou todos os descendentes de A. diaperinus da geração F1. Palavras-chave: armazenamento de sementes, insetos-praga, Azadirachta indicaBioactivity of neem oil on Alphitobius diaperinus (Coleoptera: Tenebrionidae) in stored peanut seeds ABSTRACT This work aimed to evaluate the bioactivity of neem oil on Alphitobius diaperinus, in stored seed. Peanuts seeds, cultivar BRS Havana, were treated with neem oil at concentrations of 0.0, 1.0, 2.0, 3.0 and 4.0% (volume/weight) and kept in trays for 24 h. Fifty grams of seeds were put in plastic containers and infested with 20 adult insects of A. diaperinus. The mortality, the offspring number (larvae, pupae and adults) and the number of punched seeds were evaluated at 30, 60, 90 and 120 days of storage. For variance analysis of data, Friedman test (p ≤ 0.05) was used. Student Newman Keuls test (p ≤ 0.05) was used for comparison of means. The product efficiency was also analysed by using Henderson & Tilton (1955) method. Neem oil efficiency on the mortality of A. diaperinus above 74.92% was observed from 90 days of storing for concentrations of 3 and 4%. However, the neem oil conferred protection to peanut seeds in all concentrations and studied periods, by affecting all offspring of A. diaperinus of the F1 generation.