Brazil is one of the world's largest tomato producer, but considerable part of the production is lost due to the attack of Bemisia tabaci (Genn.) B biotype. Resistant germoplasm plants can be an important method for B. tabaci control in integrated pest management approaches. The attractiveness and ovipositional preference of B. tabaci for 17 tomato genotypes were evaluated in a free-choice test. Trials were set up in a randomized block design with ten replicates. Each replicate (one tomato plant per pot) was placed in a cage (80 x 50 x 50 cm) and infested with 1,000 adults during four days. Linear correlation tests were applied between the number of insects and eggs and number of trichomes in each tomato genotype. LA716, LA444-1 and PI134418 genotypes were the least attractive, while the 'Santa Clara' was the most attractive; PI134417 trapped the largest number of adults. LA716 genotype (4.1 eggs/leaflet and 2.1 cm²/eggs per leaflet) was the least preferred for whitefly oviposition; NAV1062, 'Fanny', LA1335, 'Santa Clara' and IAC294 were the most preferred genotypes. The glandular trichomes density was negatively correlated with whitefly's attractiveness and oviposition per leaflet and per leaf, and positively with the number of trapped insects. The non-glandular trichomes density was negatively correlated with the number of trapped insects and positively with whitefly's oviposition per cm²/leaflet andper cm²/leaf. LA716 had high antixenosis level (ovipositional nonpreference) toward B. tabaci B biotype related with type IV glandular trichome.

Insecticide plants are an important tool among the new alternatives for pest control in IPM systems because they reduce the use of synthetic insecticides, preserving human health and the environment. We investigated the effects of aqueous extracts of Melia azedarach leaves and Azadirachta indica seeds and three tomato genotypes, 'Santa Clara', 'IPA-5' - Solanum lycopersicum (= Lycopersicon esculentum Mill), and LA444-1 - S. peruvianum (= L. peruvianum), on the development, reproduction and longevity of the tomato pinworm Tuta absoluta (Meyrick), under laboratory conditions. The trials were set up in a completely randomized design, with nine treatments [three genotypes x two extracts (M. azedarach and A. indica) and control]. The replication consisted on five tubes, each with three newly hatched larvae, totalizing 90 individuals per treatment. The larvae were fed with tomato leaves treated with aqueous extracts at 0.1% concentration or distilled water (control) and daily observed until adults' emergence. Larval and pupal development and mortality, pupal weight, longevity and fecundity were evaluated. The accession LA444-1 negatively affected the development and reproduction of T. absoluta; the tomato pinworm had similar development and reproduction on 'IPA-5' and 'Santa Clara' (the susceptible control). The association of resistant tomato genotypes and extracts of M. azedarach leaves and neem seeds did not result in synergistic or antagonistic effects on T. absoluta.

The colonization of Spodoptera frugiperda J.E. Smith larvae and rice seedlings by genetically modified endophytic bacterium Methylobacterium mesophilicum, and also the possible transfer of this bacterium to inside the larva's body during seedlings consumption were studied. The data obtained by bacterial reisolation and fluorescence microscopy showed that the bacterium colonized the rice seedlings, the larva's body and that the endophytic bacteria present in seedlings could be acquired by the larvae. In that way, the transference of endophytic bacterium from plants to insect can be a new and important strategy to insect control using engineered microorganisms.

Avaliou-se a influência da face foliar, do comportamento geotrópico do inseto e do tipo de tricoma foliar sobre a oviposição de Bemisia tabaci (Genn.) biótipo B em folhas de tomateiro. Para avaliação desses efeitos foram realizados vários ensaios nos quais as fêmeas foram confinadas em caixas de acrílico. Folíolos de tomateiro foram fixados no topo e na base das caixas, de tal forma a permitir o acesso dos insetos às faces adaxial e abaxial de maneira isolada e concomitante (com e sem chance de escolha). Os insetos sempre depositaram maior número de ovos quando a superfície foliar se encontrava no topo da caixa e, de maneira geral, preferiram depositar seus ovos na face abaxial dos folíolos. Para avaliar o efeito do tipo de tricoma (glandular e não-glandular) sobre a oviposição de B. tabaci, a face abaxial dos folíolos de tomateiro foi oferecida a cerca de 30 fêmeas para oviposição em cada caixa de acrílico. Foram oferecidos folíolos previamente lavados com etanol a 70% (de forma a eliminar os exsudatos glandulares) e sem lavagem prévia. A maior parte da oviposição ocorreu ao lado dos tricomas não-glandulares, demonstrando que o inseto discrimina o tipo de tricoma.

The objective of this work was to evaluate the influence of the leaf surface, the insect geotropic behavior and the type of foliar trichome on Bemisia tabaci (Genn.) biotype B oviposition on tomato leaves. Bemisia tabaci females were confined in acrylic boxes in which tomato leaflets were fixed at the bottom and top part of the boxes to allow insects to access the leaf surface to be tested (adaxial and/or abaxial) in both no-choice and free choice tests. Oviposition was always higher when the leaf was offered at the top of the box and preferably at the abaxial leaf surface. The effects of leaf trichomes (glandular and non glandular) on B. tabaci oviposition was evaluated by offering the abaxial surface of tomato leaflets to females after a 70% ethanol wash to remove glandular exsudates against a control treatment (without a ethanol wash). Oviposition was concentrated mostly near to non glandular trichomes, showing whitefly females can discriminate among the trichomes.

Avaliou-se, em condições de laboratório, o efeito de genótipos de tomateiro (Lycopersicon esculentum, cultivares Santa Clara, Stevens e IPA-5; L. hirsutum f. glabratum, linhagem PI 134417 e L. peruvianum, linhagem LA 444-1) sobre a biologia e oviposição de Tuta absoluta (Meyrick). A linhagem LA 444-1 foi, dentre os genótipos avaliados, a menos adequada à traça, provocando, em relação à testemunha ('Santa Clara'), alongamento das fases larval e pupal e redução na viabilidade larval, no peso de pupas, na fecundidade e na longevidade de adultos. A linhagem PI 134417 provocou alongamento das fases larval e pupal e redução no peso de pupas fêmeas. Dentre os materiais comerciais, o pior desenvolvimento do inseto ocorreu na cultivar IPA-5, onde houve alongamento das fases larval e pupal, redução na viabilidade larval e no peso de pupas machos. 'Stevens' foi o único genótipo que não afetou o desenvolvimento da traça quando comparado à testemunha. A oviposição de T. absoluta foi menor nos dois genótipos selvagens (PI 134417 e LA 444-1) do que nos materiais comerciais, em teste com chance de escolha. Em condições de confinamento, apenas a linhagem PI 134417 foi não preferida para oviposição.

This study evaluated, under laboratory conditions, the effect of tomato genotypes (Lycopersicon esculentum, cv. Santa Clara, Stevens and IPA-5; L. hirsutum f. glabratum, line PI 134417 and L. peruvianum line LA 444-1) on biology and oviposition of Tuta absoluta (Meyrick). The least adequate to the insect was LA 444-1 prolonging larval and pupal stages and reducing larval viability, pupal weight, fecundity and adult longevity, when compared to the control ('Santa Clara'). Line PI 134417 increased length of larval and pupal stages and reduced female pupae weight. Among cultivated tomato genotypes, the worst insect development occurred on 'IPA-5'. In this case, the length of larval and pupal stages increased and larval viability and weight of male pupae reduced. 'Stevens' was the only genotype which did not affect insect development when compared to control. Oviposition of T. absoluta was lower on wild tomatoes (PI 134417 and LA 444-1) than on cultivated genotypes, in free choice tests. Line PI 134417 was the only non-preferred to oviposition in a no choice test.

Os efeitos de alternar um genótipo de sorgo (Sorghum bicolor) resistente, Tx 430 x GR e um suscetível, BR 601 na biologia do pulgão-verde, Schizaphis graminum (Rond.) foram avaliados na Embrapa/Centro Nacional de Milho e Sorgo, Sete Lagoas, MG. Aspectos biológicos de S. graminum foram avaliados criando os insetos sucessivamente no genótipo suscetível ou no resistente por até três gerações ou alternadamente após cada geração entre cada genótipo. Em média o período pré-reprodutivo foi de 6,7 d e o reprodutivo foi de 22,6 d para os insetos criados no genótipo suscetível; no genótipo resistente os valores foram 7,4 e 15,3 d. A produção de ninfas/fêmea foi de 33,7 e 14,7, nos genótipos suscetível e resistente, respectivamente.

The effect of alternating a resistant sorghum (Sorghum bicolor) genotype, Tx 430 x GR, and a susceptible genotype, BR 601 on the biology of the greenbug, Schizaphis graminum (Rond.) was evaluated at Embrapa/National Corn and Sorghum Research Center, Sete Lagoas, MG. Biological aspects of S. graminum were evaluated by rearing it continuously on susceptible or on resistant genotypes up to three generations or alternatively after each generation between genotypes. On average it was obtained a pre-reproductive period of 6.7 d and reproductive period of 22.6 d when the insects were reared on the susceptible genotype; on the resistant genotype the values were 7.4 and 15.3 d. The production of nymphs/female was 33.7 and 14.7 on the susceptible and resistant genotypes, respectively.