Generalist predators are capable of consuming different types of prey, and as each prey may have distinct nutritional values, each may have a distinct impact on the biology of the predator. Therefore, the aim of this study was to determine how the consumption of different prey influences certain biological characteristics and the predatory capacity of Orius insidiosus (Say). The investigation was performed in climatic chamber at 25 ±1 ºC, RH 70 ± 10% and fotophase 12. Eggs of Anagasta kuehniella (Zeller), adults of Caliothrips phaseoli (Hood) and nymphs of Aphis gossypii Glover were used as prey and were provided daily ad libitum for all the mobile stages of the predator. The results showed that biological parameters of O. insidiosus are affected differently depending on the type of prey ingested. The development time of the nymphal stage was 13.1, 11.23 and 10.25 days for O. insidiosus feeding on eggs of A. kuehniella, nymphs of A. gossypii and adults of C. phaseoli, respectively. Longevity was five times larger for adults fed on eggs of A. kuehniella (56.25 days) compared to that of adults that preyed on nymphs of A. gossypii (11.44 days), and four times larger when the prey were adults of C. phaseoli (13.58 days). The consumption of eggs of A. kuehniella by predator females resulted in a shorter pre-oviposition period (3.2 days) and a longer oviposition period (44.4 days) when compared to the consumption of other types of prey. In addition, fecundity was increased with the consumption of eggs of A. kuehniella (195.25 eggs laid / female) when compared to feeding on the other prey, C. phaseoli (70.00 eggs laid / female) or A. gossypii (22.50 eggs laid / female). However, the consumption of aphids was larger (148.28 nymphs/ nymphal stage) than that of thrips (74.10 thrips / nymphal stage) or eggs of A. kuehniella (37.03 eggs /nymphal stage) for all of the nymphal stages of the predator. The results indicate that the eggs of A. kuehniella are the type of prey best suited for rearing this predator insect under laboratory conditions. Also fecundity was better with this prey even though the predator consumed during its nymphal stage a lesser quantity of eggs compared to the other prey

Studies on the diversity of social wasps in agricultural environments represent an important step to identifying the ideal species to be used in biological pest control programs. There is a growing effort to acknowledge the diversity of such Hymenoptera in the state of Minas Gerais, but information on anthropized environments is still rare. The objective of this study was to obtain data on the diversity of social wasps in the Instituto Federal de Educação, Ciências e Tecnologia de Minas Gerais (IFMG), Bambuí campus, Minas Gerais, Brazil. Sampling was conducted from July 2012 to July 2014 with two methodologies: attractive traps and active search. This work confirms that a well diversified environment, even if anthropized, is rich in social wasp species. In addition, the great number of collected species, shows the importance of a long-term survey and the use of more than one method of collection. The high rate of collections of Polistes versicolor in a predominantly agricultural environment, coupled with other studies on this species as a predator of lepidopteran caterpillars, suggests the use of this species as a tool in the biological control of pests.

Onion is the third most grown vegetable crop in São Paulo state, Brazil. Organic onion farming is expected to increase in the state due to the increasing demand. Pest management in organic onion farming is based on plant extracts with insecticide effects. However, the efficacy of such plant extracts has not been proved yet, and it was observed that they do negatively affect natural enemies. Plants surrounding onion fields, and that are attractive to natural enemies, may be a good option to farmers, since they may lead to increased diversity of arthropod species and, consequently, the natural control of pest populations. This study deals with the effect of marigold plants as a resource plant to natural enemies in onion fields. The experiment was set in a certified organic farm using marigold rows at a center of an onion field. Samples were taken from marigold and the onion plants 5 m (near) and 30 m (far) from the flowering strips. Higher numbers of arthropod pests were observed in onion plants 30 m from the marigold strip, while higher numbers of predators and parasitoids were found at 5 m distance. Species richness and Shannon's diversity index were higher at 5 m from marigold. Therefore, marigold rows next to onion fields resulted in higher number of entomophagous species, potentially enhancing the natural control of onion pests. In the study field, marigold strips may be an alternative to crop sprays for organic control of onion pests. Key words: natural control, conservation, predator, parasitoid CRAVO-DE-DEFUNTO (Tagetes erecta L.) COMO CULTURA ATRATIVA PARA INIMIGOS NATURAIS EM CULTIVO DE CEBOLARESUMO: A cebola é a terceira hortaliça mais cultivada em São Paulo, cujo cultivo orgânico tende a crescer devido ao grande mercado consumidor existente. O manejo das pragas na cebolicultura orgânica baseia-se nos extratos de plantas inseticidas que, além de terem eficiência não comprovada, podem afetar negativamente os inimigos naturais. A utilização de plantas atrativas a inimigos naturais no entorno dos cultivos de cebola pode ser uma boa opção para os produtores, pois potencialmente aumentam a diversidade da artropodofauna e podem regular naturalmente as populações de espécies pragas. Verificou-se o efeito de linhas de cravo-de-defunto (Tagetes erecta L.) como cultura atrativa a inimigos naturais em campos de cebola. O experimento foi realizado em propriedade orgânica certificada, instalando-se linhas de cravo-de-defunto nas bordaduras de dois campos de cebola. Os tratamentos foram definidos coletando-se amostras nas plantas de cebola próximas às linhas da atrativa (5m) e distante das linhas (30 m). De maneira geral, observou-se maior quantidade de artrópodes fitófagos nas plantas de cebola longe da faixa atrativa e, inversamente, maior quantidade de inimigos naturais próximos à faixa. A riqueza de espécies também foi maior nas coletas próximas, o mesmo valendo para o índice de diversidade de Shannon. Portanto, a manutenção de linhas de cravo-de-defunto próximas ao cultivo de cebola promoveu maior riqu...

Arthropod community composition in agricultural landscapes is dependent on habitat characteristics, such as plant composition, landscape homogeneity and the presence of key resources, which are usually absent in monocultures. Manipulating agroecosystems through the insertion of in-field floral resources is a useful technique to reduce the deleterious effects of habitat simplification. Food web analysis can clarify how the community reacts to the presence of floral resources which favour ecosystem services such as biological control of pest species. Here, we reported quantitative and qualitative alterations in arthropod food web complexity due to the presence of floral resources from the Mexican marigold (Tagetes erecta L.) in a field scale lettuce community network. The presence of marigold flowers in the field successfully increased richness, body size, and the numerical and biomass abundance of natural enemies in the lettuce arthropod community, which affected the number of links, vulnerability, generality, omnivory rate and food chain length in the community, which are key factors for the stability of relationships between species. Our results reinforce the notion that diversification through insertion of floral resources may assist in preventing pest outbreaks in agroecosystems. This community approach to arthropod interactions in agricultural landscapes can be used in the future to predict the effect of different management practices in the food web to contribute with a more sustainable management of arthropod pest species.

-The effect of corn (Zea mays) genotypes on the biology of Spodoptera frugiperda (J.E.Smith) was evaluated to identify possible sources of resistance. The development of the insect was compared on 5 inbred lines from Mississippi (EUA), 5 genotypes from Instituto Agronômico de Campinas and one genotype from Central America (Zapalote Chico). Results showed that the duration of larval stage and larval weight 10 days after emergence were affected by genotypes Mp707, Zapalote Chico, Mp701, Mp706 and Mp705. Viability of larval stage was affected by genotypes Mp705 and Mp706, while the pupal weight was smaller on genotype IAC103 BPl. The duration and viability of pupal stage, sexual ratio, and % of malformed adults were less important to discriminate these cultivars. It was concluded that the least suitable genotypes for development of the insect were Mp707 and Zapalote Chico, followed by Mp706, Mp705 and Mp701, while the most adequates were IAC103 N, IAC701 N and Mp496.KEY WORDS: Insecta, fall armyworm, plant resistance, Zea mays.RESUMO -Estudou-se a biologia de Spodoptera frugiperda (J.E.Smith) em genótipos de milho (Zea mays), comparando-se diferentes fontes de resistência: 5 linhagens provenientes do Mississippi (EUA), 5 genótipos provenientes do Instituto Agronômico de Campinas e uma raça centro-americana (Zapalote Chico). Nos genótipos Mp707, Zapalote Chico, Mp701, Mp706 e Mp705, os insetos apresentaram prolongamento do período de desenvolvimento e menor peso das lagartas aos 10 dias. A viabilidade da fase larval foi afetada pelas linhagens Mp705 e Mp706, enquanto que o peso de pupas foi menor na linhagem IAC103 BPl. A duração e viabilidade da fase pupal, a razão sexual e a % de deformação de adultos foram menos importantes para a discriminação dos materiais. Os resultados demonstraram que os genótipos menos adequados para o desenvolvimento do inseto foram Mp707 e Zapalote Chico, seguidos de Mp706, Mp705 e Mp701, enquanto os mais adequados foram IAC103 N, IAC701 N e Mp496.PALAVRAS-CHAVE: Insecta, lagarta-do-cartucho, resistência de plantas, Zea mays.