Effect of Cosmos, Crotalaria, Foeniculum, and Canavalia species, single-cropped or mixes, on the community of predatory arthropods.

Some plants can attract natural enemy by offering resources such as alternative food and refuge. However, studies need to be conducted before agricultural landscape diversification is implement. Our objective was to determine the best floristic compositions of cosmos (Cosmos sulphureus-Asteraceae), showy rattlepod (Crotalaria spectabilis-Fabaceae), fennel (Foeniculum vulgare-Apiaceae), and jack bean (Canavalia ensiformis-Fabaceae) to attract and maintain predatory arthropods, and know the potential of these treatments for future use in diversifying agricultural systems. The experimental design consisted in seven treatments of four species in single-crop, intercrops in three densities called mix1, mix2, and mix3, and the control (weeds). For the arthropod families classified as very frequent and constant, population dynamics in intercropping treatments was plotted according to the plant phenology. We conclude that all plants cultivated in single-cropping and intercropping treatments showed high predator richness and can potentially be used to diversify cultivated areas. Sulfur cosmos as a single crop and three mixes attracts higher numbers and greater family richness. Spider families-Oxyopidae, Araneidae and Thomisidae-and insects-Chrysopidae and Coccinellidae are more frequents. The dynamics of the predator populations varied according to the mixes treatment.

Insects related to Olive culture in Rio Grande do Sul State, Brazil / Insetos associados à cultura da oliveira no Rio Grande do Sul, Brasil

The increased cultivation of olive trees in Rio Grande do Sul State and its potential production arouse the need to characterize the assemblage of insects in olive groves, especially those with potential as pests. Therefore, the insect fauna was sampled monthly for two years, in the canopy of olive trees, using beat cloth, and collection of buds in five municipalities in Southern Rio Grande do Sul State. The faunal indices analyzed were abundance, constancy, dominance and frequency. The olive caterpillar Palpita forficiferaMunroe 1959 (Lepidoptera: Pyralidae) and mealybugs Saissetia oleae(Olivier, 1791) and Saissetia coffeae(Walker, 1952) (Hemiptera: Coccidae) are the main phytophagous insects in olive farms in the Rio Grande do Sul State, with potential to reach pest status. Eleven insect species were recorded for the first time in olive groves in Brazil. The occurrence of P. forficiferais a new record for the Rio Grande do Sul State.

Tendo em vista o aumento do cultivo da oliveira no Rio Grande do Sul e o seu potencial produtivo, houve a necessidade de caracterizar a assembleia de insetos presentes em olivais, destacando os que possuem potenciais como praga da cultura. Para tanto, a fauna de insetos foi monitorada por meio de coletas mensais, durante o período de dois anos, na copa das oliveiras, utilizando pano de batida e coleta de brotos em cinco municípios da região sul do Rio Grande do Sul. Os índices faunísticos analisados foram abundância, constância, dominância e frequência. A lagarta-da-oliveira Palpita forficiferaMunroe 1959 (Lepidoptera: Pyralidae) e as cochonilhas Saissetia oleae(Olivier, 1791) eSaissetiacoffeae (Walker, 1952) (Hemiptera: Coccidae) são os principais insetos fitófagos na cultura da oliveira no Rio Grande do Sul, com potencial para atingir status de praga. Foram registradas onze espécies de insetos pela primeira vez para a cultura no Brasil. A ocorrência de P. forficiferaé um novo registro para o estado do Rio Grande do Sul.