levantamento da entomofauna associada a cultivares de batata em duas épocas de cultivo survey of the entomofauna associated with potato varieties during two crop seasons

Abstract

Foi feito um levantamento da população de artrópodes num agroecossistema de batata, Solanum tuberosum L., em Santa Maria, RS, durante o ano agrícola 1989/90. O objetivo desta pesquisa foi comparar a entomofauna em diferentes cultivares de batata durante a época tradicional do seu crescimento e na safrinha. O experimento consistiu de nove cultivares durante a época tradicional, e de dez cultivares durante a safrinha. Amostras de insetos foram coletadas semanalmente com a rede de varredura (15 redadas por amostra). Os coleópteros foram predominantes durante a época tradicional do crescimento da cultura, e os dípteros, na safrinha. As espécies fitófagas mais freqüentes foram: Epitrix sp., na época tradicional, e Diabrotica speciosa (Germar), na safrinha, seguidas da Empoasca kraemeri Ross & Moore, em ambos os períodos de crescimento dessa cultura. Foi coletado um número maior de insetos no período tradicional de crescimento da cultura do que na safrinha. Os insetos mostraram preferência pela cultivar Bintje durante o período tradicional, e pela Pomina, na safrinha. A cultivar Sahael foi a menos procurada, nos dois períodos. As espécies de predadores Eriopis connexa (Germar) e Geocoris sp. foram as mais numerosas no período tradicional de crescimento da cultura. Durante a safrinha, a Cycloneda sanguinea (L.) predominou em todas as cultivares.
A survey of arthropods present in a potato (Solanum tuberosum L.) agroecossystem was conducted in Santa Maria, RS, Brazil, during 1989/90 field season. The objective of this research was to compare the entomofauna in different potato cultivars during the traditional and off-season time for potato growing. The experiment consisted of nine cultivars during the traditional season and ten cultivars during the off-season time. Insect samples were taken weekly with a sweep net (15 nets per sample). Coleoptera was the predominant insect order during the traditional potato growing season, and Diptera during the off-season. Epitrix sp. was quantitatively the most important in the traditional season, and Diabrotica speciosa (Germar) in the off-season, followed by Empoasca kraemeri Ross & Moore in both potato growing season. Greater number of insects was collected during the traditional season than off-season for growing potatoes. Insects preferred Bintje cultivar during the traditional season and Pomina cultivar during the off-season time. Sahael cultivar was the least preferred in both potato growing season. Eriopis connexa (Germar) and Geocoris sp. were the most abundant predator species in the traditional potato growing season. During the off-season, Cycloneda sanguinea (L.) was the predominant species in all cultivars.