Biologia de Spodoptera frugiperda (Lepidoptera: noctuidae) em diferentes cultivares de Oryza sativa L.

Abstract

Risc (Oiyza sativa L.) is one of tlic most soeially and economically important crops in thc world, as it is onc of thc main products in the basic food baskct and thc main source of calories in grains. Most insect specics tliat fecd on ricc plants occur in both flood - irrigatcd and upland rice crops. Among some of thc main pcsts is thc occurrencc of Spodoptera frugiperda that produces gradual damage, with small perforations in the leaves and, later, severe damage consuming, without distinction, seedling, leaves and stems of rice. Thus, knowledge of the insecfs biology is of fundamental importance for the development of adequate and sustainable management strategies. Soon the work aimed to evaluate the biology of Spodoptera frugiperda fed with different rice cultivars under laboratory conditions. 50 newly hatched caterpillars were used in 6 different rice varieties (IRGA 424, Bacaba, BRS Emerald, Eat raw, BRS Spring and Smooth legado). The biological aspects evaluated were: larval phase: (weight at 7 and 14 days; larval duration and viability), pupal phase: (weight after 24 hours; pupal duration and viability and percentage deformation) and adult stage: (number of eggs/females; number of eggs/laying/females, adult longevity and percentage of deformation). It is concluded that even the six varieties were willing for the insects to complete their cycle, there was an elongation of the larval stage reaching approximately 37 days, the percentage of larval, pupal and adult viability ranging from 74% to a higher value in the variety BRS Esmeralda and 10% for lower value in the IRGA 424 variety. Reduction in the number of eggs and in all varieties, thus decreasing the spread of the insect-pest.