Nutritional indices and feeding preference of the Plutella xylostella L. (Lepidoptera: Yponomeutidae) in several Brassicaceae plants

Abstract

The quantity and quality of food consumed by insects affect their growth, development; likewise, the diamondback moth Plutella xylostella (Lepidoptera: Yponomeutidae), one of the important pests of Brassicaceae plants. The study aimed to determine feed preferences and the effect of four Brassicaceae, namely cabbage (Brassica oleracea var. capitata), caisin (B. rapa), broccoli (B. oleracea var. italica), and Rorippa indica, on the nutritional indices of P. xylostella larvae. The research methods consisted of insect rearing, nutrition indices test, preference test, and proximate analysis. The results showed that the highest preference was found in R. indica (47.81%), while the other three plant species were not significantly different. Cabbage treatment showed the highest efficiency of conversion of ingested food (ECI) (8.56%), followed by R. indica, caisin, and broccoli. The same thing, cabbage treatment showed the highest efficiency of conversion of digested food (ECD) (13.02%), followed by caisin, R. indica, and broccoli. Broccoli had the highest approximate digestibility (AD) (89.38%), followed by R. indica, cabbage, and caisin. In general, the results of the nutritional indices showed that cabbage was the most suitable feed for P. xylostella larvae; in addition, with a high feeding preference, R. indica could potentially be used as a trap crop.