USE OF FRUCTOSE AND FLOWERING PLANTS TO ENHANCE Plutella xylostella CONTROL

Abstract

Access to carbohydrates is essential for parasitoids to manifest their reproductive potential in the field. In commercial agroecosystems, carbohydrate sources are limited at different periods during the crop cycle, so these resources should be provided to favor the presence, permanence and activity of parasitoids. This study aimed to evaluate different supplements and the plant Lobularia maritime (Linnaeus, 1753) Desv. (Brassicaceae) as a food source for Diadegma insulare (Cresson, 1865) (Hymenoptera: Ichneumonidae) in the laboratory and field. In laboratory, carbohydrates increased the survival probability of D. insulare (X²₆ = 793, P ≤ 0.0001), compared to proteins and the control (water); with fructose, 75 % of the individuals survived for more than 22 days, while with water or protein, 100 % of the individuals died before the sixth day. In the field, the level of parasitism in plots where fructose was applied was almost double (82 %) compared to the control (42 %), and significant differences were recorded in the total number of parasitoids emerged (F_5,24 = 3.35, P = 0.0194). Results suggest a high potential for using food supplements in biological control programs for P. xylostella.