Changes in Community Structure and Abundance of Parasitoids of Yellow Rice Stem Borer Eggs Due to Treatment of Several Insecticide Active Ingredients in Rice Fields

Abstract The yellow rice stem borer is one of the main pests of rice plants in several rice production centers in Indonesia. Egg parasitoids are an effective biological control component that occurs naturally in the field. Its performance as a natural control is often disrupted by the unwise use of insecticides in the field. This study aims to evaluate the effect of several insecticide active ingredients on changes in community structure and parasitization levels of yellow rice stem borer egg parasitoids. The research used treatment with 4 types of active insecticide ingredients, namely Fipronil 50 g/l, Imidacloprid 25%, Demihipo 400 g/l, and Abamectin 18 g/l in a Randomized Block Design, each repeated 4 times. The research results showed that the egg parasitoid community found consisted of Tetrastichus schoenobii, Telenomus rowani and Trichogramma japonicum . Insecticide treatment had a significant effect on changes in the parasitoid community in the field. Increasing the level of insecticide concentration has a significant effect on the decline in the host population (YRB), changes in the composition and abundance of the population and the level of parasitization of egg parasitoids in the field. The insecticide concentration level that had the greatest influence on reducing the level of parasitization in the three types of egg parasitoids was 1.5 cc/l for Fipronil and 2 cc/l for other types of insecticide active ingredients. Plant phenology factors also influence population development and parasitization rates of parasitoids in the field.