Analysis of Injury Timing and Compensatory Reaction of Soybean to Feeding of the Southern Green Stink Bug and the Bean Bug

Abstract

Injury occurrence and compensatory reactions of soybean to feeding of Nezara viridula and Riptortus clavatus were experimentally analyzed in relation to the density, duration of release and period of release of bugs. Severe feeding interference among individuals occurred on large pods, especially in N. viridula. The density effect considerably affected feeding frequency and consequently the total feeding time. On infested plants, seed biomass decreased remarkably, while the biomass of leaves, stems and roots increased with bug density. The total biomass of injured plants was nearly equal to that on control (non-injured) plants. During the early pod growing stage, a compensatory reaction of plants to the feeding of bugs manifested as an increase in pods. Injury levels decreased when bugs were released later in the plant life cycle. The timing of feeding had a sensitive influence on soybean yield. © 1991, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.