Electronic Monitoring of the Feeding Behavior of Phytophagous Stink Bugs (Pentatomidae)

Abstract

Stink bugs (Pentatomidae) encompass a great variety of heteropterans, many of them important pest species. Electronic monitoring of feeding behavior of pentatomids using the electrical penetration graph (EPG) technique has been conducted over a relatively short time span (10 years). To date, eight pentatomid species have been studied with EPG: Diceraeus (Dichelops) furcatus (F.); Diceraeus (Dichelops) melacanthus (Dallas); Edessa meditabunda (F.); Euschistus heros (F.); Halyomorpha halys (Stål); Nezara viridula (L.); Piezodorus guildinii (Westwood); and Tibraca limbativentris Stål. Feeding behavior of adults, and less frequently nymphs, was evaluated on different crop plants but primarily on soybean. These studies are revealing a variety of waveforms. Each one correlates with a specific behavior or a feeding site, which includes holding still on the plant surface, moving, grooming, labial dabbing, stylet penetration and secretion of gelling saliva, formation of a salivary sheath, ingestion from vascular tissues, laceration/maceration of cells, and ingestion of externally digested cell contents. Waveforms recorded in each feeding activity/tissue, are, in general, similar among species studied. Xylem waveforms share appearance and electrical characteristics; phloem ingestion and transitional waveforms (X waves), recorded from only two stink bug species, look alike, as well as waveforms of cell rupture activities observed on parenchyma/mesophyll and reserve tissue (seeds), independent of the tissue. These generated waveforms, related to their various feeding sites, allow a better understanding of the feeding process of pentatomids and the resulting damage to plants.