Influence of volatile and nonvolatile secondary metabolites from soybean pods on feeding and on oviposition behavior of Euschistus heros (Hemiptera: Heteroptera: Pentatomidae).

Identification of chemical compounds extracted from host plants that act as oviposition stimulants for pest insects has gained importance, because of the compounds' potential use in the manipulation of insect behavior in the field. However, for generalist insects, such as phytophagous pentatomids, the chemical basis for the selection of the host is not well-known. Insect response can vary according to the soybean genotypes. Chemical profile of soybean pods of cultivars 'BRS 213', 'BRS 267', 'BR-16', and 'IAC-100' were compared regarding the feeding preference and oviposition of the stink bug Euschistus heros (F.). In the no-choice test, E. heros females showed longer feeding time on pods of BR-16 (132.6 min), followed by BRS 213 (128.0 min), BRS 267 (122.5 min), and IAC-100 (82.9 min). In the choice test, there was no significant difference in the feeding time among cultivars. In the oviposition test, females deposited 60% of eggs on the pods of BRS 267, followed by BRS 213 (27.3%), BR-16 (8.8%), and IAC-100 (3.9%). The chemical profile of BRS 267 including greater presence of reducing sugars and lack of isoflavone forms might explain the preference of E. heros to oviposite on it compared with the remaining cultivars tested.