IMPACT OF ORGANIC INSECTICIDES ON THE SURVIVORSHIP AND MOBILITY OF HALYOMORPHA HALYS (ST angstrom L) (HEMIPTERA: PENTATOMIDAE) IN THE LABORATORY

Abstract

The invasive brown marmorated stink bug, Halyomorpha halys (Stal) (Hemiptera: Pentatomidae) has become a major concern for specialty and row crop growers in the United States. Management tactics against this new pest are currently limited to repeated synthetic insecticide applications, thereby making this problem even more challenging for the organic grower community. This study evaluated the insecticidal efficacy of organically-approved insecticides (azadirachtin, potassium salts of fatty acids, spinosad, pyrethrins, and pyrethrins + kaolin) and experimental biopesticides (Chromobacterium subtsugae Martin et al. strain PRAA4-1(T) [MBI-203], extract of Eucalyptus sp. [MBI-205], and Burkholderia sp. [MBI-206]). These materials were presented as 18-h old dried residues against adult H. halys in the laboratory. Nonlethal effect on horizontal walking mobility of H. halys was evaluated during a 4.5-h insecticide exposure period; vertical walking mobility was measured at 4.5 h and 7 d after the insecticide exposure. All treatments, except for azadirachtin, resulted in significantly higher mortality of H. halys over 7 d, compared with the untreated control. Pyrethrins + kaolin, MBI-203, and MBI-206 resulted in >= 80% of individuals moribund or dead after 7 d. Horizontal walking distance of H. halys was significantly greater immediately and 3 h after exposure to pyrethrins and MBI-203, respectively, compared with the untreated control. After the 4.5-h exposure to potassium salts, pyrethrins, and pyrethrins + kaolin, surviving H. halys climbed significantly shorter distances while those exposed to MBI-203 climbed significantly greater distances compared with the untreated control, in the vertical mobility bioassay. After 7 d, there was no measurable difference, in the vertical walking distance by surviving individuals, between any of the tested materials and the untreated control. The results of the study are discussed within the context of developing effective management strategies for H. halys in organic production systems.