Submitted to: Pest Management Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/7/2013
Publication Date: 9/7/2013
Citation: Leskey, T.C., Short, B.D., Lee, D. 2013. Efficacy of insecticide residues on adult Halyomorpha halys (Stal) (Hemiptera: Pentatomidae) mortality and injury in apple and peach orchards. Pest Management Science. DOI: 10.1002/PS.3653. Interpretive Summary: The brown marmorated stink bug (BMSB) is an invasive species native to Asia, which has emerged as a key pest on tree fruit especially in the mid-Atlantic region. This study reports field-based residual efficacy of insecticides for control of BMSB in apple and peach orchards. In the study, adults were collected from wild and cultivated hosts less than one week prior to testing to more accurately reflect the susceptibility of wild BMSB populations which growers deal with in their production. In general, insecticide efficacy was significantly higher early in the growing season when overwintered adults were prevalent, compared with new generations present later in the season. Also, insecticide efficacy decreased as insecticide residue became dry and aged over seven days, compared with fresh, wet materials. Typically, the addition of adjuvant did not improve insecticide efficacy against BMSB. Significantly fewer injury levels were recorded on apples treated with dinotefuran and fenpropathrin compared with untreated control for all residue ages. The results of this study will help develop and enhance season-long management programs of this invasive species in tree fruit.
Technical Abstract: The primary threat from Halyomorpha halys (Stal) (Hemiptera: Pentatomidae) originates from populations continuously dispersing from and among wild and cultivated hosts. Many individuals may not come in contact with freshly applied insecticides, but only dried, aged residues. Limited information exists regarding field-based residual activity of insecticides for management of H. halys in tree fruit. Thus, we conducted field-based bioassays in apple and peach orchards to evaluate residual activity of insecticides commonly applied against H. halys. Adults used in these trials were collected from wild and cultivated hosts less than one week prior to testing to more accurately reflect the susceptibility of wild H. halys populations in the field throughout the season. Significantly higher mortality rates of H. halys were observed early in the growing season, when overwintered adults were prevalent, compared with populations present later in the growing season that included new generation adults. Significantly higher mortality was recorded for adults exposed to fresh insecticide applications compared with three- and seven-day-old residues. Typically, the addition of an adjuvant did not enhance efficacy or residual activity of insecticides. Significantly fewer injury sites were recorded on apples treated with dinotefuran and fenpropathrin compared with the untreated apples for all residue ages. Overwintered H. halys populations are easier to kill with insecticide applications than the first and second generation which are present in the field during the mid- to late-season. Residual activity of nearly all insecticides decreased significantly by three days after application and adjuvants generally did not increase residual activity. These factors should be considered in developing season-long programs for management of this invasive species in tree fruit.