Submitted to: Journal of Economic Entomology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/11/2004
Publication Date: 2/1/2005
Citation: Snodgrass, G.L., Adamczyk Jr, J.J., Gore, J. 2005. Toxicity of insecticides in a glass-vial bioassay to adult brown, green and southern green stink bugs (heteroptera: pentatomidae). Journal of Economic Entomology. Interpretive Summary: Brown, green, and southern green strink bugs have become increasingly more important pests of cotton in the mid-South over the past several years. All three species can cause significant damage to cotton and reduce yield and fiber quality. Their increase in importance has been due to decreased use of insecticides in cotton because of boll weevil eradication and the use of transgenic cotton to control lepidopterous pests. Pesticides applied to control these pests also controlled stink bugs in cotton. In AR, LA, MS, and TN about 2,600 hectares of cotton were estimated to have been treated for stink bugs in 1995 (the first year transgenic cotton was widely grown in the mid-South), in 2002 an estimated 352,200 hectares of cotton was treated for stink bugs in the four states. In the present study, a glass-vial bioassay was developed to rapidly determine insecticide resistance in stink bug populations. It was used to establish base-line resistance data for five pyrethroid and four organophosphate insecticides for brown, green and southern green stink bugs at two collection locations, Stoneville, MS, and Eudora, AR. The tests showed that brown stink bugs were more difficult to kill than green or southern green stink bugs for all insecticides tested. In most comparisons, the susceptibility of all three stink bug species to the insecticides was the same at both collection locations. The base-line data developed in the study required the testing of over 8,000 stink bugs and will be used in the future in resistance monitoring to detect changes in the susceptibility of the stink bugs to insecticides.
Technical Abstract: Adult brown, Euschistus servus (Say), green, Acrosternum hilare (Say), and southern green, Nezara viridula (L.), stink bugs were collected from soybeans in the fall of 2001 and 2002 near Stoneville, MS, and Eudora, AR. A glass-vial bioassay was used to determine LC50 values for the three species of stink bugs for the pyrethroids bifenthrin, cypermethrin, cyfluthrin, L-cyhalothrin, and permethrin, and the organophosphates acephate, dicrotophos, malathion, and methyl parathion. LC50 values were compared between stink bug species and by collection location for each insecticide. Results of the comparisons confirmed findings of other researchers that the brown stink bug was less susceptible to pyrethroid and organophosphate insecticides than were green and southern green stink bugs. Green stink bugs were more tolerant of organophosphate insecticides than were southern green stink bugs. The susceptibility of brown, green, and southern green stink bugs collected at Stoneville, MS, to pyrethroid and organophosphate insecticides, in most comparisons, was not significantly different from the susceptibility of the same species with the same insecticide collected at Eudora, AR. The study established base-line insecticide mortality data from two locations in the mid-South for three stink bugs species that are pests of soybeans and cotton. A synergism test using S, S, S-tributyl-phosphorotrithioate (DEF) showed that esterase enzymes were important to brown and green stink bugs in the detoxification of pyrethroid insectides. Data from the tests are needed for future use in studies on resistance and for use in resistance monitoring programs.