|Da, Kedong -|
|Buntin, G. David -|
|Powell, Robert Jr. -|
|Lee, R. Dewey -|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 18, 2010
Publication Date: December 1, 2010
Citation: Ni, X., Da, K., Buntin, G., Cottrell, T.E., Tillman, P.G., Olson, D.M., Powell, R., Lee, R.D., Wilson, J.P., Scully, B.T. 2010. Impact of brown stink bug (Heteroptera: pentatomidae) feeding on corn grain yield components and quality. Journal of Economic Entomology. 103:2072-2079. Interpretive Summary: Stink bug populations and the resulting damage on field corn have been steadily increasing in recent years in the southern US. A two-year study was conducted to examine ear damage caused by the brown stink bugs on developing corn ears. The ear damage was examined when corn plants were at tasseling, mid silking, and blister stages. In 2005, a range of 0, 3, and 6 adult stink bugs was used in the study, while a narrower range of insects (0, 1, 2, 4 adults) was used in 2006. The experiment was conducted twice in each of the two years. The study showed that the stink bug infestation at the tasseling and mid silking stages caused more damage than infestation at the blister stage. In addition, 3 or more stink bug adults feeding on corn ears for 9 days caused a significant yield reduction. The findings of this study are valuable for establishing management strategies for reducing stink bug damage on field corn. In addition, the study also provides baseline information for developing effective screening techniques to identify corn germplasm with stink bug resistance.
Technical Abstract: The economic injury level by the brown stink bug, Euschistus servus (Say) (Heteroptera: Pentatomidae), on developing corn (Zea mays L.) ears was examined in 2005 and 2006. Stink bug infestations were initiated when ‘DKC6971’ (Bt-transgenic and roundup-ready) hybrid plants were at growth stages VT, R1, and R3 using 0, 3, and 6 or 0, 1, 2, and 4 bugs per ear during 2005 and 2006, respectively, and maintained for 9 d. Treatments were replicated five times per experiment, and the experiment was repeated twice each year. Ears used were individually confined using sleeve cages during the infestation period. Eight parameters recorded for each sampled ear were 1) the number of stink bug feeding punctures (or stylet sheaths) at the end of the 9-d infestation period, 2) ear length, 3) ear weight, 4) total number of kernels, 5) percentage of discolored kernels, 6) percentage of aborted kernels, 7) total kernel weight, and 8) one-hundred-kernel (or test) weight at harvest. The number of feeding punctures per ear increased with the level of infestation (stink bug number), but not by the timing of the infestation (plant growth stage). Stink bug number and plant growth stage significantly affected the percentage of discolored kernels, percentage of aborted kernels, ear weight, and kernel weight per ear. Infestation at the VT stage (i.e., before anthesis) caused more damage than later infestations at or after anthesis (stages R1 and R3). The percentages of discolored kernels and aborted kernels were negatively correlated to the ear and kernel weight. Although the 100-kernel weight was not affected by either insect infestation level or corn growth stage in either year, kernel weight per ear was affected by both of these experimental treatment factors. Ear length, ear weight, and total number of kernels per ear were affected by corn growth stage in 2005 only, not in 2006. The stink bug infestation level showed no effect on ear length, ear weight, or total number of kernels in either 2005 or 2006. This study demonstrated that corn ear and kernel weight was significantly reduced when three E. servus adults were confined on a corn ear at stages tasseling (VT) and mid silking (R1) for 9 d, whereas 1 or 2 adults per ear resulted in no significant yield reduction. Early infestation at stages VT and R1 caused more ear damage than later infestation at the blister stage (R3). This information will be useful in developing management guidelines for stink bugs in field corn during ear formation and early grain filling, as well as developing initial field screening criteria for stink bug resistance in corn germplasm.