Response of Tribolium castaneum and T. confusum adults to vertical black shapes and its potential to improve trap capture

Authors: SEMEAO, ALTAIR - Kansas State University; Campbell, James - Jim; WHITWORTH, ROBERT - Kansas State University; SLODERBECK, PHILLIP - Kansas State University Extension Center

Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2011
Publication Date: 4/1/2011
Citation: Semeao, A.A., Campbell, J.F., Whitworth, R.J., Sloderbeck, P.E. 2011. Response of Tribolium castaneum and T. confusum adults to vertical black shapes and its potential to improve trap capture. Journal of Stored Products Research. 47(2):88-94. http://dx.doi.org/10.1016/j.jspr.2011.01.002.

Interpretive Summary: The red flour beetle (Tribolium castaneum) is a major pest of food processing and storage facilities, especially flour mills, and can be monitored using pheromone and food-baited traps, although attraction to traps is relatively low. Increasing beetle response to traps could improve the utility of these traps in monitoring programs. In laboratory experiments, the potential to increase beetle captures in traps by adding tall black shapes as an additional attractant was evaluated. Against a white background, beetles were more likely to visit black pillars than white pillars when presented with a choice. Beetle captures in pheromone and food-baited traps placed in front of tall and narrow black panels was shown to be greater than captures in traps in front of white panels in a series of experiments. A similar pattern of capture was also found for a closely related species, the confused flour beetle (Tribolium confusum). Our results suggest that captures of this important pest in monitoring traps could be increased by adding dark vertical shapes behind trap locations or placing traps near dark structures, although further evaluation in food facilities is needed to determine the extent of the benefit.

Technical Abstract: Tribolium castaneum can be monitored in food processing facilities using traps baited with pheromones and kairomones, but beetle response to traps might be enhanced by adding visual cues. Against a white background, T. castaneum adults were more likely to visit black pillars than white pillars when presented with a choice (e.g., 73% of beetles visited black and 17% visited white pillar), and visits to black pillars increased with pillar height. When tested against a black background, beetles did not show a significant preference for either color pillar regardless of height. When comparing beetle captures in pheromone/kairomone-baited traps placed in front of white or black panels in a white arena under high, low, or dark light conditions, more beetles were captured in traps in front of black panels under both high and low light conditions, but not under dark conditions. A similar pattern of capture under low and dark conditions was also found for the closely related species Tribolium confusum. In a larger scale choice test, the same pattern of greater T. castaneum captures in traps in front of black panels than white panels was obtained, whether traps were placed in corners or along walls. Our results suggest that captures in monitoring traps could be increased by adding dark vertical shapes behind trap locations or placing traps near dark structures.