Monitoring of Tribolium castaneum (Coleoptera: Tenebrionidae) in rice mills using pheromone-baited traps

Authors: MCKAY, T - Arkansas State University; BOWOMBE-TOKO, M - Arkansas State University; STARKUS, L - Arkansas State University; Arthur, Franklin; Campbell, James - Jim

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/13/2018
Publication Date: 5/22/2019
Citation: McKay, T., Bowombe-Toko, M.P., Starkus, L.A., Arthur, F.H., Campbell, J.F. 2019. Monitoring of Tribolium castaneum (Coleoptera: Tenebrionidae) in rice mills using pheromone-baited traps. Journal of Economic Entomology. 112(3):1454-1462. https://doi.org/10.1093/jee/toy422.
DOI: https://doi.org/10.1093/jee/toy422

Interpretive Summary: The red flour beetle is an important pest of rice mills, but there is comparatively less information about its distribution and seasonal patterns of activity in rice mills compared to patterns in wheat flour mills. Using pheromone traps to sample red flour beetle populations in and around four rice mills in Arkansas over a two-year time period, it was shown that although there was considerable variation among mills, overall fewer beetles were found in rough rice storage areas compared to inside the mill. More beetles were trapped during the spring and summer months compared to autumn and winter. Using a target threshold for beetles captured that was previously developed to indicate an increased risk, it was found that most captures in all the mills were below this level. Temperatures inside the mills tended to follow outside temperatures, but to be about 1 degree Celsius warmer than outside. With the level of variation in red flour beetle captures among trap locations observed, this study illustrates that having a monitoring program for each particular facility is an important tool for rice processing facilities. The utilization of pheromone traps could provide information to mill managers to determine locations within a mill that are most vulnerable to infestation and to assist with the timing and targeting of control interventions.

Technical Abstract: The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), is one of the most common pests in rice mills. With limited information in the literature addressing T. castaneum in rice processing facilities, we examined the spatial and temporal distribution of T. castaneum inside and outside of three commercial rice milling facilities and one rice packaging plant from June 2012 to August 2014 using pheromone-baited dome traps. Each mill had very different population trends with fewer numbers collected in rough rice storage areas. T. castaneum were more commonly collected in processing areas. Beetle infestation at all mills was evaluated using the threshold of mean beetle capture of 2.5 beetles per trap per 2-wk period. Trap captures were generally below the threshold for all but one facility. Temperatures inside were ~1°C warmer than outside temperatures, with this temperature difference more noticeable during the cool seasons. Higher numbers of T. castaneum were captured in year 2012 in comparison to 2013, with higher numbers of beetles observed during warmer months (April - September) than cooler months (October - March). With such variation in trap capture of T. castaneum occurring among all facilities, this study illustrates that having a monitoring program that is designed for each particular facility is an important tool for rice processing facilities that would help managers decide when and where to apply pest management tactics. Results show how utilization pheromone traps could provide information that could be utilized by mill managers to determine locations within a rice mill that are most vulnerable to infestation by T. castaneum, and to also assist with the timing of control interventions.