DEVELOPMENT OF INTEGRATED PEST MANAGEMENT PROGRAMS TO REDUCE METHYL BROMIDE FUMIGATIONS FOR CONTROL OF INSECTS IN POSTHARVEST STRUCTURES
Location: Stored Product Insect Research Unit
Title: Influence of environmental and physical factors on Tribolium castaneum (Coleoptera: Tenebrionidae) trap captures in a flour mill
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 22, 2012
Publication Date: February 1, 2012
Citation: Semeao, A.A., Campbell, J.F., Whitworth, R.J., Sloderbeck, P.E. 2012. Influence of environmental and physical factors on Tribolium castaneum (Coleoptera: Tenebrionidae) trap captures in a flour mill. Journal of Economic Entomology. 105(2): 686-702. http://dx.doi.org/10.1603/EC11322.
Interpretive Summary: Pheromone traps that capture walking insects are widely used for monitoring of stored-product insect pests inside processing facilities, but variation in the local environment where traps are placed might impact the probability of capturing insects at that location. If specific factors associated with locations of greater insect activity could be identified, then they could be used to identify the optimal locations within a facility to place traps. The red flour beetle is a major pest of flour mills and is monitored using Dome traps placed on the floor. Evaluating long-term patterns in red flour beetle captures revealed that while over short periods of time beetles were more likely to be found in certain areas of the mill, over longer periods of time areas of greater insect activity moved around the mill resulting in long-term averages that were more uniform among trap locations. Although the characteristics of individual trap locations were found to be highly variable, only warmer temperatures, higher flour dust accumulation, and proximity of milling equipment were associated with traps with high levels of beetle capture. Results indicate that while the environment appeared to have some influence over pattern in beetle captures it was limited, probably because broader patterns of change in distribution within the mill over time, perhaps related to season or increase in total abundance, were more important.
Environmental and physical variables in food processing facilities can influence both the distribution of stored-product pests and the effectiveness of traps at capturing them. Data from a long-term Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) monitoring program was used to evaluate spatial variation in captures among trap locations and to determine relationships with environmental and physical variables. From the complete monitoring dataset, different subsets were created for the cool and warm season, and period of time when environmental/physical factors were measured (2009/2010), with all datasets showing significant differences among trap locations in terms of beetle captures and proportion of time that traps exceeded 2.5 beetles per trap per monitoring period. There was also considerable temporal variation in distribution among the different floors of the mill. Among the environmental and physical variables measured, mean temperature and flour dust accumulation were the factors that showed the most significant positive relationships with variation of beetle captures at trap locations. Traps with milling equipment in close proximity tended to capture more beetles, but number of pieces of equipment was not significant. Presence of equipment near traps was also associated with an increase in flour dust accumulation and temperature. Overall the environmental and physical factors appeared to have a limited influence on variation in captures among trap locations, with temporal variation in distribution perhaps overwhelming potential influences of local trap conditions.