Influence of Environmental and Physical Factors on Capture of Tribolium castaneum (Coleoptera: Tenebrionidae) in a Flour Mill

Abstract

Variation in environmental and physical factors within food processing facilities can influence both the distribution of stored-product pests and trapping efficiency. 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 data set, different subsets were created for the cool and warm seasons, and period of time when environmental and physical factors were measured (2009-2010), with all data sets 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 levels of the mill. Among the environmental and physical variables measured, mean temperature and flour dust accumulation showed the most significant positive relationships with variation of beetle captures at trap locations. More beetles were captured in traps located in close proximity to milling equipment. Presence of equipment near traps was also associated with an increase in flour dust accumulation and temperature. Overall the environmental and physical factors seemed 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.

Distribution, abundance, and seasonal patterns of Plodia interpunctella (Hübner) in a commercial food storage facility

“…Most trap locations were highly variable in terms of the number of moth captured over time, with the result that it was difficult to identify specific locations where monitoring should be focused. This could be the result of movement of infested material into and out of the warehouse, although a similar pattern was observed for Tribolium castaneum (Herbst), the red flour beetle, in flour mills (Semeao et al, 2012). In both cases, it may be that the high mobility of the adult insects is covering up the actual dispersion of the infestations.…”

“…However, the greater levels of capture inside, a trend for captures near doors not to be greater than in the warehouse interior, and observation of infested product suggests that at this location a resident population within the warehouse was of primary importance. Interpretation of pheromone trap catch data of stored product insects in relation to actual population density is confounded for a number of reasons including trap density, internal air movement, height of traps, age of pheromone lures, temperature and insect movement patterns (Campbell et al, 2002;Nansen et al, , 2008Trematerra and Gentile, 2010;Semeao et al, 2012), which ultimately affects adoption of monitoring programs and management strategies. Arbogast et al (2000) described two approaches for interpretation of trap catch data: representative, which assumes trap catch is a proportion of the total population, and indicative, which assumes trap catch as an indication of risk or a necessary management action.…”

Influence of landscape pattern in flour residue amount and distribution on Tribolium castaneum (Herbst) response to traps baited with pheromone and kairomone

“…For walking T. castaneum, landscape features such as vertical edges have been shown to influence behavior (Campbell and Hagstrum, 2002). Semeao et al (2012) measured physical and environmental features associated with trap locations and their relationship with T. castaneum captures in a commercial flour mill. Variation in captures among locations and a significant relationship between insect capture and flour dust accumulation was found.…”

“…How T. castaneum respond to commercially available traps and attractants may be influenced by the landscape of physical and environmental conditions at the locations where traps are placed inside a food facility. Semeao et al (2012) found that trap locations within a flour mill with larger captures tended to have greater flour dust accumulation, higher temperatures, and closer proximity to milling equipment. Romero et al (2009) found that T. castaneum movement patterns were influenced by the distribution pattern of flour accumulations.…”

“…The residue of food material on surfaces within a food processing facility, which can be considered as habitat for T. castaneum, can have its own spatial structure of presence and absence and depth of accumulations (Semeao et al, 2012). Neutral landscape models have been used to investigate how T. castaneum respond to spatial pattern in habitat abundance and distribution, and shown that beetles move more slowly and tortuously as the individual patches of flour habitat change from clumped to fragmented in distribution and as a result beetles tend to remain longer within individual patches of flour and on landscape as a whole (Romero et al, 2009).…”