Different trap designs and attractants affect the capture of multiple life stages of Trogoderma granarium Everts and Trogoderma variabile Ballion in the laboratory

Trogoderma granarium Everts (Coleoptera: Dermestidae) is categorized as one of the most destructive species in stored products and it is considered as an important quarantine species in many parts of the world. Some countries in Asia also consider Trogoderma variabile Ballion a biosecurity risk. In the present study, five series of laboratory tests were performed to examine 2-3 different traps and five different attractants for the capture of T. granarium adults and larvae and T. variabile larvae. In the first test, a series of four-choice assays with two different traps were evaluated separately with five different attractants each and adult/larval captures of T. granarium were recorded after 7 days. In the second test, the two different traps were placed together con-taining different attractants each time. In tests 3, 4 and 5, no-choice trapping trials were conducted with the same traps and attractants in arenas with young or old T. granarium or T. variabile larvae. There were low numbers of captured adults and larvae for both species, but larvae generally responded better than the adults in most combinations tested. Trogoderma granarium larvae responded to different attractants compared with adults which preferred oil and gel. Moreover, wheat germ was less preferred by adults than larvae for T. granarium. Moreover, the trap type affected the captures of young T. variabile larvae. The current data indicated that there are specific combinations of traps and attractants that are more effective for the detection of T. granarium, which can be further evaluated in area-wide monitoring strategies at food facilities.

Automated summary

In this study, five series of laboratory tests were conducted to examine different traps and attractants for the capture of Trogoderma granarium and Trogoderma variabile. The results showed that larvae were generally more responsive than adults for both species. Different attractants also had varying effects on the captures of adults and larvae of T. granarium. Furthermore, the type of trap used affected the captures of T. variabile larvae. Therefore, more effective trapping methods can be developed to monitor T. granarium.