Developmental period of Trogoderma variabile can be affected by many factors. The larvae of Trogoderma variabile enter diapause in unfavorable conditions. In this study, a comparison will be made between feeds (wheat flour, mixture of wheat flour and bran, dried pollack) and humidity (15%, 60%) in the same temperature (30℃ ±0.5) for 6 months. In the results, there are differences between feeds. Feeding mixture of wheat flour and bran was the shortest developmental period. Feeding dried pollack took few months to emerge, although we could not observe emergence for wheat flour. Even though humidity makes differences for feeding dried pollack, there were no significant differences for mixture on the different humidity. From that results, we could assume that the strongest affect on the developmental period is feeding material. Additionally, depends on feeding material, the other factors may affect on the developmental period.
Trogoderma variabile B. is one species of well-known stored product insect. This study was conducted to test the perforation ability of larvae of T. variabile on different packaging films which has been widely used in food industry at different thickness. The tested packaging films are polypropylene (PP) 20μm, low density polyethylene (LDPE) 20μm, polyethylene terephthalate (PET) 12μm, PP 30μm and PP 40μm. This investigation was carried out for 7 days. In the same order as the films mentioned above, the perforation rate are 33.33%, 0%, 14.81%, 29.62%, 0%. From these results, the easiest film to perforate among PP, LDPE, PET is PP, and there are significant differences on thickness. Therefore, different type of materials and thickness would be considered to be used for food packaging.
Insect pest monitoring program in subsistence warehouses can detect pest problems in early infestation stages. Temporal and spatial distributions of pests produced by monitoring allows facility managers and pest control operators to visualize pest problems and evaluate effectiveness of cleaning, sanitation and pest management practices. Pheromone-based insect monitoring traps were placed to study temporal and spatial distribution of Lepidopteran and Coleopteran stored product pests in two central distribution centers of United States Military Forces in the Republic of Korea, from March to December 2008. The two distribution centers receive store and issue subsistence and they are located in two different cities, Seoul and Taegu. As a result, three pests, Plodia inter punctella Hübner (Indian meal moth), Lasioderma serricorne F. (cigarette beetle), and Trogoderma variabile Ballion (warehouse beetle), were detected on the traps. P. interpunctella was most abundant, followed by L. serricorne and T. variabile. Different phenologies and spatial distribution of each species were seen from the two warehouses, that were related with internal temperature of the two warehouses and food availability. The program benefited to lead a better understandings for existence and extent of local pest problems in the two subsistence distribution centers, and also helped to find effective pest management periods and locations.