Skip to main content
ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Crop Bioprotection Research » Research » Publications at this Location » Publication #311167
Title: A culture method for darkling beetles, Blapstinus spp. (Coleoptera: Tenebrionidae)

Author
item Zilkowski, Bruce
item Cosse, Allard

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2015
Publication Date: 3/19/2015
Publication URL: http://handle.nal.usda.gov/10113/62245
Citation: Zilkowski, B.W., Cosse, A.A. 2015. A culture method for darkling beetles, Blapstinus spp. (Coleoptera: Tenebrionidae). Journal of Economic Entomology. 108(3):1010-1013.

Interpretive Summary: Darkling beetles of the genus Blapstinus (Coleoptera: Tenebrionidae) have become a serious pest of melon crops in California. Both adults and larvae can damage crops by cutting off young seedlings at the ground level and then later in the season by boring into ripening fruits. In order to work with Blapstinus in the laboratory it was important to find a method that would quickly produce large numbers (> 500) of adult beetles. We tested a method that involved letting adults reproduce in plastic, shoebox-sized containers that held ground chick feed as a food source and then either apple halves or zucchini slices as a moisture source. Both fruits worked well as a moisture source and exceeded our target number for adults but apples did out produce zucchini by a margin of almost two to one. We were also able to demonstrate a quick and simple method for differentiating male and female Blapstinus by examining the pupal stage for telltale growths at the tip of the abdomen that only female’s possess. The results of this study not only allow us to grow large numbers of beetles in a short time but also allow us to work with individual sexes of the beetles when needed. This research will be of interest to melon producers, entomologists studying this beetle, and to laboratory personnel who culture insects in general. In addition, this project adds important basic knowledge about Blapstinus, an insect pest for which little information was previously known.

Technical Abstract: Darkling beetles, Blapstinus spp., have become a serious pest of Cucurbitaceae crops, especially in California. A culture method was sought to provide large numbers (> 500) of adult beetles of known age and sex that could be used for laboratory testing when needed. A method previously developed for Alphitobius diaperinus (Panzer) using a diet of ground chick feed, with apple slices as a moisture source, was modified for use with Blapstinus spp. and then compared to the same method substituting zucchini as the moisture source. Rearing boxes set-up with apple slices produced significantly more pupae and adults then the boxes containing zucchini slices. However, using either zucchini or apples as a moisture source, yielded over the target of 500 adults per rearing box. A previous method designed to sex A. diaperinus based on the presence (') or absence (') of second valvifers in the pupal stage also proved effective for sexing the Blapstinus spp.