Dewey Leierer

they/them and she/her

Education: Bachelor of Science in biochemistry (May 2022)

McNair Project: Shotgun metagenomic case study of a yellow mealworm (Tenebrio molitor) colony collapse (2021)

Mentor: Brenda Oppert, Ph.D.

Yellow mealworm beetles (Tenebrio molitor) are becoming a more important source of protein for animal and possibly human consumption. In both commercial and research rearing, yellow mealworms may come in contact with pathogens. Commercially reared mealworms are kept in densely populated colonies, and the mealworm’s close contact allows pathogens to spread throughout colonies quickly. Here, we report an instance of a small colony collapse in a USDA ARS research facility. The colony was noted as sick several years ago, but it only recently faced a full collapse brought on by a mite infestation. We used shotgun metagenomic sequencing to identify pathogens present in the colony that may have led to the mite’s success. In addition to identifying bacteria pathogenic to T. molitor in the colony, we identified multiple bacteria associated with illness in humans and animals. Preventing the accumulation of pathogens present in colonies is essential to preventing colony collapses and preventing illness in animals who consume mealworms. Prioritizing the hygiene of the colony’s flour will slow the accumulation of pathogens present in a colony, and industry standards for antimicrobial processing methods should be established and enforced to ensure consumer safety. This study can be used to assist both commercial and research in preventing future colony collapses and as reference of pathogens that may affect mass rearing.