Rearing and storage in mung beans reduce medically significant molds by the seed beetle, Callosobruchus maculatus (Coleoptera: Chrysomelidae), utilized in science classrooms

摘要

To examine whether colonies of seed beetles, Callosobruchus maculatus , may be a health concern as a source of mold allergens to students and teachers, we compared the amount and type of molds present on adult beetles reared with mung beans and cowpeas, Vigna radiata and Vigna unguiculata , respectively (Family Fabaceae). Specimens were analyzed from two elementary schools, a commercial supplier and a university insectary. A total of nine fungal genera were isolated from live and dead adult beetles, consisting primarily of Aspergillus (a large proportion of which was Aspergillus niger ) and Penicillium , with lower, variable numbers of Alternaria , Cladosporium , Fusarium , Mucor , Rhizopus , Scopulariopsis , and Trichoderma . Absidia , Geotrichum , and Paecilomyces were additional genera isolated from dead beetles. These molds are medically significant as potential allergens, and others (Aspergillus , Rhizopus , Mucor ) can cause secondary infections in people. The mold profile of different beetle colonies are similar in quality and quantity, thus suggesting that beetles are acquiring molds that are commonly found or can develop on seeds in their rearing/storage containers. Rearing on mung beans suppresses total mold growth by nearly 63% compared to the amount observed when raised on cowpeas. In fact, most cultures of beetles reared in mung beans were entirely fungus-free. Our conclusion is that the amount and diversity of allergenic molds from seed beetles for use in classrooms can be minimized considerably by using mung beans for beetle rearing, along with routine colony maintenance and proper hygiene.