The connection between the gut mycobiome community of natural black soldier fly populations and their environment

Abstract

In contrast to interactions between prokaryotic organisms (e.g. bacteria) and insects, an understanding of the interactions between eukaryotic microorganisms (e.g. fungi) and insects is lacking. In this study, black soldier fly larvae were collected from natural populations in household composts. The mycobiome composition of the larval gut and environment was identified using next generation sequencing. The nutrient composition of the larvae's environment was analyzed. The mycobiome composition was divided into three groups: the first included larvae from Kfar HaHoresh that comprised mostly Meyerozyma and were influenced by the fiber and carbohydrate composition of the compost; the second included the compost samples from Kfar HaHoresh and Misgav Am that mainly comprised the Dipodascaceae family and were influenced by the fiber composition of the compost. The third group contained all the remaining compost and larvae samples and mainly comprised the genus Candida. Candida spp. are the most common in the environment and may thus affect their abundance in the insect gut. However, this species may be adapted to the insect’s gut, providing the insect with a benefit that allows the insect to disperse Candida to new resource patches and thereby help increase its abundance in the environment. In cases where dominant species are not present, it seems that the important factor determining fungal composition in the insect gut is its diet. Understanding the metabolic effect of fungi, e.g. Candida, on the BSF larvae is still a black box which requires further study.