Natures of ingested basidio-spores in dipteran larvae inhabiting sporophores of Agaricomycetidae

Abstract

Dipteran larvae are frequently observed in wild fungal sporophores. However, we have very little knowledge of the natures of the fungivorous dipteran larval feeding in sporophores. It is unknown whether dipteran larvae are able to play a role in spore dispersal. We studied dipteran larval feeding in sporophores of Agaricomycetidae with special interest in their spore ingestion （i.e., how many larvae ingest host fungal spores, and how ingested spores are affected by larval digestion） by field sampling sporophores together with dipteran larvae in them. A total of 3798 dipteran larvae were collected from 114 fungal sporophores belonging to 23 genera, 16 families, and four orders of Agaricomycetidae. Some of the larvae were dissected to examine the contents of their digestive tracts, 60.2％ （N=172） of which contained spores. Optical microscopic observations of spores stained with trypan blue to separate viable spores from dead spores identified that about 80％ of spores appears to be sound at a reduction of <11％ of control （spores from sporophores）. Scanning microscopic observations also found that ingested basidiospores appeared to be intact. These results suggested that dipteran larvae feed on spores frequently, without mechanically damaging most of the ingested basidiospores.

(Japanese Journal of Mycology 57: 69−76, 2016)