1970] 
Eberhard — Fungus Gnats 
367 
nature were on the undersurface of a log where there were larvae 
and pupae present, and in cracks between the edges of bracket 
fungus sporophores and tree trunks. 
Larvae 
The larvae found during the study period (1 July-i Sept., 1968) 
varied from 3 to 19 mm in length. They were similar to the larva 
of Leptomorphus walkeri described by Madwar (1937), with a 
sclerotized head capsule and 12 fleshy body segments. As in L. 
walkeri , the labrum bore eight prominent papillae, and each maxilla 
also carried one large papilla. Madwar termed these structures 
“sensory papillae”, and Brocher (1931) called them teeth (“dents”), 
but lines of silk were seen emerging from these papillae during 
spinning activity, so spigot seems a more logical name. 
The 12 fleshy segments behind the head capsule were all moist. 
The color of their cuticle ranged from nearly transparent to light 
brown in different individuals, with markings of darker brown. The 
heart was just under the dorsal surface, and in a nearly fully grown 
larva a peristaltic beat originated at the posterior end and moved 
forward about 50 times/minute. The larvae were always found 
upside down under more or less horizontal surfaces such as the 
undersides of fallen logs or bracket fungus sporophores. Each larva 
was on the bottom surface of a sheet of silk it had spread under the 
supporting object. The sheets were relatively flat, and often 1 mm 
or more below indentations in the supporting surface. There was 
always a dendritic network of slime trails on the silk, and the larvae 
were always on one of these trails (Fig. 3). 
Larval sites had several features in common. There was almost 
always (one exception in more than 60 cases) an open space of 
more than 3 cm (usually much more) between the larva and the 
nearest surface below; the sites were always at least slightly moist; 
and the silken 4 sheets were nearly always built under fungal sporo- 
phores. The larvae were found under several types of sporophores, 
including both brackets (probably Fomes) and others which spread 
along the surfaces of rotten logs. 
Many of the sporophores occupied by larvae appeared to be per- 
ennial, having a soft, moist, and evidently sporulating layer during 
part of the study period, but were dry and evidently not releasing 
4 The material has not been chemically analysed, and is called silk because 
it is formed in threads and is white. 
