200 
Psyche 
[Vol. 92 
deformed if they emerged from eggs which had developed at 23° C, 
and suggested that they should be reared at lower temperatures. 
These results provide support for the suggestion presented above 
that the relatively high laboratory temperatures, with occasional 
fluctuations to near 30° C, was primarily responsible for decreased 
survival of larvae in this study. 
It seems apparent that females of M. venustula mature only a 
single egg at a time. In laboratory cultures eggs were laid at an 
average rate of about 1 every other day per female, though rarely 2 
eggs were produced by a single female in a 24 hour period. These 
averages were taken under the assumption that all females in the 
cultures were equally successful at maturing eggs, an assumption 
that cannot be evaluated further. However, eggs are relatively large 
(.45 mm average length compared to a maximum adult length of 2.2 
mm). Therefore, a substantial investment of a female’s energy 
resources are put into egg production, especially so when one con- 
siders that an average of 12.1 eggs were produced per female over a 
26 day period (most in 17 days, see fecundity above). The fact that 
females were able to mature eggs at this rate suggests that they were 
receiving adequate nourishment from the food and fungal hyphae 
on which they fed. This is not to suggest, however, that these egg 
maturation rates can uncritically be assumed to represent those 
rates under natural conditions. Still, they must reflect natural ovi- 
position rates at some level. 
Time of oviposition, developmental rate of preimagos, and adult 
longevity suggest that M. venustula may be multivoltine with poten- 
tial overlap of generations under natural conditions. 
One of the most interesting findings of this study is that at least 
adults, and probably larvae also, will actively feed on fungus myce- 
lium and appear to get a significant proportion of their nutrition 
from this resource. It is not possible to infer from available evidence 
that individuals of M. venustula are primarily fungus feeders under 
natural conditions. However, several lines of circumstantial evi- 
dence, in addition to observations of adults grazing on fungus myce- 
lium, suggest that these beetles have feeding habits somewhat 
different from most other aleocharines. These include: 1) other 
aleocharine adults kept in culture under conditions similar to those 
of M. venustula showed no inclination to graze on fungus myce- 
lium; 2) cannibalism of eggs or dead adults did not occur in cultures 
of M. venustula as it did in other cultures of aleocharines, suggest- 
