1982] 
Peck — Life History of Ptomaseopus morio 
109 
Eggs were laid singly in the sand several cm to the side of the 
carrion. A mean of 13 eggs (N = 9, r = 9-16) were laid per female in 
6 days (N = 9, r = 5-8), and a new clutch was started after a 
refractory period of 6 more days (N = 8, r = 5-8). The eggs hatched 
in 5 days (N = 30, r = 4-7). Frequent adult attempts to fly and leave 
the culture containers after the egg clutch was laid may indicate that 
post-mating (for the male) or post-oviposition dispersal is normal, 
and that the adults are normally not present with their young. 
The larvae fed together under and directly on the carrion. There 
was no indication of parental attendance to, or feeding of, the 
larvae. The adults and larvae may feed on fly larvae or other insects 
associated with carrion in nature, but carrion alone is adequate 
for complete development of larvae in culture. There were 3 larval 
instars; the first lasted 1 day (N = 30, r = 1-2), the second 2 days 
(N = 30, r = 2-3). The third instar larvae fed for 7 days (N = 30, 
r = 6-9) before crawling away from the carrion and burrowing into 
the sand to form pupal cells. In total, over 300 larvae were pro- 
duced, of which about 50 were preserved for morphological study. 
Prepupae had a high mortality due to a fungal contamination. 
The prepupal phase seems to be about 30 days in duration (N = 7, 
r = 28-40). The pupal phase also seems to last about another 30 days 
before emergence of the adult (N = 2, r = 25-35). At culture 
temperatures the parental generation adults died by early Decem- 
ber, for a longevity of at least four months. This could be con- 
siderably different in the field depending on their sensitivity to cool 
fall temperatures and whether or not they overwinter as adults. 
Discussion 
There was no indication of any subsocial or other behavioral 
association between the larvae and the adults as known in Nicro- 
phorus. The brood size, reduced fecundity, and shorter larval 
developmental times are similar to those reported in Nicrophorus , 
but otherwise the life cycle characteristics are generally similar to 
those reported for the carrion-feeding Silphini (Balduff, 1935; 
Brewer and Bacon, 1975; Cole, 1942; Cooley, 1917; and Ratcliffe, 
1972). It should be noted that some Silphines appear to have derived 
feeding characteristics, being strict predators and phytophages. 
How this may have changed behavior and life cycle characteristics is 
not known. 
