1968] 
Matthews — Microstigmus 
31 
30 individuals of varying ages; he noted that the prey were frequent- 
ly dismembered, presumably by the wasps, but no such dismember- 
ment was noted for M. comes prey. 
Completed food masses (Fig. 10) averaged 1.2 mm in diameter 
and were firmly stuck to one side of the cell near its midpoint. In 
every case these food masses were of mixed species composition: 6 
species were found in 1 cell, 5 species in 10 cells, 4 species in 8 cells, 
3 species in 3 cells, and 2 species in 2 cells. Two of the six species, 
Lepidocyrtus sp. X and Paronella sp., comprised 70% of the prey 
sample (Table 2). 
The hunting behavior of M. comes was not observed. However, R. 
J. Snider (pers. comm.) states that, insofar as known, the species used 
as prey are all epigean and sun-loving; furthermore, all are brightly 
and distinctly colored and (except D euterosminthurus) possess scales 
which reflect in sunlight. These facts suggest that M. comes hunts 
primarily among low vegetation, probably in sun flecks, and relies 
upon visual cues in its search for prey. 
The sausage-shaped egg measures 1.4 mm long and 0.4 mm wide 
at the middle; it is draped over the food mass and attached by one 
end, the other end projecting free (Fig. 10). The egg is not laid 
until provisioning is complete; normally but one egg was found 
per nest (10 of 15 nests with eggs), but four nests had two eggs 
and one exceptional nest had 3 cells with eggs. 
Freshly provisioned cells are weakly closed with a rather haphazard 
crisscrossing fabric consisting of a few secreted strands. However, 
cells containing mature larvae, prepupae and pupae are open. Pre- 
pupae and pupae are always found oriented with the head in the 
bottom of the cell, the anus attached at the cell opening. As in most 
other known members of the Pemphredoninae, no cocoon is spun. 
The distinctive larva of M. comes is described elsewhere (Evans 
and Matthews, 1968). 
Nothing is known regarding the relative lengths of the develop- 
mental stages of M. comes. Attempts to rear eggs and larvae in 
gelatin capsules failed, probably due to dessication. However, sev- 
eral adults subsequently emerged from pupae in nests kept in covered 
petri dishes. Howes (1933) reports that eggs of M. guianensis 
hatch in two days and the larvae feed for one week, then pupate and 
emerge as adults two weeks later. 
Explanation of Plate 2 
Fig. 4. Microstigmus comes nest attached to underside of a Crysophila 
frond. Note nest entrance and doubly coiled pedicel. (Photo by C. W. 
Rettenmeyer.) 
