98 NINETEENTH REPORT STATE ENTOMOLOGIST OF MINNESOTA—IQ22 
side there is a small area of oak woods, and within a mile there are 
stands of oak and other trees. 
The Bembicids which were found so abundant belonged to the 
species Bembix pruinosa Fox, and Microbembex monodonta Say; the 
Sphecids were mostly Sphex argentatus Hart; while there were 17 
species of Mutillids. Mutillids were so numerous that 625 specimens 
were collected in eight hours. About 2500 specimens were taken here 
during the season. Considering the abundance of the Mutillids, and 
the enormous number of Bembicids in this situation, it would seem 
probable that at least some of the species of Mutillids were para- 
sitic in the nests of the Bembicids. While this assumption is entirely 
hypothetical, no other species of insect appeared to be numerous enough 
to furnish host material for such a large number of Mutillids. It 1s 
hoped that during the season of 1923 some definite information can 
be obtained regarding the life history and habits of the Mutillids in this 
sand dune area. 
The female Mutillid wasps at once attract attention, when seen, 
because they are wingless and their bodies are covered with velvety 
pubescence. The lack of wings gives them much the appearance 
of ants and they are therefore commonly known as ‘“‘velvet-ants.” 
The females are usually seen when running around over bare ground 
and it is seldom that more than one is seen at a time. The males, which 
are winged, may often be found visiting flowers, from which they 
secure nectar. Both sexes are fond of sweet liquids and occasionally 
are found in considerable numbers on plants where aphids are present, 
where they congregate to partake of the honeydew which the aphids 
excrete. Under such circumstances as this, and the conditions which 
existed in the blowout described above, Mutillids may sometimes be 
collected in large numbers. The female Mutillids have the reputation 
of possessing very painful and severe stings. One species in the 
southern states has received the name “cowkiller” on this account. In 
collecting female Mutillids at the sand dunes it was found that large 
numbers could be collected only by picking them up with the fingers 
and placing them in the cyanide bottle. This necessitated vettiny stune 
occasionally, but experience demonstrated that their sting was no more 
painful than the injury caused by pricking one’s finger with a sandbur, 
so that getting stung occasionally came to be regarded as a more or 
less annoying, but not painful experience. 
For the most part, these wasps are parasitic in the nests of solitary 
wasps and bees, but the actual hosts for the various species of Mutillids 
are known in only a comparatively few cases. Psecudomethoca sanbornii 
