STUDIES ON PERILLUS BIOCULATUS FAB. 99 
Blake, which is found in Minnesota, has been reared from the cells 
of a bee, Nomia patteni Cockerell. A species which occurs in Texas 
has been reared from the nests of the mud dauber, Chalybion caeruleum 
L. A species in Europe is said to be parasitic in the nests of bumble 
bees. In recent years several species have been found to be parasitic 
on the tsetse fly, Glossina morsitans Westwood, in Africa, and are 
‘therefore of considerable economic imporance. 
The Mutillidae are to be found in all parts of the world but are 
much more numerous, both in individuals and species, in the arid and 
semiarid regions of the tropics and subtropics. In the United States 
the species are especially numerous. in the southwest. As one proceeds 
northward the number becomes less and less, so that comparatively 
few species are known from Canada. It has therefore been somewhat 
remarkable to find 22 species of Mutillids in one year’s collecting for 
Minnesota, and it is probable that other forms yet remain to be found. 
Prior to 1918 no species of Mutillidae had been definitely recorded 
from Minnesota. Washburn (1918) lists eight species of Mutillidae 
as occurring in Minnesota but gives no definite dates or localities for 
any of them. Four of these records, Dasymutilla ferrugata F., D. 
macra Cresson, D. vesta Cresson, and Mutilla (Sphaerophthalina) 
mutata Blake, are misidentifications. These species, so far as known, do 
not occur in Minnesota. The specimens of Mutillidae from which the 
figures in Professor Washburn’s paper were made have been examined 
and their synonymy cited under the correct specific name. The present 
material included 22 species representing four genera, as follows : Pseudo- 
methoca, 3; Dasymutilla, 16; Timulla, 2; and Ephuta, 1. No doubt a 
number of other species will be found to occur in the state when collect- 
ing has been done in other localities. The following notes are intended 
only as a preliminary survey of the family as it occurs in Minnesota, 
and as an aid to the further investigation of these interesting wasps. 
Two male Mutillids are described here which occur commonly 
throughout the United States east of the Rocky Mountains, and which 
have heretofore been confused in collections with other species. A more 
detailed study of these two species and several related forms which 
bear a superficial resemblance to them must be made before the average 
worker will be able to identify any of them with certainty. This is 
especially true of castor Blake, fenestrata Lepeletier, agenor Fox, and 
several undescribed species. It is the intention of the writer to treat 
these in a future paper. 
