110 
live May-beetles. In some cases the flies issued the year they killed the 
beetles, but most of those forming puparia in the spring of one year did 
not issue until the spring of the following year. From this and other 
data it is certain that under natural conditions the flies normally have 
a one-year life-cycle. In our cage experiments flies began to issue soon 
after the cages were removed from their winter quarters, that is about 
April 20, and continued to issue until early in May. These dates are 
somewhat earlier than is normal out-of-doors, the first emergence of 
flies usually being coincident with or shortly after beetle emergence, 
which in the latitude of Lafayette is, as a rule, the last few days in 
April. It would appear that both sexes of beetles are attacked indiffer- 
ently, since the number of male and female beetles from which the flies 
are reared is almost exactly the same. From one to seven larvae may 
develop in a single host, although we have never reared to the adult 
more than five from one beetle, and the average of the 134 examples 
observed in 1916 is 2.8 larvae to each beetle. 
C. theutis seems to be parasitized by a very interesting hymenop- 
terous parasite (Lepidopria aberrans Brues). At Hagerstown, Md., 
‘August 15, 1913, Mr. J. A. Hyslop, of the Bureau of Entomology, found 
a dead female Phyllophaga inversa containing two dipterous puparia, 
which agreed with those of C. theutis. Each puparium showed two 
minute holes, and when opened one contained the shriveled remains of 
a fly and the other the fragments of an apterous hymenopteron which 
was determined and described by Mr. C. T. Brues as the above- 
mentioned species (10). We have occasionally found puparia showing 
minute holes, but have never found the parasite which was presumed 
to have made them. 
CRYPTOMEIGENIA AURIFACIES Walton 
This and the following species have been reported as parasites of 
Phyllophaga adults in Porto Rico but are not known to occur in the 
United States. C. aurifacies (Fig. 38, 39) was described and first 
recorded as a parasite in 1912 by Mr. W. R. Walton (80), and was 
later reported by Mr. D, L. Van Dine (78) as bred from beetles collected 
in several localities in Porto Rico. It is closely related to our common 
C. theutis, but may be distinguished from that species by the dorsal 
vittae of the thorax, which are distinctly velvety black, these markings 
being indistinct brownish in theutis; likewise the sides of the face of 
aurifacies are distinctly golden yellow pollinose, the face of theutis being 
gray. 
EuTRIXOIDES JONESII Walton 
A second tachinid parasite, not known to occur in the United States, 
was bred from Phyllophaga adults in Porto Rico by Mr. T. H. Jones in 
1912, and the species described by Mr. Walton in 1913 (81). Although 
closely related to our American May-beetle parasite, Eutriva exile, it is 
distinguished, according to Mr. Walton, by the remarkable development 
of the ovipositor (Fig. 40), and in the male by its much narrower front 
and face. 
