107 
These species are not as abundant nor apparently as wide-spread as 
our common tachinid (Cryptomeigenia theutis), but in some sections 
where they occur in sufficient numbers they are undoubtedly beneficial 
to a marked degree, especially as they most frequently attack the female 
beetles. Although these may lay a few eggs after being parasitized, 
our studies up to the present time indicate this to be the exception rather 
than the rule. 
We have never reared a parasite of Pyrgota, but Mr. E. G. Smyth 
has done so and has sent us two examples of the parasite, which were 
determined by Mr. S. A. Rohwer as a new genus and new species in 
Bethylidae. Mr. Smyth reared these from a Pyrgota undata puparium 
found in Illinois in 1914 by Mr. G. N. Wolcott, and writes that a number 
of the parasites issued from a single puparium. 
Tacuinip Fires 
In our studies three species of tachinid flies (Cryptomeigenia theutis, 
Eutrixa exile, and Biomyia lachnosternae) have been reared from May- 
beetles, and of these C. theutis is much the most common and wide-spread 
and seems to be the most beneficial of the parasites attacking the Phyl- 
lophaga adult. The three species can be readily distinguished in the adult 
and pupal stages by characters shown in the accompanying illustrations 
of the flies and the posterior spiracles of the larvae or puparia (Fig. 35, 
36, and 41-43). Two other species (C. aurifacies and Eutrixoides jonesii), 
which occur in Porto Rico, are briefly treated. 
CRYPTOMEIGENIA THEUTIS Walk. 
The first published record of the parasitic habits of this species is 
that of Coquillett (13), who reports it as having been reared by Theo. 
Pergande from an adult Phyllophaga inversa taken at Washington, D. 
C., May, 1892, the fly issuing Mar. 23, 1893. The species occurs gener- 
ally throughout the northern states east of the Rocky Mountains, and its 
distribution, according to published records and our own studies, in- 
cludes Toronto and Montreal, Canada; New Hampshire, Massachusetts, 
New York, New Jersey, District of Columbia, Ohio, Indiana, Michigan, 
Wisconsin, Illinois, Kansas, Mississippi, Virginia, and Tennessee; and 
Mr. Norman Criddle writes Jan. 10, 1918, that he has reared it from 
May-beetles collected in Manitoba, Canada. 
We have reared theutis only from Phyllophaga, including the 
species drakii (=grandis), fervida (=arcuata), fraterna, fusca, jutilis 
(= gibbosa), hirticula, ilicis, implicita, inversa, micans, rugosa, tristis, 
and vehemens, but the writer once observed it in the act of laying an egg 
on an adult Diplotaxis, and it is not unlikely that further study will show 
it to be parasitic on certain of the larger Diplotaxis and beetles of. re- 
lated genera which feed on tree foliage at night. The fly (Fig. 35), 
which is about the size of the common house-fly and superficially re- 
sembles it, is frequently seen resting on tree foliage at night. At La- 
fayette, Ind., we find it throughout the month of May, sometimes earlier, 
