26 
BULLETIN 124, U. S. DEPARTMENT OF AGRICULTURE. 
The malachiid beetle, Collops vittatus Say (fig. 18), is rather 
numerous in the alfalfa fields of Arizona and was suspected of bear- 
ing some relation to Eurymus. 
Mr. T. Scott Wilson found both 
adults and larvae feeding upon 
pupae of the alfalfa caterpillar. 
He observed as many as 20 beetles 
feeding upon as many pupae in a 
single day. This beetle seems to 
feed upon either live or dead 
Eurymus larvae and pupae and does 
not appear to have much choice 
between the two. It attacks a pupa 
or larva and, piercing it, sucks 
the juices that exude. In this way 
a hole is gradually made in the 
host, which, of course, is killed. 
Being small, the beetle does not 
consume much of its prey, but 
wanders off, and the next time it 
is hungry it attacks a new pupa or 
larva and thus kills many. Larvae were taken in the act of feeding 
upon Eurymus pupae, placed in vials, and reared to adult Collops. 
Two species of ants, Pogonomyrmex harbatus Smith and Ore- 
mastogaster lineolata Icevius- 
cula var. clara Mayr ( ? ) were 
observed to attack Eurymus 
larvae and kill them. Several 
species of robber flies have 
been observed to catch the 
adult butterflies and feed 
upon them. The writer took 
Proct acanthus milbertii 
Macq. with a butterfly in its 
claws, and Mr. H. E. Smith, 
at Koehler, N. Mex., observed 
the butterflies being carried 
off by Stenopogon picticornis 
Loew (fig. 19). 
A FUNGOUS ENEMY. 
Pig. 18. — Collops vittatus, a beetle that 
preys upon the alfalfa caterpillar 
Greatly enlarged 
(Original.) 
Fig. 19. — Stenopogon 
that preys upon 
quite natural size. 
picticornis, a robber fly 
alfalfa butterflies. Not 
(From C. N. Ainslie.) 
A fungus was found to at- 
tack the pupae in the Salt Eiver Valley in 1912. This is sometimes 
quite common, but never abundant, although more prevalent about 
August than at other times, probably owing to higher humidity. Dr. 
