THE DESERT CORN FLEA-BEETLE. 17 
possible that it is occasionally picked up by birds, yet no definite 
observations have ever been made upon this, and the Bureau of 
Biological Survey has no records bearing upon this species, though 
related species have been found to be taken as food by certain birds. 
PREDACIOUS ENEMIES. 
The larvae of this beetle are without doubt fed upon by several 
subterranean larvae of ground beetles which have been found to 
inhabit the soil in the vicinity of corn plants. The adults are preyed 
upon by the nymphs and adults of Reduviolus ferus L. Mr. Wilson 
first took specimens of these nymphs, which be found feeding upon 
Chaetocnema adults, at Tempe, Ariz., and reared them to maturity, and 
then found that both adults and nymphs were feeding upon the flea- 
beetles. It is quite likely that other reduviids also attack this species. 
At Holtville, Cal., the writer found a great many beetles with their 
bodies almost covered by a species of mite: Upon being sent to 
Washington these mites . . 
were determined by Mr. V& $J 
Nathan Banks as Pedicu- s ■*. J\lj/C^ ^ — ^\ 
loides sp. They have since ( ^=^=1^. k(/\°SSi ^^^^ ) 
been found quite frequently \ X\Vvv4- / 
upon adult flea-beetles. ^^—^zz::^ — <f 
PARASITIC ENEMIES. ^ -^^^ ^^ 
During his observations J "" L " * //l?jv\ ^ = *~~ ,> 
in 1915, 1 the writer disco v- \ X~J J 
ered that a small parasitic Vy/f 
wasp, Neurepyris sp. 2 (fig. / \. 
7), was preying upon the 
J ~™ £ j."u:„ Fig. 7.— Neurepyris sp., a parasite of the desert corn flea- 
arvae and prepupae of this b J le Gr p e ; tly e p nlarged (0riginaI) 
flea-beetle. Six specimens 
taken in the soil, already within the pupal cases, were each found to 
have very small, insignificant external larvse feeding upon them, the 
larvae being attached to the ventral side just back of the hind pair of 
legs. These were carefully placed in small vials, and subsequently 
several of the parasites died, while one specimen pupated and finally 
changed to an adult, the hymenopterous larvae in the meantime 
having completely consumed the beetle larvae. 
The adult of this parasite is very small, black, with yellow legs, 
and its pupal case, which is about the size of a Chaetocnema pupa, 
is constructed in the soil of a brown, densely woven material. The 
larval stage of this parasite was found to be about 8 days and the 
pupal stage 24 days. This was during the month of May, with the 
mean temperature about 76° F. 
i At Tempe, Ariz. 2 Determined by Mr. S. A. Rohwer. 
