THE GREEST JUNE BEETLE. 35 



There is no doubt that the female wasp often crawls into the bur- 

 rows and deposits her eggs on the larvae, while on other occasions she 

 may drag and fly about with small larvae until she finds a hole or 

 makes one herself. It has been stated by certain entomologists that 

 wasps of the family Scoliidae are not known to have the power of 

 building nests or of transporting their prey to them for their car- 

 nivorous larvae, in this respect differing from many other solitary 

 wasps such as the cicada killer {Megastizus [Sphecius] speciosus 

 Dru.) , whose habits are well known. On the other hand, J. B. Smith 

 has written that they burrow into the ground in search of white 

 grubs, in which they lay their eggs and on which their larvae develop. 

 That this habit is true of I), dubia was proved by additional observa- 

 tions conducted in 1916 at Hampton and Diamond Springs, Va., 

 where the wasp was observed entering openings of the burrows. 

 Many dead larvae were in evidence at the openings, indicating that 

 the wasp larvae had fed on them. 



It is worthy of note that the presence of the grubs of this species 

 might have escaped notice on the grounds of the Department of 

 Agriculture were it not for the unusual appearance of the wasp 

 parasites Discolia dubia. which were noticed first in 1897 and for 

 many years thereafter. During a period of 15 years there was no 

 evidence of attack by the larvae of the June beetle in Iowa Circle, a 

 little more than a mile north of the affected patch in the department 

 grounds. 13 Both are heavily manured each spring and the Iowa 

 Circle grass is kept moist by constant use of a hose during the 

 warm season. This may account for the discovery made September 

 10, 1916, that the ground was almost honeycombed with the holes 

 made by the grubs on the latter grounds, a fact which would have 

 entirely escaped notice had not the wasp Discolia dubia drawn at- 

 tention by disappearing entirely in the earth. Upon examination 

 numerous holes were found wherever there were heaps of earth, and 

 these were at intervals of no more than an inch. 



MISCELLANEOUS. 



There are no doubt many other predacious insect enemies of the 

 white grub under consideration but they have not been reported. 



Two individuals of Scarites subterraneus Fab. were observed in the 

 District of Columbia, May IT, 1914, associated with larvae of Cotinis 

 nitida, which was said to be injurious to iris. 



In the control experiments at Norfolk, Va., where flowerpots and 

 troughs were used, a carabid or ground-beetle, Cychims elevatus Fab., 

 a nocturnal sandy-looking spider, and the northern mole-cricket 



13 A parallel ease may be cited for the yellow-necked flea-beetle {Disonychu meUieoUis 

 Say), which, was found one year in great abundance at Iowa Circle, in Washington, D. C, 

 and very rarely in the department grounds on the same food plant. 



