. 83 
it from grubs collected at Broad Brook and Orange, Conn., and at 
Hadley, Mass., and Mr. N. Criddle writes of it January 10, 1918, as a 
white-grub parasite in Manitoba, Can. In addition we have reared it 
from grubs of Aphonus pyriformis collected by D. J. Caffrey at Las 
Vegas, New Mex., and by Caffrey and G. W. Barber at Maxwell, New 
Mex. It was also reared by W. E. Pennington from unknown scara- 
baeid larvae collected February 17, 1916, in a decayed stump at Gaines- 
ville, Fla., and one adult was reared, which issued March 27, 1916. 
As with Microphthalma disjuncta, the grub is not seen to be para- 
sitized until the parasitic larvae are practically full-grown. The habits 
of the larvae and their effect on the grub are like those of disjuncta 
except that there is not the conspicuous liquefying effect on the grub 
(Pl. VI, Fig. 21), previously mentioned for that species. Apparently 
Fic. 17. Ptilodexia harpasa Walk., larva, lateral view; a, view 
of posterior ‘end, showing spiracles; b, a spiracle much 
enlarged. 
the eggs are laid in early fall and the small maggots enter the grub the 
same season, remaining within it over winter and completing their life 
cycle the following spring. From grubs collected at Chelsea, Vermont, 
May 8, maggots were observed from May 16 to 20, forming the puparia 
usually a few days thereafter. From grubs collected at Austin, Texas, 
April 29, Ptilodexia larvae were first observed from May 18 to June 18. 
In these cases adult flies issued between June 11 and July 10, the 
puparium stage varying from 20 to 32 days. Grubs collected in New 
Mexico May 10 and 24 showed parasitism from May 20 to July 7, while 
larvae from the same locality collected September 7 and confined in 
indoor cages showed parasitic larvae from October 7 to February 23. 
The number of larvae infesting a single grub varies from 1 to 7 and the 
average from our 50 examples is 2.3-++. 
