66 
Psyche 
[June-Sept. 
form cocoons prior to pupation, the remains of the host 
prepupa or pupa are found as a deflated envelope upon which 
the parasite pupa lies. There is no crumpling of the remains 
into a mass, and the parasite pupa occupies the same position 
as that previously held by the feeding larva. However, the 
remains of Odontomachus pupae which have died as a result 
of attack by Chalcura deprivata or Schizaspidia convergens 
are found in a crumpled mass at the posterior end of the 
cocoon. In these species the mature larva is capable of only 
feeble muscular contractions, although these may be suffi- 
cient to push the host remains into the position mentioned. 
Incomplete information indicates that all Eucharidae nor- 
mally develop as solitary parasites, though the quantity of 
food material available may be sufficient to bring several to 
maturity. In a number of species it has been noted that an 
occasional host cocoon contains two parasite individuals, 
one on each side of the parasitized pupa. Thus the solitary 
habit is not obligatory, though the number of exceptions to 
this habit is small when compared with the number of host 
larvae which bear several planidia. 
Endoparasitic Development in Orasema 
One of the most surprising of the recent discoveries in the 
biology of the Eucharidae is the endoparasitic mode of de- 
velopment of two species of Orasema (Wheeler & Wheeler, 
1937). The first-instar larvae, both unfed and fully dis- 
tended, of 0. sixaolx W. & W. and 0. costaricensis W. & W. 
were found within the bodies of different sized larvae of 
Solenopsis tenuis Mayr and Pheidole flavens Roger var. in 
Costa Rica. They had evidently entered the host bodies by 
direct penetration of the skin and remained there with the 
posterior segments of the abdomen protruding from the 
entry hole. The fully distended planidia were found to lie 
with the dorsum immediately beneath the host skin, rather 
than free in the body cavity. The posterior portion of the 
body of these individuals is enveloped by a “collar” which 
projects inward from the periphery of the wound. This 
formation is apparently identical in origin with the respira- 
tory funnel of the Tachinidse, but its function is not so 
