402 
Psyche 
[December 
(Bussart 1937, Walton 1914). Walton suggests that the function of 
this structure is to hold the host in place as the larvapositor is forced 
through the beetle’s elytra. These ovipositor opposing structures of 
Celatoria and Catharosia probably represent convergent evolution 
of organs serving similar functions but located on different 
abdominal segments. 
Catharosia was found to parasitize both adult and nymphal 
mydochine bugs, but parasitoids only emerged from adult hosts. 
One fifth instar L. diffusus nymph collected in the field yielded a 
Catharosia after the bug had molted to an adult. All other 
Catharosia obtained from field collected hosts were reared from 
hosts collected as adults. 
In laboratory reared flies. total development time from first 
mating of parent flies until adult progeny eclosed averaged 23.5 days 
(SE = 1.15, Range = 18-29, N = 15). These data agree with the 
observed development time of the parasitoids reared from field 
collected hosts. 
The position of Catharosia larvae within the host was determined 
Figure 1. Scanning electron photomicrograph of ventral abdominal surface of a 
Catharosia sp. female showing heavily spined plates on 4th sternum. 
