1941] 
Habits of Eucharidae 
61 
observation at Koiwai, Japan, showed a maximum para- 
sitization of 47 percent in a single nest in 1921. A total of 
approximately 10 million eggs, over 4 million of which 
were in a single tree, were deposited that season in an area 
about 100 yards square, yet in 1922 the resultant maximum 
parasitization declined to 16 percent. 
The study of the biology and habits of the Eucharidae was 
long handicapped by difficulties in associating the oviposition 
habits of the females with the immature stages in the ant 
nests. Sufficient is now known regarding the general habits 
of the family so that, in most cases, the infested nest can 
be found if a female can be found or captured or, if the 
infested nest from which adults are emerging is first 
found, the oviposition habit can be quickly determined. 
The females are intent upon oviposition immediately after 
emerging from the nest and, as they fly very slowly and 
can be readily kept in view, they can be followed and their 
method of oviposition observed. This normally takes place 
within 1 hour after emergence and often almost immediately. 
If adult females have been captured or observed, the host 
nest can be located without difficulty. These females are 
usually limited to a radius of not exceeding 50 feet from 
the nest, and they fly no farther than is necessary to reach 
a tree or plant suitable for oviposition. In many species 
the actual nest entrance can be detected by the swarm of 
eucharid males hovering over it. In other cases the size of 
the parasites greatly restricts the number of possible hosts, 
so a relatively small number of nests need be examined 
definitely to establish the association. Chalcura deprivata 
and Schizaspidia convergens of Ceylon and Kapala termi- 
nalis and Kapala sp. of Cuba are all parasites of Odonto- 
machus. A consideration of the size of the adults observed 
ovipositing in trees, and of the ant species present in the 
immediate vicinity, indicated that Odontomachus was the 
only one present of sufficent size to accommodate the para- 
sites. In each case the first nest that was excavated con- 
firmed the conjecture that this was the host. 
Habits and Development of the Immature Stages 
During the course of incubation the eggs change in color 
from the original translucent white to deep amber, this 
