12 
Psyche 
[March-June 
Figure 6. Ventral dissection of gravid female Ululodes mexicana, show- 
ing normal ovarioles (O e ) and those specially modified for the production 
of repagula (Or). 
by their repagula were unassailable by any species of ant, even 
large 5mm) Formica sp. (see Table 1 ) ; on the other hand, 
unprotected eggs were quickly discovered and carried old by all ant 
species tested. Ants ascending the twigs and touching the repagula 
with their antennae would immediately and violently withdraw, 
occasionally falling to the ground. An intense period of antenna- 
cleaning, lasting from 15 to 60 seconds, always followed such con- 
tact. Experiments under laboratory conditions using the exotic 
Brazilian ant Monomorium sp. (2 mm long) indicated that con- 
tact with one repagulum alone was sufficient to discourage an ant 
from ascending the twig. Artificial “repagula” made from short 
