1957] Brown — Predation of Arthropod Eggs 115 
Predation of Arthropod Eggs by the Ant Genera Pro- 
CERATIUM AND Discothyrea. — In my recently published 
revision of the genera of the ant tribe Ectatommini (Brown, 
1958, Bull. Mus. Comp. Zool. 118: 246, 252-253, 336) I noted 
briefly observations indicating that North American spe- 
cies of Proceratium Roger (including Sysphincta auct.) 
normally feed on various arthropod eggs, and that such 
eggs are often stored in their nests in large numbers. One 
of the nests observed to contain eggs was collected by E. 0. 
Wilson and myself at Ravenel, South Carolina, during June, 
1957. This nest was packed with spherical eggs (and a few 
smaller fusiform ones) ; we assumed that they were eggs of 
geophilomorph centipedes or spiders, both of which were 
abundant in the leaf litter and rotting pine bark from which 
the ant nest was taken at the base of a large loblolly pine. 
This nest was maintained for one year in a glass-topped 
plaster ant-chamber, during which time it subsisted entire- 
ly or nearly entirely on eggs (more rarely on soft, hatching 
spiderlings) of various species of spiders gathered in east- 
ern Massachusetts. Larvae of other ants, and parts of other 
insects, were ignored by the Proceratium so far as observa- 
tions went. Spider eggs were stored in the brood chamber 
and in adjoining chambers. In feeding on the eggs, the work- 
ers and queen hold the egg against the floor with their fore- 
legs and cut through the shell, immersing their mandibles 
in the egg contents. Partly deflated eggs are placed on the 
larvae, which feed directly. 
My speculation that the similar genus Discothyrea might 
also feed on eggs of other arthropods now tends to be con- 
firmed by an interesting find by Philip F. Darlington, who 
has collected four nests of Discothyrea bidens Clark (or 
near) in the Mt. Royal Range, near Barrington Tops, north- 
eastern New South Wales, during October, 1957. Each nest 
contained numerous eggs of arthropods: spherical eggs (of 
spiders or Chilopoda?) from about 0.08 to 0.26 mm. in dia- 
meter, and fewer elliptical ones in two of the nests, averag- 
ing 0.17 X 0.08 mm. In the alcohol, none of the larvae is 
attached to eggs, but the circumstances leave little doubt 
that the eggs were being stored as food. — W. L. Brown, Jr.. 
Museum of Comparative Zoology. 
