392 
Psyche 
[December 
tially eaten bodies of isopods, where larvae actively feed. Since 
Wheeler (1918) states that the larvae of North American Ponerinae 
feed on food placed on their ventral region, or on insect parts placed 
near them (observed in L. elongata; 1910), it is possible that several 
methods of feeding are present in the same species. However, an 
alternative function of the ridged structure is a holdfast. When not 
feeding, larvae typically curve their “necks” so as to rest the ventral 
surface of the prothorax or the posteroventral surface of the head 
against the ridged structure. Perhaps posteriorly pointing spinules 
hook on the ridges, allowing the larva to maintain the resting position 
with minimum effort. 
The most advanced specializations for holding food are found in 
the Pseudomyrmecinae and the Camponotini. Many larvae of the 
Camponotini possess a well developed pocket for holding solid food 
called a praesaepium (Wheeler and Wheeler 1953). It is best deve¬ 
loped in Colobopsis as is evident in C. pylartes. In both Campono- 
tus rasilis and C. pylartes the posteriorly pointing spinules on the 
anteroventral region may function to force the food against the 
posterior wall of the praesaepium (the posterior wall in Colobopsis 
is the large ventral welt). This is supported by illustrations of a food 
pellet held in the praesaepium of C. gasseri (Forel) (Wheeler and 
Wheeler 1970). 
The “food pocket” is most highly developed in the Pseudomyrme¬ 
cinae and is called the trophothylax (Wheeler and Bailey 1920; 
Wheeler and Wheeler 1956). The spinules in the trophothylax are 
positioned to help hold food in it, although this assistance may be 
unnecessary. 
Specialized feeding regions are also described in larvae of other 
social Hymenoptera, including the transitory praesaepium of allo- 
dapoid bees and some vespids, and the shelf of Mischocyttarus 
(Vespidae: Polybiinae) (Wheeler and Wheeler 1979). We thus 
assume that morphological adaptations for holding food on the 
ventral region have evolved independently in numerous taxa within 
the social Hymenoptera. 
In conclusion, the various morphological specializations in the 
feeding regions of ant larvae are analogous, although not always 
homologous. Thus, 3 basic types of feeding regions are evident. The 
first is the “food basket” of larvae of some Myrmicinae, in which the 
specializations are in the arrangement of homologous groups of 
