YOUNG LARVAE OF VEROMESSOR PERGANDEI 
(HYMENOPTERA: FORMICIDAE: MYRMICINAE) 
By George C. Wheeler and Jeanette Wheeler 
Research Associates, Florida Department of Agriculture* 
Time was when it seemed every myrmecologist wanted to work on 
Veromessor pergandei, but we can find no mention of it in the last 
eight years of Zoological Record. When we lived with it in Death 
Valley and southern Nevada it became one of our favorite ants. 
To differentiate instars we would like the following specimens: a 
first instar inside an egg; a second instar inside a first instar that is 
ready to moult; a third instar inside a second ready to moult; etc.; a 
mature larva; a prepupa. Fortunately our V. pergandei material 
meets all the requirements, except the first. V. pergandei is poly- 
morphic, which presents another problem: when does subcaste dif- 
ferentiation begin? How can one tell whether a small larva is the 
young of a major or a mature of a minim; or whether a medium- 
sized larva is the mature of an intermediate worker or the half- 
grown larva of a major? In V. pergandei subcaste differences 
apparently begin in the fourth instar and are manifested only in size. 
V. pergandei presents another problem: there are two body 
shapes for mature worker larvae. We have no explanation for this. 
Vermessor pergandei (Mayr) 
Figures 1-6. 
Egg. Figure 1. About 0.32 X 0.52 mm. 
First Instar. Figure 2. Length (through spiracles) about 0.48 
mm. Entire larva feebly sclerotized. Body sac-like; head on anterior 
end and greater in diameter then thoracic somites. Spiracles about 
0.006 mm in diameter. No spinules nor hairs on body. Cranium 
subcircular in anterior view. Antennae represented by 2 sensilla. 
About 20 head hairs, 0.013-0.025 mm long, unbranched. Mouth 
parts small. Labrum with a ventrolateral swelling on each half of 
anterior surface; 2 or 3 sensilla on each half of ventral surface. 
Mandibles subtriangular; apical tooth straight and sharp-pointed; 
♦Mailing address: 3358 NE 58th Avenue, Silver Springs, Florida 32688 
Manuscript received by the editor June 4, 1987 
303 
