54 INSECT BEHAVIOR 



In each cell a stumpy, slightly bowed egg is laid, two and a half 

 millimeters long and a third as wide. It is yellow in the center, 

 fading to a transparent white at either end. The yellow center is in 

 reality the young wasp, and the transparent end, the extremities of the 

 film-like egg shell. The eggs are laid one at a time, that is to say, 

 the wasp deposits in one cell, waits for it to hatch, then provides the 

 young with sufficient food to bring it to maturity and plugs the cell 

 with moss before laying the second egg. 



Its chosen prey is doubtless small caterpillars, for I found three 

 uneaten heads in a cell containing a full-grown larva. The egg is 

 attached to the roof of the cell by its posterior end near the back, and 

 hangs downward. Thus the young wasp hatches with its head in 

 mid-air. 



The mother wasp guards her cells closely during the period of 

 incubation, often resting within the cell containing the new laid egg. 

 She crawls to the entrance on the roof of the nest, then turning round, 

 backs in, clinging to the underside of the roof. Her head peering 

 out, with its antennae waving here and there, adds to the illusion of 

 the nest being the shell of a snail. 



The two nests on which this life history is based were found on 

 May 14, in the deep forest. One of them I lost, but let us go back 

 to that day and the remaining nest. If I leave it upon its swaying 

 air-root for further observation, I will probably never find it again. 

 It blends perfectly with the emerald surroundings, a tiny object in a 

 part of the forest that I have visited but once. Therefore I will 

 carry it home to the laboratory just as it is, and put myself in diffi- 

 culties at once. 



The first cell contains a full-grown larva and the second is empty, 

 save for a single, freshly deposited egg. The larva is quite satisfac- 

 tory. It has finished its meal of caterpillars and will soon pupate, 

 giving me much desirable information and no trouble. But what of 



