34 
Some Solitary Wasps of Texas. 
close by. Her work was not destined to go on smoothly, however, 
for hardly had five minutes passed, when a second individual (Ho. 
73) came strutting along bearing a large green caterpillar. Wasp 
Ho. 72 remained ignorant of the approach of her sister until the 
latter came somersaulting over a stick at which the former was 
working. A fight ensued, the two clinching several times and even 
drawing their deadly weapons. They then flew away and Ho. 73 
was the first to return. She took up her caterpillar, carried it to 
her nest, but returned to it, laid the caterpillar down, and pro- 
ceeded to carry out sand as usual. At 2 :02 Ho. 72 came back, 
while Ho. 73 was within her nest hidden from view, and was about 
to make off with the caterpillar which she found so handy. The 
rightful owner intercepted the thief, however, and in another duel, 
succeeded in recovering the purloined property. She then took the 
caterpillar up and carried it off for a distance of two feet, where she 
stopped to reconsider. It seems that the struggle for the recovery 
of the caterpillar must have reminded the wasp of the struggle 
to capture it, and that her next idea was to carry the caterpillar 
home, but she discovered her mistake in a moment. It certainly 
looked as though some such reflections were going on in the mind 
of the wasp. After hesitating a moment she turned around, carried 
the caterpillar back, laid it down at the entrance and hurriedly car- 
ried out only one mouthful of sand before dragging the caterpillar 
within. She then closed the nest in a slipshod manner and flew 
away at 2 :23. 
Ho. 72 returned and finished her nest without interruption where 
she had begun. By 6 :45 she had not yet returned with her prey 
and I feared that she would not, since it was already very cool and 
since there were chances of her having been hurt in the struggle. 
She brought home a caterpillar, however, as I found one in the nest 
several days later, though she did neglect to close the nest. I found 
both caterpillars in good condition (Fig. 17) but without an egg. 
It is possible that in the duel the mature eggs, ready to be laid, 
were lost. Thus affairs sometimes go wrong even with the brilliant 
Ammonhilae. 
It xs a significant fact Ammophila Ho. 72 picked up the 
stranger’s caterpillar and walked away with it when she did. She 
had not yet dug the nest and therefore, according to Fabre, the 
instinct to procure her prey should not have yet manifested itself. 
This author experimented on Sphex ichneumonea which places her 
grasshopper at the entrance to her nest and then runs in and out 
again before dragging it down. He took advantage of a moment 
