Wasps, Bees, and Ants 
5 DI 
to its prey by its shrill singing, pounces upon a cicada, paralyzes it by a swift 
stab, and then laboriously flies with or drags the heavy body to the burrow. 
This burrow may be a foot or even more in depth, usually consisting of a 
nearly vertical tunnel for 6 inches, with a sharply diverging nearly horizontal 
part as long as or longer than the entrance one. Sometimes instead of a single 
terminal cell there are several lateral cells, in each of which one or two cica¬ 
das are stored. Another familiar group of diggers are the spider-wasps, 
Pompilidae, mostly black or steely-blue with bluish or light-bronzy wings 
(PL XII, Fig. 13). This is a large family including a few guest-wasps 
(Ceropales) and a few mud-daubers or mason-wasps (Agenia), as well as 
true diggers, but all of the members of the family which make their own 
nests provision them with spiders. The giant tarantula-killer, Pepsis jor- 
mosa (Fig. 704), largest of all our wasps, belongs to this family. It is common 
in California and the southwest, where its sensational combats with the great 
hairy tarantulas (Mygale) are often seen. It does not always come off vic¬ 
tor in these fights, or at least conquers the tarantula only at the expense 
of its own life. After one such long and fierce battle I found both fighters 
hors du combat , the tarantula paralyzed by the wasp’s sting, but the wasp 
dying from the poisonous wounds made by the great fangs of the spider. 
It is a matter of much speculation how the digger-wasps find their nests 
again after carefully covering them and going off to search for caterpillars, 
spiders, bugs, or whatever are to be stored up for the larvae. The Peck- 
hams have made many interesting observations touching the problem, trac¬ 
ing carefully the movements (Figs. 705 and 706) and behavior of individuals 
Fig. 705. Fig. 706. 
Fig. 705.—Locality study of Cerceris deserta. (After Peckham.) 
Fig. 706.—Locality study of Cerceris deserta. (After Peckham.) 
after finishing a burrow and making ready to provision it. From these 
observations they conclude “that wasps are guided in their movements by 
their memory of localities. They go from place to place quite readily because 
