110 
occupied less than a minute, more than half an hour intervening 
between the two ovipositions. Now she straddled her exposed 
victim from different sides and brushed earth over it, and finally 
spread soil over the spot and smoothed it down. To make it 
firmer, soil was hammered down here, using her down-curved 
abdomen as a hammer, the point rapidly striking the soil, not by 
the muscularity of the abdomen, but through the leverage of the 
legs. This tamping occupied much time. 
I brought home the parasitized spiders and 
soon noticed a small hymenopterous larva on 
the Pompilus egg, (Fig-53). Where had 
the invader come from? If of the same habits 
as the parasitic Ceropales wasp noted by 
Adlerz (1903), the mother of the grub in 
question lays her egg when the chance comes 
in the field—when Pompilus has caught her 
spider and is proceeding homewards ie it. 
; Adlerz noted that Ceropales laid her egg in 
Fig. 53. Ventral view one of the breathing pores on the underside 
of spider’s abdo- of the spider’s abdomen. Here it cannot be 
men, showing the ¥ : ; 
smaller freshly rushed off as the spider us, dragged: to qilte 
hatched grub of nest, and_as it precedes the egg-laying of 
ee Oe Pompilus on this same spider, it hatches 
he, eae. Seen first, crawls out of its retreat, and consumes 
hatehed egg of the rightful egg and eventually the spider. 
Pompilus — analis. Thus, later on, when I had obtained several 
Enlarged. EE Bee iC wae ae a a 
: cocoons, some produced the smaller red 
Xanthampulex wasp and others Pompilus analis. 
Another enemy of Pompilus is a very small tachinid fly. One 
pe having seen a P. analis filling up her nest depression, 
I dug up the spider that afternoon and found on and about the 
wasp egg six little fly maggots, each perhaps one-third the bulk 
of this egg, which was soon eaten up and likewise most of the 
spider. The maggots then disappeared, to emerge fifteen days 
later as flies. 
The egg in P. analis has an incubation period of about two and 
a half days, and its wasp enemy Nanthampulex has the life cycle 
(egg to adult) of about thirty-five days, and of this the feeding 
period of the larva was found to be eight days. 
Psammochares luctuwosus (Cresson), a common black spider 
wasp of the United States mainland, and now plentiful in the 
Hawaiian Islands, though digging a separate burrow for each of 
her spiders, has a tendency to bury all these close together. 

