WILLIAMS: LARRID^ OF KANSAS. 205 



I dug out this nest. It was a little more than one and one- 

 half inches long and terminated not quite an inch below the 

 surface of the ground. The tunnel was rather loosely packed 

 with soil down to the Melanoplus, which lay on its back, quite 

 immovable, its head toward the slightly enlarged end of the 

 tunnel. A long, pale greenish and somewhat curved egg of 

 Tachyspliex was fastened transversely across the prosternum 

 (fig. 117). 



The habits of this specimen typically exemplify those of 

 several other tarsatus observed. The tunnel, which is always 

 dug before the hunt begins, is left open while Tachysphex is 

 afield. It is of comparatively large bore, slightly inclined, and 

 not more than two inches long. As a rule, a single locust suf- 

 fices for one wasp grub in this species ; I have never seen more 

 than two acridians to one nest. Though more often the prey 

 is one of the Melanopli (immature), Qildipodinfe as well as 

 Tryxalinjp are also used. These are frequently placed imme- 

 diately before the burrow, which the wasp first enters, to 

 reach out again, seize the locust by the antennse and drag it 

 within. If the prey is quite small, and therefore not sufficient 

 food for the wasp's progeny, two are used, in which case the 

 tunnel may not be spacious enough to admit Tachyspliex and 

 victim together. 



This insect, among others, suffers considerably from the at- 

 tacks of a very small tachinid fly (Diptera), an exceedingly 

 quick and watchful creature, which deposits her own young 

 usually upon the food intended for the larrid grub, and as at 

 least some of the tiny maggots are found, immediately after 

 their deposition, on or near the wasp's egg, the latter is doubt- 

 less destroyed. Whilst a tarmtus was hunting, this minute 

 dipteron was seen to follow her closely, alighting near by when 

 the wasp rested, or poising directly behind her. The wasp's 

 first search being fruitless, she returned to the burrow empty- 

 handed. This seemed to suit the little fly, however, for she re- 

 mained near the revealed hole while Tachyspliex sallied forth 

 again, this time to meet with success. As she was nearing her 

 tunnel, astride her prey, a little fly flew out to meet and follow 

 her. At the hole were two other similar flies, evidently in a 

 state of excitement over the advent of the wasp and prey. The 

 owner, depositing the locust before the entrance, immediately 

 went within. At this juncture one of the tachinids alighted 

 for a second or less on the thorax of the paralyzed victim. 



