122 Psyche [August 



hairy tubercle-like process. The insect is rather sparsely pubes- 

 cent. The female, Figs. 3 and 5, averages about 5 mm. long and 

 is polished and only slightly and delicately punctate. The head 

 is blackish, or at least darker in color than the reddish to brown- 

 ish black body. The thorax is long and slender and constricted 

 into three subequal portions. The abdomen is petiolate and conic- 

 fusiform. The legs are long and the insect nearly devoid of 

 pubescence. Sharp states that this sex might well be taken for 

 an ant, and this certainly hold true for our own species, which in 

 the field superficially resembles a Formica, and to my mind ap- 

 proaches F. schauffusi more than any other species in the neigh- 

 borhood. But Methoca possesses curved and not elbowed antennae, 

 and her conically pointed abdomen has a rapid and distinctive up 

 and down movement. Locomotion is swift and more or less jerky 

 and zigzag. 



Prior to 1903 nothing appears to have been published concerning 

 the biology of the genus. In July, 1903, Adlerz observed a female 

 M. ichneumonides literally place itself in the open mouth of a 

 Cicindela larva, which seizing her, was instantly paralyzed by a 

 sting in the neck from the active wasp. Subsequently Adlerz 

 witnessed this procedure many times by placing Methocas with 

 Cicindelid larvae in a large glass vessel containing hard-packed soil 

 in which the larvae had excavated their trap burrows. The activi- 

 ties of Methoca in this connection were somewhat as follows: 

 When the tiger-beetle larva had closed the entrance to its bur- 

 row by means of its horizontally placed head and thorax, Methoca 

 was seen to run around the insect and at a suitable moment place 

 herself on this animated lid. Instantly Cicindela raised its head 

 to seize the wasp in its forminable, sickle-shaped jaws, but the 

 upward movement of the head exposed its soft neck to the im- 

 mediate and paralyzing sting of Methoca. When her venom has 

 taken full efl^ect she slides down into the burrow, indulges in further 

 stinging and malaxation, drags her prey further down, fastens her 

 long white egg behind one of the posterior coxae and completes her 

 work by filling up the hole and carefully disguising its location. 

 If the Cicindela larva is not at the top of the hole Methoca plunges 

 boldly in and does not reappear until she fills up the burrow.^ 



1 It may be remarked here that the large spider wasp, Pepsis formosa of the west does not 

 always vanquish the hairy tarantula when the latter is on the surface of the ground but kills 

 it as well when in the depth of its burrow. Judging from the manner in which Pepsis 

 plunges into hole after hole — as 1 have observed in western Kansas — it seems not improbable 

 that the tragedy more commonly takes place underground. 



