251 



from 1 j to '2 iuclies in U'ii.i;tli, and is nearly \\ hite in color. The head 

 and mouth i)arts (Fig. oG e,J\ y) are remarkably well developed for a 

 llymenopterous larva. The cocoon is constructed very rapidly, not 



Fig. ;!6. — Sphecivs speciostts : a, larva; 6, pupa from below ; c, aaiuc, from side — natural size; <■. liead of 

 larva; /, labium of same: (f, maxilla of sajiie— (>nlars:oil (original). 



more than two days being required for this purpose. The hirva in the 

 act of constructing its cocoon is shown in Fig. 37. The cocoon at 

 first consists of an open cylinder, the ends of which are ultimately 

 closed. It is constructed of earth, Avith enough silk incorporated to 

 make a rather dense 

 bod}-. About th<^ - - _ — .-~.'^^- ^ _- .>,^-.v 



middle of the cocooi 1 

 are a number (about 

 a dozen) of very 

 curious pores (Fig. 

 38) aud these have, 

 so far as I know, 

 never before been 

 observed or de- 

 scribed in the co- 

 coons of any other 

 fossorial wasps, aud 

 their use can only 

 be surmised. 



In the completed 

 cocoon they are cap- 

 ped on the inside, but during construction they must have been open 

 and afforded a means of entrance for air, for ventilation, and respira- 

 tion. They are placed in two irregular rows on one side of the cocoon 

 and rise like minute tubercles with a truncate rim somewhat above the 

 general surface exteriorly. They are composed of a glue-like substance 

 and i)euetrate the wall of the cocoon, broadening to the inside, where 



'^>s.i\£, 



Fig. 37. — Larva of Siihecius spinning its cocoon — natural size (oriijinal). 



