252 



they are closed, first, by a lining- of silk, tbeu by a thickened layer of 

 the glue, and finally by silk wliich gives this median portion of the co- 

 coon, inside, a paler coloring than the rest. In the cocoon of Bernhea 

 oh.soJotufi, which I have received from Mr. Coquillett from southern Cal- 

 ifornia, and which is composed of agglutinated sand, these perforations 

 are smaller and in a single row of seven or eight encircling the middle, 

 but they have a similar structure. 



The larva remains unchanged in this cocoon over printer, and trans- 

 forms to the pupa state in the spring, shortly befoie the appearance of 

 the mature insect. The pupa (Fig. 36 h, c. ) resembles the mature insect in 

 general ai)pearance,l)iit, as in all such cases, is soft-fleshed and whitish 

 in coloi-. It rapidly hardens and changes to the dark color of the imago, 

 which is ready in a few days to gnaw its way out 

 of the pupal cell, and, passing through the bur- 

 row mad(^ by the perfect insect the previ<nis year, 

 begins again the cycle of existence which its 

 emergence has just <;omplete<l. 



This, as I said before, will serve as a type of 

 the development and life history of the other fos- 

 sorial wasps, although they difler greatly in the 

 style of burrow and form of cell which they make 

 to protect their future progeny, and in the char- 

 acter of the food with which they provision such 

 cells. A most interesting article could, in fact, 

 be written on the habits of these different species, 

 some of which use spiders of various kinds, in- 

 cluding Tarantulas, while others use various soft 

 larvte, especially those of a Lepidopterous nature. Those who are 

 interested in further details on the subject will find a popular exposition 

 in the first volume of the American Eniomologisf^ written mainly by my 

 associate on that jouriml, the late B. D. Walsh. 



If man could do what these wasps have done from time iumiemorial, 

 viz, preserve for an indefinite period the animals he feeds on by the sim- 

 ple insertion of some toxic fluid in the tissues, he would be able to rev- 

 olutionize the present methods of shii)ping cattle and sheep, and to 

 obviate much of the cruelty which now attends the transportation of 

 live stock and mu(;h of the expense involved in cold storage. 



Fig. 38. — a, cocoon of Splieciu.s 

 natural size ; 6, enlarged 

 section of poi'c (original). 



