OF WASHINGTON', VOLUME XVII, 1915 157 



('. V. Rile}' took exception to this statement ;uxl in contradiction 

 s;iys: "Ph. punctatii* spins with its mouth, bracing itself nonius! 

 the part of the cocoon already formed while constructing the re- 

 mainder. The silk issues from the spinneret in a very perceptibly 

 liquid condition, but soon hardens, . . ." The employment 

 of the viscous secretion from the anus to aid in locomotion is in- 

 dicated on the preceding- page. 1 



This observation by Riley, of the employment of the labial 

 spinneret by the larva of Hy/x-ra in the construction of its cocoon, 

 is partly corroborated in a recent paper by Folsom, who says: 

 " The actual spinning is done with the mouth. . . . At inter- 

 vals the supply of silk fluid in the mouth gives out; then the larva 

 reaches back to the end of the abdomen and by an assiduous 

 process of nibbling secures a new supply of silk fluid from the 

 rectum, and resumes its spinning. This performance a 1 ways occurs, 

 and can be observed easily with a hand lens in the earlier stages of 

 cocoon-spinning. Riley and J. A. Osborne were each partly cor- 

 rect in their accounts of the spinning." 1 



These statements, finally, are again opposed by ('. X. Ainslie, 

 who is quoted by F. M. Webster as follows: ''Instead of spinning 

 the silk from a gland that opened into its mouth, as was supposed, 

 the fluid from which the silk is made is taken into the mouth ap- 

 parently from a gland in the caudal segment. The larva applied 

 its mouth to an opening or gland close to the anus." ? 



In conclusion may be mentioned an observation by Montandon, 

 recorded by Bourgeois, that the larva of Herpes porcelhis (Byr- 

 sopida3) makes a reticulate cocoon similar to that of l/n/xra and 

 composed of an anal secretion. 1 



The statements by Riley and Folsom, that the larva of HI//H ru 

 spins from a labial spinneret, should not be denied altogether. 

 But it appears certain to me that the bulk of the cocoon-forming 

 substance is produced from the anus and primarily from the mal- 

 pighian tubes. Perhaps the lesser supply from the silk glands has 

 some special function. Not improbably it is applied as a coating 

 over the coarser threads from the rectum, to make them insoluble 

 to water. I have noted that the larva passes its mouth along the 

 threads after they have been drawn out and put in place, and it 



1 Riley, C. V. Report of the Entomologist. Rept. ( Y in. Aric. for 

 1881 and 1882, p. 174, 175. 1882. 



2 Folsom, J. W. The insect pests of clover and alfalfa. Univ. Illinois 

 Agr. Exp. Stat. Bull. 134, p. 161. 1009. 



3 Webster, F. M. Preliminary report on the alfalfa weevil. U. S. 

 Dept. Agric., Bur. Ent., Bull. 112. 1912. (P. 23, quotes C. X. Ainslie.) 



4 Bourgeois, J. Contribution a I'cUude des metamorphoses de 1' Herpes 

 jxircelhts Lacord. Mull. Soc. Ent. France. 19f)i>, p. 94-9.~>. 



