265 



poriferous system, and said it was fully developed only in the winged 

 viviparous forms; he therefore considered reproduction by wingless 

 females examples of true larval reproduction. Mr. Weed did not think 

 so much importance should be placed on wing development. He said 

 that lice born the same day might in some cases become winged and in 

 others not, but all would begin reproducing at the same time. 



Mr. Howard stated that the idea just advanced by Mr. Smith as to 

 the larval homology of wingless viviparous females of Aphididae had 

 been advanced more than once by European writers. 



]\Ir. Smith stated that his point was in proof afforded by the antennae 

 and not on the general arguments used by others to prove or disprove 

 maturity. 



Mr. Forbes said that in his studies of the plant lice he had found that 

 the poriferous system presented good specific characters. 



Mr. A. J. Cook had studied very carefully the antennal structure of 

 bees and believes that the differences in the development of their sense 

 organs can be fully accounted for on the theory of the survival of the 

 fittest. 



On motion of Mr. Weed the committee extended a cordial invitation 

 to all entomologists present to take an active part in the meeting. 



Mr. John Marten then read a paper reporting the results of observa- 

 tions and experiments upon the Hessian fly, made at the ofi&ce of the 

 Illinois State Entomologist during the year 1890, after which the com- 

 mittee adjourned to 10 a. m., Xovember 12. 



NEW NOTES ON THE LIFE HISTORY OF THE HESSIAN FLY. 



By Jno. Marten. 

 [Author's abstract.] 



From 1,000 "flaxseeds" collected March 13 and placed in large in- 

 sectary breeding cages stocked with wheat, imagos emerged from March 

 31 to May 1, the greater number about the middle of April. From these 

 were derived larvae and "flaxseeds" in growing wheat by the 9th of 

 May, males and females of this second spring brood appearing from May 

 28 to June 14. These insectary experiments were confirmed by field ob- 

 servations carried on as a check. Both in the field and in the laboratory 

 the tillers of the wheat were much more heavily infested than the orig- 

 inal stalk. 



Out-of door cages of wheat were stocked June 20 with "flaxseeds'' 

 from the above-mentioned second spring brood, but yielded nothing 

 until September 19, when imagos began to appear. This experiment, 

 paralleled also by field observations, was held to demonstrate lestiva- 

 tiou of the insect in the puparium. 

 22595— Xo. G 2 



