584 ENTOMOLOGICAL NEWS. [November, 



Identity of Hemaris tenuis Grt. and 

 Hemaris diffinis Bdv. 



By ELLISON A. SMYTH, JR.. A. M., 



Virginia Polytechnic Institute, Blacksburg, Va.* 



The existence of seasonal dimorphism in many species of 

 butterflies and moths has been so well established that it will 

 excite no great comment to announce the completion of ex- 

 periments in breeding, whereby the fact has been established 

 by me that Hemaris tennis Grt. and Hemaris diffinis Bdv. are 

 seasonal forms of one species, their relation being the same as 

 that already proven in the allied and distinct species Hemaris 

 rufieaudis and thysbe. 



Tenuis is the spring form from wintering pupae and diffinis 

 the mid-summer form from eggs of tennis. 



On September gth, 1896, I obtained two sphingid larvae from 

 Triosteum pcrfoliatum, one of the Caprifoliaceoe. One of these 

 died in the pupa during the winter ; the other disclosed, on 

 March igth, 1897, an Hemaris with white-yellow patagiae, 

 light greenish-yellow thorax, black upper abdomen, last ab- 

 dominal segments and center of anal tuft white-yellow, sides of 

 anal tuft black and an even inner border to outer margin of 

 fore wings ; vitreous spaces covered with scales which mostly 

 fell off on handling the moth. This was identified as Hemaris 

 tennis Grt. Later in the spring I obtained from the Triosteum 

 a number of larvae similar to those found in the fall. They 

 pupated, and in July a number of imagines were disclosed 

 which were identical w r ith specimens of Hemaris diffinis Bdv. 

 in my collection from the North. I paid no attention to the 

 matter, and in late August, 1898, again obtained from the 

 same patch of Triosteum a number of larvae exactly like the 

 others. These pupated and wintered, and in the following 

 April and May they all disclosed the whitish-yellow, even- 

 margined tenuis. This time I could not help seeing the fact 

 so clearly indicated that tennis and diffinis were seasonal 

 forms of one thing, as was the case with Rnficaudis (uniformis < 

 and thysbe. In June, 1899, I therefore gathered all of the 



*The plate has been omitted by consent of the author. It was found that a half-tone 

 plate would not sufficiently show the minute differences to which the author alludes. ED. 



