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 te7iuis 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 

 riificaudis and thysbe. 



Tenuis is the spring form from wintering pupae and diffi^iis 

 the mid-summer form from eggs of temiis. 



On September 9th, 1896, I obtained two sphingid larvae from 

 Triosteum perfoliahun, one of the Caprifoliaceoe. One of these 

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

 March 19th, 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 Triostenm 

 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 with 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 tenuis and diffiinis were sca.sonal 

 forms of one thing, as was the case with Ruficatidis (^uni/ormis) 

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



*Thc plate Hm b«en omitted by content of the author. It wai found that a half-tone 

 filatc would not •ufTiciciitly khow the minute difTerenceH to which the autlior alludes.— £u. 



