68 ENTOMOLOGICAL NEWS. [Feb., '04 



Observations on Bembecia Marginata var. Albicoma 



and Sesia Acerni. 



BY HENRY ENGEL, Pittsburgh, Pa. 



For several seasons I have been on the lookout for Bembecia 

 marginata in this vicinity, but had no success until I found 

 part of an empty pupal shell protruding from a dead cane 

 of red raspberry on June 28, 1903. On further examina- 

 tion of the cane and roots, the feeding habits were noticed, 

 and a search for larvae resulted in finding three in a small 

 patch of red raspberry. From that date to July 22, nearly 

 every day, one to two hours were devoted to hunting larvae 

 and pupae of this species, resulting in the discovery of two 

 hundred and forty specimens. These were found in a com- 

 paratively small area in a ravine having clusters of blackberry 

 bushes here and there. Only five were found in raspberry 

 bushes. Both sexes of the typical form and also of the var. 

 albicoma occurred among the images resulting from the pupae 

 collected. Apparentl) 7 the female of the variety albicoma was 

 unknown when Mr. Beutenmuller concluded his Monograph 

 of the Sesiidae. A brief mention of its points of difference from 

 the typical form is appended. 



Bembecia marginata var. albicoma Hulst, 9. 



Head, thorax and abdomen sooty-black, all lines and markings on col- 

 lar and thorax reduced and straw-yellow. The line which crosses and 

 ends in a triangular patch on each side of thorax in the typical form is 

 interrupted in albicoma, extending only to lateral lines above the inter- 

 section of the primaries. The rings on the first three segments are only 

 faintly indicated on top and are narrower on the under side than in mar- 

 ginata. The tuft of hair on the dorsal part of the third segment is all 

 black. The rings on the abdomen and last two segments are straw- 

 yellow, with black hairs intermingled on the last. two segments. The 

 legs are clothed with brown hairs. The margins of the wings are some- 

 what darker brown than in marginata. 



Ova of marginata were obtained. The following description 

 has been prepared by Dr. \V. J. Holland : 



" Eggs of B. marginata: .80 mm. in length ; .60 mm. in width ; ob- 

 long oval viewed from above ; greatly flattened on base, and flattened 

 ovate viewed laterally ; profusely covered with minute, irregular, reticu- 

 lated ridges enclosing deeper pitted depressions. Deep chestnut-brown 

 in color." 



