The Ohio Naturalist, 



PUBLISHED BY 



The Biological Club of the Ohio State University, 



Volume XII. JUNE. 1912. No. 8. 



TABLE OF CONTENTS 



Metcalf— Life-Histories of Syrphidae IV 633 



Claassen— Alphabetical List of Lichens Collected iu Several Counties of Northern 



Ohio 543 



^rETCALF— Meetings of the Biological Club 549 



LIFE-HISTORIES OF SYRPHIDAE IV. 



C. L. Metcalf. 



Allograpta obliqua (Say). 

 (Plate XXX, Figs. 61-70). 



£.?,?• 

 Elongate oval in outline, narrowing slightly to the roundly- 

 pointed anterior end and the truncate, posterior, micropylar end. 

 The egg is slightly inflated dorsally, flattened against the surface 

 to which it is attached ventrally. Length about 0.8 mm., diame- 

 ter 0.3 mm. (Figs. 61 and 62.) 



Color chalk-white with the usual microscopic sculpturing. (Fig, 

 63). When highly magnified, sometimes tinted with yellowish in 

 the depressions between the sculptures. In this case the main 

 bodies of the projections are broader than in Syrphus americanus 

 (3 to -1 times as long as broad) ; somewhat oval in shape, the arms 

 thicker and not so long as in S. americanus; usually about fifteen 

 around each body. The space between the bodies is about two- 

 thirds as wide as the body. There are about 28 of these projections 

 the length of the egg, about 55 around it transversely at the 

 middle. 



Oviposition for the first spring generation began about the 

 middle of May. A female taken on May 17 laid 35 eggs on May 

 22, 13 the following day, and by May 26, when she died, had 

 deposited nearly 100 eggs. The first of these hatched the morning 

 of the 25th, a few others the 26th, making the duration in the 

 egg-stage (indoors) from 2.5 to 3.5 days. 



533 



