JUN 2 1 1912 
The Ohio ^N^aturalist , 
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 £33 
Claassen— Alphabetical List of Lichens Collected in Several Counties of Northern 
Ohio 543 
Metcalf— Meetings of the Biological Club . . 549 
LIFE-HISTORIES OF SYRPHIDAE IV. 
C. L. Metcalf. 
Allograpta obliqua (Say). 
(Plate XXX, Figs. 61-70). 
Egg. 
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 ventrallv. 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 4 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 Mav 
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 
