534 
The Ohio Naturalist. 
[Vol. XII, No. 8, 
In the field I have found eggs of this species on persimmon trees 
( Diospyros virginiana L ), at the University Campus the last of 
May, and on curled dock ( Rumex crispus L.) at Lakeville, Ohio, 
June 10-18. The eggs are deposited singly and laid flat on the 
surface of the leaf, twig, or flower. 
I know no way of distinguishing these eggs from those of related 
Syrphidae except by the size, shape and the microscopic character- 
istics of sculpturing described above; these may prove insufficient 
for specific separation when the eggs of more species are known. 
Larva. 
When just hatched (Fig. 65) the larvae have a length of 1.2 mm., 
width 0.25 mm. They are irregular in outline, nearly cylindrical, 
broadest near the middle; feeble and inactive. Color whitish, 
with a yellowish or greenish tinge. The usual small, fleshy, 
conical elevations are present, twelve to each segment, but the 
segmental bristles were not discernible, apparently absent. The 
posterior breathing appendages are rather prominent, longer than 
in a young larva of S. americanus, and light in color like the rest of 
the body. Their tips are, at first, rather remote from each other 
though with subsequent growth and their greater elevation above 
the general body surface they become contiguous. The two longi- 
tudinal fat bodies are discernible as a white line on each side of the 
dorsal blood-vessel which is more prominent in the posterior half 
of the body. The skin is faintly wrinkled transversely. 
From this condition there seems to be a gradual growth until 
the larva, when full-grown, has reached a length of about 8 mm., 
width 2 mm., heigth 1.25 mm. It may then be described as 
follows: Shape elongate oval, but much more pointed at the 
anterior end when extended. The outline is somewhat irregular 
due to folding and wrinkling of the skin. The posterior end is 
rounding, truncate except for the projections of the posterior 
breathing organ; (Fig. 66). 
Color green, very similar to that of the cabbage leaf (on which 
they occur commonly) with two longitudinal white stripes. This 
color is due to colored visceral bodies which show through the 
transparent skin. Along the mid-dorsal line for two-thirds the 
length can be seen the narrow, dark, pulsating blood-vessel, its 
prominence varying with different specimens. It is irregularly 
limited at the sides by a narrow mass of greenish, fatty globules 
changing gradually to whitish. This whitish adipose matter forms 
the two prominent longitudinal white stripes, 0.2 or 0.3 mm. wide 
and extending to within a few millimeters of either end where they 
become much attenuated. The rest of the body, except the ap- 
pendages is green, darker on the sides. The breathing tubes are 
light brown, black at the tips where the spiracles are located. 
