17 ° 
The Ohio Naturalist. 
[Vol. II, No. 2 , 
bur, rag-weed and wild-rice are given as their food-plants. In 
some eases a single species of fly has been reared from a half 
dozen or more different plants. Agromyza setosa Loew, as deter- 
mined by Coquillett, was reared in numbers from leaves of wild- 
rice, Zizania aquatica, at Sandusky during August of each of the 
years 1900 and 1901. Professor Osborn studied the species and 
its work in 1900, while my observations were made a year later. 
Although I include the notes taken by both of us, many points 
are needed before a detailed account of the habits and life history 
of the species can be given. 
The eggs are conspicuous on account of their abundance and 
white color, and are deposited chiefly on the upper surface of the 
leaves of the food plant. 
The larvae upon hatching bore into the leaf and feed beneath 
its upper covering. When full grown they measure about 6 mm. 
in length, are white, or greenish on account of chlorophyl taken 
in with their food, and are furnished with strongly chitenous 
mouth parts. The mines which they make in the leaves are 
irregular in width and extend for varying lengths on one side or 
the other of the mid-rib. These variations in extent are usually 
explainable from the fact that a variable number of lavae occup3 r 
the different mines. The work of the larvae is apparent from 
the first on the upper side of the leaf, and may be seen beneath 
after a few days because of the fact that the parts beneath the 
mine sooner or later turn yellow. 
The pupa is to be found either in the mine or clinging to the 
surface of the leaf. It is brown in color, with two prominences 
anteriorly where the attachment with the leaf is effected, and is 
contained within the last larval skin so that the legs and wing- 
pads are at no time visible from the outside. 
Bibio arbipennis Say — Larvae observed in colonies under 
fallen logs, and boards which were lying on the ground. Speci- 
mens taken April 4th pupated May 5th and the adults appeared 
May 13th. The adults were unable to fly for several hours after 
they emerged on account of their wings remaining soft. I ob- 
served the first males flying out of doors on the 23d of May. 
Chrysopila ornata Say — Larva about an inch and a half 
in length, white in color, cylindrical, with an enlargement at the 
posterior end bearing a number of fleshy elongations which are 
about the length of their basal breadth. Found under rotten 
wood May 1st Pupa brown, last segment armed with six 
spinose teeth, the two on the ventral side arising from the same 
base, the remaining abdominal segments furnished with a circlet 
of spines near the posterior third. The adult emerged the 18th 
of June. 
