Dec., 1901.] 
Observations on Insects. 
169 
in abundance crawling over the trunks and foliage of trees, on the 
fence along the woods and flying about generally. One pair was 
observed in copulation on the fence, and I am of the opinion that 
the presence of so many flies in the locality at the time is ex- 
plained on the ground that it was the general mating place of the 
sexes. On several occasions I have made observations which lead 
me to believe that the sexes of various species of the family 
copulate among foliage often high up in the trees. As Tabanids 
are not easily procured with a net from the surface of a rough 
rail, I tried the experiment of picking the specimens off with my 
fingers and found that it was surprisingly successful, if the move- 
ment toward them was made very slowly until just ready to touch 
them when the fingers were gripped quickly. Xear a watering 
trough where a herd of cattle drank daily I found males in num- 
bers resting on the ground where the turf had been tramped off. 
Along Rocky River I observed both sexes fly down to the water 
and dip several times in succession and then awa)^ to alight on a 
stone on the bank or disappear from sight altogether. 
On July 29th I rode from Sandusky to Cleveland by boat. 
Although we were from two to five miles off shore all the time, 
males and females of T. sulcifrons often came on board and 
alighted on the canvas and rigging of the boat. From this it is 
evident that this species at least may fly for some distance over 
water. 
We have taken Goniops chrysocoma on several occasions. It 
has a habit which is of value to the collector. At Hinckley, 
Medina County, I took several females and observed that they 
have the habit of stationing themselves on the upper side of a 
leaf, where by vibrating their wings rapidly and striking the 
upper surface of the leaf at each downward stroke, make a rat- 
tling noise which can be heard plainly several feet away. At 
Vinton last spring Mr. Morse and myself identified the charac- 
teristic sound of the species and were guided by it to procure 
specimens. 
I have taken the male of Pangonia rasa on blossoms of sumac 
at Medina, Ohio, in August. 
OBSERVATIONS ON INSECTS. 
James S. Hine. 
Agromyza setosa Loew — The larvae of several species of the 
genus Agromyza are known to mine the leaves and stems of 
various plants Cabbage, potatoes, corn, clover, strawberries, ver- 
benas. chrysanthemums and sunflowers are among the cultivated 
plants from which various species of the genus have been reared; 
while plantain, round-leaved mallow, golden-rod, aster, cockle- 
