48 OHIO STATE ACADEMY OF SCIENCE. 
TABANUS ATRATUS Fabricius. 
Length 16-28 mm. The male and female of this common species are 
easily associated as they differ only in sexual characteristics. The whole 
insect is uniformly black and the thorax and abdomen in well preserved 
specimens are thinly covered with a whitish dust which is easily rubbed 
off when specimens are not properly cared for. 
It cannot be confused with any species recorded from Ohio but 
the smaller specimens resemble wiedemanni very closely. The wider front, 
the longer basal process of the third antennal segment, and the shape 
of the frontal callosity, which is square in wiedemanni and wider than 
high in atratus, are distinctive characters. Its much larger size and 
less shining color distinguish it from lugubris. 
Habitat: Common all over Ohio, 
Never numerous enough to be a particularly striking pest, 
but specimens have been taken in every month from June to Sep- 
tember, so that it is one of the species one may expect to see at 
any time during the summer. The eggs are deposited around 
marshy places on grasses and sedges, and the larve are to be 
found by digging in the mud. Larve are easily kept in confine- 
ment for months, and feed on various invertebrate forms. Fish- 
worms seem to suit them well, and they have no hesitation in 
eating their own species, therefore, in rearing each larva must 
have a separate cage. In one instance where I placed a larva in 
the same cage with a pupa it was not long before the former 
bored through the covering of the latter and began feeding upon 
the soft inner parts. The larve push through the soil in all 
directions in search of food, and the earth in the breeding cage 
where an active larva is confined usually proves that it is capable 
of finding everything that will sustain life before giving up in 
despair. 
TABANUS BICOLOR Macquart. 
Length 10-13 mm. Whole insect bright yellowish but thorax and 
a rather wide middorsal stripe on the abdomen darker than the other 
parts. Eyes pilose but no ocelligerous tubercle present in either sex: 
Antennae, palpi, proboscis and legs yellow, dorsum of thorax including 
the scutellum brown in ground color but uniformly covered with yellow 
pollen; wings hyaline with yellowish veins; middorsal stripe of the 
abdomen brown, also covered with yellow pollen, usually widest on 
the first segment and gradually narrowing to the end of the abdomen 
or sometimes slightly widened again on the last two or three segments. 
The male and female are marked alike, but in the latter sex there is a 
tendency for the dark color of the abdomen to be more diffuse with limits 
not plainly apparent. 
Habitat: Sandusky and Danville. 
The bright yellowish color of this species is characteristic. 
It has not been observed annoying stock. Most of my specimens 
were taken by sweeping in grasses in marshy places. 
