OHIO STATE ACA.DEMY 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 eared for. 



It cannot be confused with any species recorded from Ohio but 

 the smaller specimens resemble zviedemanni 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 larvae are to be 

 found by digging in the mud. Larvae 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 larvae 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 

 poHen; 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 place^. ' ,.,., 



