No. 2.] Note on the " Potu " or " Pipsa " Fly. 55 



Western Himalayan Simulia belong to one and the same species. 

 Mr. Vincent A- Mackinnon has been so good as to collect a large num- 

 ber of the perfect female flies for me, which are now deposited in the 

 Indian Museum, Calcutta, and has given me the following notes on 

 them, based on his experiences of this pest at Mussooree, in the West- 

 ern Himalayas. It would be advantageous to collect specimens in 

 Sikkim (so far, I have not succeeded in doing this, but am still endea- 

 vouring to do so), and send them with the Western Himalayan 

 examples to Dr. Becher for specific determination. 



At Mussooree it is very plentiful in the spring, but small numbers 

 can be found at all seasons. In the Western Himalayas it occurs at 

 Mussooree, Chakrata, and thence, northwards, as far as the Niti Val- 

 ley, near the snows. The Balti people say that it is well known in 

 their country (Baltistan). It is found both in forests and in open 

 grass-covered downs, and at all elevation, from 3,000 to 10,000 feet. 

 At the latter elevation, Mr. Mackinnon was once so badly bitten, that 

 he had to lay up from the effects for two days. The effects of the 

 bite vary greatly in different people : to some it causes but little ap- 

 parent inconvenience, a small black spot only being visible where the 

 insect has bitten ; in other people it causes intense irritation, which, 

 when the itching places are scratched, raise large lumps beneath the 

 skin ; these may be some days before they disappear. Animals suf- 

 fer as well as men— a tame deer (Kakhur), which Mr. Mackinnon pos- 

 sessed, nearly died from the effects of the bites. The fly chiefly at- 

 tacks the ears, entering the external orifice in large numbers. They 

 also attack the region of the eye orbits very largely. When the 

 Chakrata-Saharanpur road was being constructed, numbers of the 

 work-people were reported as having died from the eflPects of the 

 bites. In the Western Himalayas, the fly is called Potu in Hindu- 

 stanij Phisniari in Pehari, and Phisho in Balti. 



