THE AMERICAN ENTOMOLOGIST. 



191 



could be seen at almost all times of the 

 day wandering through the potato fields, 

 seeking the grubs, and they performed 

 their work so thoroughly that not a hill 

 of potatoes was seriously injured in the 

 field, while other potatoes near by would 

 have been, if no poisons had been used, 

 entirely destroyed by the beetles, or their 

 larvae. 



If poultry can be induced to seek the 

 grubs for food, it is well to encourage 

 them by dispensing with the usual appli- 

 cation of poisons. — A. S. F. 



NOTES ON THE DEVELOPMENT OF A BLACK- 

 FLY (SIMULIUM) COMMON IN THE RAPIDS 

 AROUND ITHACA, N.Y. 



BY PROF. W. S. BARNARD, ITHACA, N. Y. 



For several years entomologists and 

 others about Ithaca, N. Y., have had their 

 curiosity aroused by the appearance of 

 masses of black worm-like larvae coating 

 the surfaces of the rocks, etc., in the 

 swiftest waters of this vicinity. They 

 form large black patches, seen beneath the 

 water only at the points where it rushes 

 with the greatest velocity in our falls and 

 rapids. How they can withstand the im- 

 mense momentum of the water in these 

 places is truly astonishing. But such is 

 tlie habitat of their choice. Since they do 

 not thrive in quiet aquaria, the problem of 

 breeding them is a difficult one. From a 

 study of the larvae, I concluded that they 

 belonged to the genus Sinuilium, which is 

 proved by the adults I have bred, and, 

 although I have not yet been able to de- 

 termine the species, I have worked out its 

 complete biography, and own specimens of 

 all its stages : egg, larva, pupa and adult. 



The species of this genus are famous for 

 their fierce, voracious habits. It includes 

 the Black-fly of the North, which has a 

 dagger-like upper-lip and a piercing " pro- 

 boscis, which draws blood profusely;" the 

 Buffalo-fly of Illinois and the West, which 

 I have observed killing poultry in great 

 numbers, and which is known to torment 

 horses and other animals to death, when 

 very numerous; a Hungarian species, often 



killing cattle; while in tropical America 

 they are a dreadful scourge, where for 

 several nights I was kept awake by them 

 when trying to sleep in the forests near 

 the rivers, sometimes finding myself and 

 my shirt thickly specked with blood, from 

 their punctures. These minute sand-flies 

 of the Amazon have hard bodies, and the 

 swarm seeks entrance beneath one's gar- 

 ments, from which they cannot be kept 

 out. There they were especially active at 

 night, together with the mosquitoes. 



In studying the larvE at Buttermilk 

 Creek (on July 26th), I saw that in some 

 places they graded down smaller and 

 smaller toward the shore, and then saw 

 in one place, they were thus graded quite 

 up to the water-line, where they were so 

 small as to be hardly visible without a 

 microscope, and then saw the smallest 

 ones on the rocky surface above the water 

 and detected their source. They were 

 issuing from thin brownish masses just a 

 little way above the water on the sunny 

 e.xposure of the sloping rock. A micro- 

 scopic examination showed these to be the 

 masses of eggs. I have also found the eggs 

 abundant on the ist of June. From these 

 the young were passing downward into the 

 water to begin an aquatic life. Here I col- 

 lected and preserved a large quantity of ma- 

 terial, representing the early development 

 from the egg to the full-grown larva. Also 

 I obtained in the rapids, where the larvee 

 were plentiful, a quantity of pupae and 

 cocoons, which I supposed (and afterwards 

 proved) to belong to the same species. 

 After watching these insects in several of 

 our streams without further success, and 

 failing to rear them in aquaria, I planned 

 to supply their normal conditions and in- 

 duce their development where it could be 

 observe;d. Covering one end of a glass 

 tube with gauze, I inserted several ad- 

 vanced larvae, and connected the other 

 end with a faucet over a sink so that the 

 water passed through it swiftly. These I 

 observed for many days until they made 

 their silken cocoons and assumed the pupal 

 form, from which the perfect insect finally 

 appeared. But the velocity of the water 



I 



