174 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



these forms in such localities were accustomed to obtain their 

 blood-supply from other sources. He states that Simulium 

 pertinax molests not only horses but also dogs and probably 

 other domestic animals and that originally all the species 

 must have depended upon native animals, particularly the 

 larger mammals. The assumption of such diversification of 

 habits in the same species is hardly in accord with the speciali- 

 zation of the different species in this respect, which Dr. L,utz 

 himself sets forth. The reviewer is inclined to think that 

 such differences in behavior may be due to the fact that sim- 

 ilar species have been confused. This view is given some 

 support by the fact that Dr. L,utz, after more careful study, 

 narrowed his specific concepts and increased the number of 

 species. Therefore it will be necessary to readjust his obser- 

 vations on the feeding habits from this new viewpoint. 



In the second paper we have some additional notes on the 

 biting habits. We find here the interesting statement that 

 most of the species found in a given region, including those 

 which do not molest man, can be captured on horses and 

 mules if one seeks on the proper parts the belly and inside 

 the ears. Thus certain species almost exclusively infest the 

 interior of the ear and their presence results in an eczetna- 

 tous condition of the skin, from which, in some localities, 

 all horses and mules suffer. Even when no blood-sucking 

 insects are in evidence a few well-filled individuals often may 

 be found inside the ears. On the belly the Simulium settle 

 mostly near the median line and not far from the hind legs; 

 in lesser numbers the same species go to the breast, between 

 the fore legs and near them. Still other species swarm about 

 the mane and penetrate among its hairs. 



None of the Brazilian species are a menace in any such de- 

 gree as has been reported with Simulium in Hungary and 

 North America; but they are sufficiently troublesome to cause 

 man to avoid certain regions and their bites often help to pro- 

 duce ulcerating swellings. 



The Simuliidae are not, strictly speaking, diurnal. While 

 a few individuals are in evidence throughout the day, Si- 

 mnlium is nevertheless adjusted to a certain strength of light. 

 They are most abundant shortly before twilight. However, 

 the number of individuals of the different species at this time 

 by no means corresponds in every case with the abundance of 

 their larvae and pupae in nearby breeding places. Lutz states 

 that sometimes Simulium of both sexes are found at consid- 

 erable distances from their breeding-places, their presence be- 

 ing clearly traceable to the direction of the wind. 



