NOTES ON BLOOD-SUCKING FLIES IN NORTH RUSSIA. 197 



Haematopota. — Representatives of this genus were found everywhere, and were 

 most plentiful during the first three weeks in July. From ten to twelve were the 

 most ever seen to settle on one person at the same time. Considering its numbers 

 as compared with those of Tabanus, Haematopota appeared to be the more active 

 biter. 



Chrysops. — First seen in the last week of June, Chrysops was met with until the 

 end of the first week of August. Where the forest runs down to the edge of the 

 Maliozerki Lake, as many as four or five of Chrysops No. 2 [C caecutiens, L. — 

 E.E.A.] would settle on one at once, but in the forest at some distance from water 

 only one or two of these flies were encountered at a time. They were particularly 

 fond of sitting on one's cap. On cautiously removing my cap, after hearing the 

 fairly characteristic buzz indicating the presence of one of these flies, I more often 

 than not found the insect resting on it. 



Owing to their relatively small numbers, and their habit of rarely commencing 

 to bite on first alighting, flies of the genus Chrysops were not a very great nuisance, 



Blood-Sucking Flies other than Culicidae and Tabanidae. Midges {CuUcoides) 

 and Simulium were troublesome everywhere. 



Phlehotomus was not found. 



Stomoxys were first seen at the end of June, but it was rather exceptional to come 

 across more than an occasional specimen until August, when they could be found 

 in fair numbers. 



Enemies of Blood-sucking Flies. Dragonflies, which were numerous throughout 

 the summer, were frequently seen to capture specimens of the various species of 

 Tabanus. 



Evidence of Disease. There was no evidence that any of the flies with which 

 this paper is especially concerned conveyed any disease to human beings or domestic 

 animals. 



APPENDIX. 



(By Major E. E. Austen, D.S.O.). 



The interesting statement by Major Fraser printed above confirms what is already 

 known as to the extraordinary abundance and aggressiveness of Tabanidae in 

 Russia. Thus, according to the late Prof. Portschinsky (see Review Appl. Ent., 

 iii, B, pp. 195-196), to whose long-continued researches previous knowledge of the 

 subject is chiefly due, in Russia over 100 species of Tabanidae are found, including 

 some 60 species of Tabanus, 18 Chrysops, and 6 Haematopota, the remainder con- 

 sisting of representatives of the genera Nemorius, Silvius, Pangonia and Heptatoma. 

 In the polar regions of North Russia, where the number of species is limited, those 

 which occur are frequently present in enormous numbers. According to an earlier 

 paper by the same author (see Austen, British Blood-Sucking FHes, p. 33, 1906), 

 in the Gdov District of the Petrograd Government, Tabanidae in summer are so 

 excessively numerous and bloodthirsty that agricultural operations have to be 

 carried out by night ; while in parts of Siberia, such as the shores of the River Om, 

 settlers have been compelled entirely to abandon the zone infested by these flies. 



