195 



NOTES ON BLOOD-SUCKING FLIES IN NORTH RUSSIA DURING THE 



SUMMER OF 1919. 



By Major A. D. Eraser, D.S.O., M.C., R.A.M.C. 



With an Appendix containing a List of Species, by Major E. E. Austen, D.S.O. 



Locality. 



Most of the following observations were made in the vicinity of Obozerskaya, 

 a small village on the Archangel- Vologda Railway, 474 versts from Vologda or 

 roughly 80 miles due south of Archangel, I arrived at Obozerskaya and reported 

 to the Headquarters of the Vologda Force on 14th June 1919, a few days after 

 disembarking at Archangel. 



Further experience and a few of the specimens collected were obtained during 

 tours of inspection on the Onega River Front in the last week of June, and on the 

 Seletskoe Front early in August. 



Nature of Country. 



The country in the whole of this district is one continuous forest of pines, firs, 

 etc., and although there is comparatively little undergrowth, any movement through 

 the forest other than along the recognised tracks is rendered extremely difficult 

 on account of the swampy nature of the groimd, which remained waterlogged 

 even in July, when the heat was quite trying. 



Excepting those along the railway, most of the villages are situated on the banks 

 of rivers or lakes, and around the majority smaU clearings are cultivated or used 

 for grazing. At Obozerskaya the clearing was very small, and there was no culti- 

 vation ; the nearest open water was a lake about two miles from the village. Along 

 one or two of the larger rivers grazing land is more plentiful, and fair-sized herds of 

 cattle are to be seen. 



Remarkably few birds or animals of any kind are met with in the forest, though 

 ants are numerous everywhere. 



Tabanidae. 



Before I arrived in the country mosquitos were numerous and troublesome, and 

 the troops had been provided with mosquito-nets and veils. Midges were also 

 annoying, but otherwise no biting flies were in evidence until 20th June, a warm 

 sunny day following a couple of days of rain, when numbers of Tabanidae appeared. 

 A day or two later they had increased to such an extent that they were present 

 ever3rwhere in swarms, and although at their worst in the forest, they were a pest 

 in the villages, houses, trains, etc. Near the edge of the forest many more than a 

 hundred Tabanids could be counted on one person at the same time, while hundreds 

 of others would be flying around. In the forest itself they were present in almost 

 incredible numbers. There were many officers and men in the Force who had 

 lived and travelled in all parts of the world, but all those I met agreed that never 

 before had they encountered these flies in such swarms. 



