196 



found there, especially iu human dwellings, wintering images of 

 A. claviger and ^4. superpictus. 



A. pidcherrimus is considered to be the chief cause of malaria 

 amongst the population of the southern part of Russian 

 Turkestan. The author reports that in those places of the pro- 

 vince of Samarkand where this disease prevails, the above insect 

 is found more commonly than any other species of Anoplielea; 

 while near the railway station of Syr-Daria A. jjulcherrivius is 

 practically the only representative. During the first half of 

 August 1911 the author and his assistant collected there 319 

 specimens of malaria-carrying mosquitos, out of which there 

 were 314 specimens of A. pidcherrimus and only 5 of A. claviger. 

 jN^o other species was found there. The author refers to two 

 previous papers of his, in which he dealt with the question of 

 fighting the malaria mosquitos and his recommendations apply 

 also to A. pidclierrimus. But its mode of wintering and its 

 early flight in the spring suggest that the breeding places ought 

 to be treated with kerosene not later than the end of March, so 

 that the insects cannot hatch out. 



Besides A. pulcherriinus, the author has previously discovered 

 three other species of malaria-carrying mosquitos in Turkestan : 

 — Anopheles claviger, T., A. pseudopictus, Grassi, var. fleroivi, 

 Portch., and ^1. s^iperpictus, Grassi v. vassilievi, Portch. In 

 December 1912, he found a fifth species of these mosquitos, 

 A. hifurcatiis, L. This insect winters in Turkestan in much the 

 same manner as A. pnlcherrimiis, namely, as a larva, which fact 

 is in accordance with the investigations of Galli-Valerio, ]Varbel 

 and Rochaz in Switzerland. The author found on the 21st and 

 24th December 1912 over 90 larvae of ^4. hifurcatus near Tash- 

 kent in an " arick," neglected and grown over with canes and 

 Chara, the water of whicli Avas 10-15 cm. deep and had a smell of 

 sulphuretted hydrogen. All the larvae were obtained from the 

 bottom of the water-liole, or ratlier from the M-ater-plants cover- 

 ing the bottom ; the temperature of the water on the 21st Decem- 

 ber was 5° E. (43° F.) and on the 24th 1° E. (34° F.), with 

 a thin cover of ice. Most of the larvae were half-grown, but 

 there w^ere also young and fully grown ones. 



Besides these insects there were also obtained from the bottom 

 of the hole wintering larvae of Culex and Dixa as well as some 

 rapacious larvae of CJdoe and Agrion. About 30 specimens 

 were taken to St. Petersburg where one half was kept in an 

 aquarium between the frames of the double window of a dwelling- 

 room ; while the other half was left inside and kept at the room 

 temperature. The larvae between the window frames dropped 

 to the bottom of the aquarium when the temperature was near 

 freezing point and attached themselves, as did those of A. pul- 

 cherriinus, to the leaves of the plants there. During the 2h, 

 months of their wintering- they stood very well a temperature 

 of 3'5° E. (40° F.) and freezing of the water in the aquarium. 

 On the 14th March they were taken into the room, where at the 

 end of that month 11 specimens of A. hifurcatus emerged. The 

 larvae which remained since the 30th December inside the room 

 produced mosquitos throughout January. 



