77 



Theo., C. nocturnus, Theo., Finlaya poiciUa, Theo., Aedes argenteus, 

 Poir. {Stegoniyia fasciata, F.), 5. pseudoscutellaris, Theo., and Taenio- 

 rhynchus brevicellulus, Theo. 



Evans (W.). An Anopheline Mosquito in East Lothian, — Scottish 

 Naturalist, Edinburgh, no. 119-120, November-December 1921, 

 pp. 185-186. 



Anopheles plunibeus, Steph., is recorded from East Lothian, 

 apparently for the first time. 



Sen (S. K.). A Note on the Effect of Mercurous Chloride on Culicid 

 Larvae. — Rept. Proc. 4th Ent. Meeting, Pusa, February 1921, 

 Calcutta, 1921, pp. 184-191, 2 plates. 



During experiments to test the effect of various salts on the larvae 

 of mosquitos, some results were obtained with calomel (HgCl), which 

 seems to offer possibiUties as a larvicide against mosquitos, in view 

 of the desirability of replacing kerosene (until now practically the 

 only larvicide in use) by a more convenient and less expensive material. 

 The results of the tests are shown by means of graphs, and present 

 considerable discrepancies. These may be due to a debilitated con- 

 dition of the larvae at the time of the experiments, or to the fact that 

 death is dependent on the extent to which the salt particles are dis- 

 tributed over the surface of the water, or they may be the result of 

 variation in atmospheric temperature. It was noticed that larvae 

 experimented with in June and July died more quickly than those 

 dealt with in November. The slight solubiUty of calomel, together 

 with the fact that an exceedingly minute quantity of the salt is 

 necessary to kill the larvae, while having no effect on the human 

 system, renders it quite safe for treatment of drinking water in ponds, 

 etc. The transitory nature of the effect of kerosene, however violent 

 its immediate action, imposes severe limitations on its practical value 

 as a larvicide, as it involves continuous replenishment in any collection 

 of water, whereas the action of calomel, though slow and unsteady, 

 is generally sure, while its cost is about one-fourth that of kerosene. 



Calomel has, however, two serious drawbacks : firstly, it generally 

 fails to kill the larvae [sic, ? pupae] , and, secondly, it would be difficult 

 to keep the salt particles floating for any considerable period. Its 

 superiority over the other halogen salts of mercury lies in its cheapness 

 and the fact that the soluble salts are apt to form precipitates with 

 the alkaloidal and other constituents of various kinds of vegetation 

 likely to occur in the breeding-places of mosquitos. Over kerosene 

 its great advantage is that it is not inflammable. 



The larvae experimented with were those of Aedes {Stegoniyia) 

 albopictus ; tests with Anophelines have not yet been made. 



Sharma (H. N.) & Sen (S. K.). Oviposition in Culieidae.— /?(?/>^ Proc. 

 4th Ent. Meeting, Pusa, February 1921, Calcutta, 1921, pp. 192- 

 198, 5 plates. 



These experiments with Culex fatigans, C. vishnui and Aedes 

 {Stegoniyia) albopictus were conducted with the object of determining 

 whether choice of water for oviposition is influenced in these mosquitos 

 by the condition of the water as regards temperature, osmotic pressure 

 and surface-tension, and whether their choice can be influenced by 

 the addition of small quantities of sweet, salt, astringent or alkaline 



