Mosquito Life in Surrey during 1921

Extract

Mr. Malcolm E. MacGregor's interesting paper, “The Influence of Drought upon Mosquito Life in Surrey” (Bull. Ent. Res. xii, p. 205), has led me to examine our records of observations made in that county in connection with inquiries into indigenous malaria in England. As regards certain areas of the country during the past year, our experience of the scarcity of some kinds of mosquitos is the same as Mr. MacGregor's, but (if it is desired to draw conclusions for the country as a whole) it seems important also to note that there are other areas in which the findings differ from those in the particular locality upon which he reported. Dorking, Epsom and Arbrook Common, which are within a few miles of Wisley, are examples of such areas. In these and some other localities in the county we have obtained larvae of A. bifurcatus without difficulty throughout the year. At Epsom, large numbers of larvae of this species in the fourth instar were found early in February this year in a well-shaded permanent pool, which we have examined regularly since 1917, and adults were caught in the open in April. Larvae were numerous throughout the year, and adults, both male and female, were captured in the open as late as 22nd October. At Dorking, larvae of bifurcatus were plentiful in several natural collections of water throughout the year. One of them—the “Mill Ponds stream”—is only 100 yards from a row of houses; another—the “Stonebridge stream”—yielded bifurcaus larvae on 19th August at every place examined along a stretch of 400 yards. On the same day many larvae of this species were found, along with larvae of C. pipiens, in the rainwater barrel of a house about 200 yards from the stream.