I04 N. J. Mosquito Exte:rmination Association 



Migfration as a Factor in Control 



BY THOMAS J. HEADI.e:K, PH.D.^ ENTOMOI.OGIST 0^^ THE NEW 

 JERSEY AGRICUI^TURAIv EXPERIMENT STATIONS, AND 

 STATE ENTOMOI.OGIST 



The practical work of mosquito control has gone far enough 

 to demonstrate that migrating adults of various species of mos- 

 quitoes frequently so complicate the problem of freeing a limited 

 area as to render successful work impossible. This fact, when 

 taken with the further fact that interest in the practical problem 

 of control is growing, would seem to justify an examination of 

 the data bearing upon mosquito migration in the hope of finding 

 out how to minimize its effects. 



EVIDENCE 01? MOSQUITO mCHT 



Howard, Dyar and Knab^ have brought together a mass of 

 data bearing on the question of mosquito migration. As might 

 be expected, there is much evidence of flight without any indica- 

 tion of the species concerned, but there is also much where the 

 species has been determined. Table i will serve to give the facts. 



It thus appears that the far-migrating species are those which 

 breed on the salt marshes, that 25 or 30-mile movements are 

 common, and that extremes of 60 miles may be reached. 



The writer has traced the salt-marsh species A. cantator and 

 A. sollicitans during each of the last five summer seasons and 

 has found them penetrating the back country for long distances. 

 Twenty-five-mile migrations are common, and 35 to 40-mile mi- 

 grations take place when the brood emerging is very large. A. 

 cantator has not been observed to cover the distances reached by 

 A. sollicitans, but the difference may be due to the cooler weather 

 and the smaller broods of the former. 



Russell (see table) has shown a flight of two miles for Anoph- 

 eles annulipalpis. LePrince and Orenstein^ have cited incon- 



^ Howard, L. O., Dyar, H. G., and Knab, Frederick, 1912. The mosquitoes 

 of North and Central America and the West Indies, v. i, p. 339-345, Carnegie 

 Inst., Pub. 159. 



^ Le Prince, J. A., and Orenstein, A. J., 1916. Mosquito Control in Panama, 

 p. 94-114. G. P. Putnam's Sons, New York. 



