FOURTEENTH ANNUAL REPORT OF STATE ENTOMOLOGIST il 



of mosquitoes made in the river valleys and plains area a majority 

 of the specimens collected will generally belong to this species. 



Larval Records. — Our earliest seasonal record of larvae is May 

 6, and our latest August 22. This indicates that larvae are hatching 

 from the eggs throughout the late spring and summer months when- 

 ever there is sufficient moisture to bring* about hatching conditions. 



The length of the larval period in eastern Montana was ascer- 

 tained by Dr. R. R. Parker, in rearing experiments conducted in 

 1915. On July 16 an inch of rain fell, forming many temporary 

 pools. Larvae collected from one of these pools on July 18 pupated 

 on July 22 and emerged as adults July 25. On August 16 another 

 heavy fall of rain occurred. Larvae collected August 22 from a 

 pool formed by this rain pupated August 21 and emerged as adults 

 August 27. Assuming that the eg'gs hatched within twenty-four 

 hours after flooding, the larval period would be from five to seven 

 days and the pupal period two to three days. 



Larvae have been found in the following situations : "Irrigation 

 water along roadside," "irrigation overflow," "temporary wayside 

 pool," "permanent pool near railroad track," "pool connected with 

 irrigating ditch," "irrigation water in alfalfa field," "temporary pool 

 caused by summer rain." 



Record of Adults. — The earliest seasonal record for adults is 

 May 6 and the latest September 5. Specimens were taken on the 

 latter date by H. L. Seamans at Whitehall even though there had 

 been a severe frost the previous night. Adults were very abundant 

 on this late date. 



Adults have been found in the following: situations : "On edsre 

 of slough," "in river bottom." "in town," "hotel porch," "alfalfa 

 field," "damp place in willows," "blue-joint meadow," "sweet clover 

 along railroad track," and in all manner of places. 



The adults are voracious at all times except when forced into 

 inactivity by low temperatures or high winds. 



Distribution. — This species has been taken in the following local- 

 ities : Harlem. Chinook, Turner, Miles City, Hardin, Laurel, Hunt- 

 ley, Bozeman, Three Forks, Lombard, Salesville, Dillon, Armstead, 

 Cascade, and Judith Basin. 



