JO NEW YORK STATE MUSEUM 



though so far we have not been able to demonstrate this. Full- 

 grown larvae and pupae were found July 7th at Wintergreen point, 

 attached to the roots of aquatic plants. Some idea of the abundance 

 of this species may be gained from the following data: July 10th 

 typical areas, each about 1 foot square, were examined and the 

 results secured on five such plots are as follows: 6 larvae, 2 pupae; 

 8 larvae, 1 pupa; 2 larvae, 2 pupae; 4 larvae, 2 pupae and 1 larva, 

 4 pupae, respectively, an average of over 6 to the square foot. A 

 similar examination made on the 10th resulted in the following data: 

 2 larvae, 3 pupae; no larvae or pupae; 12 larvae, 7 pupae; no larvae, 

 1 pupa; no larvae or pupae; 4 larvae, 2 pupae, respectively, an average 

 of over 5 insects to the square foot. It is hardly probable that in 

 any of these counts all the insects were secured and it is evident 

 that comparatively small areas may produce enormous numbers 

 of this annoying mosquito. The larvae and pupae were in all 

 cases found only where the water was deep and with an abundance 

 of debris covering the roots of the plants. Most of the areas were 

 in the immediate vicinity of small pools, sometimes close to the main 

 channel and almost invariably in connection with floating or semi- 

 floating plants. The transformation of larvae evidently begins in 

 early June, since pupae, pupal skins and recently transformed adults 

 were found June 14th. At this time four recently • emerged adults 

 with limp wings were taken from the surface of the water. It is 

 probable that most of these insects complete their transformations 

 between the middle of June and the middle of July, stragglers only 

 issuing after this time. There is no reason for thinking that there 

 may be more than one generation ; the adults are presumably long- 

 lived. Repeated examinations of localities where full-grown larvae 

 were abundant up to and including early September, have been 

 without results so far as finding young larvae is concerned, though 

 they have been found upon the roots of aquatic plants by other 

 observers. 



An attempt was made to determine the possibility of preventing 

 the development of this species by the application of oil, and a 

 number of larvae and pupae well established upon cat -tail roots 

 were put into a bottle and the surface covered with a film of oil. 

 No insects were reared under such conditions, though a few were 

 obtained from similar plants in water which had not been oiled. 

 This test was repeated twice under practically the same conditions 

 and it is very probable that judicious oiling, especially during the 

 period indicated above, when the adults issue in large numbers, 

 would be a very effective method of destroying the insects. Unfortu- 

 nately we were unable to test this out under natural conditions. 



