No. 34-] HEMIPTERA OF CONNECTICUT: GERRIDAE. 66 1 



2. Antero-lateral margin of pronotum with a lighter stripe 3 



Antero-lateral margin of pronotum concolorous ; second emargina- 



tion of sixth abdominal segment in male, narrow and rounded; 

 female genital segment comparatively narrow; connexivum 

 flavous marginatus 



3. Second emargination of sixth abdominal segment in male broadly- 



rectangular ; bases of hemelytra dark buenoi 



Second emargination of sixth abdominal segment in male narrow, 

 semicircular ; bases of hemelytra white-marked argenticollis 



G. (Gerris) marginatus Say. (PL xvi, n.) 



Het. New Harm., 36, 1832; Compl. Writings, i, 362, 1859. 

 This small stout form is an abundant inhabitant of our lakes and 

 ponds, where it preys on other insects. This, too, has five nymphal 

 stages and a life cycle of from five to six weeks. It ranges over 

 the whole United States, and in Connecticut has been taken as 

 follows : 



West Stratford, 16 Aug., 1904; Putnam, 12 July, 1905 (H. L. V.) ; 

 Orange, 13 Apr., Hamden, 24 Apr., 28 May, Cheshire, 6 May, New Haven, 

 4 May, 191 1 (B. H. W.) ; Lyme, 14 May, 191 1 (A. B. C.) ; So. Meriden, 

 26 Apr., 1914 (H. L. J.). 



G. (Gerris) buenoi Kirkaldy. (Figs. 150 and 151.) 



Ent. News, xxii, 246, 191 1. 



This small species, shown in figures 150 and 151, has frequently 

 been confounded with the preceding. It ranges from British 

 Columbia as far as New Jersey at least. In Connecticut it is 

 recorded as follows : 



Milford, 10 Aug., 1905 (W. E. B.) ; New Haven, 14 Apr., 4 May, 191 1 ; 

 Cheshire, 6 May, 1911 (B. H. W.) ; Hamden, 18 May, 1919 (M. P. Z.) ; 

 Litchfield, 26 July, 1901 (L. B. W.). 



EE© 



Fig. 151. Gerris buenoi Kirkaldy,— (a) lateral view of head, (b) male 

 genitalia, (c) female genitalia. All greatly enlarged. Drawing by Dr. 

 Philip Garman. 



G. (Gerris) argenticollis Parshley. 



Ent. News, xxvii, 103, 1916. 



This species is recorded by the author from Massachusetts and 

 North Carolina. 



