258 



FAMILY VI. — HYDROPHILIByE. 



gg. Meso sternum with a compressed conical process ; tarsal claws 

 broadly toothed at base in male, less so in female; elytra 

 striate. XIV. Helocombus. 



dd. Last joint of maxillary palpi longer than the third. 



h. Elytra either with stria? or with punctures arranged in rows ; 

 larger species, more than 5 mm. XV. Hydrobius. 



hit. Elytra with confused punctuation; smaller species, less than 

 4 mm. XVI. Creniphilus. 



VIII. Berosus Leach. 1817. (Gr., a proper name.) 



This genus is composed of convex, elongate beetles, usually pale 

 in color with darker spots on thorax and elytra. They may be 

 known also by the 7- jointed antennas, elongate scutellum and the 

 hind pair of tibiae and tarsi pilose. Three species are known from 

 Indiana., while two others probably occur. 



KEY TO INDIANA SPECIES OF BEROSUS. 



a. Elytra with two spines at apex; fifth abdominal segment truncate at 

 middle. pugnax. 

 aa. Elytra without spines at apex. 



1). Filth segment of abdomen with one tooth at middle of notch. 

 c. Abdomen of male with segments 2, 3 and 4 slightly carinate. 



d. Elytra with well defined black spots. 498. pantherinus. 



del. Elytra with spots indistinct. . 499. peregrinus. 



gg. Abdomen of male not carinate ; both head and abdomen dull yel- 

 low. EXIGUUS. 

 hh. Fifth segment of abdomen with two teeth at middle of notch; ab- 

 domen never carinate ; elytral spots indistinct. 500. striatus. 



498 (1608). Berosus pantherinus Lee, Proe. Phil. Acad. Nat. Sci., VI, 



1855, 364. 



Elongate-oval, convex. Pale, dull yellow ; head blackish-bronzed ; thorax 

 with two black spots at middle; elytra each with ten distinct black spots 

 as follows ; two near base, four in a sinuous transverse band in front of 

 middle, three in another band behind middle, and one near apex ; abdomen 

 reddish-brown. Thorax finely punctured, the sides slightly converging in 

 front. Elytral strke coarsely punctured; intervals rather thickly and irregu- 

 larly punctate. Length 4 mm. 



Posey County; rare. June 3. Known from Illinois, Missouri 

 and Texas. 



499 (1609). Berosus peregrinls Herbst, Col., VII, 314. 



Oval, convex. Head black with bronzed surface; thorax and elytra 

 light brownish-yellow, the former with two brown spots on disk, the latter 

 with four or five indistinct oblong, double spots. Elytral striae less dis- 

 tinct on disk than on sides, the intervals finely punctured. Head thickly 

 punctured, with a longitudinal impression between the eyes. Length 4 mm. 



Throughout the State ; frequent. June 6-August 20. 



