342 



Leech and Chandler: Coleoptera 



Genus Helophorus Fabricius 



It is not possible to give a satisfactory key to the 

 California species of Helophorus until the publication 

 of a revision of the North American forms, by the 

 late F. E. Winters and K. F. Chamberlain. Following 

 is a list of the species reported from the state. 



//. angustulus Mannerheim 1853 California. 

 H. fortis LeConte 1866 California. 

 H. linearis LeConte 1855 Western U.S. 

 H . obscurus LeConte 1852 California. 



Kay to the California Species of Hydrochus 

 Adults 



1. Head and pronotum with numerous small, rounded, 

 flat scales, which obscure the punctation (northern 

 U.S. and adjacent Canada) . .. squamifer LeConte 1855 



— Head and pronotum without scales, the punctation 

 clearly defined 2 



2. Pronotal foveae deep; strial punctures of elytra large, 

 wider than the interspaces (fig. 13:31<f); California 



variolatus LeConte 1852 



— Pronotal foveae shallower; elytral interspaces as wide 

 as striae; California vagus LeConte 1852 



Key to the California Species of Berosus 

 Adults 



1. Elytra emarginate and/ or spinous or bispinous apically 

 (subgenus Enoplurus Hope); larger species, 6-8 mm. 

 long 2 



— Elytra not emarginate, not spinose, the apices acute 

 or a little produced at most (subgenus Berosus s. str.); 

 smaller species, 2.75-6 mm. long 3 



2. Femora bicolored, basal section (covered with hydro- 

 fuge pubescence) black; pronotum coarsely, densely 

 punctate, punctures tending to be subserially arranged, 

 often confluent, surface between either shining or 

 alutaceous; elytral interspaces roughened by coarse 

 punctures with scabrous or almost asperate margins; 

 Washington-Baja California, Arizona 



punctatis simus LeConte 1852 



— Femora entirely yellow; pronotum with dual punctation, 

 the relatively sparse coarse ones intermixed with 

 numerous much finer ones, surface shining or aluta- 

 ceous; elytral interspaces smooth, punctures slightly 

 scabrous on some lateral intervals; Kings, Eldorado 

 counties ? maculosus Mannerheim 1853 



3. Apical emargination of 5th abdominal sternite rounded 

 at middle or vaguely shallowly emarginate, not dentate; 

 pronotum immaculate; only alternate elytral intervals 

 punctate, if any; southern California to Tres Marias 

 Island, Mexico, in saline pools, lagoons, ocean beaches 



metalliceps Sharp 1882 



— Apical emargination of 5th abdominal sternite with a 

 single prominent blunt median tooth, or with 2 sharp, 

 often small, teeth 4 



4. Hind edge of apical emargination of 5th abdominal 

 sternite with a single glabrous median tooth; small 

 species, 3-3.75 mm. long; strial punctures of basal 

 discal region of elytra very coarse, each elytron with 

 a pale spot on disc just behind middle; California 



? calif ornicus Motschulsky 1859 



— Hind edge of apical emargination with 2 small glabrous 

 teeth; larger species, more than 4 mm. long 5 



5. Crest of mesosternal protuberance with a prominent 

 falcate tooth anteriorly; California to Texas, South 

 Dakota; Butte County, Tulare County 



styliferus Horn 1873 



Crest of mesosternal protuberance at most with a low 



tooth on its anterior part 6 



Raised area of mid-metasternum trifid posteriorly, 

 median tooth projecting much farther back than lateral 



ones 7 



Mid-metasternum nearly triangular posteriorly, without 

 obvious lateral teeth; elytra of female either shining 

 as in male, or alutaceous; California to British Columbia 



to New York fraternus LeConte 1855 



Elytra of female shining, as in male; male with basal 

 segment of front tarsi only slightly enlarged, apical 

 half covered with a dense pad of adhesive hairs, tips 

 of which are not obviously dilated; hind edge of hind 

 femora of male margined above and below, angulate 

 at middle; coarsely punctate species, discal striae 

 impressed almost or quite to base; California to British 



Columbia to South Carolina striatus (Say) 1823 



Elytra of female dull, alutaceous; male with basal 

 segment of front tarsi enlarged, somewhat triangular, 

 all but extreme base covered by a pad of adhesive 

 hairs, tips of those near apexexpanded to form palettes; 

 hind edge of hind femora of male not margined above, 

 not angulate at middle; more finely punctate species, 

 discal striae not or very lightly impressed toward 



base 8 



Parameres of aedeagus of male much swollen dorsally 

 in apical third, forming a declivity, apices abruptly 

 narrowed, together triangular in dorsal view, not on 

 same plane as declivity; San Diego north at least to 



Napa County ingeminatus d'Orchymont 1946 



Parameres of aedeagus of male forming a gradual 

 declivity from about mid-point to apices, slightly 

 widened at apical third, thence gradually narrowing to 

 apex; Louisiana to Arizona, and southeast corner 

 of California, San Bernardino and Imperial counties . 

 infuscatus LeConte 1855 



Fig. 13:40. Hydrophi I idae. o, Tropisternus columbianus, hind 

 femur of adult, pubescent area shaded; b, Tropisternus californi- 

 cus, hind femur of adult; c, Tropisternus sublaevis, posterior 

 claw of middle tarsus of male; d, Tropisternus columbianus, 

 posterior claw of middle tarsus of male; e, Tropisternus salsa- 

 mentus, hind femur of adult; f, Hydrophilus triangularis, front 

 tarsus of male; g, Tropisternus lateralis, adult; h, Hydrophilus 

 insularis, front tarsus of mole (a-e, Leech, 1945; i, Wilson, 1923; 

 g. Leech, 1948; h. Regimbart, 1901). 



