Heterocerus sinuosus (Pacheco)

King, Jonas G. & Lago, Paul K., 2012, The variegated mud-loving beetles (Coleoptera: Heteroceridae) of Mississippi and Alabama, with discussion and keys to the species occurring in the southeastern United States, Insecta Mundi 2012 (275), pp. 1-53 : 24

11. Heterocerus sinuosus (Pacheco)

New Combination

( Fig. 19 , 40 , 64 )

Lanternarius sinuosus Pacheco 1964: 58 .

Description. Length 3.8 - 4.7 mm. Brown or reddish brown. Pronotum lighter than elytra, often with a more reddish hue ( Fig. 19 ); pale elytral markings distinct, trifasciate, pale bands variable; striae vaguely indicated. Post-metathoracic coxal lines absent, post-mesothoracic coxal lines prominent. Male genitalia ( Fig. 40 ) of the typical Heterocerus type; anterior phallobase gradually narrowed to approximately 75% of posterior width; median plate approximately 30% greatest width of phallobase, not constricted anteriorly, attached to body of phallobase near the posterior edge of the parameres, point of attachment broad with squared anterior edge; parameres elongate, about one-half the length of the body of the phallobase and rounded at their apices, median edges separated by approximately half the basal width of one paramere and parallel to one another; dorsal plate ovoid, with a small sclerotized cleft on its left anterior edge, posterior edge flattened. Hypermandibulate males unknown.

Diagnosis. The difference in coloration between the light reddish-brown pronotum and the darker brown elytra distinguishes H. sinuosus from all other southeastern species in which post-mesothoracic coxal lines are present. The genitalia are also distinctive. The parallel edges of the median plate and its broad, squared attachment to the body of the phallobase is unique among southeastern species and, within the New World fauna, is shared only with H. infrequens Miller (1988a) , a rare northern species.

Notes. During this study, H. sinuosus was collected at two localities in Mississippi. One series of twenty specimens was taken from a Salix- dominated oxbow off of the Tallahatchie River in Tallahatchie County (N 34 o 01.484', W -90 o 08.460'). Another small series was collected near the Pearl River in a suburb of Jackson, Hinds County.

Distribution. Heterocerus sinuosus is known from southern Canada and the United States west of the hundredth meridian as far south as northern Mexico. It had also been recorded from the eastern coast of the U.S. as far south as Virginia ( Miller 1996). The Mississippi records mentioned above represent a new state record and extend the known range of this species over 500 miles to the southwest of its previously known distribution in the eastern United States ( Fig. 64 ).

Specimens examined. 26 (See Appendix).

Figures

Figures 18-20. Habiti of large Heterocerus species with post-mesocoxal lines. 18) H. insolens. 19) H. sinuosus. 20) H. mollinus. Specimens 20a and 20c are hypermandibulate. Scale line = 1mm.

Figures 32-44. Male genitalia of southeastern Heterocerus species. The ventral view is shown unless otherwise stated. 32-39) Species that lack post-mesocoxal lines. 32) H. fatuus. 33) H. glicki. 34) H. intermuralis. 35) H. angustatus; left - ventral view, right - dorsal view. 36) H. longilobulus. 37) H. pallidus; left - ventral view, right - dorsal view. 38) H. gnatho; left - ventral view, right - dorsal view. 39) H. sandersoni; left - ventral view, center - dorsal view, left - lateral view. 40-44) Species with post-mesocoxal lines. 40) H. sinuosus; left - dorsal view, right - ventral aspect. 41) H. mollinus. 42) H. insolens; left - dorsal view, right - ventral aspect. 43) H. parrotus. 44) H. brunneus.

Figures 58-65. Distribution by county in the United States. 58) Heterocerus fatuus. 59) Heterocerus sandersoni. 60) Heterocerus intermuralis. 61) Heterocerus angustatus. 62) Heterocerus mollinus. 63) Heterocerus selanderi.64) Distribution of Heterocerus sinuosis by county in Mississippi. 65) Distribution of Heterocerus collaris by county in the United States.