Aegithus clavicornis ( Linnaeus 1758 )

Skelley, Paul E., 2009, Pleasing fungus beetles of the West Indies (Coleoptera: Erotylidae: Erotylinae), Insecta Mundi 2009 (82), pp. 1-94 : 22-24

Aegithus clavicornis ( Linnaeus 1758)

Figure 1b , 4, 6 , 38, 40 , 42

Chrysomela clavicornis Linnaeus 1758: 370 ~ Linnaeus 1767: 590, #29; Linnaeus in Gmelin 1790: 1678, #29; Degeer 1775: 351-352, #4, t. 16; Lacordaire 1842: 285.

Erotylus clavicornis (Linnaeus) ~ Olivier 1792: 435, # 21 f. 11; Olivier 1807: 479, pl. 2, fig. 28; Dejean 1821: 128; Duponchel 1825: 42, #14; Sturm 1826: 139.

Aegithus clavicornis (Linnaeus) ~ Fabricius 1801: 9, #1; Chevrolat 1834 (fascicle 4): [pages unnumbered]; Crotch 1873b: 147; Crotch 1876: (117) 493; Gemminger and Harold 1876: 3705; Gorham 1888: 87-88; Gorham 1898: 336; Kuhnt 1909: 18; Kuhnt 1911: 8-9; Leng and Mutchler 1914: 412; Leng and Mutchler 1917: 200 [ex Dominica, misidentification]; Deelder 1942: 57-58; Blackwelder 1945: 457; Woodruff et al. 1998: 25; Teixeira and Casari 1998: 459-463.

Coccinella surinamensis Linnaeus 1763a: 393 , #12 ~ Linnaeus 1763b: 10, #12; Linnaeus 1767: 579, #2; Linnaeus in Gmelin 1790: 1645, #2; Fabricius 1775: 79, #2; Fabricius 1781: 93, #2; Fabricius 1787: 53, #4; Fabricius 1792 [1(1)]: 266-267, #4; Crotch 1876: (117)493 [synonymy with A. clavicornis ]; Gemminger and Harold 1876: 3705; Kuhnt 1911: 8-9.

Erotylus surinamensis (Linnaeus) ~ Fabricius 1792 [1(2)]: 39, #18; Olivier 1792: 435, #19; Herbst 1799: 373, #15, pl. 137 f. 12; Olivier 1807: 480, pl. I., fig. 9; Schönherr 1808: 328, #30; Duponchel 1825: 156, #59, t. 3, f. 59; Sturm 1826: 139.

Aegithus surinamensis (Linnaeus) ~ Fabricius 1801: 9-10; Illiger 1804: 160; Illiger 1806: 232; Lacordaire 1842: 285-287; Kirsch 1876: 102.

“ Aegithus surinamensis Fab. ” [erroneous attribution] ~ Dejean 1836: 427, Dejean 1837: 451; Sturm 1843: 305.

Diagnosis. Aegithus clavicornis is readily distinguished from other members of Aegithus by its hemispherical black body ( Fig. 4, 6 , 38 ) with red-orange elytra and abdomen.

Description. Length: 10.5-13.0 mm; width: 8.0- 9.5 mm. Body globose, dorsally hemispherical ( Fig. 4 ), laterally rounded; weakly microreticulate, weakly glossy. Body and appendages black except as noted: palpi brown; abdomen and elytra red-orange.

Head interocular width = 3.5 x ocular width; ocular striae attaining base of epistome; vertex finely punctate, puncture size = an ocular facet diameter, separated by 2-4 x their diameter; epistome with dulling microreticulations; puncture size = an ocular facet diameter, separated by 1-2 x their diameter. Eyes finely faceted. Antenna attaining basal quarter of pronotum; antennomere II length = width; antennomere III length = 3 x width, length = length of antennomeres IV+V combined; antennomeres IV- VIII equal in length; IV-VII length = 1.5 x width; VIII triangular, part of club, length = width at apex; antennomere IX roughly trapezoidal, length = width at apex; antennomere X crescent shape; antennomere XI subcircular, length = IX length. Terminal maxillary palpomere securiform, width = 3 x length. Terminal labial palpomere triangular, width = 3 x length, expanded medially, width = 0.5 x width of terminal maxillary palpomere. Mentum with triangular plate, length = width at base. Genal lobes present, short, blunt.

Pronotum transverse, width = 2.5 x length, anterior width = 0.5 x posterior width; discal puncture size and distribution as those on vertex, evenly distributed; base with row of large punctures, puncture size = 2 x ocular facet diameter; base weakly V-shaped, marginal bead absent. Scutellum pentagonally rounded, length = width. Elytra with scattered punctures, puncture size = 2 x ocular facet diameter; striae not evident; base lacking marginal bead.

Prosternum length = 3 x intercoxal width; anterior edge with marginal bead, weakly pinched anteriorly; prosternum convex, depressed anterior and posterior coxa, not punctate; sternal lines continuous around coxal cavity; base concave. Mesosternum truncate, sternal lines divergent anteriorly, continuous around coxal cavity; with minute punctures. Metasternum with lines not meeting medially at mesosternal junction, not continuous around mesocoxal cavity, sternal lines long, extending onto sternal surface, often attaining lateral margin ( Fig. 40 ); with a few scattered fine punctures. Abdomen with coxal lines not meeting medially; continuous around metacoxal cavity; punctures scattered. Male with a very small group of setose punctures at center of first abdominal ventrite. Male genitalia with median lobe narrowed, strongly curved at base, apex acutely curved; flagellum long and thin ( Fig. 42 ).

Distribution. Aegithus clavicornis is widespread in tropical America from Mexico to Argentina. In the West Indies it is known only from the Dominican Republic ( Medrano-Cabral 2009) where it has been recently established, and Grenada where it is apparently native ( Fig. 1b ).

Type Material. Type material of Chrysomela clavicornis Linnaeus was stated as “Habitat in America. Rolander”, present repository unknown. Type material of Coccinella surinamensis Linnaeus was stated as “Habitat Surinami” with no comment whose collection it was in, present repository unknown.

The concept of this species is based on literature descriptions and comparison with a multitude of identified specimens present in various historic collections. Any potential designations of lecto- or neotypes should be done in the context of a revision of Aegithus . Therefore, none is proposed here.

Specimens Examined. Thousands of specimens have been studied over the years, from Mexico to Argentina, but only five from the West Indies: Dominican Republic: Santo Domingo ( Medrano-Cabral et al. 2009). Grenada: St. Andrews , Chantilly , 6-APR-1990, J. Telesford (1- PESC) ; Morne Delice , 9-JUN-1990 ,

M. C. Thomas, fungus on old logs (1- FSCA). Gorham (1898) reported material from “ Grenada: Mount Gay Estate and Mount Maitland on the leeward side.”

Remarks. Naturally occurring West Indian populations of A. clavicornis appear to be restricted to Grenada ( Gorham 1898, Leng and Mutchler 1914, Woodruff et al. 1998). Leng and Mutchler (1917) cited A. clavicornis from Dominica, which was repeated by Blackwelder (1945) and Peck (2006). No specimens have been seen from Dominica, and this record is likely based on a misidentification of Iphiclus suturalis . However, A. clavicornis has been found on Hispaniola, and this is considered to be a new establishment (Medrano- Cabral et al. 2009; see Erroneous Records in the Materials and Methods).

Figures

Figure 1. West Indian maps. 1a) Map of West Indian countries mentioned in the text. 1b) Map indicating species occurring on specific islands with distribution of Notaepytus flavitarsis (Lacordaire) indicated by the white triangles.

Figure 2-11. Key characters. 2-3) Anterior view of head and pronotum. 2) Iphiclus suturalis. 3) Notaepytus flavitarsis. 4-5) Lateral habitus. 4) Aegithus clavicornis. 5) Iphiclus suturalis. 6-11) Dorsal habitus. 6) Aegithus clavicornis. 7) Aegithus lebasii. 8) Iphiclus guadeloupensis. 9) Iphiclus suturalis. 10) Cubyrus sapphirus. 11) Ischyrus quadripunctatus.

Figure 38-41. Aegithus spp., dorsal and ventral habitus. 38, 40) A. clavicornis. 39, 41) A. lebasii.

Figure 42-45. Aegithus spp., male genitalia and larva. 42) A. clavicornis. 43) A. lebasii. 44-45) A. lebasii larva, lateral and dorsal view. Genitalic scale line = 1 mm.