Aegithus lebasii Lacordaire 1842

Skelley, Paul E., 2009, Pleasing fungus beetles of the West Indies (Coleoptera: Erotylidae: Erotylinae), Insecta Mundi 2009 (82), pp. 1-94 : 24-25

Aegithus lebasii Lacordaire 1842

Figure 1b , 7 , 39, 41 , 43-45

Aegithus lebasii Dejean in Dejean 1836: 427 ~ Dejean 1837: 451 [both listings are nomina nuda].

Aegithus lebasii Lacordaire 1842: 285 ~ Crotch 1876: 494 (118).

Aegithus lebasi [sic] (Lacordaire) ~ Kuhnt 1909: 18; Kuhnt 1911: 9; Deelder 1942: 59; Blackwelder 1945: 457.

Aegithus cassideus Lacordaire 1842: 295 ~ Crotch 1876: 494 (118) [synonymy with A. lebasii ]; Gemminger and Harold 1876: 3705.

Diagnosis. In the West Indies, A. lebasii is recognized by the body shape, short coxal lines on the metasternum, black body and abdomen with red-orange elytra. However, differentiation from some mainland Aegithus is more difficult, and characters used to recognize it include: minute differences in body shape and coxal line lengths.

Description. Length: 7.5-9.5 mm; width: 5.5-7.0 mm. Body dorsally convex, somewhat hemispherical (not globose), laterally rounded ( Fig. 7 ); strongly microreticulate, dull. Body and appendages black with red-orange elytra.

Head interocular width = 3.5 x ocular width; ocular striae attaining base of epistome; vertex finely punctate, puncture size = an ocular facet diameter, obscured by microreticulations, separated by 2-3 x their diameter; epistome puncture size = an ocular facet diameter, separated by 1-2 x their diameter, impressed. 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; antennomere IX trapezoidal, length = width; antennomere X crescent shape; antennomere XI subcircular, length =antennomere IX length. Terminal maxillary palpomere securiform, width = 2.5 x length. Terminal labial palpomere triangular, width = 2 x length, expanded medially, width = 0.66 x terminal maxillary palpomere. Mentum with triangular plate, length = width. Genal lobes present, short, blunt.

Pronotum transverse, width = 2.5 x length, anterior width = 0.5 x posterior width; punctation as on vertex, obscured in microreticulation; base with row of large punctures, puncture size = 2-3 x ocular facet diameter; base weakly V-shaped; basal marginal bead present at sides, absent medially. Scutellum pentagonally rounded, length = width. Elytra with strial punctures small and obscured in microreticulations, same size as scattered interval punctures; striae weak, paired; base lacking marginal bead.

Prosternum length = 3 x intercoxal width; anterior edge lacking marginal bead, not pinched; prosternum convex, depressed anterior and posterior of coxa, not punctate; sternal lines continuous around coxal cavity; base concave. Mesosternum truncate, lines divergent anteriorly, continuous around coxal cavity; minutely punctate. Metasternum with sternal lines almost meeting medially at mesosternal junction; not continuous around mesocoxal cavity; sternal lines extending onto sternal surface, short, at most, attaining half way to lateral margin ( Fig. 41 ); with few scattered fine punctures obscured in microreticulations. Abdomen with coxal lines not meeting medially; continuous around metacoxal cavity; punctures fine, indistinct. Male with a small group of setose punctures at center of first abdominal ventrite. Male genitalia with median lobe normal thickness, weakly curved at base, apex curved and acute; flagellum moderate in length, moderately thickened along entire length ( Fig. 43 ).

Distribution. Aegithus lebasii is found on the mainland from Costa Rica to Venezuela. In the West Indies, it is known only from Jamaica where it was recently established ( Fig. 1b ).

Type Material. Lacordaire (1842) stated the types of A. lebasii as “Il a été découvert aux environs de Carthagene, en Colombie, par M. Lebas, à qui M. Dejean l’a dédié.” Dejean’s collection is in MRSN. Specimens of this species were not requested for this study and may or may not be present in the MRSN. Present repository unknown.

For Aegithus cassideus, Lacordaire (1842) stated “De la Colombie, Collection de M. Dupont”, present repository unknown.

The identity of the Jamaican Aegithus is based on comparison with A. lebasii specimens in the NHML and CUMZ (Crotch Collection). On the mainland, there are many species similar to A. lebasii , all differing subtly in body shape and other characters. Any potential designations of lectoypes or neotypes and confirmation of the Jamaican Aegithus identification should be done in the context of a revision of Aegithus . Therefore, none is designated here.

Specimens Examined. Several specimens from the mainland were studied, distributed from Costa Rica to Venezuela. Only 19 specimens were studied from Jamaica: Middlesex , Mt. Diablo, 4mi. S. Moneague, 28-MAR-1991, K. Philips & L. Gerofsky (1- PESC) ; St. Anne , 7-14-JAN-1990, C. Springer (1- EIUC) ; St. Anne , Ocho Rios, 27-MAR-1991, K. Phillips (16- HNHM, PESC, TKPC, WIBF) ; St. Mary , Dunnes River Falls, 18-JUL-1990, V. Golia (1- VGIC) .

Remarks. In the early 1990s, numerous specimens were collected at multiple localities, some at lower elevations in Jamaica, and some even at a beach resort. Being a large and colorful beetle, if this species had been present in Jamaica throughout the last 200 years, it should have been collected previously. The lack of earlier records supports the conclusion that A. lebasii has only recently become established on Jamaica.

The original spelling of the species by Lacordaire (1842) is “ lebasii ”, which was emended to “ lebasi ” and followed by several workers. However, following ICZN rules (1999, Articles 31.1.3, 32.3, 33.4), the original spelling is correct, and is therefore followed here.

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.