Antoinettia Skelley, 2020

Skelley, Paul E., 2020, A new Central American genus of pleasing fungus beetles (Coleoptera: Erotylidae) from the Ischyrus-Megischyrus complex, Insecta Mundi 2020 (804), pp. 1-11 : 3-4

Antoinettia Skelley , new genus

Type species. Ischyrus kovariki Skelley, 1998 , present designation.

Diagnosis. Distinguished from other genera of the Ischyrus - Megischyrus complex by the triangular elongate antennomere IX ( Fig. 4 ; semicircular or trapezoidal in Ischyrus , compare Skelley 1998 fig. 6a–k), prosternum anteriorly flattened and lacking pinch or angulation ( Fig. 1–2, 5 ; usually forming a keel in Ischyrus and Megischyrus ), setose groove anterior to procoxae (unique for Antoinettia ), presence of 8 distinct elytral striae, and metaventrite with post mesocoxal line continuous around base of mesocoxa (rarely continuous around mesocoxae in Ischyrus and Megischyrus ).

Description. Length 3.7–6.4 mm; Width: 2.0– 3.9 mm. Body shape elongate, parallel-sided to ovoid, slightly convex dorsally; microreticulation weak, surface glossy; with distinct color patterns.

Head with ocular striae ending before anterior angle of eye; frons lacking distinct impression at each side; epistome wedge-shaped with truncate apex; epistome and vertex similarly punctured. Eye large, bulging from side; facets coarse. Antenna ( Fig. 4 ) reaching base of pronotum; antennomere I large, elongate; antennomere II circular, ball-like, length = 0.5 × antennomere I; antennomere III elongate, length less than next 2 combined; antennomeres IV–VIII about 1.5 × width; antennomeres IV–VII apically rounded; antennomere VIII edged and angled apically; antennomeres IX–XI form a loose club; antennomere IX triangular, as long as wide; antennomere X semicircular to trapezoidal, apically concave; antennomere XI transversely oval to circular; antennomeres X–XI symmetrical.

Maxillary terminal palpomere securiform ( Fig. 1–2, 5 ), length about 0.66 × width. Labial terminal palpomere width approaching width of terminal maxillary palpomere. Mentum with a pore on each side in front of basal corner; mental plate triangular. Genal braces present, broadly rounded, forming inner side of groove next to the eye for reception of antennomeres II–III.

Pronotal disc evenly rounded; sides variably arched inwardly toward eyes; anterior angles closer together than posterior angles; anterior edge lacking marginal bead between eyes; anterior angles forwardly produced, making anterior edge concave; base sinuate, lacking marginal bead, lobed at middle, with group of large punctures at each side along edge. Scutellar shield pentagonal, wider than long. Elytra with sides parabolically rounded to apex; 8 distinct striae, stria 9 evident by rows of punctures on apical half; striae lacking at humerus and extreme apex; intervals flattened; base lacking marginal bead; elytral epipleuron widest at base, strongly narrowed at level of metacoxae, gradually folding under to apex.

Prosternum not pinched, not keeled, complete marginal bead anteriorly; sternal plate trapezoidal; lines anteriorly converging, not surpassing front of procoxae, lines continuous or indistinctly broken from anterior coxal line; prosternal line anterior to coxa form a groove that deepens laterally, lined with setae ( Fig. 1–2, 5 ); posterior edge of prosternum concave, lacking marginal bead. Mesoventral lines anteriorly divergent; not continuous with line anterior to mesocoxae. Metaventral lines continuous around mesocoxae. Legs with femora slightly swollen, complete marginal bead on inner surface; tibia straight, almost parallel-sided, slightly widened toward apex; tarsi pseudotetramerous. Abdominal ventrite I with coxal lines present, continuous around metacoxae.

Male genitalia with penis short, apically blunt; flagellum variable with virga thickened in some manner ( Fig. 11 , 16 , 21 ). Female genitalia with acute process at inner base of gonocoxite ( Fig. 3 ); spermatheca with head bean-shaped, tail thickened, curving back onto self, giving spermatheca an overall S-shape. Stridulatory files on occipital region of head absent in both sexes. No external sexual dimorphism observed.

Etymology. This colorful little genus is named for my mother, Antoinette, who fostered my entomological career by simply allowing me the freedom to pursue such an unusual interest. She once confessed, “Your father and I had no idea how to help.” She remained supportive while I worked on my dissertation ( Skelley 1998) from which most of this manuscript is derived. Gender feminine.

Remarks. The prosternal setae-lined groove anterior to the procoxa is a unique character not known from any other erotylid. While most erotylids studied thus far have male genitalia with a narrow hair-like virga of the flagellum, a thickened and modified virga also occurs in the West Indian genera Altisessor Skelley, 2009, Epytus Dejean, 1836 , and Notaeptytus Skelley, 2009. However, these modifications are highly variable between species within these genera.

Figures

Figures 1–6. Miscellaneous structures of Antoinettia Skelley, new genus.1) A. audbala (Skelley), holotype, ventral head and prosternum. 2) A. kovariki (Skelley), holotype, ventral head and prosternum. 3) A. kovariki (Skelley), allotype, female genitalia. 4–6) A. huhnei Skelley, new species. 4) Antenna, holotype. 5) Ventral head and prosternum, holotype. 6) Ventral view of elytra with abdomen removed to show brachypterous wings of this species, paratype from El Progresso.

Figures 7–11. Antoinettia huhnei Skelley, holotype except as noted. 7) Dorsal view. 8) Ventral view, note deformity of abdominal ventrite II of this specimen only. 9) Lateral view.10) Anterior oblique view.11) Genitalia, male paratype from El Progresso.

Figures 12–16. Antoinettia audbala (Skelley), holotype. 12) Dorsal view. 13) Ventral view. 14) Lateral view. 15) Anterior oblique view. 16) Genitalia, media strut almost invisible in picture.

Figures 17–21. Antoinettia kovariki (Skelley), holotype except as noted. 17) Dorsal view. 18) Ventral view. 19) Lateral view. 20) Anterior oblique view. 21) Genitalia, paratype, arrow points to uniquely modified flagellum.