Apetasimus pleomelarrosus Ewing

Ewing, Curtis, 2006, Revision of the endemic Hawaiian sap beetle genus Apetasimus Sharp 1908 (Coleoptera: Nitidulidae), Zootaxa 1385, pp. 1-30 : 22-24

Apetasimus pleomelarrosus Ewing sp. nov.

Gonioryctus kauaiensis Swezey, 1954: 70 . [misidentification].

Diagnosis

Large species with unique form, color, and habits. Distinguishable by rounded temple, smoothly curved to neck, striae of elytral definite, wide and granular, head and elytra black with red luster, abdomen, pronotum, legs and antennae pale to dark red. Pronotum with posterior margin narrower than anterior. This species is associated with axils of Pleomele aurea in mesic forests in the Kokee area of Kauai. They are most common on stressed Pleomele , i.e. those blown down or broken.

Description

Size: Length 6.3–8.3mm, Width 2.0– 2.6mm.

Color: Head and elytra nearly black, legs and abdomen orange-red to dark brick red, disc of pronotum darker in center, individuals varying from brick red to dark brick red at pronotal margin, and from dark brick red to black at center of disc.

Head: Transverse, 0.87–1.11mm L, 1.22–1.57mm W, L/W ratio 0.70–0.72 ( Fig. 5 A). Punctation variable, shallow and granular near eyes, antennal insertion and labrum, more definite at vertex, many punctures crowded together forming irregular lines, intervals subglabrous, microsculpture of fine lines. Lateral margins of labrum straight, convergent, with smoothly concave medial emargination, lateral angles acute, tips rounded. Eye length 0.40mm, facets 27, sub-parallel anteromedially, abruptly curved laterad to temple, temple convex indistinct transition to shallowly concave postgena. Antennomeres 2–5 elongate, 6 quadrate, 7 and 8 transverse.

Prothorax: Pronotum transverse, 1.30–1.70mm L, 1.78–2.39mm W, L/W ratio 0.71–0.73 ( Fig. 5 C). Anterior angle broadly rounded, lateral margins rounded anterad, straighter posterad, posterior angle obtuse. Widest anterior of midpoint, anterior/posterior width ratio 0.93. Shallowly emarginate anteriorly, posterior margin convex, slightly sinuate medially. Marginal bead distinct from anterior margin at angle, along lateral margin to posterior angle, less distinct and wider along posterior margin, narrowed and obsolete at midline. Punctation shallow, distinct, coarse, intervals granular. Prosternal process long, narrowed between coxae, expanded posterad and appressed on mesosternum, posterior margin rounded with long fimbria ( Fig. 5 E). Prosternal process in lateral view weakly recurved dorsad behind coxae ( Fig. 5 D).

Elytra. 2.41–3.03mm L, 1.18–1.48mm W, L/W ratio 2.03–2.05 ( Fig. 5 B). Entire surface with coarse, granular microsculpture. Overall appearance of striae regular, with coarse, irregular, shallow punctures. Elytral interstices with 2 irregular rows of fine punctures, setae obsolete. Impression on lateral surface, immediately posterad of humeral angle. Lateral margin weakly explanate from humeral angle posterad for 1/3 length. Lateral margin broadly convex anterad, nearly straight posterad to broadly rounded hind angle. Posterior margin broadly rounded.

Legs: Tarsomeres 1–3 with lobes of subequal length, tarsomere 2 broadest, tarsomere 3 narrowest ( Fig. 5 P). Ventral setae dense.

Abdomen: Tergite 5, 6, and pygidium with coarse, granular microsculpture. Male; pygidium short, apex broadly rounded, fimbria obsolete ( Fig. 5 N), ventrite 7 deeply bisinuate, fimbria fine ( Fig. 5 O). Female; pygidium short, apex rounded, fimbria longest at midline ( Fig. 5 L), ventrite 7 broadly rounded, fimbria shorter at angles, obsolete at midline ( Fig. 5 M).

Male genitalia: Tergite 8 with broad, shallow median emargination, subapical setae present on ventral and dorsal surface ( Fig. 5 I). Sternite 8 with obtuse triangular emargination medio-posterad, sinuate laterad, setae long, dense, 12–19 per side ( Fig. 5 K). Tegmen broadly rounded at apex with shallow medial emargination. Setae at apex, obsolete on angles and at midline, dense from behind angle to position even with lip of anterior excavation. Anterior excavation spiculate from floor to edge of lip, nearly obsolete in median triangle ( Fig. 5 J). Aedeagus subparallel, apex rounded, tip with small, definite, notch ( Fig. 5 H). Basisac evenly spiculate ventrally from near aedeagus to just before distal end, dorsal surface with spicules concentrated on 2 internal lateral folds, medially nearly aspiculate, at distal end spiculate patch forming bridge between lateral folds. Manicasac with proximal 2/3 gradually expanded, distal 1/3 abruptly attenuate and spiculate. Sclerites-primary of perisac dorsal, separate proximally, distal apices forming small ventrally directed hooks. Flagellum short, distal end appressed to inner margins of proximal ends of sclerites-primary, flagellum proximad junction with sperm duct directed sharply ventrally. Dorsal notch deep, 4/5 of length, ventral notch 1/6 of length, proximal 1/ 2 spiculate.

Female genitalia: Gonocoxites elongate, fused for entire length, apical notch definite, shallow. Lateral groove long, 1/3 length of gonocoxite 2, 3 prestylar setae, stylus subapical, approximately stylus length from tip, 2 apical stylar setae ( Fig. 5 G). Bursa copulatrix slightly expanded distad of junction with vagina. Spermatheca with apical depression elongate, narrowest near base, apex rounded ( Fig. 5 F).

Holotype ɗ, labeled: "Hawaii; Kauai; Kokee; Halemanu Rd. E of Kokee Rd., 24-May- 2005, 1074m; Pleomele aurea axils, C.P. Ewing Coll., #H85, UTM4 0431326E, 2446222N" (CUIC).

Paratypes: 2 Ψ, 2 ɗ (BPBM). 1 Ψ, 1 ɗ (BMNH). 1 Ψ, 1 ɗ (CUIC).

Etymology: Pleomele ; genus of host plant. (L.) arrosor; nibbler, gnawer.

Distribution: Endemic to Kauai, collected in mesic forests in Kokee area of Kauai where host occurs.

Habits: Found in leaf axils of Pleomele aurea where it feeds around sap extruded from small wounds which the beetles create. The sap often has a brick red color, similar in hue to the pronotum and abdomen.

Figures

FIGURE 5. Apetasimus pleomelarrosus sp. nov. A. Head, labral macrosetae broken; B. Elytron, dashed line delimits explanate margin at lateral excavation; C. Pronotum; D. Prosternum (lateral view); E. Prosternal process (ventral view); F. Spermatheca (torn at base); G. Gonocoxae (ventral view); H. Aedeagus (ventral view), showing internal structure; I. Male tergite 8 (ventral view), bottom half showing ventral setae, top half showing dorsal setae; J. Tegmen (ventral view); K. Male sternite 8 (ventral view); L. Female pygidium; M. Female sternite 7; N. Male pygidium; O. Male sternite 7; P. Left mesotarsi. ad apical depression, ae anterior excavation, ag accessory gland, br basal ring, gx 1 gonocoxite 1, gx 2 gonocoxite 2, le lateral excavation, lg lateral groove, lp lip of anterior excavation, mt median triangle, pe posterior excavation, ps prestylar setae, spd spermathecal duct, st stylus, sts stylar setae.