Meatopida, Kiałka & Ruta, 2018

Kiałka, Agata & Ruta, Rafał, 2018, Meatopida gen. nov., a new genus to accommodate two species originally described in Atopida White, 1846 (Coleoptera: Scirtoidea: Scirtidae), Zootaxa 4382 (2), pp. 242-260 : 243-247

Genus Meatopida gen. nov.

( Figs 1–13 )

Type species: Atopida testacea Broun, 1880 (by present designation).

Diagnosis. Relatively small, elongated ( Fig. 1 ), covered with rather long, semierect setae. Pronotum narrower than base of elytra, widest anteriorly, with crenate margins ( Fig. 4 ). Base of pronotum with rounded margin, projecting further posteriorly than posterior angles. Antennal insertions not very depressed, shallow ( Figs 2A–B ). Antennomere II cylindrical. Rows of very distinct, club-shaped setae present on outer side of apical maxillary palpomere ( Figs 3F–I ). Trigonium of penis divided into two processes ( Figs 7 , 8 , 11 ). Parameres of tegmen bifid, parameres connected at base by a narrow cuticular ring. Prehensor large ( Figs 10 , 12 ), covered with spines, female abdominal ventrites without setal patches.

Description. Male. Body elongated, small (TL ca. 2.4–3.1 mm), 1.9–2.3× longer than its width, moderately convex. Body yellowish to yellowish brown, elytral suture often darkened, legs slightly lighter. Punctation on head and pronotum granulate, strong and dense, distance between punctures ca. 0.5 diameter of puncture, punctation on elytra simple, distance between punctures 0.7–1.0 diameter of puncture. Body covered with moderately long, yellowish, semierect setae.

Head ( Fig. 2 ) wider than long, base covered by pronotum. Eyes moderately large, oval, moderately protuberant. Distance from posterior margin of eye to occipital ridge about 1 eye diameter; distance from ventral margin of eye to subgenal ridge about 1/2–2/3 of eye diameter. Frons moderately convex; supra-antennal ridges well marked, slightly elevated, extended into margin of clypeus. Antennal insertions not very depressed, subantennal area wide, reaching margin of eye and extending towards bottom of head, not separated from eye with raised carina. Frontoclypeal suture absent. Clypeus short, strongly transverse, lateral margins strongly diverging anteriorly, anterior edge semicircularly emarginated. Anteclypeus very short, narrower than clypeus. Ventral side of head between subgenal ridges concave. Gular area convex, square. Subgenal ridge well marked, without buttonhole configuration. Submentum wider than mentum, shorter or of similar length, flat, hexagonal, about 1.5– 2.2× wider than long. Antennae filiform; antennomere 1 cylindrical, broad, slightly flattened; antennomere 2 cylindrical, shortest; antennomere 3 narrow, 1.3× longer than antennomere 2; antennomere 4 longest, antennomeres 5–10 as long as antennomere 1, antennomere 11 distinctly longer than preceding ones. Labrum narrower than clypeus, transversely rectangular, anterior margin semicircularly indented, with long setae, front angles rounded. Mandibles ( Fig. 3A ) slightly asymmetrical, narrowly triangular, ca. 2× longer than wide at bases, apices unidentate, quite acute; with short carina on external edge, abruptly curved in apical third, with setae covering 0.5–0.7 of its length; internal edge with more or less pronounced triangular denticle and carina with 3 denticles, not covered with setae; denticles on left mandible slightly better developed. Prostheca absent; molar region not developed. Basistipes with distinct setation. Maxillary palpi ( Fig. 3D ) short; palpomere 1 shortest, subconical, palpomeres 2 and 3 distinctly longer than palpomere 1; apical maxillary palpomere about same length as palpomere 1, slightly wider, bulbous at base and pointed at apex, with two rows of very distinct, club-shaped setae on outer edge of palpomere ( Figs 3F–I ); outer edge of palpomere with comb-like emarginations where apical portions of setae rest; galea slightly elongated, apex with setae forming two fan-shaped rows. Lacinia elongate, its mesal portion covered with straight, sparse setae, with two apical hooks ( Fig. 3E ). Mentum ( Fig. 3C ) more or less as wide as long, slightly trapezoid. Ligula narrow at base, then expanded strongly, transversely rhomboid, weakly sclerotized, anterior edge broadly triangular, covered with numerous setae. Labial palpomere 1 geniculately bent, long, almost devoid of setae; palpomere 2 broadly oval, shorter than palpomere 1; apical palpomere mounted laterally on inner margin, more or less globular, about same length as palpomere 2, without setae.

Pronotum ( Fig. 4A ) transverse, about 1.6–1.7× wider than its length, subtrapezoidal, widest in anterior portion, not flanged. Lateral edges curved, subcrenate. Front edge slightly rounded, projecting a little beyond front angles, covering base of head. Anterior angles triangular, posterior angles obtuse, rounded. Disc convex in middle. Sides of pronotum not explanate. Prosternum reduced in anterior portion; prosternal process longitudinally lanceolate, elongated (ca. 1.7–2.0× longer than wide), apex subtly bent ventrally.

Scutellar shield triangular, subequilateral to subtly transverse (1.1–1.2× wider than long), flat, with slightly rounded edges and acute apex. Elytra distinctly wider than pronotum, elongated, sides subparallel in proximal 1/2– 2/3, gap between sides of elytra and pronotum marked. Humeri pronounced, apices regularly rounded. Outer margin of elytra crenulate in humeral portion. Elytral striae weakly marked or absent, sutural stria subtly noticeable. Epipleuron flat, narrow, slightly narrower than metanepisternum at base, then strongly, regularly tapering towards apex of elytra, complete to apex. Sides of elytra not explanate.

Hind wing (Fig. 5) ca. 2.1× longer than its width; radial cell suboval; apical portion of r3 subtly marked, short; r4 not marked; rp-mp2 arcuate, forming right angle with MP1+2; MP4 long, oblique, joining MP3 but separated from CuA+AA1+2; anal field with one straight AP. Medial field with 3 free veins; pigmented areas in radial cell, central and apical fields.

Mesoventrite ( Fig. 6 ) short, anterior edge with pair of oblique procoxal rests, suture present throughout mesoventral process. Prosternal process rest triangular, with slightly rounded edges, slightly concave. Mesoventral process triangular, ca. 2.0× longer than wide, apex bilobed. Mesocoxal cavities widely separated. Mesanepisternum moderately wide, rhomboid, middle part with depression for procoxae, not sculptured. Mesepimeron narrower than mesanepisternum, triangular. Mesocoxae weakly elongated, suboval.

Metaventrite ( Fig. 6 ) long, convex, discrimen complete. Metanepisternum subtrapezoidal, ca. 2.5× longer than its width, slightly narrowing posteriorly. Metacoxae large, ca. 3× wider than its length, extending laterally to epipleura; metacoxal plate obliquely narrowing, absent in outer half. Metendosternite ( Fig. 4C ) elongated, lateral furcal arms relatively long; ventral processes well marked, triangular; anterior furcal arm reduced, in form of small denticles.

Legs rather long, femora extending beyond elytral margin; tibiae as long as or slightly longer than femora, slightly extended at apex, with pronounced paired carinae; metatibial spurs well developed, either dorsal spur slightly longer than ventral one or spurs of about same length.

Abdomen ca. 1.2× longer than wide, moderately convex. Ventrites 1–5 of subequal length, regularly covered with setae; ventrite 5 rounded, apex rounded. Laterosternites narrow, reduced in two-thirds of length of apical ventrite. Tergites I–VII slightly sclerotized, regularly covered with setae, apodemes on tergite VII not marked.

Male terminalia conform to Scirtidae ground plan ( Zwick 2015) except for penis morphology which has additional elements. Aedeagus symmetrical. Tegmen oval, with narrow parameres, with hooked projections in middle and cuticular ring connecting them at base. Trigonium widely bifurcate, very short or longer than parameroids. Pala oval, base semicircularly emarginated, slightly longer than parameroids. Parameroids narrow, with acute apices. Tergite VIII rectangular, with distinct apodemes and numerous short setae in apical portion; tergite IX rectangular with membranous apical portion, almost devoid of setae, with long apodemes. Sternite VIII transversely rectangular, U-shaped with very few setae and punctures concentrated on apical margin, distinctly wider than long; sternite IX oval to triangular, barely sclerotized, apodemes not visible.

Female. As for male except. TL 2.6–2.9 mm. Head narrower, as long as wide. Eyes small, distance from posterior margin of eye to occipital ridge about 1.5 larger than eye diameter. Elytra as in males ( M. testacea ), or with suboval depressions in apical portion of elytra (in M. dorsale , Fig. 4B ). Hind wings with distinctly shortened apical field (Fig. 5) or fully developed. Ventrite 5 rounded, apex truncate. Tergites I–VII slightly sclerotized, regularly covered with setae; apodemes on tergite VII present. Tergite VIII long, with paired apodemes; sternite VIII shorter, with paired apodemes which are connected at base; ovipositor long, with membranous coxites; prehensor suboval, massive, strongly sclerotized, covered densely with numerous spines. Ovipositor long, without branchlets, with membranous gonocoxites. Each gonostylus with two pairs of setal tufts ( Figs 10B , 12B ).

Etymology. Combination of Greek prefix “me” (µη), meaning “not” and the genus name Atopida ; genus different than Atopida . Gender feminine.

FIGURE 5. Meatopida testacea (Broun) , hind wing of male (A) and female (B). Abbreviations: AA—anterior anal veins, AP—posterior anal veins, CuA—anterior cubital vein, CuA+AA1+2—fusion of anterior cubital and anterior anal veins, MPposterior medial veins, r—radial cross-veins, rp+mp2—second radio-medial cross-vein.

Figures

FIGURE 1. Meatopida gen. nov., habitus. A) M. dorsale (Broun), male, B) M. dorsale (Broun), female, C) M. testacea (Broun), male, D) M.testacea (Broun), female. Scale bar = 1.0 mm.

FIGURE 2. Meatopida gen. nov., head. A) M. dorsale (Broun), dorsal view, B) M. dorsale (Broun), anterior view, C) M. testacea (Broun), anterovental view.

FIGURE 3. Male of Meatopida testacea (A–C, E–I) and M.dorsale (D), mouthparts. A) mandible, B) maxilla, C) labium, D) maxillary palpus, E) laciniar hooks, F) apical maxillary palpomere in lateral view, G) detail of apical maxillary palpomere in lateral view, H) apical maxillary palpomere in dorsal view, I) detail of apical maxillary palpomere indorsal view.

FIGURE 4. Meatopida gen. nov., morphological details. A) M. testacea (Broun), pronotum, B) M. dorsale (Broun), female, apex of elytra with excitators,C) M.testacea (Broun), male, metendosternite.

FIGURE 6. Meatopida testacea (Broun), ventrum. Abbreviations: mf—mesoventral fossa, sgr—subgenal ridge.

FIGURE 7. Meatopida gen.nov., male genitalia. A) M. testacea (Broun), B) M. dorsale (Broun).

FIGURE 8. Meatopida dorsale (Broun), male genitalia.A) penis, B) tegmen, C) tergite VIII, D) tergite IX, E) sternite VIII, F) sternite IX. Scale bar = 0.1 mm.

FIGURE 9. Meatopida dorsale (Broun), male genitalia in dorsal (A, C, E) and dorsolateral (B, D, F) view. A, B), specimen from Waitaanga Plateau, C, D), specimen from Erua, E, F), specimen from Great Barrier Island.

FIGURE 10. Meatopida dorsale (Broun), female genitalia. A) genital tract, B) coxites and styli, C) prehensor.Scale bar (A) = 0.5 mm.

FIGURE 11. Meatopida testacea (Broun), male genitalia. A) penis, B) tegmen, C) tergite VIII, D) tergite IX, E) sternite VIII, F) sterniteIX. Scale bar = 0.1 mm.

FIGURE12. Meatopida testacea (Broun), female genitalia.A) genital tract,B) coxites and styli, C) prehensor.Scale bar (A) = 0.5 mm.

FIGURE 13. Meatopida testacea (Broun), copulating pair collected in Waipoua Forest, genitalia fixed during copulation. A) male & female genitalia, dorsal view, B) male & female genitalia, lateral view, C) male genitalia of the same specimen, separated from female genitalia, D) female genitalia of the same specimen, prehensor everted. Abbreviations:cx—gonocoxite, pe—penis, preh—prehensor, s—sternite, st—gonostylus, t—tergite, tg—tegmen.