Picolistrus Majer, 1990 - Majer 1990: 377.

Body small-sized and stout, 1.3–3.0 mm in length. Upper body surface densely covered with very fine, short and recumbent pubescence. Lateral margins of pronotum and elytra fringed with erect hairs obliquely directed backwards (Fig. 1). Antennomeres 6–9 at most as wide as long, mostly transverse. All tibiae with fixed spines along the length of the outer face in both sexes and males with enlarged fixed spurs at the apical inner base of one or all tibiae (pro-, meso- and/or metatibiae); tarsi shorter than tibiae, tarsomeres 1–4 wider than long; tarsal claws symmetrical, with a pair of completely membranous appendages, which are about as long as claws. Abdominal sternite VIII completely separated, with median process often expressively reduced or absent in males (Fig. 2A). Apex of tegmen without any setae, not or slightly protruding apically (Fig. 2C); apical limb of median lobe elongate triangular at distal half and sharp at apex in ventral view (Fig. 2E), basal limb strongly bent ventrally, at an angle of at least 90˚ with the apical limb, apical limb prominently angled near middle, tapered apically and apex slightly incurved ventrally in lateral view (Fig. 2F). Spiculum gastrale (Fig. 2G) Y-shaped. Ovipositor (Fig. 3C) stout and membranous, gonostylus long and nearly cylindrical, transverse coxital baculus short and bisinuate, baculus long and oblique.

Figure 1.  

Habitus of Picolistrus flavoapicalis Y. Yang & Miao, sp. nov., dorsal view: A male; B female. Scale bars: 1.0 mm.

Figure 2.  

Picolistrus flavoapicalis Y. Yang & Miao, sp. nov., holotype, male: A abdominal sternite VIII, ventral view; B pygidium, dorsal view; C tegmen, ventral view; D tegmen, lateral view; E median lobe, ventral view; F median lobe, lateral view; G spiculum gastrale, ventral view. Scale bars: 0.2 mm.

Figure 3.  

Picolistrus flavoapicalis Y. Yang & Miao, sp. nov., paratype, female: A abdominal sternite VIII, ventral view; B pygidium, dorsal view; C ovipositor, ventral view. Scale bars: 0.2 mm.

China (Yunnan), Myanmar (Tenasserim) (Fig. 4).

Figure 4.  

Distribution map of all Picolistrus species.

Male (Fig. 1A). Body length 2.25 mm, width 0.78 mm.

Body black with slight lustre, elytral apices brownish-yellow. Antennomeres 1 blackish-brown, 2–11 brownish and gradually darkened towards apex. Legs brownish-yellow, with femora, tibiae and tarsomeres more or less darkened at apices. Body surface densely and shallowly punctate, densely covered with short and recumbent light yellow pubescence, pubescence on pronotum directing medially and posteriorly towards the mid-point of posterior margin.

Eyes moderately prominent, head width across eyes feebly wider than anterior margin of pronotum. Antennae extending to posterior 1/8 length of pronotum when inclined, with antennomeres 1 nearly conical, 2 ellipsoidal, 3–5 triangular and longer than wide, 6–10 globular, 11 fusiform, 1.5 times as long as wide.

Pronotum transverse and 1.2 times as wide as long, widest behind middle, anterior and posterior margins slightly arcuate, lateral margins arcuate with sparse crenation, anterior and posterior angles widely rounded. Elytra subparallel-sided, 1.9 times longer than humeral width, 2.3 times longer than pronotum, elytral edges fine, but distinct, rounded at apices. Protibia and mesotibia each with a concave, lamellate fixed spur at apical inner base.

Abdominal sternite VIII (Fig. 2A) strongly transverse and bilobed, rectangularly emarginate at posterior margin, acute at antero-lateral angles, present with a very short median process, surface covered with a few erect setae near posterior margin. Pygidium (Fig. 2B) slightly longitudinal, 1.2 times longer than wide, feebly narrowed posteriorly, slightly arcuate at anterior margin, not emarginate at posterior margin, with antero-lateral angles protruding and acute at apices, surface covered with a few long erect setae and short erect hairs along posterior margin.

Aedeagus: tegmen (Fig. 2C) with an elliptic subapical ring extending beyond middle from apical 1/8, both apex and base approximately triangular in ventral view; median lobe with apical limb more than 9.0 times longer than basal width in lateral view (Fig. 2F). Spiculum gastrale (Fig. 2G) with basal trunk shorter than apical branch.

Female (Fig. 1B). Similar to male, but body larger, 2.49–2.54 mm in length, 0.82–0.83 mm in width. Antennae slightly shorter, extending to posterior 1/4 length of pronotum when inclined, with antennomeres 6–10 slightly transverse. Pronotum 1.3 times as wide as long. Elytra distinctly dilated across apical third, 2.1 times longer than humeral width, 2.5 times longer than pronotum. Each tibia with two ordinary, sharp spurs at apical inner base. Abdominal sternite VIII (Fig. 3A) bilobed, with antero-lateral angles acute, median process very slender and distinctly extending beyond antero-lateral angles. Pygidium (Fig. 3B) shallowly emarginate in middle of anterior margin, not emarginate at posterior margin, with antero-lateral angles obviously protruding and round at apices.

This species can be easily distinguished from all other species of Picolistrus by the bicoloured elytra, which are black and brownish-yellow at apices (Fig. 1), tegmen sharp at apex in ventral view (Fig. 2C) and apical limb of median lobe slender, more than 9.0 times longer than basal width (Fig. 2F). In comparison, the elytra of all others are uniformly black or brown, except for P. palleatus Majer 1990, whose elytra are testaceous with a large shadowy spot around black scutellum. Tegmen of all others are broadly rounded (Majer (1990): fig. 71; Plonski (2016): fig. 3) or slightly emarginate at apex (Majer (1990): fig. 52). Apical limb of median lobe is less elongate, at most 6.0 times longer than basal width in others (Majer (1990): figs. 53, 69, 72 and 73; Plonski (2016): fig. 2).

The species epithet is derived from the Latin flavus (yellow) and apicalis (of or belonging to an apex), referring to its elytra with brownish-yellow apices.

China (Yunnan) (Fig. 4).