Argopistes unicolor Jacoby, 1885

Lee, Chi-Feng, Chiang, Ming-Yao & Suenaga, Haruki, 2024, The genus Argopistes Motschulsky from Japan and Taiwan, with descriptions of three new species from Taiwan (Coleoptera, Chrysomelidae, Galerucinae, Alticini), ZooKeys 1215, pp. 151-183 : 151-183

Argopistes unicolor Jacoby, 1885

Figs 8 D – F , 10

Argopistes unicolor Jacoby, 1885: 738 ( Japan: Yuyama); Chûjô 1936: 109 (catalogue); Csiki 1940: 524 (catalogue); Chûjô and Kimoto 1961: 174 (catalogue); Kimoto 1965: 438 (redescription); Takizawa, 2012: 38 (faunistics).

Type material examined.

Lectotype • ♂ (here designated, NHMUK): “ (aedeagus glued on the transparent card) // Yuyama / 10. V. - 14. V. 81. [p, w] // Japan / G. Lewis. / 1910-320 [p, w] // Type / H. T. [p, w, circle label with red border] // Argopistes / unicolor. Jac. [h, b] // Argopistes unicolor JACOBY, / LECTOTYPUS 1885 / J. Král m. dit 1969! [h, w] // lecto- / typus [p, r] ” . Paralectotype. • 1 ♂ ( TARI): “ Yuyama [h] / Japan [p] / 10. V. 1881 [h] / Col. G. LEWIS [p, w] // Argopistes / unicolor Jac. [h] / Det. T. Shiraki [p, w] // Co / Type [p, w, circle label with yellow letters and border] // Argopistes / unicolor Jacoby [h] // DET. M. CHUJO [p, w] // 1527 [p, w] ” .

Additional material examined.

Japan. Kyushu. Nagasaki: • 3 ♂, 3 ♀ ( SEHU), Shimbara-shi, Senbuki , 8. V. 1984, leg. S. Imsaka ; • 2 ♂, 2 ♀ ( HAPC), same but with “ Senfujiki ”, collected on Ligustrum japonicum .

Diagnosis.

Adults of A. unicolor are recognized easily by their small body sizes (<3.5 mm;> 3.5 mm in others except A. tsekooni ), black antenna with three basal antennomeres paler (entirely yellowish-brown antennae in others except A. tsekooni with five dark apical antennomeres), and the entirely black elytra. Additionally, most genitalic characters are unique, including strongly curved aedeagus in lateral view (Fig. 10 E ), and anterior opening from apex to middle (Fig. 10 C ); straight apical margin of abdominal ventrite VIII in females (Fig. 10 F ) with setae reduced at medial area (other species with straight margin of abdominal ventrite VIII in female always with setae on median area); and longitudinally square gonocoxae (Fig. 10 H ).

Redescription.

Length 3.2–3.4 mm, width 2.3–2.5 mm. Color (Fig. 8 D – F ) black; legs and mouthparts dark brown; antenna black but three basal antennomeres dark brown; abdominal ventrites yellowish brown but medially darkened. Pronotum broad, convex, lateral margins narrowly explanate; 1.9–2.0 × wider than long, disc with dense coarse punctures; lateral margin rounded, anterior margin strongly concave, posterior margin moderately convex. Elytra broadly oval, 1.1 × longer than wide, disc with coarse punctures arranged into longitudinal striae, and with fine punctures between striae.

Male. Antenna filiform (Fig. 10 A ), antennomere I much longer than others, approximate ratios of length of antennomeres I – XI 1.0: 0.4: 0.3: 0.4: 0.4: 0.4: 0.4: 0.4: 0.4: 0.5: 0.7; approximate ratio of length to width of antennomeres I – XI 3.8: 1.8: 1.8: 2.0: 1.8: 1.6: 1.6: 1.7: 1.5: 1.6: 2.7. Aedeagus (Fig. 10 C – E ) widest at apical 1 / 4, slightly narrowed at middle, apically narrowed from apical 1 / 4, apex broadly rounded; anterior opening large, ~ 0.45 as long as aedeagus, from apex to middle; tectum composed of one pair of sclerotized processes, long, ~ 0.78 as long as anterior opening, paired processes with apices recurved in lateral view; endophallic sclerite laterally flattened, with one pair of long apical processes.

Female. Antenna (Fig. 10 B ) similar to males, ratios of length of antennomeres I – XI 1.0: 0.4: 0.3: 0.3: 0.4: 0.3: 0.4: 0.4: 0.4: 0.4: 0.6; ratios of length to width of antennomeres III – XI 3.4: 1.9: 1.9: 1.9: 1.7: 1.5: 1.6: 1.7: 1.5: 1.6: 2.4. Ventrite VIII (Fig. 10 F ) weakly sclerotized, T-shaped, with several pairs of setae along apical margin, spiculum long. Spermathecal receptaculum (Fig. 10 G ) longer and wider than pump, moderately swollen; pump emarginate at inner side of base; spermathecal duct with long basal part, ramus rounded. Gonocoxae (Fig. 10 H ) wide and separated, base membranous, each gonocoxa subquadrate, with sparse setae along apical areas.

Color variation.

One male has a black body and lacks transparent spots on the elytra. Another male has an entire yellowish-brown body.

Host plants.

Oleaceae : Osmanthus heterophyllus (= Olea ilicifolia Hassk. ) ( Chûjô and Kimoto 1961), Ligustrum japonicum (based on collecting data).

Biology.

Unknown.

Distribution.

Japan (Honshu, Kyushu, Hirado-jima Is.).

Figures

Figure 8. Habitus of Argopistes species A A. tsekooni Chen, male, dorsal view B ditto, ventral view C ditto, lateral view D A. unicolor Jacoby, female, dorsal view E ditto, ventral view F ditto, lateral view.

Figure 10. Argopistes unicolor Jacoby A antenna, male B antenna, female C apex of aedeagus, front view D base of aedeagus, dorsal view E aedeagus, lateral view F abdominal ventrite VIII, female G spermatheca H gonocoxae.