Argopistes yuae sp. nov.

Figs 14 C, D, 15, 16

Type material examined.

Holotype • ♂ (TARI). Taiwan. Taitung: Lanyu (蘭嶼), 16. IV. 2023, leg. Y. - F. Hsu . Paratypes • 11 ♂, 7 ♀ (TARI), same data as holotype; • 10 ♂, 5 ♀ (TARI), same but with “ 20. III. 2023 ”; • 8 ♂, 5 ♀ (TARI), same but with “ 17. VI. 2023 ”; • 2 ♂, 3 ♀ (TARI), same island, 14. III. 2023, leg. Y. - Y. Liu & Y. - F. Hsu; • 1 ♀ (TARI), same island, 28. IV. 2022, leg. S-F. Yu; • 1 ♂ (TARI), same island, 4. IV. 2016, leg. Y. - T. Chung; • 1 ♂ (TARI), same island, 14. IV. 2013, leg. B. - X. Guo; • 1 ♂ (TARI), same island, 26. IV. 2009, leg. U. Ong; • 3 ♂, 3 ♀ (TARI), same island, 18. III. 2024, leg. Y. - F. Hsu; • 4 ♂, 3 ♀ (TARI), same island, 24. IV. 2024, leg. J. - C. Chen; • 6 ♂, 3 ♀ (NHMUK), same island, Lanyu Weather Station (蘭嶼氣象站), 22 ° 02.238 ' N, 121 ° 33.287 ' E, 26. VII. 2008, hand collecting, leg. M. V. L. Barclay & H. Mendel ; • 2 ♂, 1 ♀ (TARI), same island, Tataienchih (大天池), 19. III. 2024, leg. Y. - F. Hsu.

Diagnosis.

Adults of this new species are not separable from those of A. rufus except by genitalic characters, including parallel-sided apex of aedeagus with anterior opening very close to apex of aedeagus, from apical 1 / 12–3 / 5 (Fig. 16 C) (apically narrowed aedeagus with anterior opening not so close to apex of aedeagus, from apical 1 / 8–3 / 5 (Fig. 6 C) in A. rufus); deeply notched apical margin of abdominal ventrite VIII (Fig. 16 E) in females (shallowly notched apical margin of abdominal ventrite VIII (Fig. 6 E) in females of A. rufus). In addition, this new species is restricted to Lanyu Island, and thus is isolated from other species geographically. Moreover, larvae and adults of this new species feed on leaves of Chionanthus ramiflorus Roxb. (Fig. 14 C, D) but not those of Osmanthus fragrans based on laboratory rearing tests. Thus, both species are allopatric ecologically since Osmanthus fragrans is one of the host plants for A. rufus .

Description.

Length 4.2–4.3 mm, width 3.5 mm. Color (Fig. 15 A – C) blackish brown, elytron with one large transparent area at basal 1 / 3, near or connected with suture; tarsi and antennae yellowish brown. Pronotum broad, convex, lateral margin narrowly explanate; 2.3 × 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 confused, dense, fine punctures.

Male. Antenna filiform (Fig. 16 A), antennomere I much longer than others, approximate ratios of length of antennomeres I – XI 1.0: 0.4: 0.3: 0.5: 0.4: 0.4: 0.4: 0.5: 0.5: 0.4: 0.6; approximate ratios of length to width of antennomeres I – XI 3.8: 2.0: 2.0: 2.7: 2.0: 1.9: 1.9: 1.9: 1.8: 1.9: 2.8. Aedeagus (Fig. 16 C, D) parallel-sided from basal 1 / 3–2 / 3, apically narrowed from apical 1 / 3–1 / 6, apex tube-like; anterior opening large, ~ 0.53 as long as aedeagus, from apical 1 / 12–3 / 5; tectum composed of one pair of sclerotized processes, small, ~ 0.43 as long as anterior opening; wide and slightly curved in lateral view; paired processes curved at apical 1 / 3 in lateral view; endophallic sclerite laterally flattened, with basal processes slightly sclerotized, and one pair of small processes near apex.

Female. Antenna (Fig. 16 B) similar to males, 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: 0.4: 0.5; ratios of length to width of antennomeres III – XI 4.9: 1.9: 2.3: 2.5: 2.0: 1.8: 1.9: 1.8: 1.8: 1.9: 2.5. Ventrite VIII (Fig. 15 E) weakly sclerotized, T-shaped, with several pairs of setae along apical margin, setae smaller at sides, apical margin medially depressed, spiculum long. Spermathecal receptaculum (Fig. 16 F) longer than pump, moderately swollen, curved in lateral view; pump emarginate at inner side of base; spermathecal duct with long basal part, ramus rounded. Gonocoxae (Fig. 16 G) wide and separated, base membranous, each gonocoxa asymmetric, apically narrowed from near base, with sparse setae along apical areas, setae longer at apical 1 / 2.

Variation.

A few specimens have black bodies and lack red spots on elytra (Fig. 14 D – F).

Host plant.

Oleaceae: Chionanthus ramiflorus Roxb.

Biology.

This species seems to be univoltine. The larvae (Fig. 14 D) were found only during late March.

Etymology.

This new species is named for Su-Fang Yu (余素芳), the first person to collect specimens.

Distribution.

Endemic to Lanyu Island (Fig. 5).