Argopistes tsekooni Chen, 1934

Figs 8 A – C, 9

Argopistes tsekooni Chen, 1934 b: 316 (China: Shanghai, Hangchow); Csiki 1940: 525 (catalogue); Chûjô and Kimoto 1961: 174 (China, Japan); Gressitt and Kimoto 1963: 813 (China: Jiangsu); Kimoto 1965: 437 (redescription); Lee and An 2001: 183 (South Korea); Lee and Cho 2006: 91 (host plant); Takizwa, 2012: 38 (faunistics); Cho and An 2020: 15 (North Korea); Won et al. 2023: 9 (South Korea: Ulleungdo).

Argopistes biplagiatus: Baly 1874: 202 (misidentification).

Type material examined.

One syntype • (sex undetermined, IZAS): “ 浙江 (= Zhejiang): 杭州 (= Hangchow) / 1934. [h] / 中国科學院 (= Chinese Academy of Sciences) [h, p] // 害水蜡樹 (attacking Ligustrum obtusifolium) [h, w] // Argopistes / tsekooni / Chen [h, w] ”. Although this specimen does not bear any type label, it should be regarded as type specimen since it fit the original description.

Additional material examined.

Japan. • 1 ♀ (NHMUK): “ Argopistes / biplagiatus / Motsch / Japan [h, w] // Baly Coll. [p, w] ” ; Honshu. Shizuoka: • 1 ♂ (SEHU), Tagata-gun, Tohi, 4. V. 1985, leg. Y. Komiya ; Tokyo: • 1 ♂ (HAPC), Komae-shi, Komai-machi, 10. VI. 2021, leg. R. Seki ; Yamaguchi: • 1 ♂ (NHMUK); Kyushu. Fukuoka: • 1 ♀ (HAPC), Fukuoka-shi, Higashi-ku, Shimobaru (alt. 100–360 m), 27. V. 2009, leg. S. Sejima ; • 1 ♀ (NHMUK), Mt. Mikazuki, 2. V. 1954, leg. K. Morimoto ; Nagasaki: • 1 ♂, 2 ♀ (SEHU), Sasebo-shi, Mt. Yahirodake, 14. IV. 1981, leg. J. Okuma ; • 1 ♂ (SEHU), same locality but with “ 21. IV. 1981 ”; Oita: • 2 ♂, 3 ♀ (HAPC), Hita-shi, Miwa, Chikura, 11. IV. 2016, leg. S. Sasaki.

Diagnosis.

Adults of A. tsekooni are recognized easily by their small body sizes (<3.5 mm;> 3.5 mm in others except A. unicolor), elongate ovate body shapes (elytra 1.2 × longer than wide; but 1.1 × longer than wide in others), and the combined red spots on elytra (usually separate red spots on the elytra in others); additionally, most genitalic characters are unique, such as the tube-like apex of the aedeagus (Fig. 9 C); few setae on apical margin of abdominal ventrite VIII in females (Fig. 9 E); and transverse gonocoxae with dense, long setae on the widely rounded apical margin (Fig. 9 G).

Redescription.

Length 2.8–3.2 mm, width 2.1–2.4 mm. Color (Fig. 8 A – C) blackish brown, elytron with one transverse orange area at basal 1 / 3, and narrowed towards suture; tarsi and front tibiae yellow; antennae dark brown but seven basal antennomeres yellow. Pronotum broad, convex, lateral margin narrowly explanate; 2.0–2.1 × wider than long, disc with dense coarse punctures; lateral margin rounded, anterior margin strongly concave, posterior margin moderately convex. Elytra elongate oval, 1.2 × longer than wide, disc with confused, dense, coarse punctures.

Male. Antenna filiform (Fig. 9 A), antennomere I much longer than others, approximate ratios of length of antennomeres I – XI 1.0: 0.4: 0.3: 0.5: 0.5: 0.5: 0.5: 0.5: 0.5: 0.5: 0.7; approximate ratios of length to width of antennomeres I – XI 3.1: 1.8: 2.0: 2.5: 2.3: 1.9: 1.8: 2.1: 2.1: 2.2: 2.9. Aedeagus (Fig. 9 C, D) gradually widened from basal 1 / 9–1 / 2, then gradually narrowed to basal 1 / 2, strongly widened posterior – basal 1 / 2; anterior opening large, ~ 0.39 as long as aedeagus, from apex to apical 2 / 5; tectum composed of one pair of sclerotized processes, long, ~ 0.85 as long as anterior opening, wide and slightly curved from basal 2 / 4 to apex in lateral view, recurved near apex; endophallic sclerite laterally flattened, with base twisted.

Female. Antenna (Fig. 9 B) similar to males, but antennomeres VII – X wider, 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: 0.6; ratios of length to width of antennomeres I – XI 3.8: 1.8: 2.0: 1.8: 1.9: 1.9: 1.6: 1.5: 1.5: 1.5: 2.4. Ventrite VIII (Fig. 9 E) weakly sclerotized, only part of apical margin well sclerotized, with several setae along apical margin, spiculum long and base wider. Spermathecal receptaculum (Fig. 9 F) longer than pump, moderately swollen, curved in lateral view; pump emarginated at inner side of base; spermathecal duct with long basal part, ramus truncate. Gonocoxae (Fig. 9 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.

Color variation.

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

Host plants.

Oleaceae: Ligustrum obtusifolium (Chûjô & Kimoto, 1961); Syringa oblata Lindl., L. japonicum, L. licidum, and L. sinense (Zhang et al. 2008 b) .

Biology.

The biology and life history of A. tsekooni were studied under laboratory and outdoor conditions in Huangshan City of Anhui Province, China (Zhang et al. 2009). Argopistes tsekooni overwintered as adults and had three overlapping generations in Anhui Province.

Distribution.

China, Japan (Honshu, Kyushu, the Goto Isls., Hirado-jima Is. Tsushima Is.), North Korea, South Korea.