Argopistes rufus Chen, 1934

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 rufus Chen, 1934 stat. nov.

Figs 1 , 2 G, H , 6 , 7

Argopistes coccinelloides Baly, 1874 (nec Suffrian, 1868): 202 ( Japan); Chûjô 1935 a: 87 ( Japan: Okinawa); Chûjô 1935 b: 211 (catalogue).

Argopistes biplagiatus : Schönfeldt 1890: 175 ( Japan: Loochoo); Chûjô 1936: 110 (Taiwan), misidentification ( Gressitt and Kimoto 1963).

Argopistes biplagiatus var. rufus Chen, 1934 a: 72 ( China).

Argopistes coccinelliformis Csiki, 1940: 524 (new replacement name for A. coccinelloides Baly, 1874); Chûjô and Kimoto 1961: 174 (catalogue); Gressitt and Kimoto 1963: 812 (South China); Kimoto 1965: 436 (redescription); Takizwa, 2012: 38 (faunistics).

Argopistes ryukyuensis Shigetoh & Suenaga, 2022: 4 ( Japan: Okinawa). syn. nov.

Type material examined.

Argopistes coccinelloides . Holotype • (sex undetermined, NHMUK) (Fig. 2 G, H ): “ Argopistes / coccinelloides / Baly / Japan [h, b] // Type / H. T. [p, circle label with red border] // Baly Coll. [h, w] // BMMH (E) / # 1024843 [p, w] ”.

Argopistes biplagiatus var. rufus . Lectotype • ♀ (here designated, NHMUK): “ China [p] // Bowring / 63 • 37 * [p] // Argopistes coccinelliformis / Csiki, 1940 / det C. - F. Lee, 2023 [p] ♀ [h, w] // NHMUK 015998267 [with OR Code, p, w] ” . Paralectoypes • 3 ♀ ( NHMUK), same as lectotype but with “ 0155998268–0155998270 ” .

Argopistes ryukyuensis . Paratypes. Japan: Kitadaitô-jima Island (北大東島) : • 1 ♂, 3 ♀ ( HAPC), Kitadaitô-jima , 21. IV. 2018, leg. H. Kawase ; Okinawa-jima Island: • 1 ♂ ( HAPC), Tomigusuku-shi , Tomigusuku, 10. V. 2020, leg. H. Shigetoh ; 1 ♂, 1 ♀ ( HAPC), same but with “ 11. III. 2021 ” ; Ou-jima Island: • 1 ♀ ( HIPC), Nanjo-shi , Tamashiro-ou, 6. V. 2019, leg. H. Shigetoh ; • 3 ♂, 1 ♀ (1 ♂: HAPC; 2 ♂, 1 ♀: HIPC), same but with “ 2. III. 2021 ” ; Tonaki-jima Island : • 1 ♂, 1 ♀ ( HIPC), Tonaki-son , Uaki, 1. IX. 2018, leg. H. Shigetoh ; Tsuken-jima Island: • 1 ♀ ( HAPC), Uruma-shi , Katsurentsuken, 14-16. VII. 2020, leg. H. Shigetoh ; Yonaguni-jima Island: • 1 ♂, 1 ♀ ( HAPC), Kita-Bokujô , 28. III. 2001, leg. S. Tsuyuki.

Additional material examined.

China. Guandong: • 7 ♂, 6 ♀ ( TARI), Yangtaishan (阳台山), 23. IV. 2022, leg. Y. - Y. Ruan ; • 13 ♂, 11 ♀ ( TARI), Wutongshan (梧桐山), 5. IV. 2023, leg. Y. - Y. Ruan ; Hong Kong: • 2 ♂, 1 ♀ ( NHMUK), 56 / 157, 894 / 7 / 8 / 63 ; • 1 ♂ ( NHMUK), Walker Coll., 93—58 ; • 1 ♂ ( NHMUK), Tailung National Park , 12. III. 1963, leg. P. Y. So ; Japan. Honshu. Gumma: • 1 ♀ ( NHMUK), Maebashi-shi, Iwakami-chô , 18. IV. 2003, leg. Y. Komiya ; Okayama: • 1 ♀ ( HAPC), Mimasaka-shi, Yono , 10. IV. 2016, leg. H. Suenaga ; • 1 ♂ ( HAPC), Okayama-shi, Kita-ku, Kibi service area , 1. VII. 2012, leg. O. Yamaji ; • 2 ♂, 2 ♀ ( HAPC), Tsuyama-shi, Yamakita , 3. IV. 2014, leg. H. Suenaga ; Tokyo: • 3 ♂, 3 ♀ ( HIPC), Hachiôji-shi, Kinugaoka , 18. VI. 2016, leg. H. Shigetoh ; Hachijô-jima Island: • 2 ♂, 2 ♀ ( SEHU), Okagô , 3. VIII. 1963, leg. Y. Kamiya ; Ogasawara Haha-jima Island: • 1 ♂ ( SEHU), Funamidai , 24. VI. 1987, leg. H. Akiyama ; Kyushu. Fukuoka: • 1 ♀ ( HAPC), Fukuoka-shi, Higashi-ku, Hakozaki Kyushu Univ. , 7. VI. 2008, leg. Y. Matsumura ; • 1 ♀ ( HAPC), Fukuoka-shi, Hakozaki , 16. VIII. 2011, leg. H. Suenaga ; Kagoshima: Koshiki-jima Island: • 1 ♀ ( SEHU), Teuchi , 16. V. 1965, leg. Y. Komiya ; the Ryukyus. Okinawa: Kita-daitô-jima Island: • 2 ♂, 2 ♀ ( HIPC), Kita-daitô-jima , 21. IV. 2018, leg. H. Kawase ; Taiwan. Hsinchu: • 3 ♂, 6 ♀ ( TARI), Hsinchu (新竹市), 23. IV. 2021, leg. C. - Y. Tsai ; Kinmen: Kinmen Island (金門島): • 1 ♀ ( TARI), Botanic Park (植物園), 12. VII. 2023, leg. C. - F. Lee ; • 3 ♂, 14 ♀ ( TARI), Jinsha (金沙), 12. IV. 2023, leg. C. - F. Lee ; Matsu Islands: • 10 ♂, 11 ♀ ( TARI), Beigan Island (北竿島), 12. IV. 2024, leg. C. - F. Lee ; • 6 ♂, 10 ♀ ( TARI), Nangan Island (南竿島), 12. IV. 2024, leg. C. - F. Lee ; Nantou: • 4 ♂, 5 ♀ ( TARI), Chichi (集集), 26. V. 2023, leg. T. - W. Hsu ; • 2 ♂ ( TARI), Mingchien (名間), 14. VII. 2022, leg. Y. - J. Tung ; Taipei: • 1 ♂, 1 ♀ ( TARI), Kuantu (關渡), 8. IV. 2020, leg. M. - H. Tsou ; • 4 ♂, 1 ♀ ( TARI), same locality, 18. X. 2010, leg. S. - F. Yu ; • 1 ♀ ( TARI), same but with “ 20. II. 2011 ” ; • 5 ♂, 6 ♀ ( TARI), Kuanyinshan (觀音山), 21. III. 2016, leg. H. - T. Cheng ; • 2 ♂ ( TARI), same locality, 20. V. 2011, leg. H. Lee.

Diagnosis.

Adults of A. rufus look similar to those of A. biplagiatus with a similar color pattern, but differ from A. biplagiatus in having lines of punctures much coarser than those between the lines (lined punctures slightly coarser than those between lines, sometime confused in A. biplagiatus ) and a narrower interspace between eyes. Genitalic characters are diagnostic for both species. Those of A. rufus possess widely rounded apices (Fig. 6 C ) and the aedeagus is narrow in lateral view (Fig. 6 D ) (pointed apex (Fig. 3 C ) and wider aedeagus in lateral view (Fig. 3 D ) in A. biplagiatus ); females have medially widened gonocoxae (Fig. 6 G ) (narrow and parallel-sided base of gonocoxae (Fig. 3 G ) in A. biplagiatus ), and abdominal ventrite VIII medially depressed and without setae on median area (Fig. 6 E ) (evenly rounded and with dense setae on apical margin of abdominal ventrite VIII (Fig. 3 E ) in A. biplagiatus ).

In addition, adults of A. rufus in Taiwan are smaller (3.8–4.3 mm) than those of A. biplagiatus (4.7–4.9 mm). Moreover, distinct color patterns occur to both species respectively (yellowish brown elytra with distinct arrangement of black spots in A. rufus ; black elytra with reddish brown central area in A. biplagiatus ).

Redescription.

Length 3.6–4.3 mm, width 2.9–3.4 mm. Color variable (see below). Pronotum broad, convex, lateral margin narrowly explanate; 2.1–2.2 × wider than long, disc with dense fine 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 dense fine punctures between striae.

Male. Antenna filiform (Fig. 6 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: 0.4: 0.5; approximate ratios of length to width of antennomeres I – XI 4.3: 2.0: 2.0: 2.0: 2.0: 1.8: 1.5: 1.6: 1.7: 1.7: 2.7. Aedeagus (Fig. 6 C, D ) apically and strongly narrowed from apical 1 / 3, apex truncate; anterior opening large, ~ 0.52 as long as aedeagus, from apical 1 / 8–3 / 5; tectum composed of one pair of sclerotized processes with bifurcate apices, outer apex hooked, small, ~ 0.36 as long as anterior opening; narrow and slightly curved in lateral view; paired processes apically curved in lateral view; endophallic sclerite laterally flattened, with small process near apex, and with basal processes.

Female. Antenna (Fig. 6 B ) similar to males, ratios of length of antennomeres I – XI 1.0: 0.4: 0.3: 0.4: 0.4: 0.3: 0.3: 0.4: 0.4: 0.4: 0.5; ratios of length to width of antennomeres III – XI 4.4: 1.9: 2.0: 2.2: 1.8: 1.6: 1.4: 1.7: 1.6: 1.6: 2.3. Ventrite VIII (Fig. 5 E ) weakly sclerotized, T-shaped, with several setae along apical margin, apical margin medially depressed, spiculum long. Spermathecal receptaculum (Fig. 6 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. 6 G ) wide and separated, base membranous, each gonocoxa asymmetric, apically narrowed from basal 1 / 3, with sparse long setae along apical areas.

Color variation.

In Japanese populations, antennae yellowish brown; pronotum and elytra black, each elytron with one large red spot, sometimes widened and spots connected to each other, red spot reduced in some individuals; mesoventrite and abdominal ventrites reddish brown but medially black; femora blackish brown, tibiae dark brown, tarsi yellowish brown; few individuals have entirely reddish-brown bodies. In the Ryukyus, adults usually have larger red spots on the elytra and reddish-brown elytral margins (described as A. ryukyuensis Shigetoh & Suenaga, 2022 ).

On Taiwan Island, adults separate into two color forms. Typical form (Fig. 7 A – C ): black elytron with one large red spot, same as Japanese populations; yellowish brown color form (Fig. 7 D – F ): elytra with wide black stripe along suture, starting from base, apically narrowed and abbreviated at basal 1 / 3, with two pairs of black spots halfway between suture and lateral margin, anterior pair at base, posterior pair at apical 1 / 3, one wide black stripe along lateral margin, starting from base, apically narrowed, abbreviated at basal 1 / 3 or 1 / 4; abdominal ventrites medially darker. This color form is also found in Nangan Island.

In China and Kinmen Island, almost all adults belong to the typical form. A few specimens have entirely reddish-brown bodies (Fig. 7 G – I ). Three specimens collected from Hong Kong also have reddish bodies.

Host plants.

Inoue (2014) recorded Osmanthus × fortunei , O. heterophyllus , O. fragrans (桂花), O. fragrans var. aurantiacus , O. insularis Koidz , Ligustrum japonicum (日本女真), L. licidum , L. ovalifolium , L. obtusifolium , Syringa vulgaris , S. reticulata , Jasminum nudiflorum Lindl. , and Olea europaea L. as host plants in Japan. In Taiwan, larvae mine the leaves of the following plants: Chionanthus retusus (in Taiwan Island, Nangan, and Beigan islands), Ligustrum japonicum (in Beigan island), and Osmanthus fragrans (in Kinmen Island).

Biology.

Various aspects of the biology of A. rufus were studied in Japan, including feeding habits, habitat selection, seasonal development, and developmental biology on various host trees, developmental success of larvae on two different host trees, seasonal trends of feeding and oviposition activities of adults, effects of food condition on oviposition, overwintering and oviposition ability of adults that emerge late in the season, effects of photoperiod and temperature on induction of reproductive diapause in newly emergence adults, and occurrence on olive trees ( Inoue and Shinkaji 1989 a – c, 1990; Inoue 1990 b, 1991 a, 1998, 2001, 2014).

The seasonal development of this species was studied in the field in southern Kantô, Central Japan ( Inoue 1996). Overwintered adults appeared on host trees beginning mid-March, with a peak in mid-April to early May. Females began to deposit eggs from mid- to late April. The eggs were laid singly, embedded in young leaves, and coated with excrement. Leaf-mining larvae only developed in new leaves. Larvae underwent three larval instars and mature larvae crawled down to pupate in the upper layers of soil. Adults eclosed in mid-June, with a peak in later June-early July. They mainly fed on mature leaves. Adults passed the winter near the ground, mainly under fallen leaves. The egg, larval, prepupal, and pupal period took ~ 10, 20–30, 10–15, and 10–15 days respectively during spring to early summer. In Taiwan, larvae and adults can be found during April.

Remarks.

Argopistes biplagiatus var. rufus was described by Chen (1934 a) based on four reddish brown individuals (Fig. 7 G – I ) deposited in the NMHUK. We found the determination label: “ Argopistes / biplagiatus / var. rufa ”, handwritten by Chen pinned with one typical form (Fig. 7 A – C ). Four adjacent females fit the original description (reddish brown body form) and bore two labels “ China / Bowring ” although no determination labels were found. Thus, those specimens were designated as lectotypes and paralectotypes. Bezděk and Konstantinov (2024) placed this name as a junior synonym of A. coccinelliformis Csiki, 1940 . Actually, it is a distinct species and attributed to the oldest available name. Thus, the valid name is Argopistes rufus Chen, 1934 , stat. nov.

Adults of A. rufus and A. ryukyuensis are not separable when Taiwanese and Chinese specimens are included. Aedeagi of both areas are intermediate between A. rufus and A. ryukyuensis . Moreover, one distinct color pattern (yellowish-brown elytra with black spots) occurs in Taiwanese populations. Thus, color patterns may not be considered as diagnostic characters. Other diagnostic characters provided by Shigetoh and Suenaga (2022) are not diagnostic for species delimitation. Thus A. ryukyuensis Shigetoh & Suenaga, 2022 is regarded as junior synonym of A. rufus Chen, 1934 .

Distribution.

China, Japan (Honshu, the Izu Isls., Ogasawara Isls., Shikoku, Kyushu, Okinoshima Is., Kashiwa-jima Is., the Koshiki-jima Isls., Yakushima Is., the Ryukyu Isls.), Taiwan including Kinmen Island and Matsu Islands (Beigan and Nangan Islands) (Fig. 5 ).

Figures

Figure 1. Field photographs of Argopistes rufus Chen A adults feeding on leaves of Chionanthus retusus surrounding Hsinchu City Government on April 23, 2021 B mature larvae mining leaves of the same tree C blooming C. retusus at Qingshui Village (清水村), Nangan Island (南竿島), on April 21, 2024 D larvae mining leaves near the ground of the same tree E larvae mining leaves of Osmanthus fragrans at Yingshan Temple (鶯山廟), Kinmen Island (金門島), on April 11, 2023 F larvae mining leaves of Osmanthus fragrans at the guesthouse, Jinhu Township (金湖鎮), Kinmen Island, on May 20, 2024 G C. retusus (red arrow) and Ligustrum japonicum (blue arrow) planting surrounding Chinbe Village (芹壁村), Beigan Island (北竿島) on 22 April 22 2024 H feeding marks caused by adults on leaves of L. japonicum.

Figure 2. Type specimens and labels A Argopistes biplagiatus Motschulsky, 1860, syntypes B one syntype with typical color form C one syntype with enlarged red spots on elytra D labels pinned with syntypes E A. undecimmaculata Jacoby, 1885, lectotype F labels pinned with lectotype G A. coccinelloides Baly, 1874, holotype H labels pinned with holotype.

Figure 3. Argopistes biplagiatus Motschulsky A antenna, male B antenna, female C aedeagus, dorsal view D aedeagus, lateral view E abdominal ventrite VIII, female F spermatheca G gonocoxae.

Figure 5. Distribution map of Argopistes species in Taiwan, solid line: 1000 m, broken line: 2000 m. Red dots A. rufus Chen; blue dots A. biplagiatus Motschulsky; green dots A. tsoui sp. nov.; orange dots A. yuae sp. nov.; purple dot A. jungchani sp. nov.

Figure 6. Argopistes rufus Chen A antenna, male B antenna, female C aedeagus, dorsal view D aedeagus, lateral view E abdominal ventrite VIII, female F spermatheca G gonocoxae.

Figure 7. Habitus of Argopistes rufus Chen A typical color form, male, dorsal view B ditto, ventral view C ditto, lateral view D yellowish brown color form, female, dorsal view E ditto, ventral view F ditto, lateral view G reddish brown color form, male, dorsal view H ditto, ventral view I ditto, lateral view.