Phygasia diluta Chûjô, 1963

Lee, Chi-Feng, 2012, The genus Phygasia Chevrolat (Coleoptera: Chrysomelidae: Galerucinae: Alticini) in Taiwan, Zootaxa 3256, pp. 27-37 : 30-32

Phygasia diluta Chûjô, 1963 , status resurrected

( Figs 4, 5 , 10, 11 , 15, 18, 21, 24, 26–32)

Phygasia ornata: Chûjô, 1936: 18 (part); Kimoto, 1991: 24 (part).

Phygasia ornata diluta Chûjô, 1963: 400 ; Kimoto, 1966: 35 (part); Kimoto and Takizawa, 1997: 411 (synonymized with P. ornata ).

Phygasia diluta: Kimoto, 1971: 78 (raised to species rank).

Phygasia taiwanensis Ge et al., 2010: 325 . New synonym

Description. Male. Length 5.8–6.4 mm, width 3.1–3.5 mm. General color ( Fig. 4 ) yellowish-brown; antennomeres III-XI darkened, tibia basally darkened; elytron white; one transverse black spot at humerus and subapically, apex orange, with narrow transverse black band between white and orange areas. Pronotum about 1.8 times wider than long, disc smooth, with scattered fine punctures. Elytra 1.4 times longer than wide, lateral margin slightly rounded, widest just behind middle, disc with densely distributed small punctures and randomly occurring large punctures.

Antennomeres III-VII widened ( Fig. 10 ); ratio of length of antennomeres III to XI about 1.0: 0.8: 0.9: 0.9: 0.9: 0.9: 0.8: 0.8: 1.0, ratio of length to width of antennomeres III to XI about 1.7: 1.4: 1.5: 1.6: 1.8: 1.8: 2.1: 2.5: 3.2. Penis (Figs 15a, b) elongate, about 4.3X longer than wide, apex of tectum a little lower than that of penis, subparallel-sided, strongly narrowed subapically, apex rounded, moderately curved in lateral view; ventral side evenly convex.

Female. Length 5.3–7.0 mm, width 3.0–4.0 mm. Similar to males, but antennomeres III-VIII narrower ( Fig. 11 ), ratio of length of antennomeres III to XI about 1.0: 1.0: 1.1: 1.0: 1.0: 1.0: 0.8: 0.8: 1.2, ratio of length to width of antennomeres III to XI about 2.1: 2.0: 2.2: 2.2: 2.3: 2.6: 2.4: 2.6: 4.0. Gonocoxa ( Fig. 18 ) medially connected, apex widely rounded, base weakly sclerotized, three long setae at apex, three long setae at outer side. Spermatheca ( Fig. 21 ) with receptacle strongly swollen; pump strongly curved, apex rounded; proximal spermathecal duct wide. Spiculum of sternite VIII ( Fig. 24 ) longer then P. chengi but shorter than P. o r n a t a. Bursa-sclerites highly variable. Some individuals with only one pair of bursa-sclerites, each with single seta; others with two pairs of bursa sclerites, dorsal pair ( Figs 27 a, 28a) better developed, with three or four prominent setae, base well-sclerotized; ventral pair ( Figs 27 b, 28b) with one to three prominent setae but base weakly-sclerotized.

Color variation. In some specimens, the transverse black spots on humerus and near elytral apex form transverse bands across elytral base and apex and the antennomeres III-XI, tibia, and tarsus are almost black ( Fig. 5 ).

Diagnosis. Phygasia diluta differs from P. ornata and P. chengi by its yellow-brown or dark brown antenna, tibia, and tarsus (antenna, tibia, and tarsus black in P. ornata and P. chengi ); relatively wider penis (4.3 times longer than wide) compared to P. ornata (4.6 times longer than wide) and narrower penis compared to P. chengi (3.9 times longer than wide); relatively longer sternite VIII compared to P. chengi and shorter sternite VIII compared to P. ornata ..

Type material examined. Holotype 3 ( Fig. 29 ) of Phygasia ornata diluta Chûjô labeled ( Fig. 30 ): “ Formosa Sauter / Takao (= Kaoshiung city) 1907. VIII.1 / Holotypus Phygasia ornata ssp. diluta Chujo / Holotype / Phygasia ornata diluta CHUJO Det. M. CHUJO, 1961” ( HNHM). Allotype Ƥ ( Fig. 31 ) labeled ( Fig. 32 ): “ Formosa Sauter / Kanshirei (= Kuangtyling, Tainan county) 908. VI.7 -(19)15. / Allotypus Phygasia ornata ssp. diluta Chujo / Allotype / Phygasia ornata diluta CHUJO Det. M. CHUJO, 1961” ( HNHM).

Material examined (27 specimens). 1Ƥ, Pingtung, Kankau (= Changkou), 27.V.1932, leg. R. Takahashi ( TARI); 1Ƥ, Pingtung, Kuaru (= Kenting), 15.VI.1937, leg. M. Chujo ( TARI); 1Ƥ, same locality, 18–23.III.1981, leg. K. S. Lin & T. Lin ( TARI); 13, same locality, 22-26.III.1982, leg. T. Lin & S. C. Lin ( TARI); 1Ƥ, same locality, 24.XI.2009, leg. C.-F. Lee ( TARI); 43, 4ƤƤ, Pingtung, Sheting, 15.VIII.2009, leg. S.-F. Yu ( TARI); 23, 5ƤƤ, same but with “leg. M.-H. Tsou” ( TARI); 23, 2ƤƤ, Pingtung, Shuangliu, 19.VII.2007, leg. S.-F. Yu ( TARI); 13, same locality, 30.V.1997, leg. C. W. & L. B. O’Brien ( NMNS); 1Ƥ, Pingtung, Tahanlintao, 22.VIII.2011, leg. J.-C. Chen ( TARI); 13, Taitung, 4km N. Chinglun, 30.V.1997, leg. C. W. & L. B. O’Brien ( NMNS).

Host plant. Asclepiadaceae : Gymnema sylvestre (Retz.) Schultes.

Distribution. Southern Taiwan ( Fig. 26 ). This species is restricted to lowlands.

Figures

FIGURE 26. Distribution map of Phygasia species, solid line: 1000 m, broken line: 2000 m; blue dot: P. c he ng i; red dot: P. diluta; black dot: P. chengi and P. diluta; green dot: P. o r n a t a.

FIGURES 1 – 6. Color habitus of Phygasia species, dorsal. 1 - 3. P. chengi; 4 - 5. P. diluta; 6. P. o r n a t a.

FIGURES 7 – 13. Antenna. 7. P. chengi, male; 8. P. chengi, male; 9. P. c h e n g i, female; 10. P. diluta, male; 11. P. diluta, female; 12. Phygasia ornata, male; 13. P. o r n a t a, female. Scale = 1.0 mm.

FIGURES 17 – 25. Female genitalia. 17. P. chengi, gonocoxae; 18. P. diluta, gonocoxae; 19. Phygasia ornata, gonocoxe; 20. P. chengi, spermatheca; 21. P. diluta, spermatheca; 22. P. ornata, spermatheca; 23. P. chengi, sternite VIII; 24. P. d i l u t a, sternite VIII; 25. P. o r n a t a, sternite VIII.

FIGURES 27 – 28. Bursa-sclerites of Phygasia diluta, a: dorsal bursa-sclerites, b: ventral bursa-sclerites. 27. Collected from Tahanshan; 28. Collected from Kenting.

FIGURES 29 – 32. Type specimens of Phygasia diluta. 29. Holotype; 30. Labels on the holotype; 31. Allotype; 32. Labels on the allotype.