Pamphilius padus Shinohara

Shinohara, Akihiko & Wei, Mei-Cai, 2016, Leaf-rolling sawflies (Hymenoptera, Pamphiliidae, Pamphiliinae) of Tianmushan Mountains, Zhejiang Province, China, Zootaxa 4072 (3), pp. 301-318 : 309-312

Pamphilius padus Shinohara , sp. nov.

( Figs 5–7 )

Description. Female. Holotype ( Fig. 5 A). Length about 11 mm. Head pale yellow, with large black mark covering most of dorsal surface ( Fig. 5 D); occiput with black mark dorsally. Mouth parts pale yellow; mandible with inner margin black, apical part brown and edge ferruginous. Antennal scape pale yellow, with inner upper surface largely black; pedicel and flagellum brown, becoming blackish apically. Thorax black, with following pale yellow: broad posterior margin (medially interrupted) and lateral surface of pronotum, ventral half of cervical sclerite, tegula, posterior 1/2 of mesoscutal median lobe, large rectangular spot in posterior part of mesoscutal lateral lobe (adjacent to mesoscutellum), mesoscutellum, almost all of mesepisternum (pectus marked with black), mesepimeron (except for narrow anterior and ventral margins), metascutellum, most of metepisternum, and metepimeron (except for narrow anterior and ventral margins). Wings faintly stained with blackish brown; veins blackish brown, except for pale brown veins C and Sc and part of veins in basal part of forewing; stigma pale brown, with anterior and posterior margins blackish. Legs pale yellow, with very narrow coxal bases black. Abdomen black above and pale yellow beneath; dorsum with very narrow lateral margins of all segments, posterior margin of 8th tergum and more posterior segments pale yellow; 2nd to 5th segments (except for narrow lateral black parts) orange.

Head with eyes comparatively small ( Fig. 5 D). Upper frons below ocelli weakly convex, triangularly raised in posterodorsal view, without distinct notch medially; ocellar basin shallow, indistinct; median fovea indistinct; clypeus with anterior margin weakly roundly convex medially; rounded crest between antennae; facial crest moderately inflated and bluntly carinate. Head densely covered with large, deep punctures and golden hairs, narrow interspaces very weakly coriaceous, shiny; transverse area between dorsal parts of eyes, including upper part of frons, ocellar area and facial crests, particularly densely and coarsely punctate, almost reticulate; clypeus and posterior median part of postocellar area rather sparsely punctate, with broad weakly coriaceous interspaces. Right mandible ( Fig. 5 G) tridentate, basal tooth with large shoulder, with incision between apical and median teeth wider and much shallower than incision between median and basal teeth; left one ( Fig. 5 F) tridentate, with rather high median tooth. Antenna with 20 antennomeres; 1st flagellomere about 2.7× length of 2nd. Cell C of forewing entirely glabrous. Sawsheath ( Fig. 5 C) with appendage basally very thick and apically thin, directing upwards, setose.

Male. Paratopotype ( Fig. 5 B). Length about 9.5 mm. Head pale yellow, with large black mark covering most of dorsal surface ( Fig. 5 E); occiput mostly black. Mouth parts pale yellow; mandible with inner half of anterior surface and most of posterior surface black, apical part brown and edge ferruginous. Antennal scape pale yellow, with inner upper surface largely black; pedicel brown with blackish spot above; flagellum brown, becoming blackish apically. Thorax black, with following pale yellow: lateral surface of pronotum, ventral half of cervical sclerite, tegula, posterior half of mesoscutal median lobe, mesoscutellum, almost all of mesepisternum, dorsal part of mesepimeron, metascutellum, most of metepisternum, and dorsal part of metepimeron. Wings and legs as in female. Abdomen black above and pale yellow beneath; dorsum with very narrow lateral margins of all segments pale yellow; 2nd to 5th segments (except for narrow lateral black parts) orange.

Structure generally similar to that of female. Antenna with 19 antennomeres, with 1st flagellomere about 2.5× length of 2nd. Subgenital plate with posterior margin medially produced and rounded at apex. Genitalia as in Fig. 6 .

Larva. Late instar ( Fig. 7 E): About 20 mm, head dark chocolate brown with large creamy white area including frons (except for very large median black spot) and area surrounding dorsal margin of frons ( Fig. 7 H); antenna light brown; trunk greenish white; prothorax with very large dorsal spot black; cervical sclerite black; thoracic legs and subanal appendage whitish. Mature larva (prepupa) ( Fig. 7 F, G): About 18 mm, similar to late instar; trunk light green, with lateral and posterior margins very slightly yellowish; thoracic legs and subanal appendage light green.

Variation. Female: Length ranges from 9.0 to 11 mm. The extent of the black areas on the head shows some variation. The antennae of 15 specimens measured have 19 to 22 antennomeres, with the 1st flagellomere about 2.6 to 2.9 times as long as the 2nd. Male: Length ranges from 8.5 to 10.5 mm. The blackish spot on the antennal pedicel often becomes obsolete or missing. The antennae of 15 specimens measured have 18 to 20 antennomeres, with the 1st flagellomere about 2.4 to 2.7 times as long as the 2nd.

Specimens examined. Holotype: ♀, “[ CHINA: Zhejiang], Kaishan Laodian, N30°20’ E119°26’, 1150 m, Tianmushan, 10. IV. 2014, A. Shinohara” ( CSCS). Paratypes: Zhejiang Province: 1♀, Kaishan Laodian, 1150 m, Tianmushan, 8. IV. 2014, A. Shinohara ( NSMT); 5♀ 3♂, same data but 9. IV. 2014 ( NSMT); 2♀ 3♂, same data but 10. IV. 2014 ( NSMT); 1♀ 1♂, same data but 11. IV. 2014 ( NSMT); 1♀, same data but 14. IV. 2014 ( NSMT); 2♀, same data but 15. IV. 2014 ( NSMT); 16♀ 3♂, same data but 4. IV. 2015 ( NSMT); 15♀ 9♂, same data but 5. IV. 2015 ( NSMT); 3♀ 3♂, same data but 11. IV. 2015 ( NSMT); 3♀ 5♂, same data but 12. IV. 2015 ( NSMT); 1♂, Kaishan Laodian, 1142 m, E119°26’05” N30°20’33”, Tianmushan, 10. IV. 2014, H.-Y. Nie & P. Hu ( CSCS); 1♀, same data but T. Liu & X.-J. Yu ( CSCS); 1♀, same locality, 14. IV. 2014, H.-Y. Nie & P. Hu ( CSCS); 2♀, same data but T. Liu & X.-J. Yu ( CSCS). Material for molecular data: 2♀, Kaishan Laodian, 1150 m, Tianmushan, 10. IV. 2014, A. Shinohara ( NSMT); 1♂, same data but 9. IV. 2014 ( NSMT); 5 larvae, same locality, larvae on Padus obtusata collected 16. IV. 2014, matured and fixed in ethanol 27. IV. 2014, A. Shinohara ( NSMT).

Distribution. China (Zhejiang).

Etymology. The specific epithet refers to the genus name of the host plant.

Host plant. Rosaceae : Padus obtusata (Pursh) Lindl.

Field observations. In April, 2014, Shinohara found adults, eggs and larvae on the leaves of Padus obtusata in Kaishan Laodian at an altitude of 1155 meters. Only one egg (rarely two eggs) was found on the underside of a leaf, near the branching point of the lateral vein from the main vein ( Fig. 7 A–D). The larva solitarily makes a leaf-roll on the underside of a leaf. Shinohara found numerous eggs but no larvae on April 9. Some very small larval rolls were first found on April 10 and more and more larvae were found thereafter. On April 16, some larvae were collected and reared in the laboratory. Eleven larvae matured on April 27, eleven larvae on May 1 and one larva on May 5, and all of them were fixed in ethanol.

Remarks. This new species is similar to P. xiaoweii Shinohara, 2012 (Shinohara & Wei 2012) , from Hunan Province, China, in having the heavily punctured head with comparatively small eyes, the tridentate right mandible, and the long 1st flagellomere. Pamphilius padus is a smaller species (length 9 to 11 mm in the female, 8.5 to 10.5 mm in the male) and has the antennal flagellum brown, the 1st flagellomere about 2.6 to 2.9 times as long as the 2nd in the female and 2.4 to 2.7 times as long as the 2nd in the male, the stigma mostly pale brown, and the 2nd to 5th abdominal terga (except for narrow lateral black parts) orange. Pamphilius xiaoweii is larger (length 11.5 to 12 mm in female, 10 to 11 mm in male) and has the antennal flagellum black, the 1st flagellomere about 2.3 to 2.4 times as long as the 2nd in the female and 2.1 to 2.4 times as long as the 2nd in the male, the stigma blackish brown, and the 2nd to 5th abdominal terga (except for narrow lateral margins) black, without orange areas. Pamphilius sinensis Shinohara, Dong & Naito, 1998 , from Shaanxi and Yunnan provinces, China, has a similar color pattern and the structure of the head, but the female is much larger (length about 13.5 mm), the antennal scape is entirely black, the 1st flagellomere is about 1.7 to 2.3 times as long as the 2nd, and the sawsheath appendage is small (see fig. 7G in Shinohara et al. 1998). The male of P. sinensis is unknown.

Two similar species are known to feed on Padus , P. albopictus ( Thomson, 1871) distributed in the huge areas from Europe to Korea and P. kamikochensis Takeuchi, 1930 , from Japan (Shinohara 1998). These two northern species are distinguished from P. padus by the mostly black frons and paraantennal field in the female, shorter 1st flagellomere (1.8 to 2.6 as long as the 2nd in the female and 1.7 to 2.3 times in the male) and the pilose cell C in the forewing. The male genitalia of P. padus ( Fig. 6 ), particularly the penis valve, are very different from those of P. kamikochensis (figs 9, 10 in Shinohara 1998; the male is unknown for P. albopictus ).

The CO1 sequences of five larvae feeding on Padus obtusata and three adults of P. padus all collected at the type locality agreed (Kiyoshi, personal communication) and they are doubtless conspecific.

Figures

FIGURE 5. Pamphilius padus, ♀, holotype (A, D, F, G), ♂, paratype, Kaishan Laodian (B, E) and ♀, paratype, Kaishan Laodian (C). A, B, Dorsal view; C, sawsheath, lateral view; D, E, head, dorsofrontal view; F, left mandible; G, right mandible.

FIGURE 6. Pamphilius padus, ♂ genitalia, paratype, Kaishan Laodian. A, Dorsal view; B, ventral view; C, penis valve, lateral view (right dorsal).

FIGURE 7. Pamphilius padus, egg (A), remains of egg shells and leaf-rolls (B – D) and larvae (E – H). A, An egg on a leaf of Padus obtusata, April 9; B, same leaf with a leaf roll made by a young larva and remains of an egg shell, April 11; C, same leaf, April 16; D, two leaf-rolls and remains of two egg shells on one leaf, April 16; E, late instar larva, April 27; F, mature larva, April 29; G, mature larva, April 29; H, late instar larva, head, April 27. Photographs taken in Kaishan Laodian (A – D) and in the laboratory (E – H) in 2014 by A. Shinohara.