Onycholyda xanthogaster Shinohara, 1999

Shinohara, Akihiko, Kakuda, Tsuneo, Wei, Meicai & Kameda, Yuichi, 2018, DNA Barcodes Identify the Larvae and Unassociated Male of Three Onycholyda Sawflies (Hymenoptera, Pamphiliidae) from China, Zootaxa 4403 (1), pp. 123-132 : 126-127

Onycholyda xanthogaster Shinohara, 1999

( Fig. 2 )

Onycholyda xanthogaster Shinohara, 1999: 66 ; Shinohara & Xiao, 2006: 288.

Distribution. China (Sichuan [new record], Shaanxi).

Host plant. Rubus inopertus (Focke) Focke.

Field observations (by Shinohara). Sichuan Province, Mt. Emeishan, approximately 32 km west of Baoguosi.

In May, 2014, larvae were found on bushes of Rubus inopertus along a narrow unpaved car road at about 1600 m above sea-level. On May 24, four larval abodes were collected (three of them Fig. 2A–C ), each containing one larva, and one egg ( Fig. 2C ). Two larvae matured on May 30 ( Fig. 2J , sample nos. 606, 607) and two on June 2 (sample nos. 637, 638), whereas the egg did not hatch. On May 25, three larval abodes with solitary larvae were found. One of them died in a few days, one matured on June 2 (sample no. 634) and the third one matured on June 6 (sample no. 635). On May 30, one larval abode was found. The larva matured on June 8 (sample no. 636). All the mature larvae were fixed in ethanol.

The remains of the egg shells were often not located, probably because the larva had already consumed the part of the leaf with the egg shell, but, when found, they were always on the under surface of the leaf. The eggs were deposited on or close to the main or lateral vein ( Fig. 2B ). The larval abodes were always on the under surface of the leaf. The larval abodes were rather irregular in shape ( Fig. 2A–C ).

Larva. Early instar ( Fig. 2D, E ): Head black; antenna whitish; trunk creamy white; blackish spot on dorsal surface of prothoracic shield; cervical sclerite black; thoracic legs and subanal appendage whitish. Middle to late instar ( Fig. 2F–I ): Similar to early instar, but head mostly pale brown with irregular black areas along posterior margin, frons and mouth parts. Mature larva ( Fig. 2J ): Similar to the preceding, but antenna pale brown and trunk, including thoracic legs and subanal appendage, vivid pale green.

Remarks. Onycholyda xanthogaster was first described based on a single male specimen from Shaanxi Province ( Shinohara 1999), and the female was described later by Shinohara & Xiao (2006) also from Shaanxi Province. The two adult males used for molecular work are from Shaanxi Province and agree well with the holotype ( Shinohara 1999), except that the large pale mark on the mesepisternum is missing. The larval material from Sichuan Province agreed with the Shaanxi adults in DNA barcodes and we determine them as O. xanthogaster . This is the first record of O. xanthogaster from Sichuan Province.

The mature larva of this species is characterized by the largely pale brown head and the almost entirely pale green trunk. A similar color pattern is known for the mature larvae of O. minomalis (Takeuchi, 1930) and O. similis Shinohara, 1987 , from Japan (Shinohara & Kojima 2013; Shinohara & Ibuki 2014), and O. fulvicornis (see below). The mature larvae of the four species are not at present distinguishable, except by their different host plants.

Figures

FIGURE2. Onycholydaxanthogaster, larvalleaf-rolls (A–C) and larvae (D–J),photographs takenat the site about 32 km from Baoguosi on Mt. Emeishan, Sichuan Province (A–C) and indoors (D–J) by A. Shinohara in 2014. --- A, Two leaf-rolls on Rubus inopertus, May 24, seen from above; B, same leaf-rolls, seen from below; C, leaf-roll on R. inopertus, May 24; D, E, early instar larva, May 24; F, H, I, middle instar larva, May 24; G, late instar? larva, May 28; J, mature larva (sample no. 607), matured on May 30, photographed on June 2.