Key to the Macrophya zhaoae group (Hymenoptera, Tenthredinidae) with description of a new species from China

The Macrophya zhaoae group is reviewed and five species are recognized in China, including a newly described species, M. lishuii Li, Liu & Wei sp. nov. from Zhejiang Province, and four previously known species, M. hainanensis Wei & Nie, 2002, M. minutitheca Wei & Nie, 2002, M. nigrospuralina Wei, 2005 and M. zhaoae Wei, 1997. A key to all Chinese species and a distribution map of the M. zhaoae group in China are provided.


Introduction
Macrophya Dahlbom, 1835 is the third largest genus in the subfamily Tenthredininae (Hymenoptera, Tenthredinidae). It contains 309 species worldwide, of which 170 have been recorded in China up to December 2019 Liu et al. 2019aLiu et al. , 2019bLiu et al. , 2019c.
The Macrophya zhaoae group is a small species group in Macrophya, with four extant species worldwide, all of which are present in China. Among them, M. hainanensis Wei & Nie, 2002 from Hainan Province (Wei and Nie 2002a), M. minutitheca Wei & Nie, 2002 from Guizhou Province (Wei and Nie 2002b), M. nigrospuralina Wei, 2005 from Guizhou and Hubei Provinces (Wei 2005) and M. zhaoae Wei, 1997 from Hubei and Zhejiang Provinces (Wei and Ma 1997). The species of the Macrophya zhaoae group are all similar in general morphology and constitute a clearly defined species group in Macrophya. In this study, a new species belonging to this species group is described from China, named Macrophya lishuii Li, Liu & Wei, sp. nov. According to the available data, species in this group are mainly distributed in southern China. A key to all species found in China is provided.

Materials and methods
The specimens of the newly described species were obtained by sweeping in forest fringe zones in Zhejiang Province at Mt. Jiulong (Eastern China) in May 2019. The Mt. Jiulong (28°23.640'N, 118°50.700'E) reaching 1724 meters above sea level is the fourth highest mountain in Zhejiang Province and belongs to the Wuyi mountain system. Three specimens of the new species and seven specimens of other species of the Macrophya zhaoae group were examined and studied for this work. The specimens were examined with a Motic-SMZ-171 stereomicroscope. Images of the imagines were taken with a Nikon D700 digital camera and a Leica Z16APO. The genitalia were examined with a Motic BA410E microscope and photographed with Motic Moticam Pro 285A. Images were focus-stacked using Helicon Focus (Heli-conSoft, Kharkiv, Ukraine) and further processed with Adobe Photoshop CS 11.0.
The terminology of genitalia follows Ross (1945) and that of general morphology follows Viitasaari (2002). For a few terms (e.g. middle fovea and lateral fovea), we follow Takeuchi (1952).
The specimens of four known species examined in this study are deposited in the Insect Collection of Central South University of Forestry and Technology, Changsha, Hunan, China (CSCS). The holotype is deposited in the Scientific Research and Management Center of East China Pharmaceutical Botanical Garden, Lishui, Zhejiang, China (formerly Lishui Academy of Forestry, LSAF).

Abbreviations
OOCL The distance between a lateral ocellus and the occipital carina, or the hind margin of the head where this carina would be if it was developed (Benson, 1954).

OOL
The shortest distance between an eye and a lateral ocellus.

POL
The distance between the mesal margins of the two lateral ocelli.

Macrophya zhaoae species group
Diagnosis. The Macrophya zhaoae group is a small species group, well defined by morphological characters within Macrophya. A diagnosis of the M. zhaoae group including body length, body color, morphological characters of body parts and external genitalia was provided by Li et al. (2018). Species of the M. zhaoae group can be recognized by the following characters (Li et al. 2018): body mainly black, some apical segments bright yellowish-white; fore and middle legs yellowish-brown, hind leg yellowish-brown to orange-brown; face and frontal area distinctly depressed, top of middle ocellus distinctly lower than upper margin of compound eye; the postocellar area flat, clearly less than twice as broad as long; posterior corner of metepimeron without appendage; metabasitarsus sturdy, claw of hind tibia with inner tooth broader and longer than outer tooth. Description. Body mainly black. The following parts are always yellowish-white: palps mostly, center of mandibles, labrum, clypeus, postocellar area, antennomeres 7-9 at least, posterior margin and large maculae on lateral corners of pronotum, apical margin of tegula at least, double triangular maculae on bottom of prescutum, lateral round maculae on mesoscutellum, post tergite mostly, cenchrus, narrow macula on posterior margin of anepimeron, a large macula of katepimeron and a row of lateral maculae on abdominal terga 1-7 (8). Legs mostly orange-brown, parts black. Body hairs dense and short, mostly silver; setae on ovipositor sheath curved and long, blackish-brown. Wings hyaline, most veins and pterostigma blackish-brown. Vertex more or less shiny. Labrum elevated medially, anterior margin slightly truncate; clypeus roundly elevated, base clearly broader than distance between lower corners of eyes, lateral sides distinctly convergent apically, anterior margin shallowly incised to approximately 1/4-1/3 of its length, lateral corners somewhat short and broad, apical margins of lobe obtuse; malar space linear, approximately 0.5× breadth of diameter of middle ocellus; frontal area and face clearly depressed, lower than top of upper margin of compound eye in lateral view; head narrowed behind eyes in dorsal view, occipital carina complete. Antenna slender, middle antennomeres more or less inflated. Mesoscutellum elevated, higher than top of mesonotum in lateral view; posterodorsal platform of mesepimeron as broad as diameter of middle ocellus; metepimeronal appendage with a small platform-shaped area; distance between cenchri 2.5×-3.0× breadth of a cenchrus. Inner tibial spur of hind leg approximately 0.6× length of metabasitarsus, claw with inner tooth slightly longer and clearly broader than outer tooth. Ovipositor sheath shorter than metabasitarsus, setae on ovipositor sheath curved and long in dorsal view, apical margin roundish in lateral view. Fore wing with cross-vein cu-a joining cell 1M in basal 1/3-2/5, petiole of anal cell slightly shorter than cross-vein 1r-m; petiole of anal cell in hind wing 1/4-2/5 length of cross-vein cu-a.
In China, the Macrophya zhaoae group includes a new species from Zhejiang Province described here (the collection site of the new species at Mt. Jiulong is shown in Figure 3) and another four species from Guizhou, Hainan, Hubei and Zhejiang Provinces, China. They can be separated using the following key.
Description. Female. Body length 15 mm. Body mostly black. The following parts are yellowish-white: palp mostly, center of mandibles, labrum, clypeus, postocellar area, narrow macula on outer margin of eyes, antennomeres 6-9 except base of antennomere 6 with some black macula, posterior margin and large maculae on lateral corners of pronotum, apical half of tegula, double triangular maculae on bottom of prescutum, lateral round maculae on mesoscutellum, post tergite mostly, metascutellum except a black macula, cenchrus, narrow macula on posterior margin of anepimeron, a large macula of katepimeron, narrow macula on posterior margin and a small macula on posterior corner of metepimeron, a row of lateral maculae on abdominal terga 1-8 (the widest macula of abdominal tergum 1, the narrowest macula of abdominal tergum 8), posterior margins of abdominal terga 1-8 with long maculae (macula full between posterior margins and lateral maculae of abdominal terga 1-2, the narrowest macula with long macula of abdominal tergum 8), long triangular macula on posterior margin of abdominal tergum 10. Legs mostly orange-brown; fore and middle coxae except bases with black maculae, apical 1/3 and outer surface with an oval macula of hind coxa and all trochanters yellowish-white; apical dorsum of hind femur, apical parts of hind tibia (black macula on inner surface 1/4 length of hind tibia) and claw of hind tibia black. Body hairs dense and short, mostly silver; setae on ovipositor sheath curved and long, blackish-brown. Wings hyaline, apical 1/3 of fore wing smoky roundishly below pterostigma, most veins and pterostigma blackish-brown. (Figure 1a, b) Vertex less shiny than in M. nigrospuralina; frontal area shallowly and sparsely punctured, smooth interspaces distinct and smooth, microsculpture weak ( Figure 1c); labrum and clypeus less shiny, punctures on its surfaces sparse and shallow, microsculpture weak (Figure 1d). Mesonotum less shiny, punctures on mesonotum smaller and denser than punctures on head, interspaces distinct and smooth; center of mesoscutellum with some large punctures, interspaces broader than diameter of a puncture; mesoscutellar appendage mostly and metascutellum entirely smooth and shiny, but bottom of mesoscutellar appendage with weak microsculpture and sparse shallow punctures; metascutellum dull, without distinct punc-  tures, but with weak microsculpture. Mesopleuron less shiny, mesepisternum with dense and coarse punctures, upper half with punctures large and interspaces broad, lower half with punctures small and interspaces narrow; anepimeron dull, with coarse wrinkles; anterior margin of katepimeron very smooth and shiny, without punctures or microsculpture, posterior area of katepimeron with some shallow large punctures, dorsal half with some deep punctures; metepisternum dull, with minute and dense punctures; metepimeron less shiny, depressed area with some punctures and weak microsculpture, interspaces broader than diameter of a puncture, without metepimeronal appendage (Figure 1e). Abdominal tergum 1 shiny, laterally abdominal tergum 1 with some shallow punctures, nearly smooth submedially, basal 1/3 of abdominal tergum 1 punctured and 2/3 smooth; other abdominal terga less shiny, anterior 2/3 with some shallow punctures and weak microsculpture, posterior 1/3 smooth, abdomen in lateral view as shown in Figure 1h. Outer surface of hind coxa with somewhat dense and coarse punctures, outer surface of hind femur with sparse shallow punctures and fine microsculpture. Surface of ovipositor sheath coriaceous, with indistinct punctures and fine microsculpture.
Male. Unknown. Host plants. Unknown. Distribution. China (Zhejiang). Etymology. The specific name "lishuii" is derived from Lishui City belonging to Zhejiang Province where the holotype specimen was collected.

Macrophya minutitheca Wei & Nie, 2002
Macrophya minutitheca Wei & Nie, 2002 Diagnosis. This species is smaller than the other species in general morphological characters, i.e. the body length 10-11 mm; mesoscutellum with sparse large punctures, center with complete and long black stripe in longitudinal direction; hind femur and apex of hind tibia with black maculae; below pterostigma in apical 1/3 of fore wing with smoky macula; middle serrulae with minute teeth.

Discussion
The Macrophya zhaoae group is the second smallest among the defined species groups of Macrophya Dahlbom, 1835 in terms of number of species. At present, five Chinese species belong to this group, including a new species described in this study from Zhejiang Province: M. hainanensis Wei & Nie, 2002, M. lishuii Li, Liu & Wei sp. nov., M. minutitheca Wei & Nie, 2002, M. nigrospuralina Wei, 2005 zhaoae Wei, 1997. The included key and the distribution map of the M. zhaoae group (Figure 2) should facilitate the recognition and identification of the Chinese species.
As we know, the host plants of Macrophya species add up to six families and nine genera, and belong to Begoniaceae (Begonia), Caprifoliaceae (Lonicera, Sambucus), Euphorbiaceae (Euphorbia), Geraniaceae (Geranium, Pelargonium), Oleaceae (Fraxinus, Ligustrum) and Verbenaceae (Clerodendrum) (Li et al. 2018). However, we surmise that the Macrophya zhaoae group uses different host plants, and we hope that we will be able to find out the host plant in future research.