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ZooKeys 1071: I—9 (2021)

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First report of Eutrichosomella Girault
(Hymenoptera, Aphelinidae) from China,
with description of a new species

Ye Chen!', Hai-feng Chen!

| Hebei Key Laboratory of Animal Diversity, College of Life Science, Langfang Normal University, Langfang,
065000, China

Corresponding author: Hai-feng Chen (chenhaifeng@lfnu.edu.cn)

Academic editor: Miles Zhang | Received 21 July 2021 | Accepted 12 October 2021 | Published 16 November 2021
http://zoobank.org/65D43F2B-BF6 1-4FED-9490-5AE4026F D456

Citation: Chen Y, Chen H-f (2021) First report of Eutrichosomella Girault (Hymenoptera, Aphelinidae) from China,
with description of a new species. ZooKeys 1071: 1-9. https://doi.org/10.3897/zookeys.1071.71909

Abstract
The genus Eutrichosomella Girault is recorded for the first time from China (Yunnan Province), and Eutricho-

somella yunnanensis sp. nov. (2, 3) is described and illustrated. A distribution map of this genus is presented.

Keywords

Aphelininae, Eutrichosomellini, Chalcidoidea, parasitic wasp, taxonomy

Introduction

The genus Eutrichosomella Girault, containing 11 valid species, is distributed in the
Indomalayan and Australasian regions (Noyes 2019). Hosts of this genus are known
for only three species, which were all reared from cockroach oothecae (Girault 1915;
Hayat 2014; Hayat and Veenakumari 2016). Eutrichosomella differs from other genera
of Aphelinidae by the following combination of characters: antenna with 6 antenno-
meres; mesopleuron convex, large and undivided; axilla large with small interaxillar

Copyright Ye Chen, Hai-feng Chen This is an open access article distributed under the terms of the Creative Commons Attribution License (CC
BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

2 Ye Chen & Hai-feng Chen / ZooKeys 1071: 1-9 (2021)

distance compared to most other Aphelinidae, and width of axilla at least equal to
anterior width of mesoscutellum; axilla not exceeding anterior line of mesoscutellum
(Figs 7, 13); scape not or very slightly ventrally expanded, at least 3x as long as wide;
clava more than 2.5x as long as wide. Currently, Eutrichosomella and five other gen-
era (Saengella Kim & Heraty, Samariola Hayat, Mashimaro Kim & Heraty, Umairia
Hayat, and Zubairia Hayat) belong to the tribe Eutrichosomellini (Kim and Heraty
2012; Hayat 2014). Kim and Heraty (2012) discussed the phylogeny of Aphelininae
based on morphological characters, with Eutrichosomella as the sister group to Saen-
gella, Samariola, and Mashimaro.

Girault (1915) established Eutrichosomella and described three species from Aus-
tralia: E. albiclava Girault, 1915, E. blattophaga Girault, 1915, and E. multifasciata
Girault, 1915, designating E. albiclava as the type species. Later, Girault (1923, 1924)
described another two Australian species, respectively E. albifemora Girault, 1923 and
E. aereiscapus Girault, 1924. Timberlake (1941) described E. insularis Timberlake,
1941 from Nuku Hiva Island. Eutrichosomella was treated as an encyrtid (Timberlake
1941; Trjapitzin 1973) for a long time, until Hayat (1983) placed the genus within
Aphelinidae. Hayat and Fatima (1990) transferred Aphelinus voltairei (Girault, 1921)
to Eutrichosomella. These seven species described in the last century were all from the
Australasian Region. The remaining four species, E. indica Singh & Srinivasa, 2010,
E. keralaensis Manickavasagam & Menakadevi, 2012, E. veenakumariae Hayat, 2014
and E. ibra Hayat & Veenakumari, 2016 were all described from India.

In the present paper, we describe the twelfth species in the genus, E. yunnanensis
sp. nov., from the Yunnan Province of China. This is the first report of the genus Eu-
trichosomella from China.

Material and methods

Samples were obtained using a pyrethroid fog generated from a thermal fogger (Swing-
fog SN50, Germany, Model 2610E, Series 3). Specimens were dissected and mounted
in Canada Balsam on slides, following the method described by Noyes (1982). Prior to
slide mounting, specimens in ethanol were photographed with an Axiocam 305 color
digital camera attached to a ZEISS Discovery V12 stereomicroscope. Slide-mounted
specimens were photographed with a digital CCD camera attached to an Olympus
BX53 compound microscope. Images were processed using Helicon Focus 6 and Ado-
be Photoshop CS5. Absolute measurements were made using Measurement Systems of
the ZEISS Discovery V12 stereomicroscope. All measurements are given in microme-
ters (um), except body length, which was measured in millimeters (mm). Scale bars are
100 um except where otherwise indicated. In the descriptions below, measurements/
ratios in parentheses after measurement/ratio ranges refer to the measurement/ratio
of the holotype. The distribution map was generated with the SimpleMappr software
(Shorthouse 2010) and ArcMap 10.4.1. All specimens listed below are deposited in
Langfang Normal University (LFNU), Langfang, China.

Eutrichosomella yunnanensis sp. nov. is described from China 3

Terminology follows the Hymenoptera Anatomy Consortium (2021) for most
body parts except the linea calva, which follows Hayat (1998).
The following abbreviations are used in the text:

F1-3 funicle segments 1—3;
Gt,, Gt, etc. tergites 1, 2, etc. of gaster.

Taxonomy

Eutrichosomella yunnanensis sp. nov.
http://zoobank.org/BEOEB460-BB33-446B-9 FF0-958AC43FF96B
Figs 1-15

Type material. Holotype: Cuina * 19; Yunnan Province; Xishuangbanna; Mengla
County; Menglun Town; 21°53.72'N, 101°17.08'E; 611m a.s.l.; 22 Aug. 2020; Y.
Chen, H.-f. Zhao, Y.-g. Qin, Z.-g. Chen, leg.; LFNU A-Eut202101 [on slide]. Para-
types: 14; same data as holotype; LFNU A-Eut202102 [on slide]. 12; Yunnan Proy-
ince; Xishuangbanna; Mengla County; Menglun Town; 21°54.28'N, 101°16.75'E;
629m a.s.L.; 25 Jun. 2019; Z.-l. Bai, Z.-g. Chen, Y.-j. Lin, C. Wang, Y.-f. Tong, H. Yu
leg.; LFNU A-Eut202103 [on slide]. 12; Yunnan Province; Xishuangbanna; Mengla
County; Menglun Town; 21°54'N, 101°16.9'E; 561m a.s.L; 27 Jun. 2019; Z.-l. Bai,
Z.-g. Chen, C. Wang, Y.-f. Tong, H. Yu leg.; LFNU A-Eut202104 [on slide].

Diagnosis. Females of Eutrichosomella yunnanensis sp. nov. can be distinguished
from females of other species in this genus by the following combination of characters:
dark brown gaster; characteristically pigmented forewing as in Figs 2, 8; long pedicel
and F3 as in Fig. 6; linea calva broadening from the anterior forewing margin to the
posterior forewing margin; long postmarginal vein, almost as long as the stigma vein
(Fig. 8, inset) and location of setae on mesoscutellum as in Fig. 7.

Description. Female. Body length 1.18—1.63 mm (1.48 mm).

Coloration (Figs 1, 2). Head with face and malar space pale, vertex orange yel-
low and with dark setae, occiput pale. Eyes yellow, ocelli dark brown. Antenna with
scape pale yellow and with ventral surface brown, pedicel pale brown to brown, funicle
brown, clava with basal half to two thirds brown and remainder parts yellow. Man-
dible pale with apex dark. Pronotum yellow. Mesosoma mostly orange yellow, with
lateral lobe of mesoscutum paler; propodeum with two brown patches interior to each
spiracle. Mesopleuron pale. Forewing (Fig. 8) largely infuscated, with hyaline parts as
follows: submarginal vein, a curved band adjacent to stigmal vein and apex narrowly.
Hindwing (Fig. 9) infuscated medially and apically. Legs generally yellow and suffused
with brown on tibiae and tarsomeres. Metasoma with petiole pale yellow, gaster mostly
dark brown and with blue reflections, Gt, and third valvula brown yellow.

Head (Fig. 5), in frontal view, scaly reticulated, with the reticulation becoming elon-
gate laterally. Frontovertex 0.3x head width, vertex with about 30 brown setae. Ocellar tri-

4 Ye Chen & Hai-feng Chen / ZooKeys 1071: 1-9 (2021)

Figurel—4. Euzrichosomella yunnanensis sp. nov., paratypes | body (2), dorsal view 2 body (9), lateral
view 3 body (4), dorsal view 4 body (4), lateral view.

angle with apical angle acute. Mandible with two teeth and a truncation. Antenna (Fig. 6)
with scape 4.3-4.6x (4.5x) as long as wide; pedicel 3.2—3.6x (3.6x) as long as wide, about
as long as funicle segments combined; an anellus (Fig. 6, inset) is present between pedicel
and F1; F1 transverse, with ventral margin a little longer than dorsal margin, 0.7—0.9x
(0.9x) as long as wide; F2 quadrate, 1.2 as long as F1; F3 1.5—1.8x (1.8x) as long as wide,
1.3x as long as Fl and F2 combined; clava 3.0-3.7x (3.7x) as long as wide, 0.8x length

Eutrichosomella yunnanensis sp. nov. is described from China 5

Figure 5-11. Eutrichosomella yunnanensis sp. nov., holotype 5 head 6 antenna 7 mesosoma 8 forewing,

inset shows postmarginal vein (pmv) and stigma vein (sv) 9 hindwing 10 legs II gaster.

of scape, and 2.5—2.6x (2.6x) as long as F3. F3 and clava with 4 and 16 longitudinal sen-
silla, respectively. Measurements of holotype, length (width): scape, 320.9 (70.7); pedicel,
171.4 (47.6); F1, 37.0 (42.0); F2, 42.8 (42.8); F3 101.7 (57.3); clava, 256.4 (69.7).
Mesosoma (Fig. 7). Dorsum of mesoscutum polygonal reticulate, with the sculp-
ture of lateral lobe of mesoscutum elongate on inner side; mesoscutellum mostly re-

6 Ye Chen & Hai-feng Chen / ZooKeys 1071: 1-9 (2021)

Figure 12-15. Extrichosomella yunnanensis sp. nov., paratype (3) 12 antenna 13 mesosoma 14 forewing
[5 genitalia.

ticulate, smooth posteriorly, and with a pale longitudinal groove medially; metano-
tum reticulate on median region; propodeum smooth, but with finely polygonal
reticulate sculpture on lateral sides. Pronotum with 4—5 rows of setae, the row along
the posterior margin longer. Midlobe of mesoscutum 0.8x as long as wide, with
21-24 (24) setae, the seta on the anterolateral corner and the apical pair of setae
long. Lateral lobe of mesoscutum with 3 or 4 setae. Axilla with 1 long seta, its width
1.3x anterior width of mesoscutellum. Mesoscutellum hexagonal, as long as wide,
with two pairs of long setae located in anterior part and posterior part, respectively.
Distance between anterior pair of scutellar setae 0.4x that between posterior pair.
Placoid sensilla located in median region of mesoscutellum; distance between sen-
silla 0.5x that between posterior scutellar setae. Metanotum 0.7x as long as propo-
deum in median length. Propodeum with 13-15 (15) short setae (Fig. 7) proximal
to spiracle, and with a digital projection on median area posteriorly.

Wings. Forewing (Fig. 8) 2.8x as long as wide. Costal cell 0.8x length of marginal
vein, with 12 fine setae; submarginal vein with 5 setae; parastigma with | seta; marginal
vein with 14 setae along anterior margin; postmarginal vein long, about as long as stigmal
vein; stigmal vein swollen posteriorly and with 3 big and 1 small sensilla arranged nearly
in a line (Fig. 8, inset). Linea calva becoming broader posteriorly, not closed. Hindwing
(Fig. 9) 4.2x as long as wide, with longest marginal fringe 0.2—0.3x (0.3x) wing width.
Measurements of holotype, length (width): forewing, 1441.6 (529.4); costal cell, 350;
marginal vein, 460; postmarginal vein, 40; stigmal vein, 40; hindwing 1189.7 (282.4).

Legs (Fig. 10). Mesotibial spur 0.7x as long as corresponding basitarsus. Length meas-
urements of holotype: mesotibia, 564.4; mesotibial spur, 147.1; mesobasitarsus, 216.

Eutrichosomella yunnanensis sp. nov. is described from China 7

Metasoma (Fig. 11). Dorsum of metasoma generally smooth, except median area
of Gt, and lateral sides of gasteral tergites with fine reticulations. Ovipositor originat-
ing from Gt, to apex of Gt,, 0.8—-0.9x (0.8x) as long as mesotibia and slightly exerted.
Second valvifer 2.7x as long as third valvula; third valvula 0.6x as long as mesobasi-
tarsus. Length measurements of holotype: ovipositor, 465.2; second valvifer, 340.7;
third valvula, 124.5.

Male. Body length 1.16 mm. Similar to female except as follows. Forewing (Figs
4, 14) with the infuscate patches a little paler than in the female. Legs paler. Gaster
(Fig. 3) with Gt, and Gt, yellow, Gt, mostly yellow and with a transverse short brown
band on each lateral side, Gt, brown posteriorly, Gt.—Gt, brown.

Head with ocellar triangle with apical angle obtuse. Antenna (Fig. 12) with scape
expanded ventrally, 3.4x as long as wide; Fl and F2 subequal in length and width, F3
about as long as Fl and F2 combined. F3 and clava with 2 and 7 longitudinal sensilla,
respectively. Genitalia (Fig. 15) with paramere 1.8x as long as wide; each digitus 0.3x
length of paramere, with two short denticles and a fine seta at apex; aedeagus 1.5x as long
as paramere and 1.2x as long as mesobasitarsus. Measurements, length (width): scape,
230.7 (67); pedicel, 122.1 (37); F1, 28.5 (30.5); F2, 31 (31); F3, 57.5 (42.3); clava, 149
(50); forewing 1185.2 (426.7); hindwing 1010 (210); mesotibia, 431.3; mesotibial spur,
96.9; mesobasitarsus, 168.6; genitalia, 245.3; paramere, 132.5; aedeagus, 198.8.

Host. Unknown.

Etymology. Named after the locality of type specimen.

Distribution. China (Xishuangbanna Dai Autonomous Prefecture of Yunnan
Province).

Comments. This species does not run to any couplet in the key to Indian species
of Eutrichosomella (Hayat & Veenakumari 2016), and differs from the four Indian
species (E. ibra, E. indica, E. keralaensis, and E. veenakumariae) by the following
combination of characters: antenna mostly brown with scape and apical of clava pale
yellow to yellow (vs. antenna white to yellow, or antenna dark brown with a subapical
band on scape and most of clava white; cf. fig. 3 in Manickavasagam and Menakadevi
2012), F3 1.5—-1.8x as long as wide (vs. less than 1.4x as long as wide), forewing
largely infuscated, with the following parts hyaline: the area below the submarginal
vein, a curved band adjacent to the stigmal vein and apex narrowly (vs. forewing
with broad or narrow infuscation below margin vein, without hyaline band adjacent
to stigmal vein; forewing of E. keralaensis similar to the new species but with a large
suboval hyaline spot in the median infuscate area; cf. fig. 6 in Manickavasagam and
Menakadevi 2012), postmarginal vein of forewing long, about as long as stigmal vein
(vs. absent, or three-fourths of stigmal vein), two pairs of setae on mesoscutellum
located in anterior part and posterior part, respectively (vs. both located in posterior
part; cf. fig. 4 in Hayat 2014, except E. keralaensis). Apart from the above differences,
the new species can be distinguished from E. keralaensis by having scape 4.3—4.6x
as long as wide (vs 3.1x), Fl a little wider than long and F2 quadrate (vs. Fl and F2
both 0.5x as long as wide), and propodeum with 13-15 setae proximal to spiracle
(vs. at least 3, possibly 4, setae according to redescription of Hayat 2014).

8 Ye Chen & Hai-feng Chen / ZooKeys 1071: 1-9 (2021)

® Eutrichosomella aereiscapus and E. albifemora
* E. albiclava, E. blattophaga and E. multifasciata
@ £. ibra
®@ E. indica
@ E. insularis
© E. keralaensis
© E.veenakumariae ee ee
® E. voltairei = =
| Se
® £. yunnanensis sp. nov. “= 16

Figure 16. Distribution of all species of Eutrichosomella Girault 1915. Inset shows distributions of E.
ibra, E. indica, and E. keralaensis.

Eutrichosomella yunnanensis sp. nov. seems morphologically close to E. albiclava.
Based on Girault’s description and images (QMDIU_03328—QMDIU_03335 from the
Queensland Museum), £. yunnanensis differs from E. albiclava by following characters:
color of gaster apparently darker than mesosoma in slide-mounted specimen (vs. nearly
the same according to QMDIU_03330 and QMDIU_03331), pedicel about as long
as funicle segments combined (vs. two thirds), F3 1.5—1.8x as long as wide (vs. a little
longer than wide), forewing infuscated below marginal vein and subapically (vs. only
infuscated below marginal vein, without any distal pigmentation, cf. QMDIU_03332).

Acknowledgements

We would like to thank two anonymous reviewers and the subject editor for pro-
viding valuable comments on earlier drafts of this manuscript. This study was sup-
ported by the National Natural Science Foundation of China (Grant No. 31970396)
to Hai-feng Chen; the Natural Science Foundation of Hunan Province (Grant No.
2020JJ5269), the Doctoral Scientific Research Foundation of Langfang Normal Uni-
versity (Grant No. XBQ202034), and the project of Langfang Science and Technology
Bureau (Grant No. 2020013024) to Ye Chen. We are grateful to Professor Shu-qiang
Li (Chinese Academy of Sciences, Beijing) for providing the materials. Special thanks
to Professor Mohammad Hayat (Aligarh Muslim University, Aligarh) for his kind help
sending some papers by e-mail. We express great respect for Christine Lambkin, Geoff
Thompson and Karin Koch from the Queensland Museum (Brisbane, Australia) for
their help freely providing images of Eutrichosomella albiclava. We thank all specimen
collectors. Zhu-jun Pan, Yi-fan Wang and Jia-nan Han, junior students at LFNU,
sorted out aphelinids from large chalcidoid samples, and we appreciate their work.

Eutrichosomella yunnanensis sp. nov. is described from China )

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