Quadrastichus johnlasallei, Gates & Chao & Lin & Yang, 2020

Gates, Michael W., Chao, Yi-Min, Lin, Sheng-Feng & Yang, Man-Miao, 2020, Description of two new Quadrastichus (Hymenoptera: Eulophidae) reared from Litchiomyia chinensis (Diptera: Cecidomyiidae) on commercial lychee (Litchi chinensis; Sapindaceae) in Taiwan, Journal of Natural History 54 (9), pp. 635-646 : 641-644

Quadrastichus johnlasallei , sp. n. ( Figs 1 , 3 )

Female Holotype. Length: 4.0 mm. Colour: Head, mesosoma, fore coxa, ovipositor sheaths, and gaster dorsally dark brown (except as noted beyond); antenna, middle and hind legs, gaster (anterodorsal quarter, anterolateral two-thirds, anteroventral two-thirds, dorsolaterally on gastral tergum 5) pale yellow ( Figure 1 (a)). Fore wing hyaline, venation yellow.

Head, in frontal view ( Figure 3 (a)), 1.5 X as broad as high, 1.7 X as broad as frontovertex at its narrowest; malar space 0.6 X as long as an eye, the sulcus slightly curved, without a triangular fovea beneath the eye; POL 3.2 X OOL, OOL 1.3 X OD; mandible tridentate; head finely setose, eyes very sparsely setose, setae short, <1 ommatidial diameter ( Figure 3 (a)); lower margins of toruli approximately two torulus diameter above lower eye margins; clypeus bilobate ( Figure 3 (a)).

Antenna ( Figure 3 (d–h)) with scape 3.6 X as long as broad, longer than the length of an eye, just exceeding vertex; pedicel approximately 2.5 X as long as broad, 1.5 X as long as basal funicle segment; one transverse anellus present; funicle three-segmented, F1 just shorter than the subequal F2–F3, F1 2.6 X, F2 3.8 X, F3 3.8 X as long as broad; clava 5.0 X as long as broad; apical spine ~0.8 X length apical segment; sensilla sparse, flagellum rather sparsely setose ( Figure 3 (d–e)).

Mesosoma ( Figure 3 (b–c)) 1.3 X as long as broad; mesoscutum in profile gently convex dorsally, in dorsal view gently rounded laterally; mesoscutal midlobe approximately as long as broad, with fine median line; with 2 adnotaular setae at each side, in posterior half; mesoscutum with very fine lineate sculpture; scutellum convex in profile, 1.2 X broader than long with submedian lines; sculpture as in mesoscutum; scutellum with 2 pairs of setae; dorsellum convex, smooth, medially about as long as propodeum; propodeum without median carina, with curved spiracular sulcus mesad reminiscent of paraspiracular carina, with very fine reticulate sculpture; spiracles ~1x their own diameter from anterior propodeal margin; cali each with 2 setae.

Fore wing ( Figure 1 (a)) 2.2 X as long as broad; costal cell 15.0 X as long as broad, 0.7 X length of marginal vein, asetose; submarginal vein with 1 dorsal seta; marginal vein 3.0 X as long as stigmal vein, the postmarginal vein 0.3 X stigmal; subcubital line of setae extending basally as far as basal setal line, closing speculum posteriorly; longest marginal cilia ~1.4 X as long as longest setae on marginal vein.

Metasoma elongate, 2.6 X longer than mesosoma, 2.0 X longer than broad, tapered apically; epipygium 2.3 X longer than broad; hypopygium reaching to about 0.3 X the length of gaster; ovipositor sheaths short, hardly protruding apically; one cercal seta twice length others and curved.

Male

Length: 3.1 mm. Colour: much as in female except following lacking anterodorsal yellow patches on gastral tergum 5 and all coxae brown. Differing structurally from the female mainly in the antenna ( Figure 3 (f–h)): scape with a linear ventral plaque, placed in middle half ( Figure 3 (f)); a single transverse anellus present; funicle four-segmented, F1 2.0 X, F2 2.5 X, F3 2.5 X, F4 2.8 X, as long as broad, all broadest basally and narrowing apically, clava 8.3 X as long as broad; flagellum sparsely setose, the setae on funicle segments fairly long, slightly curved, basal dorsal whorls on F1 – 4 reaching beyond following segment; clava sensilla not recurved ( Figure 3 (g–h)).

Variation

One female has the dorsoapical margin of gastral tergum 6 yellow and basal ¼ hind coxa brown.

Diagnosis and recognition. This species keys to the anysis -group to a large extent, ultimately to couplet 21 where it roughly matches diagnostic features of Q. xanthosoma , namely the elongate metasoma and epipygium. However, Q. johnlasallei differs from Q. xanthosoma in having brown head and mesosoma, partially brown metasoma (head and body mostly to wholly yellow), female clava 5.0 X as long as broad (3.0 X), clypeus bilobate (straight). Quadrastichus xanthosoma is known from Europe and USSR where it attacks Massalongia spp. ( Diptera : Cecidomyiidae ) on Betula spp. ( Noyes 2019). In the key of Narendran (2007), ours runs to Q. suhderi Narendran and roughly matches in overall colouration, 2 adnotaular setae and hypopygium not extending to middle of gaster, but differs in lacking characteristic banding patterns on the middle and hind femur and tibia (legs wholly yellow). Biologically, Q. sudheri is phytophagous in tender shoots of mango, Mangifera indica L. ( Anacardiaceae ), causing desiccation of the branches in India. Finally, in the Reina and La Salle (2004) key to Old World species of the anysis -group, Q. johnlasallei runs to Q. anysis Reina & LaSalle as both share mesoscutum dark brown and male ventral plaque ~0.5 X scape length, but differ in speculum ~0.5 X length MV (0.2 X), but dark brown band on gastral terga 3–4 (most gastral terga brown) and propodeum distinctly reticulate (sculpture effaced reticulate). Further, Q. citrella is an idiobiont ectoparasitoid of the leafminer P. citrella in SE Asia and parts of Europe whereas Q. anysis is known from M. buxi that mines the leaves of Buxus spp. throughout Europe and North America.

Etymology

Named in honour of our friend and colleague, Dr John La Salle, for his numerous contributions to our knowledge of Eulophidae .

Biology

This species was reared from leaf blister galls of Litchiomyia chinensis . Its specific biology within the gall remains unknown.

Type material examined

Female holotype, 1 female: TAIWAN: Nantou Co.: Caotun Township, Jianxing Rd., 23° 59 ʹ 39.7”N 120°46 ʹ 18.1”E, 15.VIII.2018, em 15.VIII.2018, Coll. Yi-Min Chao; sp. 3 female #9;

USNMENT01525920 ( NCHUC). 2 female paratypes, same data as holotype, except dates are 27.VII.18, em. 14.VIII.2018; secondary label reads: sp. 3, female #8, USNMENT01525921 ( NHMUK); USNMENT01525922 ( CNCI) . 2 females, same data as holotype, except dates are 25.VII.2018, em. 20.VIII.2018; secondary label reads: sp. 1, male #3, USNMENT01525919 ( NCHUC); USNMENT01525918 ( NHMUK) . 1 female paratype, same data as holotype, except dates are 18.V.2018, em. 15.VII.2018 (1 f, NCHU). 3 females, 3 male paratypes: TAIWAN: Changhua Co.: Fenyuan Township, No. 139 Zhongshan Rd., 24°00 ʹ 9.2”N 120° 37 ʹ 32.3”E, 19.IX.2018, Heyieh, Coll. Yi-Min Chao; sp. 2 female #6, USNMENT01525917 (1 f, USNM); same locality, dates and secondary labels as follows: 15.VIII.18, em. 9.IX.2018, sp. 3 male #11, USNMENT01525916 (1 m, USNM); 25.V.18, em. 21.IX.2018, sp. 3 female #10, USNMENT01525915 (1 f, NCHUC); 16.VIII.18, em. 15.IX.2018, sp. 3 male #12, USNMENT01525912 (1 m NHMUK); 13.IX.18, em. 21.IX.2018, sp. 1 female #1, USNMENT01525914 (1 f, USNM); 19.IX.18, em. 22.IX.2018, sp. 2 female #11, USNMENT01525913 (1 f, CNCI); same locality and collector, 12.III.2018 (1 f, NCHU). 3 female paratypes: TAIWAN: Chiayi Co.: East Dist ., No. 2 Minquan Rd., 23°29 ʹ 07.7”N 120°28 ʹ 13.5”E, 14.VIII.2018 Coll. Yi-Min Chao, em. 3.IX.2018 (2 f, NCHU); em. 6.IX.2018 (1 f, NCUH).

We hope that this work will stimulate research on Quadrastichus worldwide, especially larger regional treatments. However, the necessity of recent work to date on various pestiferous/beneficial Quadrastichus ( Kim et al., 2004; Kim et al. 2008; Prinsloo and Kelly 2009; Jansen-Gonázlez et al. 2019) is undeniable and underscores the need for further research.

Figures

Figure 1. (a) Quadrastichus johnlasallei, lateral habitus, female. (b) Quadrastichus lasallei, lateral habitus, female.

Figure 3. Quadrastichus johnlasallei, female: (a) anterior head; (b) dorsolateral mesosoma; (c) dorsolateral propodeum; (d) lateral flagellum; (e) lateral clava. Q. johnlasallei, male: (f) lateral scape; (g) lateral antenna; (h) lateral clava.