Xyrosaris insularis Ponomarenko et Beljaev, 2023

Ponomarenko, Margarita G. & Beljaev, Evgeny A., 2023, Description of a new species of the genus Xyrosaris Meyrick (Lepidoptera: Yponomeutidae) from the Far East of Russia with notes on congeneric species, Zootaxa 5306 (1), pp. 135-143 : 137-140

Xyrosaris insularis Ponomarenko et Beljaev sp. n.

Type material. Holotype: ♁, Russia, Primorskii Krai , 1 km SW of Vladivostok, Russkii Isl., Rogozin cape, 42°59'13" N 131°44'47" E, 18.07.2022, reared from Celastrus orbiculatus , gen. slide 181 MP (leg. E. Beljaev).

Paratypes: Russia: 1 ♀, same locality, date, collector and host plant, gen. slide 182 MP; 33 ♁, 40 ♀, same locality and host plant, 22.08– 09.09.2022, gen. slide 190 (♁) MP (leg. M. Ponomarenko and E. Beljaev), voucher Nos / DNA Nos – 777 (♀), 22.08.2022; 778 (♁), 23.08.2022; 781 (♁) 25.08.2022; 782 (♁), 783 (♁), 784 (♁), 785 (♁), 785 (♁), 29.08.2022; 788 (♁), 31.08.2022; 29 ♁, 17 ♀, Khasanskii distr. , 59 km SW Slavyanka, Furugelm Isl., 42°27′55″ N 130°55′10″ E, 20– 22.09.2012, gen. slide 186 (♁) YuZ, 187, 189, 191 (♁♁), 188, 192, 193 (♀♀) MP (leg. M. Ponomarenko) .

Diagnosis. A new species is similar to X. lichneuta Meyrick, 1918 , X. dryopa Meyrick, 1907 and X. obtorta Meyrick, 1924 by the labial palpi with third segment bearing a dense brush-like tuft concealing its apex, and by some elements of forewing pattern, specifically by oblique dark stripe on the dorsal half before the middle and light small costal spot at 4/5 of forewing. A new species can be easily distinguished in the male genitalia by a relatively large valval harpa bearing strong thorns on the triangular distal part and in the female genitalia by sterigma covered with strong setae externally and having sclerotized lobes on the anterior margin. In the related species X. lichneuta and X. dryopa valval harpa is slender, slightly dilated distally and without thorns, and sterigma lacks strong setae on the external surface; furthermore, it is without lobes on the anterior margin.

Adult ( Figs 1–10 ). Forewing length 6.0– 7.6 mm. Head covered with raised elongated scales, with light-grey apices ( Fig. 3 ). Palpi also covered with elongated scales, concolorous to those on the head; the first segment is short and arched, the second and third segments are flattened dorso-ventrally, the second segment dilated at distal 2/3, third segment slightly shorter than second one and hidden in long, loose bundle ( Figs 4, 5 ). Eyes large, diameter 3/4 of head length along the longitudinal body axis. Antenna filiform, with alternating light grey and dark grey rings, 4/5 wing length. Forewing elongated, rather narrow, with raised tufts of scales light at apices. Coloration and pattern of the wing are very variable ( Figs 1 , 7–10 ). Ground colour uniformly dark or light reddish-brown, slightly darker in distal third, some specimens with light-grey ground colour along basal half of dorsal margin. The pattern of wing, if distinct, is formed by a dark-brown transverse polyline, as a mirror image of the Greek symbol sigma (Σ), before the middle, brown wide longitudinal band on the basal third of the wing, dark-brown costal margin at basal third, concolorous two spots (costal one on sub-apex and another on tornus) and a light small mark in a small concavity at 4/5 of costal margin; distal third with two greyish or reddish-brown longitudinal bands under the median axis and along the dorsal margin. In many specimens, only some of the described elements are visible. Fringe motley, three stripes of dark brown scales alternating with light ones border the wing apex. Hindwing brownish-grey, with apex curved backward and basal lobe about 1/3 of wing length, surrounded by elongated light scales along the costal margin and Sc+R 1, forming shiny plate when opening wings ( Fig. 2 ); fringe grey. Forewing with Sc to costa at about 2/5 of wing length; R 1 –R 4 to costa, each separate at the base, R 4 and R s separate basally; R 5, M 1 –M 3, CuA 1 and CuA 2 to dorsal margin, each separate basally; CuP present at distal part only, 1A and 2A merged. Hindwing with Sc + R 1 to costa at about 1/3 of wing length, Rs to costa at about 6/7 of wing length, M 1 and M 2 close at base, M 3 and CuA 1 merged (after Moriuti, 1977), M 3 + CuA 1 and CuA 2 remote basally, CuP to 2/5 of dorsal margin ( Fig. 6 ).

Second abdominal sternite with a relatively deep rounded incision between long well-developed apodemes, distinct longer venulae, and sclerotized arch between them ( Fig. 17 ).

Male genitalia ( Figs 13–16 ). Uncus more or less triangular; socius arched, narrowed distally, with a thorn at the apex. Tuba analis wide and membranous, with ventral linear sclerotization. Tegumen arcuate, with longitudinal sclerotized comb-like muscular apodeme at anterior 1/4. Gnathos large bucket-shaped, curved at the middle, its basal part consisting of two narrow band-like arms and its distal part finely spiny and with a median gutter-shaped cavity, enclosing the aedeagus; ventral sclerotized ridge roundly convex or sinuous and with lateral projections between basal and distal parts of gnathos ( Figs 15, 16 ). Valva with almost parallel dorsal and ventral edges, slightly notched before dorsal protruding corner; dorso-basal process narrow and long, at about 1/5 of total valval length; harpa slightly longer than valval length, with inflation at the middle and 4–7 strong thorns along the convex edge of expanded distal part. Vinculum triangular ventrally and narrow laterally, with saccus more or less bulbous distally. Aedeagus slender, longer than valva, tube-like, with sclerotized sides at distal third and ring-like basal scape, cornuti composed of minute spines in distal fourth.

Female genitalia ( Figs 18–20 ). Ovipositor relatively moderate, intersegmental membrane between 9 th and 8th abdominal segments almost 2 times shorter than the length of papillae anales. The latter sclerotized laterally. Sclerotized plate between the base of papillae anales is distinct, triangular, and almost 1/3 of the papilla analis length. 8 th tergite is deeply notched on the posterior edge. Apophysis anterioris branched in the posterior part, its dorsal arm merged with the lateral edge of 8 th tergite and its ventral branch joined with strongly sclerotized and ventrally convex 8 th sternite forming sterigma; the anterior not branched part is three times shorter than apophysis posterioris. Sterigma densely covered with short strong setae on external surface; posterior edge with rounded lobes bearing long setae; anterior edge with a rounded cut at the middle and ear-like lobes laterally. These lobes joined with the posterior margin of the 7 th sternite, the latter with a relatively deep cut and sclerotized laterally ( Figs 19, 21 ). Ostium round, placed behind inflated middle part of sterigma. Antrum sclerotized, cylindrical, ductus bursae membranous, long and narrow, three times longer than corpus bursae, slightly dilated towards corpus bursae. Corpus bursae is more or less pear-shaped with signum at about the middle of the lateral side; signum with triangular thorns on a transversal gutter-like part and with one anterior lobe-like and two posterior triangular sclerotizations. Both ductus and corpus bursae with microtrichia on the inner side.

Distribution. Russia (south of the Far East).

Bionomics. Numerous larvae of different ages were collected on Celastrus orbiculatus Thunb. (Celastraceae) , growing in a narrow strip of the sea coast along rocks and rocky slopes on 12.08.2022.The larvae were predominantly light green in colour with a light grey head and prothoracic shield. The head of larvae is wider than thorax, with distinct epicranial suture dividing it into two slightly inflated halves. They fed on leaves folded in the form of a cradle with silk threads ( Fig. 11 ). In the laboratory, larvae began to pupate from 14.08.2022 onwards. Pupation took place in a loose silken cocoon ( Fig. 12 ). The duration of pupal development in the laboratory was 7–10 days. Imago emerged from 22.08 to 09.09.2022.

Considering the capture of the first 2 specimens of this species in the middle of July and the rearing of specimens in late August –early September, it can be stated that X. insularis has 2 generations in the south of Primorskii Krai.

Etymology. The name of the species, insularis , is derived from the Latin insula, meaning island, and corresponds to the insular habitat of the species.

Remarks. Since the genetic distance between sequences of the new species and specimen from South Korea 0%, they might be conspecific, however other independent character set as detailed genitalia morphology needs to be examined. In case the specimens from Russia, Primorskii Krai, presented in this study, and the specimens captured in South Korea are conspecific, then the distributional range of X. insularis includes the territory of this country. To confirm this further investigation is required.

Figures

FIGURES 1–6. External morphology of adult of Xyrosaris insularis sp. n. 1, holotype, male; 2, paratype, male, hindwing with basal lobe on costa (shown with a white arrow); 3, head, lateral view; 4, palpus, dorso-ventral view, distal segment above; 5, basal segment of palpus, lateral view, enlarged; 6, wing venation. Scale bar for figures 1–4, 6—1 mm; for figure 5—0.5 mm.

FIGURES 7–12. Adults, paratypes, and preimaginal stages of Xyrosaris insularis sp. n. 7–10—variations of wing pattern: 7, 9—males, Russkii Is.; 8, 10—males, Furugelm Is.; 11—larva on leaf of Celastrus orbiculatus with skeletonized upper surface; 12—cocoon with larva in process of pupation. Scale bar 1 mm.

FIGURES 13–21. Abdominal morphostructures of Xyrosaris insularis sp. n. 13–17, male: 13, male genitalia, ventral view, holotype, GS 181 MP; 14, aedeagus, lateral view, holotype, GS 181 MP; 15, uncus and deflected gnathos, latero-ventral view, paratype; 16, gnathos supporting aedeagus, ventral view, paratype; 17, 2nd abdominal sternite, paratype; 18–21, female: 18, female genitalia, ventral view, paratype, GS 182 MP; 19, 8th abdominal sternite, ventral view, paratype; 20, signum, paratype; 21, 7th abdominal segment, ventral view, paratype. Scale bar 0.5 mm with the exception of enlarged figures 15, 16, 19, 20.