Bucculatrix duanwuia Liu, 2020

Wang, Encui, Li, Wei & Liu, Tengteng, 2020, Bucculatricidae associated with Asteraceae in China, with one new species (Lepidoptera: Gracillarioidea), Zootaxa 4766 (1), pp. 181-191 : 182-188

Bucculatrix duanwuia Liu , sp. nov.

Îūẹ [Chinese name]

( Figs 1–3 , 5 , 7–21 )

Diagnosis. Bucculatrix duanwuia resembles B. nota Seksjaeva, 1989 , B. notella Seksjaeva, 1996 , B. laciniatella Benander, 1931 , and B. splendida Seksjaeva, 1992 in the adult appearance and/or the male genitalia, and finds B. notella as the closest relative based on available genetic data ( Fig. 1 ). All of the four congeners feed on Artemisia spp. and are recorded in Japan and/or the Russian Far East ( Kobayashi et al. 2010). The new species can be separated from B. nota by the acute triangular socius reaching far away from the end of tuba analis, the valva equilateral triangular in outline on distal 1/3 and the antrum as long as width of ostium bursae; in B. nota , the socius is oblong and almost reaches the end of tuba analis, the valva is narrowed at apex by cupping on dorsal margin (Seksjaeva 1989: 622, Fig. 4 ; Kobayashi et al. 2010: 22, Fig. 4E , 42, Fig. 9B ), and the antrum is twice as long as the width of ostium bursae ( Baryshnikova 2013b: 72, Fig. 12 (3)). These morphological characters can also separate the new species from B. notella and B. laciniatella . In B. notella , the valva is sharply curved on dorsal margin and narrowed distally, and the socius is indistinct; in B. laciniatella , the distal 1/3 of the valva is almost same in width. The new species can be distinguished from B. splendida by the curved and helical distal part of the phallus which is slightly curved only but not helical in the B. splendida .

Type material. Holotype, ♂, CHINA: Shandong: Mingguangsi Forest Farm, 35°35'42"N, 117°50'56"E, Mt. Meng , Linyi City , 900 m, collected on 28.vii.2019, larva mine in Artemisia princeps , emerged on 6.viii.2019, leg. Tengteng Liu, field no. LTT00656 , registration no. SDNU. Ent 012043, genitalia slide no. WEC19029. Paratypes: 5♂, 3♀, emerged on 6–11.viii.2019, other data same as holotype, registration nos. SDNU.Ent012037, SDNU. Ent012038 ( WEC 19028 ♀), SDNU.Ent012039 (slide and DNA barcode no. WEC 19012 ♂), SDNU.Ent012040 ( WEC 19019 ♀), SDNU.Ent012041 (slide and DNA barcode no. WEC 19011 ♂), SDNU.Ent012042 ( WEC 19021 ♂), SDNU.Ent012044 ( WEC 19022 ♂), SDNU.Ent012045 ( WEC 19020 ♀).

Adult ( Figs 2, 3 ). Wing span 7.0 mm in holotype, 6.8–7.2 mm in paratypes, body length 2.9 mm in holotype, 2.8–3.0 mm in paratypes. Forewing white with yellow stripes mixed with black.

Head. Face white, hair tuft on vertex white. Antenna with scape white having long white hairy scales anteriorly which covers the eye, flagellum yellowish brown. Labial palpus minute and smooth.

Thorax. Mesothorax white. Forewing ground color white, one light yellow stripe extending from middle of base almost join yellow patch on middle of dorsum, sometimes with scattered minute black spots at conjunction; one costal stripe at basal 1/3 extending to middle of wing; one yellow costal streak beyond middle, extending outwards to tornus, with a black spot above tornus; a yellow patch at apex, with scattered black scales; cilia grayish white, scattered with black scales on termen. Hindwing and cilia grayish white. Fore and mid legs yellow with black dot dorsally; hind leg yellow, with long beige fringe on tibia dorsally, longer in male. Yellow stripes slenderer and mixed with more black scales on forewing patterns in female specimens ( Fig. 3 ).

Abdomen. Yellowish brown dorsally, light yellow ventrally.

Male genitalia ( Fig. 5 ). Tegumen distinctly sclerotized laterally. Tuba analis broad, sclerotized laterally, covering short setae ventrally. Socius acute triangle, blunt on apex with short setae, reaching far away from the end of tuba analis. Vinculum strongly sclerotized, concaved at middle anteriorly. Juxta strongly sclerotized in a trapezoidal way as a whole, split distally. Valva strongly sclerotized and thickened dorsally, basal 2/3 almost same in width, distal 1/3 straight on dorsal and ventral margin, equilateral triangular in outline, with short dentate setae apically. Phallus about twice as long as valva, thick basally, gradually narrowed towards apex, with S-shaped curve before apex, distal hook around 1/7 as long as phallus.

Female genitalia ( Fig. 7 ). Papillae anales sclerotized, covering dense spikes distally; posterior apophyses slen- der, almost reaching anterior margin of eighth segment; eighth sternite weakly sclerotized posteriorly, with paired hair tufts laterally at middle, anterior half sclerotized, waved on anterior margin; ostium bursae covered with dense micro spines, with sclerotized ventral margin; antrum funnel-shaped, as long as width of ostium bursae, densely covered with micro-spines on inner wall of posterior half, with anterior half smooth and almost membranous ( Fig. 8 ); ductus bursae membranous and slender; corpus bursae elongated oval, membranous, signa two groups of some 15 spiked combs. Seventh sternite waved on posterior margin; seventh tergite rounded posteriorly ( Fig. 9 ).

Biology. Adult lay eggs besides the main vein on upper surface of the blade ( Fig. 13 ). Larvae of earlier instars mine along veins and the black frass totally fill the mine during this time ( Figs 10, 11 ). One or two mines per leaf. Larvae vacate the mine by chewing a circular hole on the upper side of the leaf ( Fig. 12 ), then they feed exposed by making several irregular windows on the under surface of the same blade or other blades ( Figs 15, 16, 18 ). The larva moults in a white flat cocoonet on the under surface ( Fig. 14 ). The cocoon is white, having six to ten ridges on surface ( Figs 17 , 21 ). The pupa bears a small triangular cocoon cutter and the cremaster is comprised of one pair of teeth dorsally and one pair similar but smaller teeth laterally ( Fig. 20 ).

DNA barcodes. DNA barcodes of two paratypes (SDNU.Ent 012039 and SDNU.Ent 012041) were generated. The genetic distance between B. duanwuia and the closest relative B. notella ranges from 3.79% to 4.11% based on populations from China.

Distribution. China (Shandong).

Host plant. Artemisia princeps Pamp. ( Asteraceae , Fig. 19 ) ( Gao et al. 2017).

Etymology. The specific name duanwuia refers to the name of a traditional Chinese festival, during which branches of the host plant or other related Artemisia species will be hanged on doors for driving away evils and for pursuing happiness.

Figures

FIGURE 1. Neighbor-joining tree of Asteraceae-feeding Bucculatrix based on DNA barcodes (mitochondrial COI gene).

FIGURES 2−4. Adults of Bucculatrix spp. 2−3, B. duanwuia, 2, male, paratype, registration no. SDNU.Ent012037, 3, female, paratype, registration no. SDNU.Ent012041; 4, B. notella, male, registration no. SDNU.Ent000605.

FIGURES 5−6. Male genitalia of Bucculatrix spp. 5, B. duanwuia, holotype, SDNU.WEC19029; 6, B. notella, SDNU. LIU0162.

FIGURES 7−9. Female genitalia of Bucculatrix duanwuia. 7, female genitalia, paratype, SDNU.WEC19028; 8, ostium bursae and antrum, identical slide to fig. 7; 9, seventh abdominal segment, identical slide to fig. 7.

FIGURES 10−19. Leaf mine, larva, cocoon, and host plant of Bucculatrix duanwuia. 10 & 11, leaf mines with larvae; 12, vacant leaf mine; 13, egg shell besides a vein, enlarged from fig. 12; 14, cocoonet with a larva; 15, larva mining on the underside of a leaf: head inserted; 16, feeding windows, underside view; 17, white cocoon attached on a branch of the host plant; 18, feeding windows, upperside view; 19, host plant Artemisia princeps.

FIGURES 20−21. Pupa and cocoon of Bucculatrix duanwuia. 20, pupa, a, ventral view, b, dorsal view, c, lateral view; 21, pupa extruded from a cocoon.