Eucalantica nestori, Ruiz-Galvan & Sohn, 2023

Ruiz-Galvan, Isabel & Sohn, Jae-Cheon, 2023, A new species of Eucalantica Busck (Lepidoptera, Yponomeutidae) poses potential concerns on blueberry industry in Mexico, Zootaxa 5351 (2), pp. 287-292 : 288-290

Eucalantica nestori n. sp. ( Figs 1A–E )

Type series. Holotype —male, “HOLOTYPE | Eucalantica | nestori | R. & S. 2023” [red label], “ Atzingo , Puebla | 5/08/2021 [5 viii 2021] | Arándano | Isabel Ruiz Galván”, “ Eucalantica sp. | Lepidoptera | Yponomeutidae ♁ [handwritten]”, USNM.

Paratypes (6♁ 17♀)— 1♀, same data as holotype, [ GSN] SJC-1377, GJUE ; 1♀, Puebla, Zacatlán, Atzingo (19°59’N 97°58’W, alt. 2174 m), 10 viii 2020 (IR Galván leg.), on blueberries, PHIM ; 1♁, ditto (19°59’N 97°57’W, alt. 2020 m), 8 X 2020 (IR Galván leg.), [ GSN] IRG-001 ; 2♀, ditto, 29 iv 2021 (IR Galván leg.), on blueberries, PHIM ; 1♁, ditto, 5 viii 2021 (IR Galván), on blueberries, PHIM ; 2♀, ditto (19°59’N 97°57’W, alt. 2020 m), 29 iv 2021 (IR Galván leg.), on blueberries, PHIM ; 1♁ 4♀, ditto, 30 iii 2021 (IR Galván & O Rodríguez leg.), on blueberries, PHIM ; 1♀, Puebla, Zacatlán, Xoxonacatla (20°00’N 97°56’W, alt. 1847m) 30 iii 2021 (IR Galván leg.), on blueberries, PHIM ; 1♀, ditto (20°01’N 97°55’W, alt. 1847m), 30 iii 2021 (IR Galván leg.), on blueberries, PHIM ; 1♁, ditto (20°00’N 97°55’W, alt. 1847m) 19 v 2021 (IR Galván leg.), on blueberries, PHIM ; 1♁ 1♀, ditto (19°59’N 97°56’W, alt. 2020m), 6 vi 2021 (IR Galván leg.), on blueberries, PHIM ; 1♁, ditto, 6 vii 2021 (O Rodríguez leg.) on blueberries, PHIM ; 4♀, ditto, 5 viii 2021 (IR Galván leg.), on blueberries, PHIM .

Diagnosis. This species is similar to Eucalantica polita in the overall appearance but it differs from the latter generally in the smaller size (the forewing length 5.1–5.6 mm in E. nestori n. sp. vs. 5.5–8.0 mm in E. polita ) and the presence of the pale-reddish brown forewing fringe (white in E. polita ), the distally broader valva and the larger projection above the sacculus in the male genitalia ( Figs 1C for E. nestori n. sp. and 1D for E. polita ).

Description. Head—Vertex white, intermixed with dark grayish brown scales anterolaterally; frons pale brownish gray, darkened laterally. Antenna 3/4 as long as forewing; scape white; basal seven flagellomeres white dorsally; rest flagellomeres annulated with white. Labial palpus porrect; 1 st palpomere pale grayish brown; 2 nd palpomere denser distad, 4x longer than 1 st palpomere, white dorsally, dark grayish brown ventrally; 3 rd palpomere as long as 2 nd palpomere, white dorsally, dark grayish brown ventrally, with triangular scale-tuft. Thorax—Patagium, tegula and mesonotum white. Foreleg lustrous; coxa and femur white laterally, pale grayish brown mesally; tibia and tarsomeres dark grayish brown. Midleg lustrous; coxa white; femur white, tinged with pale grayish brown distally; femur dark grayish brown dorsally, white ventrally; tarsomeres dark grayish brown. Hindleg lustrous white. Forewing length 5.1–5.6 mm, lustrous white, narrowly round apically; costal band in basal 1/5 grayish brown; discal spot black; dorsal patch present in distal half of dorsal margin, expanded at basal 1/5, reddish brown, accompanied with black scales above basal expansion; terminal area dot-lined with few black scales; fringe pale reddish brown. Hindwing lustrous gray, darkened to apex; fringe pale gray. Abdomen—Terga and sterna lustrous white.

Male genitalia ( Figs 1C, D )—Uncus 1/5 as long as socii, linguiform, with subconical tubercle posterolaterally; socius 5x longer than uncus, elongate, digitate, with a row of four ventral spines terminally; spines on socius gradually smaller distad. Tegumen parallel-sided, slightly narrowed in distal 1/3; subscaphium bulged and granulate ventrad. Valva gradually enlarged distad, broadly round apically, setose on distal and ventral areas; costa narrow, enlarged in basal 1/4; saccular margin evenly rounded; sacculus narrow, gradually enlarged to base; a small semielliptical mound above basal 1/8 of saccular margin. Saccus 2/3 as long as socius, elongate, slightly dilated in apex. Phallus 2x longer than saccus, slender, weakly sinuate; cornutus absent.

Female genitalia( Fig.1E )—Sternite VIII sclerotized,with a shallow,semielliptical,setose humps posterolaterally. Papilla analis semirectangular, dilated dorsally, setose. Apophysis posterioris 4x longer than apophysis anterioris excluding basal Y-fork. Minute thorns on area around humps of sternite VIII. Antrum subquadrate, concave posteromarginally, with minute thorns on internal wall. Ductus bursae 1/4 as long as corpus bursae, narrow; bulla seminalis long-obovate. Corpus bursae 2x larger than bulla seminalis, oval; signum absent.

Distribution. Mexico (Puebla).

Etymology. This species is named after Prof. Néstor Bautista Martínez who was a doctorate advisor of the first author and had dedicated most parts of his life to the Mexican insects of agricultural importance. The species epithet is a noun in the genitive case.

Host plant. Ericaceae — Vaccinium ashei Reade.

Remarks. This new species has been found only in a small area of the Puebla state in Mexico. An expanded inventory on blueberry farms in other states may reveal the broader distribution of the species than depicted in the present article. Another congener, E. vaquero Sohn widely occurs in Arizona, United States and Veracruz, Mexico ( Sohn & Nishida 2011). This species seems associated with the blueberry family, likewise other congeners but its host plants remain unknown.

2. Biology

Larvae of E. nestori n. sp. were observed almost all year round. The new Eucalantica species was found in all the sampled plantations in the surveyed region but the economic damage it causes is still unknown. On the infested blueberries, they feed on young shoots and flowers, except in the months of hibernation when the foliage is reddish and soon later dropped. The larvae primarily feed on leaves, leaving only the leaf skeletons. A silken net produced by the larva for protection can be seen among the leaves. The nest can be confused with ones of tortricids associated with blueberries. The silken web of the larva can often be expanded to flowers. In such cases, the larvae feed on the pistil and stamens and completely destroy the whole flowers ( Fig. 2A ). Because they are borers, most of the damage is observed in young vegetative buds ( Fig. 2B ). The infested shoots show initially wilting of stems and leaves, followed by a color change to reddish brown and finally necrosis. The shoots then bend into a cane shape and remain on the plant for several months ( Figs 2D, E ). The damaged shoots have an average length of five to 12 cm, and in the lower part a circular orifice can be observed where the larva enters and exits and where its excreta are expelled ( Fig. 2C ). When the larva is fully developed, it leaves the shoot and seeks refuge for pupation in the leaves nearby. The pupa develops inside a silken cocoon.

Figures

FIGURE 1. Eucalantica nestori n. sp. (A–C, F) and E. polita (D–E). A. Holotype (male) in dorsal view; B. Paratype (male, IRG-001) in lateral view; C. Male genitalia (paratype, IRG-001) in ventral view; D. Male genital capsule in ventral view (after Sohn & Nishida 2011); E. Phallus (after Sohn & Nishida 2011); F. Female genitalia and abdominal segments VIII–IX (paratype, SJC-1377). Scale bars = 2 mm.

FIGURE 2. Damage caused by Eucalantica nestori n. sp. in blueberry shrubs.A. Destruction of flowers and leaves agglomerated by silk; B. Interior of the bored stem and excreta; C. Larva entry and exit orifice and excreta; D. Shoot with dry leaves on the cane-shape of withering stem with a larva; E. Shoots adhered to the plant after the moth has emerged.