Introduction

The family Tortricidae is one of the largest and most diverse lineages within the order Lepidoptera, more than 11,000 described species worldwide (Brown, 2005). In this family, the subfamily Olethreutinae represents a highly diversified group with more than 4,400 species known worldwide, successfully adapting to a wide range of ecological niches (Nasu, 2022;Jeong et al., 2024;Zhang, 2018). Among its various tribes, Enarmoniini contains several taxa that present unique evolutionary and morphological traits.

The genus Pseudacroclita was established based on the type species P. hapalaspisMeyrick (1931). Morphologically, the genus is characterized by the absence of a costal fold and raised scale-tufts on the male forewing, alongside the presence of stalked veins R₇ and R₈. Although the venation follows the general Acroclita-Rhopobota pattern, the genitalic structures remain unique, providing a clear separation from allied genera such as Ancylis and Gypsonoma. In the male genitalia, the uncus forms a distinctive hairy dome at the top of the tegumen, the gnathos is reduced, and the wide aedeagus is armed with numerous thorn-like cornuti. The female genitalia are characterized by normal papillae anales and horn-like, unflattened signa with a developed basal dilation (Oku, 1979;Nasu, 2022). The larvae are specialist herbivores that feed on the foliage of several Rubus species, including R. sieboldii, R. buergeri, R. crataegifolius, and R. palmatus var. coptophyllus, but notably avoid R. parvifolius. These larvae exhibit highly specialized behaviors; they construct a tubular nest on the lower leaf surface, feed on the upper surface through an opening under a sparse net, and eventually cut off a section of the leaf to build an erected pupation case upon maturation (Nasu, 2022;Oku, 1979).

The genus Pseudacroclita, established by Oku (1979), remains a small group comprising only eight known species worldwide (Brown, 2005;Nasu, 2022;Kuznetsov, 1979;Zhang, 2018). Four species of the genus have been recorded from Japan (Nasu, 2022). Also, six species were known from China (Zhang, 2018). In Korea, P. hapalaspis (Meyrick, 1931) has been recorded for the first time from Korea (Byun et al., 1998;Park and Lee, 2021). Recently, one species, P. luteispecula (Kuznetsov, 1979) was added (Jeong et al., 2024). This study aims to report a newly recorded species, P. microplaca (Meyrick, 1912) from Korea.

Material and Methods

The specimens examined in this study, including the genitalia slide glass, are preserved in the Systematic Entomology Laboratory, Hannam University (HNUSEL). Images of adult and genitalia were taken using a digital camera (Canon EOS 600D; Canon Inc., Ota, Tokyo, Japan), microscope LEICA M205C (© Leica Microsystems, Wetzlar, Hesse, Germany) and software, Image Lab version 2.2.4.0 MCMDesign (Hillerød, Denmark). The dissecting method of the genitalia followed after Holloway et al. (1987). The abbreviations used here are as follows: CN- Chungcheongnam-do; gen. slide no.-Genitalia slide number; HNUSEL-Systematic Entomology Lab., Hannam University, Daejeon, Korea.

Systematic accounts

Order Lepidoptera Linnaeus, 1758.

Family Tortricidae Latreille, 1803

Subfamily Olethreutinae Walsingham, 1895

Genus PseudacroclitaOku, 1979

Type species:Acroclita hapalaspisMeyrick, 1931

Pseudacroclita microplaca (Meyrick, 1912) 작살나무애기잎말이나방 (신칭)

Olethreutes microplacaMeyrick, 1912: 873. Type locality: Khasi Hills, Assam, India.

Olethreutes microplaca: Clarke, 1958: 527.

Pseudacroclita microplaca: Nasu, 2022: 45 (comb. nov.).

Adult (Fig. 1A). Wingspan 8.5 mm. Head covered with dark brown scales. Thorax covered with blackish brown scales, appearing rough in texture; tegulae slightly paler. Forewing elongate, apex slightly rounded; costal margin gently arched near base, then nearly straight to apex; ground color dark brown, heavily mottled with blackish brown scales throughout; an irregular, diffuse ocherous-white fascia or patch visible in the basal third, extending toward the dorsum; wing surface characterized by a rough-scaled appearance; cilia brown, becoming paler towards the tornus. Hindwing dark grayish brown, somewhat lustrous; narrowed apically; cilia long, exceeding the width of the wing lamina, grayish brown. Hind leg slender and elongate; femur and tibia predominantly grayish brown; tibia possessing a pair of distinct, long spurs at the apex; tarsus segments appearing slightly paler than the tibia, with subtle ocherous-white scales.

Male genitalia. Unknown.

Female genitalia (Fig. 1B). Papillae anales small, narrow, and rounded; covered with fine, scattered hairs. Apophyses anteriores moderate and elongate; apophyses posteriores elongate, slender, twice as long as the former. Ostium bursae located in a simple, membranous area, rounded, slightly sclerotized at the opening area. Ductus bursae long, slender, and membranous throughout; without visible sclerotization, twisting, diameter appears relatively uniform, widening slightly before connection with the corpus bursae. Corpus bursae ovate in shape, relatively large, entirely membranous, and distinguished by a small, triangular sclerotized fragment located on the upper part near the connection with the ductus bursae; a minute signum on the lower part of corpus bursae.

Material examined. [KOREA] 1♀, Donghyul Temple, Gongju-si, CN (36°33′45.58″N 127° 9′19.37″E), 9.VIII.2016 (B. K. Byun), gen. slide no. ♀3502-coll. HNU/SEL.

Host plants.Callicarpa japonica Thunb., 1784 [Lamiaceae] was known from Japan (Nasu, 2022).

Remarks. According to Nasu (2022), this species has been known as Olethreutes microplaca (Meyrick, 1912) (cf. Clarke, 1958: 527, pl. 262, fig. 4). Recently, Nasu (2022) formally transferred it to the current genus as a new combination.

Distribution. Korea (new record), Japan, India.

Discussion

The genus Pseudacroclita, established by Oku (1979), remains a small group comprising only eight known species worldwide (Brown, 2005;Nasu, 2022;Kuznetsov, 1979;Zhang, 2018). Members of this genus are notoriously difficult to distinguish due to their highly similar adult wing patterns.

Pseudacroclita microplaca (Meyrick, 1912), newly recorded from Korea in the present study, is morphologically very similar to P. luteispecula (Kuznetsov, 1979). Also, the female genitalia of the two species are very similar, making structural identification challenging; however, a minute diagnostic character can be found in the ostium bursae: the sclerotized portion of the ostium in P. microplaca is relatively shorter and blunter compared to the more elongated form in P. luteispecula. Ecological information serves as an additional line of evidence for species discrimination. P. luteispecula is known to feed on Isodon spp., whereas P. microplaca is associated with Callicarpa spp.

Taxonomically, P. microplaca had long been treated as incertae sedis due to its uncertain generic placement (Brown, 2005). However, Nasu (2022) recently transferred the species to the genus Pseudacroclita as a new combination (comb. nov.). With the addition of P. microplaca in this study, the Korean fauna of the genus Pseudacroclita now includes a total of three species: P. hapalaspis, P. luteispecula, and P. microplaca.