Four new species and seven new records of Promalactis Meyrick, 1908 (Lepidoptera, Oecophoridae) from Laos

Abstract The genus Promalactis Meyrick, 1908 is recorded for the first time from Laos in mainland Southeast Asia and four new species are described: P. crassasp. nov., P. retusasp. nov., P. senispinasp. nov., and P. uniclavatasp. nov. Additionally, seven species are newly reported from the country: P. albisquama Kim & Park, P. apicisetifera Du & Wang, P. bitrigona Kim & Park, P. zolotuhini Lvovsky, P. parasuzukiella Wang, P. suzukiella (Matsumura), and P. spiraliola Kim. Distributional data and diagnoses and/or descriptions for all species in Laos are provided, along with illustrations of adults and genitalia.


Introduction
Promalactis Meyrick, 1908 is one of the largest genera of the family Oecophoridae (Lepidoptera, Gelechioidea), comprising 341 species (Kim et al. 2018;Wang and Liu 2019). They are highly diverse in China and the Indomalayan realm (Kim et al. 2017b). Promalactis, which includes fungivores and scavengers, is close to the genera Harpella Schrank, Oecophora Latreille, and Schiffermuelleria Hübner in the recent phylogeny of Kim et al. (2016), but it can be distinguished from them in having the forewing ground color brownish yellow to yellowish brown with distinct markings, such as white bands, patches, or fuscous suffusions (Kim et al. 2017c), and in having R 4 and R 5 stalked (Kim et al. 2014).
Laos is a andlocked and mountainous country located in Mainland Southeast Asia, bordered by Myanmar and China to the northwest, Vietnam to the east, Cambodia to the southwest, and Thailand to the west and southwest. It lies in the monsoon belt and experiences a rainy season between May and November, and a dry season from December to April.
The aim of this study is to report the first distributional data of Promalactis in Laos, with four new species described and seven other species newly recorded. Illustrations of all known species in Laos have been provided along with diagnosis and distributional information.

Material and methods
Materials in this study were collected from 2012-2017 at several sites of three provinces of Laos, Vientiane (Northwest), Xiang khaung (Northeast), and Bolikhamsai (Central) ( Fig. 1; Table 1). The collections were mainly from Phou Khao Khouay National Biodiversity Conservation Area (PKK National Park). It is considered as one of the most stunning preserves, with mixed deciduous forest dominating the lighter which less humid and shallow soils.
The forest consists of Dipterocarpus and Shorea, with a dry, evergreen forest centrally. Using either a mercury vapor lamp (220V/400W) or a black light lamp (20W), all individuals were taken alive, put in vials with cork lids, and killed with ammonia. Genitalia preparations for voucher specimens followed Kim et al. (2017a). All specimens were examined under a Leica 400B microscope (Leica Microsystems, Germany) and digital images were taken using Image Lab software, version 2.2.4.0 (MCM Design, Hillerød, Denmark). All specimens including type specimens will be deposited in two institutions: SNU, Seoul National University; INU, Incheon National University in Republic of Korea.

Genus Promalactis Meyrick, 1908
Promalactis Meyrick, 1908a: 806. Type species. Promalactis holozona Meyrick, 1908a.  Diagnosis. This species ( Fig. 2A) is externally most similar to P. suzukiella (Matsumura) in the forewing pattern, but it can be easily distinguishable from that species by the subbasal band which traverses from the costa to the posterior margin and the fuscous suffusion rarely developed under the circular costal patch at 2/3 of the forewing. The male genitalia ( Fig. 3A-D) are differentiated from those of P. suzukiella in having the gnathos with a pointed apex and the aedeagus bent at 3/5 of its length. The female genitalia ( Fig. 6A-C) are distinguished from those of P. suzukiella in having the ductus bursae bearing a long, serrated spine and another tiny spine.
Distribution. Laos (northeast, central; new record), China (south) and Thailand (central). Diagnosis. This species (Fig. 2B) is similar to P. uniclavata sp. nov. in the wing pattern but can be easily distinguished from the latter in having the forewing without a subbasal band which traverses from the costa to the posterior margin, and in having the male genitalia ( Fig. 3E-H) with the uncus having a thumb-like apex and a touguelike gnathos.
Distribution. Laos (northeast; new record), China (south), Vietnam; Palaearctic: Korea (South), China (northwest, northeast, central), Japan, Russia (Far East); Nearctic: USA. Diagnosis. The species is superficially most similar to P. suzukiella in the similar forewing pattern but can be easily distinguished from the latter by the subbasal band which traverses from the costa to the posterior margin and with a fuscous suffusion below the costal patch at 2/3 of the posterior margin. The male genitalia are characterized in having the uncus bifurcate, the gnathos digitate, and the juxta large and club-shaped.

Promalactis uniclavata
Description. Adult (Fig. 2C). Head: frons grayish brown tinged with white; vertex white, tinged with dark brown; occiput yellowish brown. Antenna: scape white entirely, shorter than diameter of eye; flagellum white from base to 2/3 of its length, dorsally dark brown and white alternately from 2/3 to apex. Labial palpus: 2 nd palpomere pale-yellow tinged with dark brown, as long as 3 rd palpomere; 3 rd palpomere dark brown, except pale yellowish white at apex dorsally. Thorax: thorax and tegula dark brown. Wingspan 7.5-8.0 mm. Forewing ground color brownish yellow, darker near base; two bands and one costal patch all white, edged by fuscous scales: one subbasal band traversed from costal margin to posterior margin just near wing base; one antemedial band, oblique, not reaching costa; one costal patch semicircular at 3/4 of forewing, connected to fuscous suffusion before tornus; fuscous scales somewhat dense near apex; fringes grayish brown near tornus, yellow near apex. Hindwing ground color grayish brown; fringes grayish brown.
Distribution. Laos (northeast, northwest, central; new). Etymology. The name is derived from the Latin, uni (= one) plus the Latin clava (= club), referring from the large, club-shaped juxta in the male genitalia. Diagnosis. The species (Fig. 2D) is externally similar to P. suzukiella in the wing pattern but can be easily differentiated from the latter in having the forewing without a subbasal band and in having the fuscous suffusion denser near apex. The male genitalia (Fig. 3M-O) are also distinguished from those of P. suzukiella by the bifurcate uncus, the distinct juxta, and the extremely longer saccus.

Promalactis albisquama
Distribution. Laos (northwest; new record), Cambodia (northwest), China (south), Vietnam (north). Diagnosis. The species (Fig. 2E) is externally characterized by the narrow, medial band not connected to the white costal patch on the forewing. The male genitalia (Fig. 4A-E) are also distinguished by the weakly developed gnathos and large aedeagus. The female genitalia (Fig. 6G, H) are characterized in having the ductus bursae coiled  Diagnosis. This species is externally similar to P. lophacantha Wang, Du & Li by having irregular bands of forewing, but it can be easily differentiated by the extended saccus and the prolonged aedeagus, which bears six projections in male genitalia.

Promalactis spiraliola
Description. Adult (Fig. 2F). Head: frons pale yellowish white; vertex white; occiput white. Antenna: scape white entirely, longer than diameter of eye; flagellum dark brown and white alternately from base to apex dorsally. Labial palpus: 2 nd palpomere pale yellowish brown, slightly longer than 3 rd palpomere; 3 rd palpomere pale yellow tinged with white, except dark brown apically. Thorax: thorax and tegula dark brown. Wingspan 7.0-7.5 mm. Forewing ground color yellowish brown; three bands, one costal patch, and one apical patch all white: one subbasal band traversed from costal margin to posterior margin near wing base; one antemedial band broad, slightly oblique toward wing base, traversed from costa to posterior margin; one medial band connected to postmedial short band on lower margin of cell; one apical patch accupied after 3/4 of forewing to apex; fuscous scales scattered followed by posterior margin of forewing; fringes yellow, except pale yellowish white near medial and postmedial bands. Hindwing ground color grayish dark brown; fringes dark grayish brown.
Male genitalia (Fig. 4F-I). Uncus wide at base, gradually narrowed to pointed apex, setose apically, as long as gnathos. Gnathos wide at base, gradually narrowed to apex, thumb-shaped apex, bearing sclerotized and serrated projection inner margin, as long as uncus. Valva symmetrical; costal margin convex after middle; saccular margin moderate, setose from 1/2 of its length to apex. Saccus extremely long, 1.5 times longer than valva. Aedeagus straight, elongated, as long as total length of genitalia, with six spines, differently sized apically; cornutus absent.
Female unknown.

Distribution. Laos (central; new).
Etymology. The specific name is derived from the Latin, seni (= six) and -spina (= spine), referring from the aedeagus bearing six spines in males.  Diagnosis. The species (Fig. 2G) is similar to P. zolotuhini Lvovsky, 2013 in the wing pattern but can be easily recognized from the latter species by the yellowishbrown ground color and relatively broad subbasal band and the absence of medial band of the forewing. The male genitalia (Fig. 4J-M)  Diagnosis. This species (Fig. 2H) is close to P. apicisetifera Du & Wang in its wing pattern, but it can be easily distinguished in having the forewing ground color tinged with reddish dark brown. The male genitalia (Fig. 5A-D) are differentiated from the those of P. apicisetifera in having the gnathos bearing round apical tips, the cucullus sclerotized, and the valva rounded apically.

Promalactis apicisetifera
Distribution. Laos (northeast; new record), Vietnam (north).  Fig. 3D-F), and by the female genitalia ( Fig. 7A-C), which is characterized in having the antrum with a thumb-shaped caudal margin and the signum somewhat triangular-pyramid-shaped.

Promalactis bitrigona
Distribution. Laos (northeast; new record), Vietnam (north). Diagnosis. This species is superficially similar to P. diorbis Kim & Park, 2012, but it can be differentiated in having the large costal patch at 4/5 of the length of the forewing and in having the small antrum and the thick ductus bursae bearing several tiny spines in the female genitalia.

Promalactis crassa
Description. Adult (Fig. 2J). Head: frons pale grayish dark brown, tinged with dark brown; vertex dark brown; occiput yellowish dark brown. Antenna: scape entirely white, except dark brown apically, shorter than diameter of eye; fragellum dark brown and white alternately from base to apex dorsally. Labial palpus: 2 nd palpomere pale yellowish dark brown, 1.5 times longer than 3 rd palpomere; 2 nd palpomere dark brown, except white at apex. Thorax: thorax blackish dark brown; tegula dark brown. Wing expanse 11.0-11.5 mm. Forewing ground color yellowish brown; five bands, one spot, two costal patches, one posterior patch, and one apical patch, all white edged with fuscous scales: one subbasal band short and one tiny spot near base, not connected each other; two antemedial bands: one just below subcostal (Sc) vein and the other at 1/6 posterior margin, both irregularly shaped, connected to each other at antemedial part of medial cell; the other antemedial band just before middle narrowed, arched connected to postmedial band; two costal patches: large one at 3/5 and somewhat semi-ovate, after pale grayish suffusion; small one at 4/5 and irregularly shaped, after fuscous suffusion; one small posterior parch after tornus; one apical patch larger than near costal and posterior patches; fringes yellowish brown near apex, mixed with fuscous scales near tornus. Hindwing more or less lanceolate; Hindwing ground color grayish brown; fringes dark grayish dark brown.
Distribution. Laos (northeast; new). Etymology. The name of this species is derived from the Latin, crass (= thick) and the suffix -a, referring from the ductus bursae thickly developed in the female genitalia.  Diagnosis. This species is externally similar to P. crassa sp. nov. in its wing pattern, but it can be easily recognized in having the costal and apical patches not large in the forewing. The male genitalia are differentiated by the inverted funnel-shaped uncus and the rectangular gnathos with blunt apex.

Promalactis retusa
Description. Adult (Fig. 2K). Head: frons and vertex grayish dark brown; occiput grayish dark brown. Antenna: scape dark brown dorsally, white ventrally, shorter than diameter of eye; fragellum dark brown dorsally. Labial palpus: 2 nd palpomere pale yellowish brown, except dark brown at apex dorsally, 1.5 times longer than 3 rd palpomere; 3 rd palpomere dark brown, except white at base dorsally. Thorax: thorax grayish dark brown partly mixed with whitish scales; tegula dark grayish brown. Wing expanse 8.0-8.5mm. Forewing ground color yellowish brown tinged with grayish dark brown near wing base, middle, and sub-apex on costa; five bands, one costal patch, four spots, and one apical patch, all white edged with fuscous scales: two subbasal bands, one from Sc vein, oblique toward apex, the other from anal vein, oblique toward costa, both connected to each other; two antemedial bands at 1/5, 2/7 of posterior margin, short, oblique toward costa; one antemedial band at 1/3 of costa, oblique toward before tornus; two spots medially, one on posterior vein of medial cell, the other at 1/2 of posterior margin; one costal patch, not connected to under tiny spot on posterior vein of medial cell; one spot at tornus; one apical patch occupied after 6/7 to apex with fuscous scales; fringes yellow near apex, mixed with fuscous scales middle and near tornus. Hindwing more lanceolate; ground color pale grayish dark brown; fringes grayish brown.
Female unknown. Distribution. Laos (northeast; new). Etymology. The name of species is derived from the Latin, retus (= blunt) and the suffix -a, referring from the gnathos with blunt apex of male genitalia. through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2017R1D1A1B03030640). This research was also supported by the Research Institute for Agriculture and Life Sciences (RIALS), Republic of Korea.