• Taxonomic Accounts
• Acrolepiopsis nagaimo Yasuda, 2000 마좀나방(신칭)
• Diagnosis.
• Adult
• Male genitalia
• Femaile genitalia
• Material examined
• Distribution
• Host plants.
• Remarks.
• Acknowledgment

The family Acrolepiidae is a small group of moths in Microlepidoptera, belonging to the superfamily Yponomeutoidea (Dugdale et al., 1998). It comprises three genera, Acrolepia Curtis, Acrolepiopsis Gaedike, and Digitivalva Gaedike (Gaedike, 1997), with nearly 120 described species worldwide (Bisby et al., 2012). 

 In Japan, the leek moth infesting cultivated Chinese yam, Dioscorea opposita was in fact noticed long time ago but was simply recorded as a Plutella species (Takahashi, 1916). This species was found to feed also on D. japonica (Takahashi, 1922). Later, Moriuti (1961) described a new species, Acrolepia dioscoreae, based on specimens reared from two kinds of yam, D. tokoro and D. japonica and considered A. dioscoreae conspecific with the species first noticed by Takahashi. However, three years later A. dioscoreae was sunken as a synonym of A. suzukiella (Moriuti, 1964), the Plutella-like species feeding on D. oposita had been left unidentified but considered as A. suzukiella until 2000. Yasuda (2000) compared many specimens reared from D. oposita with A. suzukiella and A. japonica, a little known species from D. japonica, and found they are different from either species. He described it as a new species, A. nagaimo.

 This species is known to be a serious pest on cultivated Chinese yam, which is an economically important crop as a local special product in the sand-dune area of Tottori Prefecture (Tanaka, 2001). In Korea, we recently found a species infesting D. batatas, another Chinese yam species. Upon close examination, we found they are A. nagaimo, known to Korea for the first time. So far only one species, allium leafminer (파좀나방), Acrolepiopsis sapporensis (Matumura, 1931) has been known to the Korean fauna of Acrolepiidae. In this study, we present a brief morphological characteristics of A. nagaimo, with the adult and their male and female genital images.

Taxonomic Accounts

Acrolepiopsis nagaimo Yasuda, 2000 마좀나방(신칭)

 Acrolepiopsis nagaimo Yasuda, 2000: 419-425 (type locality: NIAES, Tsukuba, Japan).

 Plutella sp.: Takahashi, S., 1916: 108.

Acrolepiopsis suzukiella: JSAEZ, 1980: 127. 

Diagnosis.

 This species is a small sized moth and characterized by a narrow triangular white patch on the dorsum. In comparison to Korean species A. sapporensis (파좀나방), the forewing apex of A. nagaimo is slightly less pointed, and the forewing has four short white streaks from costa toward tornus on outer half, somewhat obvious or with mottled white scales whereas those of A. sapporensis are not apparent. A white spot on dorsum at basal 2/5 is apparent but narrow, while that of A. sapporensis is more broad and subtriangular in shape.

Adult

 (Fig. 1) Wingspan 6.7-10.4 mm (78n). Head gray to light brown, vertex with tuft hairs; palpus dark fuscous, with tip of terminal segment white or light gray; Antenna gray, with fuscous ring. Thorax light ochreous, mixed with fuscous scales; Leg grayish and with fuscous; femur lighter than tibia and tarsi, inner side lighter than outer side; tibia and tarsi with white stripes. Abdomen grayish with dark fuscous dorsally, underside light fuscous, posterior end with ochreous cilia. Forewing from costa to apex and termen gently curved, slightly concave beneath apex; ground color dark brown, four short white streaks from costa toward apex on outer half; a white narrow triangular spot on dorsum near basal 2/5; a small white spot near middle of dorsum, three to five small white spots from near middle of termen to tornus; grayish fuscous cilia from apex to tornus. Hindwing: dark gray, with dark gray cilia.

Fig. 1. Adult of Acrolepiopsis nagaimo and the wing venation. a) just emerged adult sitting on another mesh-type cocoon, a typical in Acrolepiidae; b) dorsal view of an adult; c) wing venation; d) wing. Scale bar = 0.5 mm.

Male genitalia

 (Fig. 2) Valva slender, strongly curved near basal 1/3, basal 1/4 bulbed with long setae. Gnathos weakly sclerotized. Anellus weakly sclerotized. Saccus slender, very long and straight, slightly bulbed apically. Aedeagus about 1.5 times as long as saccus, basal 1/3 broadened. Vesica without cornuti.

Figs. 2-3. Genitalia of Acrolepiopsis nagaimo. 2. Male genitalia (2a-aedeagus). Scale bar = 0.1 mm; 3. Female genitalia. Scale bar = 0.5 mm.

Femaile genitalia

 (Fig. 3) Genital plate unsclerotized. Ductus bursae posterior 1/3-1/2 sclerotized; corpus bursae oval, with an additional sac at anterior end. Posterior apophysis rather straight; anterior apophysis posterior half rather straight, slightly angled outwardly near middle to posterior 2/5, anterior half slightly curved convexly.

Material examined

1♂, Deogsan-li, Daedeog-myeon, Gimcheon-si, GB, KOREA, 26.Ⅶ.2003 (S.W. Cho leg.), genitalia slide T.H 46; 9♂, 7♀, Dochon-ri, Bukhu-myeon, Andong-si, GB, KOREA, 20 Ⅸ 2009 (M.K. Kim leg); 17♂ ditto, genitalia slides T.H 1-6, 8, 13, 15, 18, 19, 22, 24-26, 28, and 29; 14♀ ditto, genitalia slides T.H 7, 9-12, 14, 16, 17, 20, 21, 23, 27, 30, and 31 

Distribution

 Korea (Gimcheon, Andong), Japan (Hokkaido, Honshu)

Host plants.

 Dioscoreaceae: Dioscorea oposita Thunberg, D. batatas Decne.

Remarks.

 This species in Japan is known to be very similar to A. japonica in superficial appearance, but differs from it in having the termen gently curved, in being slightly concave beneath apex of forewing instead of being obviously concave in A. japonica, the valva almost straight (not dilated) in apical half instead of being dilated at apical 1/6, and a cross line before the apex of the valva (edge of wall of pocket-like structure) almost invisible by optical microscopic observation instead of being distinct in the male genitalia. However, it is impossible to distinguish them by female genitalia, but the difference of the host plant may serve this purpose (Yasuda, 2000). This species is also superficially similar to A. sukukiella, but can be readily distinguished from it by the shorter saccus and aedeagus in the male genitalia and the short sclerotized portion of the ductus bursae in the female genitalia (Yasuda, 2000).

Acknowledgment

 This work was supported by the research grant of the Chungbuk National University in 2011.