Paralipsis eikoae

Paralipsis eikoae (Yasumatsu, 1951) Figs 4 A – N, 5 A – D Suppl. materials 8 –10 Myrmecobosca eikoae Yasumatsu, 1951: 171–174. Korean name. 동글밑뿌리진디벌 (신칭). Diagnosis. Paralipsis eikoae is characterized by the following combination of characters: antenna with 16–17 segments (Fig. 4 B); F 1 approximately 1.1 × as long as F 2 (Fig. 4 C); longitudinal placodes absent on F 1 and F 2 and beginning on F 3; maxillary palp with two palpomeres and labial palp with one palpomere (Fig. 4 D); notauli very shallowly impressed (Fig. 4 E); forewing venation strongly reduced, with R 1 and 2-1 A absent; pterostigma approximately 2.3–2.4 × as long as wide (Fig. 4 J); propodeum with two short divergent carinae at the base (Fig. 4 F); petiole approximately 1.7–1.9 × as long as its maximum width at the level of the spiracles (Fig. 4 H, I); ovipositor sheath relatively short and broad, bearing long setae (Fig. 4 N) (Takada 1976). Morphology of Korean specimens. In addition to the characters described by Takada (1976), the following morphological measurements and character states were observed in the Korean specimens. Head. Width of head 1.5 × middle length in dorsal view; head 1.1–1.2 × wider than mesosoma at tegulae (Fig. 4 D, G). Tentorial index 0.6–0.7; malar space 0.8–0.9 × as long as longitudinal eye diameter (Fig. 4 D). F 1 and F 2 2.0 × and 1.7 × as long as their middle width, respectively; F 2 2.4 × as long as its basal width (Fig. 4 B, C). Mesosoma. Pronotum without pronope and subpronope; without pronotal sulcus (Fig. 4 E). Mesopleuron finely rugulose – reticulate, with dense shallow impressions throughout (Fig. 4 K). Scutellum nearly circular, protuberant; bearing numerous long setae, without scutellar sulcus carina (Fig. 4 E). Forewing. Pterostigma with colorless area in anteriorly (Fig. 4 J). Leg. Legs sparsely semi erected setose. Fore femur 4.2 × as long as maximum width. Fore tibia 7.0 × as long as maximum width with one tibial spur. Fore femur length subequal (0.9 ×) to fore tibia. Fore tarsus 3.1 × as long as fore basitarsus; fore basitarsus with a single row of densely comb – shaped setae; second to fourth fore tarsomeres length equal to width, claws acute (Fig. 4 M). Middle femur 3.8 × as long as maximum width. Middle tibia 7.7 × as long as maximum width with two tibial spurs. Middle femur length subequal (0.9 ×) to middle tibia. Middle tarsus 3.2 × as long as middle basitarsus. Hind femur 3.7 × as long as maximum width. Hind tibia 7.6 × as long as maximum width. Hind femur 0.7 × as long as hind tibia. Hind tarsus 2.3 × as long as hind basitarsus (Fig. 4 L). Metasoma. Petiole 2.1 × as long as width at level of posterior spiracles (Fig. 4 H, I). Ovipositor sheath 1.9 × as long as maximum width (Fig. 4 N). Comparison with previous description of Takada (1976). The antenna is shorter in the Korean specimens (1.8 mm; Fig. 4 A) than in the material examined by Takada (2.0– 2.2 mm). The eye is 0.7 × as long as the temple in dorsal view in the Korean specimens (Fig. 4 G), whereas Takada reported the temple to be approximately 0.59–0.63 × as long as the eye. The face is 2.7–2.9 × as wide as high in the Korean specimens (Fig. 4 D), largely overlapping the range of 2.3–2.8 × reported by Takada. F 1 is slightly shorter relative to its basal width in the Korean specimens (2.3 ×; Fig. 4 C) than in Takada’s material (2.5–2.8 ×). Despite these differences, the principal diagnostic characters of the Korean specimens agree with those reported by Takada (1976). Distribution. Japan, Russia, South Korea (this study). Biology. Parasitoids of Sappaphis piri Matsumura, 1918 [Host plant: Artemisia princeps Pamp. (Asteraceae)] associated with colonies of Lasius niger (Takada and Hashimoto 1983); collected from nests of Lasius japonicus Santschi, 1941, with no aphids observed (this study). Specimen examined. South Korea • 3 ♀; San 14–4, Wonho–ri, Iljik–myeon, Andong–si, Gyeongsangbuk–do from Lasius (Lasius) japonicus colony; 05. V. 2025; leg. S. Yoon; • 1 ♀ dried mounted; GenBank (Ap 26008, YPC 003131): COI, PZ 412706; 28 SD 2, PZ 411505; COII, PZ 416386; Cytb, PZ 420654; Wingless, PZ 447457; • 1 ♀ slide mounted; GenBank (Ap 26007, YPC 003129): COI, PZ 412705; 28 SD 2, PZ 411504; COII, PZ 416385; EF 1 – alpha, PZ 447455; • 1 ♀ alcohol preserved; specimen code: YPC 003160. Biological notes. Paralipsis eikoae was collected from within nests of Lasius japonicus, but root-aphid colonies were not observed at the time of collection. The specimen (YPC 003129) collected on 5 May 2025 retained intact wings at the time of collection. During laboratory observations, the female was repeatedly observed pulling its wings posteriorly using the apical parts of the hind tibiae (Suppl. material 8). Direct removal or detachment of the wings was not observed. However, at a later observation, part of the posterior margin of the forewing was found to be missing. Although wing removal by aphid-attending ants was not observed, it remains unclear whether the repeated pulling behavior contributed to the observed wing loss. When encountering ant workers, P. eikoae exhibited riding behavior by mounting the dorsal surface of the ant. During riding (Fig. 5 C, Suppl. material 9), the body of the parasitoid was positioned in close contact either between the legs of the ant worker or between the associated ant’s gaster and hind leg. One foreleg grasped either the ant petiole or one of the legs, whereas the opposite foreleg was used to hook either the ant fore coxa or the mid leg. The P. eikoae repeatedly scraped the surface of the associated ant’s gaster toward its own body with the mid tibia in a sawing motion while the antennae contacted those of the ant. Riding behavior was observed repeatedly and was frequently followed by trophallaxis with associated ant workers. After repeated riding behavior, aphid-attending ants were observed grooming the body of P. eikoae (Fig. 5 B). Trophallaxis was observed more frequently after honey water was provided. P. eikoae actively solicited trophallaxis by repeatedly tapping the mandibles of aphid-attending ant workers with its antennae and fore legs (Fig. 5 D, Suppl. material 10). The parasitoid was also observed periodically in an antenna-cleaning behavior. During the behavior, the wasp hooked the base of antennae with the fore tibial spur (= calcar) and pushed it distally, cleaning the antenna with the dense comb of setae on the basitarsus (= 1 st tarsomere). A myrmecophilous cricket (Myrmecophilus sp.) collected from the same colony was observed licking the hind legs of P. eikoae during or immediately after riding behavior. Because Myrmecophilus crickets are known to acquire host-ant cuticular hydrocarbons through direct physical contact, and P. eikoae can acquire ant cuticular hydrocarbons through mounting and rubbing against workers, this licking behavior may be related to ant-derived cuticular hydrocarbons present on the parasitoid (Akino et al. 1996; Akino and Yamaoka 1998). However, this is possibility was not chemically tested in the present study.