Pterolichidae Trouessart and Mégnin, 1884

Waki, Tsukasa, Sasaki, Mizuki, Matsubara, Hajime & Shimano, Satoshi, 2021, The First Report of the Feather Mite Pseudalloptinus milvulinus (Acariformes: Pterolichidae) from the Black Kite Milvus migrans in Japan, Species Diversity 26, pp. 273-279 : 274-278

Family Pterolichidae Trouessart and Mégnin, 1884 Subfamily Pterolichinae Trouessart and Mégnin, 1884 Genus Pseudalloptinus Dubinin, 1956

Pseudalloptinus milvulinus (Trouessart, 1884) [New Japanese name: Tobi-usuge-ashibuto-umou-dani] ( Figs 1–5 )

Material examined. MPM Coll. No. 21696a–f, 3 males and 3 females, from the Black Kite Milvus migrans ( Accipitriformes : Accipitridae ), Japan, Ishikawa Prefecture, Noto City, 37°19′26.1″ N 137°00′05.6″ E, 30 July 2019, collected by Hajime Matsubara.

Depository. Meguro Parasitological Museum ( MPM), Tokyo, Japan .

Male ( Figs 1A, D–E , 2A, B , 4A , 5A–D ). Body. Total body length including gnathosoma 367–394. Length of gnathosoma including palps 45–54, greatest width 42–47. Idiosoma roughly diamond-shaped, length 297–344 and greatest width 159–193. Prodorsal shield occupying most part of prodorsum, length along midline 77–84, greatest width 98–103. Length of hysterosoma 217–237. Hysteronotal shield triangular, without ornamentation, covering most part of dorsal hysterosoma except lateral areas, length 217–237, greatest width 135–150. Length of dorsal setae: vi 17–27; si 4; se 107; c1 5–6; c2 16–20; c3 17–18; cp 85–107; d2 4–8; e2 30 –39; h2 207–249; h3 122–165. Venter: 1a 33–53; 3a 41–51; 4a 34–40; 4b 19–25; g 11–18; ps1 48–58; ps2 40–46; ps3 11–16. Setae vi filiform, not delated, and almost extending to palpal apices. Setae se long. Setae c2 filiform, situated in anterior parts of humeral shields. Setae c3 dagger-shaped. Setae d2 short and narrow. Setae e2 spiculiform, situated close to the base of seta h2. Setae ps1 and ps2 filiform. Setae h2 and h3 long and whip-like. Distance between setae: se-se 60–62; si-si 47–52; h2-h2 58–60; h3-h3 37–41; c2-d2 103–110; d2-e2 87–101; e2-h3 21–22. Distance between dorsal setae: g-4a 41–45; 4a -ps3 43–45; 4a-g 41-45; 4a-ps3 43–45; 4b-g 27–32; ps3-h3 63–67. Setae 4a closer to g than to ps3. Setae 3a and 4b approximately at same transverse level. Epimerites I fused Y-likely, with sternum shorter than free parts. Genital apparatus situated between levels of trachanters III and IV. Epimerites IVa large, with anterior ends flanking genital apparatus laterally. Setae 4a situated on epimerites IV, slightly closer to setae g than to setae ps3. Adanal apodemes absent. Postgenital sclerite stirrup shaped, with strongly extending posterior corners. Adanal suckers longitudinally ovate, 11–17 in length, surrounding membrane with circular striae ( Figs 1E , 2B , 4B ). Terminal cleft semi-ovate, approximately as long as wide. Terminal membranes well developed, entire, occupying margin of terminal cleft ( Figs 1E , 2A, B ), their greatest width subequal to that of width of opisthosoma at level of ps2.

Legs ( Fig. 5A–D ). Length of tarsi I-IV 31–37, 33–37, 37 and 21–29. Setation on legs (I-IV, excluding solenidia) tarsi I-IV 8-8-6-4; tibiae I-IV 1-1-1-1; genua 2-2-0-0; femora 1-1- 0-0; trochanters 1-1-1-0. Solenidia on tarsi I-IV 2-1-0-0, tibiae I-IV 1-1-1-1, genua 1-1-1-0. Seta ba on tursus I inserted distally from solenidion ω 1 ( Fig. 5A ). Length of solenidia: ω1 I 14–19, ω3 I 33–45, ω1 II 14–20, σ1 I 69–79, σII 62–71, σ III 33–43. Genu I with solenidion σ inserted at distal 1/4 of the segment. Leg IV hypertrophied, greatest width of each segment of leg IV ca. 1.5 times wider than that of leg III. Tarsus IV without setae d and e. Tarsus IV with spineshaped apical extension ( Fig. 5D ).

Female ( Figs 1B, C , 3A–C , 4B , 5E, F ). Body. Total body length including gnathosoma 519–584. Gnathosoma as in male, length including palps 66–76, greatest width 67–79. Idiosoma length 442–469 and greatest width 223–251. Prodorsal shield as in male, greatest width 102–120, length along midline 137–150. Length of hysterosoma 240–289. Hysteronotal shield split into main shield and small pygidial shield shaped as small transverse sclerite. Hysteronotal shield covering most part of dorsal hysterosoma except anterior hysterosoma and area between e2 to ps2, anterior margin concave, surface without ornamentation, length 183–213, greatest width (at anterior margin) 191–197. Setae c1 on anterior margin of hysteronotal shield. Length of dorsal setae: vi 50–59; si 5-8; se 149–162; c1 7–11; c2 23–32; c3 21–22; cp 123–162; d2 11–13; e2 26 –33; h2 167–187; h3 138–189; ps1 22–24; ps2 14–20. Venter: 1a 47–59; 3a 38–59; 4a 60–63; 4b 29–40; g 16–29; ps3 18–22. Setae c3 lanceolate, ca. 6 times longer than width. Setae e2 filiform. Seta g situated posterior to the level of 3a. Distance between setae: se-se 74–80; si-si 56–62; h2-h2 31–39; h3-h3 16–18; c2-d2 214–239; d2- e2 43–45; e2-h3 31–38; 4a-g 57–59; 4b -g 27–32; 4a-ps3 43–45; ps3-h3 63–67. Epimerites I fused Y-likely. Epimerites IVa present. Posterior margin of opisthosoma with cone-shaped external copulatory tube. Spermatheca and spermaducts as in Fig. 4B .

Legs ( Fig. 5E, F ). Legs I and II similar to those in male. Leg IV not hypertrophied, width of each segment close to that of leg III ( Fig. 5E, F ). Length of tarsi I-IV: 46–50, 47–50, 51–63 and 71–82. Length of solenidia: ω1 I 14–18, ω3 I 43– 53, ω1 II 23–28, σ1 I 100–113, σ II 90–104, and σ III 71–74.

Host associations and distribution. Brahminy Kite Haliastur indus (Boddaert, 1783) : Australia and New Guinea (Trouessart 1884; Dubinin 1956); Long-Crested Eagle Lophaetus occipitalis (Daudin, 1800) : Cameroon and Zaire ( Gaud 1988); Red Kite Milvus milvus (Linnaeus, 1758) : Europe (Trouessart 1884), Russia (European part) ( Dubinin 1956); Black Kite M. migrans (Boddaert, 1783) : Russia (both European and Asian parts) ( Dubinin 1956), Azerbaijan, ( Dubinin 1956), and Japan (this study).

Remarks. The mites collected were identified as Pseudalloptinus milvulinus based on the following combination of characters. In both sexes, setae c3 are lanceolate. In male, the genital apparatus is situated at the midlevel between trochanters III and IV; the terminal membranes are large and occupy entire margin of terminal cleft, the terminal cleft is semi-ovate, approximately as long as wide; ventral setae 4a are closer to g than to ps3; setae e2 are spiculiform, the postgenital sclerite is stirrup-shaped. In female, setae c3 are ca. 6 times longer than wide; ventral setae g are situated posterior to the level of setae 3a; and dorsal setae c1 are situated on the anterior margin of the hysteronotal shield.

Pseudalloptinus milvulinus resembles P. africanus in having similar shapes of terminal membranes, positions of setae g, 4a and ps3 and form of dorsal setae e 2 in males. Moreover, in females of these species, genital setae g are situated posterior to the level of 3a, dorsal setae c1 are situated on the anterior margin of the hysteronotal shield, and in both sexes, setae c3 are similar in shape. Males of P. milvulinus differ from those of P. africanus by the following characters: the terminal cleft is semi-ovate with its greatest width being equal to its length (vs. shaped as a low arch, 3–4 times wider than long), setae 4a are closer to g than to ps3 (vs. equidistant), and the postgenital sclerite is stirrup-shaped with parallel lateral sides (vs. convex lateral sides). Female of P. milvulinus differ from those of P. africanus in having setae c3 ca. 6 times longer than width (vs. ca. 4 times in P. africanus ).

The Japanese name newly established for the mite refers to the wide leg IV of male, loss of some setae on the dorsal idiosoma and the Japanese name of the Black Kite.

Figures

Fig. 1. Pseudalloptinus milvulinus: A, D, E, male (MPM Coll. No. 21696a). B, C, female (MPM Coll. No. 21696d). A, B, Ventral view; C, idiosomal seta c3; D, disposition if setae g, 4a and ps3 (arrowheads) on ventral idiosoma; E, ventral view of opisthosoma with terminal membranes (white arrowhead) and adanal suckers (dark arrowhead).

Fig. 2. Pseudalloptinus milvulinus, male (MPM Coll. No. 21696a). A, Dorsal view; B, ventral view.

Fig. 3. Pseudalloptinus milvulinus, female (MPM Coll. No. 21696e). A, Dorsal view; B, ventral view; C, right setae c3 (ventral view).

Fig. 4. Pseudalloptinus milvulinus: A, male (MPM Coll. No. 21696a). B, female (MPM Coll. No. 21696d). A, Ventral view, terminal membrane (white arrowhead) and adanal suckers (dark arrowhead); B, spermatheca and speprmaducts of female.

Fig. 5. Pseudalloptinus milvulinus, legs: A–D, male (MPM Coll. No. 21696c). E, F, female (MPM Coll. No. 21696d). A, B, Legs I and II of male, respectively; C, E, tarsus, tibia and genu of male and female, respectively; D, F, tarsus and tibia of male and female, respectively.