Neottialges (Caloenectes) vulturis ( Dubinin, 1956 ) Liberato & Magliano & Tancredi & Eleni & Posillico & Mironov, 2018

Liberato, Claudio De, Magliano, Adele, Tancredi, Francesco, Eleni, Claudia, Posillico, Mario & Mironov, Sergey, 2018, Neottialges (Caloenectes) vulturis (Dubinin, 1956) (Acari: Hypoderatidae) from the Eurasian griffon vultureGyps (fulvus) in Italy: first record in Europe, redescription and pathological changes in the host, Acarologia 58 (2), pp. 255-264 : 258-262

Neottialges (Caloenectes) vulturis ( Dubinin, 1956) n. comb.

( Figures 2–4 )

Gabucinia vulturis Dubinin, 1956: 213 , fig. 83-86.

Neottialges vulturis, Fain 1967: 107 .

Gypsodectes vulturis, Fain 1984: 271 .

Zoobank: C40C42B7-8DD4-43BB-A21F-615E4ECD21F8

Material examined — 15 deutonymphs from Gyps fulvus ( Accipitriformes : Accipitridae ), Italy, Central Italy, Rieti Province, Borgorose Municipality, 6 March 2015, mite collector F. Tancredi.

Description — Deutonymph (range for 10 measured specimens). Idiosoma widely ovate, with very short and wide rostral extension, length 660 – 740, greatest width 300 – 400. Most surface of dorsal and ventral cuticle of idiosoma monotonously and roughly punctuated, borders of any shields indistinct ( Figure 2 ). Sejugal furrow dorsally pronounced. Length of hysterosoma 510 – 570, central part with a pair of narrow longitudinal ridges, posterolateral parts with oblique poorly sclerotized grooves. Vertical setae vi filiform, situated on rostral extension submarginally, 12 – 15 long. Scapular setae si situated slightly anterior to level of setae se; distances between scapular setae: se:se 145 – 170, si:si 95 – 115, si:se 8 – 15; length of setae: se 145 – 170, si 10 – 12. Hysterosomal setae filiform; only three pairs of hysteronotal setae (cp, c3, and h3) distinctly long and comparable in length to scapular setae se; remaining setae of dorsal side and posterior end of hysterosoma not exceeding 20; length of long setae: cp 90 – 100, c3 85 – 95, h3 105 – 150. All cupules (ia, im, ip and ih) indistinct.

Gnathosoma reduced to small trapezium-shaped sclerite 15 – 20 long and 27 – 32 wide at base, with two pairs of rudimentary setae represented by alveoli ( Figures 3 , 4A ). Supracoxal setae scx situated close to lateral margins of gnathosomal plate in small invaginations. Sternum 22 – 25 long, approximately half the length of free parts of epimerites I. Coxal fields I–IV open. Inner tips of all epimerites free, with irregular pennate striation on body cuticle. Bases of all trochanters I–IV flanked by narrow sclerotized bands. Coxal setae 1a and 3a rudimentary, represented by alveoli. Genital field ovate, situated at level of trochanters IV well outlined. Genital sclerite well developed, narrow, one-pieced; anterior and posterior ends T-shaped, width of anterior end nearly twice as wide as posterior end; length of sclerite 34 – 36, width of anterior end 10 – 12, width of posterior end 5 – 7 ( Figure 4B ). Genital papillae ovate, large, anterior and posterior pairs similar in size, length 11 – 12. Anal opening rudimentary, situated near posterior end of genital sclerite. Coxal setae 4b 30 – 35 situated at midlevel of coxal fields III, genital setae g 33 – 37 long.

Leg segments normally developed, tarsi I, II subequal to total length of corresponding tibiae and genua, tarsi III, IV nearly 2 times longer than corresponding tibiae and genua. Length of legs excluding trochanters: I 80 – 85, II 82 – 86, III 115 – 120, IV 85 – 90; length of tarsi: I 30 – 33, II 30 – 34, III 58 – 62, IV 42 – 45. Tarsus I with setae ba, d, wa long filiform; setae la, ra, p, and q long filiform with foliate distal tips, seta aa, represented by alveolus, seta e short filiform, seta f spine-like, solenidion ω1 distinctly punctated and slightly attenuate apically; solenidion𝜔3 elongate, situated apically; famulus𝜖 at midlevel of tarsus, at same level as setae ba and wa ( Figure 4C ). Tarsus II similar in structure to tarsus I (except for absence of seta aa and famulus) ( Figure 4D ). Tarsus III strongly elongate and straight, with small bidentate apical spine, with 8 setae: setae d long filiform, setae e, f, p, q, and r filiform with foliate apices, seta s short spiculiform, seta w strongly thickened basally, with filiform apex ( Figure 4E ). Tarsus IV with small apical spine and with 4 setae of uncertain homology: apical seta d represented by macrosetae nearly 3 times longer than leg IV and with small sparse barbs in basal part; two spine-like setae w, r situated basally, and thin spine-like setae s situated subapically (Figures 4F). Empodial claws of tarsi I, II slightly longer than half-length of corresponding tarsi, acute and slightly curved apically, 15 – 17 and 14 – 16 long, respectively; empodial claw of tarsus III bidentate apically and slightly curved, 7 – 9 long. Tibia I with longitudinal dorsal crest, seta gT long filiform, seta hT thick spine-like, solenidion𝜑 about 1.5 times longer than this segment. Tibia II similar to tibia I except both setae gT and hT spine-like. Tibia III: with seta kT thick spine-like, solenidion𝜑 short, attenuate to apex, similar in length to this segment, with empodial claw bidentate. Tibia IV with seta kT thick spine-like and solenidion𝜑 half the length of this segment. Genu I with seta mG thick spiculiform, seta cG thin spiculiform, solenidion𝜎1 a very short and blunt spine. Genu II with seta mG filiform, seta cG as in tarsus I, and solenidion𝜎 spiculiform. Genu III with seta nG thick spine-like, and with solenidion𝜎 small spiniform. Femora I, II, IV with seta vF filiform, shorter than corresponding legs. Setae pR of trochanters I, II subequal in length to corresponding tarsi, seta sR of trochanter III shorter than corresponding tarsus. Leg chaetotaxy (solenidia in brackets): tarsi 10(3)-9(1)-8-4, tibiae 2(1)-2(1)-1(1)-1(1), genua 2(1)-2(1)-1(1)-0, femora 1-1-0-1, trochanters 1-1-1-0.

Remarks — Dubinin (1956) described this hypoderatid species from a deutonymph, thinking it was part of the feather mite genus Gabucinina Oudemans, 1905 ( Gabuciniidae ), since he erroneously suggested that feather mites ( Astigmata : Analgoidea and Pterolichoidea) can have a deutonymph in their life cycle. In the world revision of hypoderatids, Fain (1967) provisionally placed this mite species in the genus Neottialges Fain, 1966 , because he had no specimens to examine. In the present paper, we confirm this mite belongs to the genus Neottialges and place it in the subgenus Caloenectes Fain, 1966 based on the following subgeneric characteristics observed in this species: the cuticle of the entire idiosoma is strongly and monotonously sclerotized and dorsomedian setae d1, e1 and h1 are very short. Among the seven previously known species of this subgenus ( Fain 1966, 1967 and 1973; Pence 1973; Fain and Lawrence 1986), N. (C.) vulturis is most similar to N. (C.) kutzeri Fain, 1967 in having laterocoxal setae scx situated closely to the gnathosomal plate, coxal setae 1a and 3a rudimentary, and oblique poorly sclerotized grooves in posterolateral parts of idiosoma. Nevertheless, deutonymphs of N. (C.) vulturis clearly differ from those of the latter species by the following features: coxal fields II and III are open vs (. closed), the genital sclerite is well developed vs (. absent), the rudimentary anal opening is close to the genital fields vs (. situated far posteriorly), setae c1 and c2 are short, not exceeding 20μm (vs. subequal to macrosetae cp), and setae 4a and g are 30 – 40 μm long (vs. about 80 μm). The presence of the well sclerotized genital sclerite and the position of the anal opening close to the genital field differentiate this species from all previously known species of the subgenus Caloenectes .

It is necessary to note that Fain (1984) established a new hypoderatid genus Gypsodectes Fain, 1984 with the type species, Gypsodectes verrucosus Fain, 1984 , described from a single female found in the nest of Gyps coprotheres (Forster JR) in South Africa. Based on this finding, he suggested that Neottialges vulturis , known only from deutonymphs, also belongs to the genus Gypsodectes . However, he did not have any real proof, such as pharate specimens (deutonymph in exuvium of protonymph or tritonymph in exuvium of deutonymph), to show that N. vulturis hypopi correspond to adult mites of the genus Gypsodectes . Deutonymphs in Astigmata are so morphologically different from all other stages of hypoderatids that it is practically impossible to guess their correspondence without pharate specimens, even when hypopi and other stages are found in the same nest. Indeed, there are a number of examples where birds simultaneously house several different hypoderatid species, usually belonging to different genera (Fain 1967; Fain and Lukoschus 1986; Mironov and Kivganov 2010; Mironov and OConnor 2013). Therefore, we retain the hypoderatid mite considered herein in the genus Neottialges .

Figures

Figure 2 Neottialges (Caloenectes) vulturis, dorsal view of deutonymph.

Figure 3 Neottialges (Caloenectes) vulturis, ventral view of deutonymph.

Figure 4 Neottialges (Caloenectes) vulturis, details of deutonymph: A – anterior end of propodosoma, ventral view; B – genital field; C–F – legs I–IV, respectively, dorsal view.