Vitznyssus erici, Knee, Wayne, 2018

Knee, Wayne, 2018, New species of parasitic nasal mites infesting birds in Manitoba, Canada (Mesostigmata, Rhinonyssidae), ZooKeys 786, pp. 1-17 : 5-10

Vitznyssus erici sp. n. Figs 6, 7, 8, 9

Material examined.

Type material. Holotype: female (CNC535647) from common nighthawk (WK273), Chordeiles minor , Winnipeg, Manitoba, Canada, 4.ix.2010, coll: T.D. Galloway. Paratypes: two females (CNC991938, CNC991939) same collection information as holotype.

Diagnosis female.

Large mite with one dorsal shield, podosomal shield longer than wide, rounded anteriorly, constricted posteriorly with irregular margins posterolaterally, six pairs of setiform setae, vacuolate areas and irregular transverse lines on podosomal shield. Subposterior setal pair on podosomal shield elongate, nearly twice as long as all other podosomal shield setae. Four pairs of setiform setae lateral and posterolateral of podosomal shield. Doral and ventral hysterosoma without small shieldlets. Sternal shield small, poorly sclerotised, constricted posteriorly, seta st1 and lyrifissure iv1 on sternal shield, setae st2, st3, and lyrifissure iv2 off sternal shield. Genital shield elongate and narrow with parallel sides, seta st5 off genital shield. Paranal setae setiform with filamentous tip anterior to anus, postanal seta setiform with filamentous tip slightly shorter than paranal setae. Well-developed tritosternum with paired laciniae. Palp apotele two-tined with bifid tips.

Description female.

Dorsal idiosoma (Figure 6). Idiosoma 1016 (953-1168) long excluding gnathosoma, 493 (434-550) wide. Podosomal shield 387 (372-410) long, 261 (256-270) wide, rounded anteriorly, constricted posteriorly with irregular margins posterolaterally, six pairs of setiform setae, vacuolate areas and irregular transverse lines on podosomal shield. Subposterior setal pair on podosomal shield elongate 23 (21-27), almost twice as long as all other podosomal shield setae 12 (8-16). Dorsal integument finely striated, four pairs of setiform setae in unsclerotised integument lat eral and posterolateral of podosomal shield, 15-16 pairs of setiform setae 20 (15-22) and two pairs of pore-like structures in dorsal opisthosomal unsclerotised integument. Stigmata with short peritremes 54 (53-55).

Ventral idiosoma (Figure 7). Sternal shield reduced and poorly sclerotised, 83 (80-87) long and 86 (86-87) maximum width anteriorly, constricted posteriorly, shield with irregular transverse lines, seta st1 (18) and lyrifissure iv1 on sternal shield. Setae st2 (20), st3 (19), and lyrifissure iv2 in unsclerotised integument off sternal shield. Genital shield elongate and narrow, 196 (193-200) long and 40 (37-43) wide, parallel sides and reticulated lengthwise, seta st5 (11) and pair of lyrifissures iv5 off genital shield. Cuticle finely striated, 11 pairs of setiform setae in ventral opisthosomal unsclerotised integument. Anal shield 162 (155-169) long and 114 (112-115) wide, thickened lateral margins, cribrum present, paranal setae 46 (45-48) setiform with filamentous tip anterior to anus, postanal seta 32 (30-36) setiform with filamentous tip slightly shorter than paranal setae.

Gnathosoma (Figure 8). Gnathosoma terminal, ventral length including palps 236 (225-242), width 160 (152-166) posterior to pc seta. Subcapitulum with 10 rows of paired deutosternal denticles. Subcapitular setae setiform, pc 20 (15-23), h1 13 (12-14), h2 13 (11-15), and h3 33 (26-39). Well-developed tritosternum 233 long, with paired laciniae. Palps five-segmented, chaetotaxy of palps 0 –4–4–8– 9, palp apotele two-tined with bifid tips. Chelicerae elongate 242 (237-249), expanded proximally 50 (45-56), marked constriction distally with small pointed moveable and fixed digits.

Legs (Figure 9). Excluding ambulacra, length of leg I 541 (483-591), leg II 520 (487-541), leg III 518 (512-521), and leg IV 615 (596-627). Setation of legs I– IV: coxae 2 –2–2– 1; trochanters 4 –4–4– 4; femora I (2 –3/1,2/2– 1), II (2 –3/1,2/0– 1), III (1 –2/1,2/0– 0), IV (1 –2/1,2/0– 0); genua I (2 –2/1,2/1– 1), II (2 –2/0,2/0– 2), III (2 –2/0,2/0– 2), IV (2 –2/1,1/0– 1); tibiae I (2 –1/1,2/1– 1), II (2 –1/1,2/1– 2), III (2 –1/1,2/1– 2), IV (2 –1/1,2/1– 2); tarsi 33 –18–18– 18. Leg setae are setiform with filamentous tip.

Male and immatures. Unknown.

Etymology.

This species is named after Eric Schewchuk, a close friend who has been beside me throughout the entirety of my studies on mites.

Remarks.

The female of Vitznyssus erici sp. n. is most similar that of V. afrotis Fain, which was described from the southern black bustard ( Afrotis afra ) in South Africa ( Fain 1966b). These two species are most similar in that they are large mites (at least 1000 µm long), and both have: one dorsal shield which is longer than wide and eroded along the margins, especially posterolaterally; sternal shield reduced, with seta st1 on the shield; elongate and narrow genital shield; palp apotele two-tined with bifid tips; elongate tritosternum with two laciniae; elongate paranal setae anterior to anus, and elongate postanal setae present.

Female V. erici differ from that of V. afrotis by: the presence of irregular transverse lines on the podosomal shield, which are absent in V. afrotis ; the posterolateral margins of the podosomal shield are more eroded, invaginated and irregular than that of V. afrotis ; the anterior margin of the podosomal shield is broadly rounded with no setae in the integument anterior of the shield, the anterior margin is slightly eroded in V. afrotis and a pair of setae are off the shield anteriorly; the sternal shield is larger, with a posteromedial projection, and lyrifissure iv1 is on the shield, V. afrotis sternal shield is smaller and without a posteromedial projection, iv1 is off the shield; the genital shield margins are parallel and not flared posteriorly like they are in V. afrotis ; and by the absence of small accessory shieldlets on the dorsal or ventral hysterosoma, which are present in V. afrotis . Fain (1966b) described V. afrotis as lacking a sternal shield; however, the holotype and paratype specimens examined have a small narrow sternal shield with seta st1 on the shield. Comparisons were made using the species description for V. afrotis and examination of the holotype and paratype specimens loaned from the Royal Belgian Institute for Natural Sciences.

Including V. erici there are now four Vitznyssus species known from Otididae (bustards) and four species known from Caprimulgidae (nightjars) hosts. Bustards only occur in the Eastern Hemisphere, while nightjars are broadly distributed in both hemispheres. Considering the geographic distribution of these mites and the disparate host bird orders, the monophyly of the genus and species boundaries should be investigated using molecular markers and morphometric analyses.

The common nighthawk ( Chordeiles minor ) has been a focus for studies of ectoparasites in Manitoba ( Galloway 2006, Galloway and Lamb 2015). Despite the apparent decline in populations of common nighthawk in the province ( Taylor 1996), these birds are frequently submitted to rehabilitation hospitals. However, using the methods described here, nasal mites are either rare or rarely collected. Out of 138 common nighthawks examined for this study since 1999, nasal mites were collected from only one. The conservation status of this mite certainly deserves consideration.