Guimaraesiella lais (Giebel, 1874)

Gustafsson, Daniel R., Oslejskova, Lucie, Najer, Tomas, Sychra, Oldrich & Zou, Fasheng, 2019, Redescriptions of thirteen species of chewing lice in the Brueelia - complex (Phthiraptera, Ischnocera, Philopteridae), with one new synonymy and a neotype designation for Nirmus lais Giebel, 1874, Deutsche Entomologische Zeitschrift 66 (1), pp. 17-39 : 34-35

Guimaraesiella lais (Giebel, 1874) Figs 83-84 , 85-89

Nirmus …. Giebel, 1866: 366 [species 25].

Nirmus lais Giebel, 1874: 143.

Degeeriella lais Giebel, 1874; Harrison 1916: 116.

Brueelia lais (Giebel), 1874; Hopkins and Clay 1952: 57.

Brueelia (Allobrueelia) lais (Giebel); Balát 1955: 503.

Allonirmus lais (Gieb.); Złotorzycka 1977: 45.

Guimaraesiella lais (Giebel, 1874); Gustafsson and Bush 2017: 222.

Allobrueelia lais (Giebel, 1874); Mey 2017: 177.

Type host.

Luscinia megarhynchos (Brehm, 1831), common nightingale ( Muscicapidae ).

Type locality.

None given in original, but likely Germany. Neotype (designated herein) is from Nejdek u Lednice, Czechia.

Description.

Both sexes. Head broad, rounded pentagonal (Fig. 85 ), lateral margins of preantennal area convex, frons broadly concave. Marginal carina moderate in width, with undulating median margin. Exact posterior extent of dorsal preantennal suture not clear in examined specimens, but suture does not appear to reach ads. Ventral anterior plate with deeply concave anterior margin. Head chaetotaxy and pigmentation patterns as in Figure 85 ; pigmentation of preantennal head rather uniform. Preantennal nodi with slight median bulge. Preocular nodi larger than postocular nodi. Marginal temporal carina thin, of more or less equal width. Gular plate short, broad, with median point. Thoracic and abdominal segments and pigmentation patterns as in Figures 83 , 84 .

Male. Sternites II-IV partially ruptured and displaced in neotype, and here illustrated approximately. Thoracic and abdominal chaetotaxy as in Figure 83 ; neotype has no setae on dorsal side of abdominal segment XI, but this is likely an anomaly. Male genitalia partially obscured by gut content. Basal apodeme widens proximally, with slightly concave lateral margins in distal half (Fig. 86 ). Proximal mesosome widening proximally, with concave lateral margins (Fig. 87 ). Ventral sclerite obscured by gut content, and illustrated approximately; seemingly narrowly rectangular. Mesosomal lobes slender, converging in distal end, fused distally. Mesosomal chaetotaxy as in Figure. 87. Rugose area absent. Gonopore almost terminal, semi-oval. Parameral heads large (Fig. 88 ), parameral blades of approximately uniform width in proximal half, tapering in distal half, with pst1-2 as in Figure 81 . Measurements (n = 1): TL = 1.32; HL = 0.34; HW = 0.33; PRW = 0.21; PTW = 0.30; AW = 0.43.

Female. Thoracic and abdominal chaetotaxy as in Figure 84 . Examined specimens poorly cleared, and exact shape of distal subgenital plate not clear, and here illustrated as accurately as possible; seemingly rounded-triangular, with broad distal section, including wide lateral submarginal bulges (Fig. 89 ). Vulval margin flattened medianly, with 3 or 4 short, slender vms and 8 short, thorn-like vss on each side; 3 or 4 short, slender vos on each side of subgenital plate; distal 1 vos median to vss. Measurements (n = 3): TL = 1.61-1.66; HL = 0.36-0.38; HW = 0.35-0.37; PRW = 0.21-0.22; PTW = 0.31-0.34; AW = 0.46-0.51.

Type material.

Neotype 1♂, Nejdek u Lednice, Czechia, 6 May 1953, F. Balát, 1114 (MMBC). Neoparatypes: 3♀, same data as neotype, 1113, 1114 (MMBC).

Remarks.

Gustafsson and Bush (2017) included Nirmus lais Giebel, 1874, in Guimaraesiella Eichler, 1949, without comment; they did not examine any specimens of this species. The placement of this species in Guimaraesiella followed Balát (1955), who placed it in Allobrueelia Eichler, 1951, a synonym of Guimaraesiella , and Złotorzycka (1977), who placed it in Allonirmus Złotorzycka, 1964, also a synonym of Guimaraesiella . However, they overlooked that Giebel (1874) stated that this species was close to Nirmus intermedius Nitzsch [in Giebel], 1866, which Gustafsson and Bush (2017) placed in Brueelia Kéler, 1936. This apparent contradiction requires some additional discussion.

Giebel’s description of N. lais was based on a single female, and does not contain any specific character that can be used to place N. lais in either Brueelia or Guimaraesiella with certainty. Giebel (1874) did not illustrate this species. Giebel (1866) recorded lice from the same host merely as " N …” [species 25 under the genus Nirmus ], but lists specimens from Erithacus rubecula (Linnaeus, 1758) under the same heading; the lice from E. rubecula were later ( Giebel 1874) described as Nirmus tristis Giebel, 1874, which was also placed in Guimaraesiella in the revision of Gustafsson and Bush (2017).

Giebel’s (1874) statement that N. lais is similar to N. intermedius is unreliable, as his other statements about similarity between louse species are often confusing. For instance, on the page before the description of N. lais , Giebel (1874: 142) stated that Nirmus intermedius is similar to Nirmus ruficeps Nitzsch [in Giebel], 1866, and N. limbatus Burmeister, 1838. The former species is a head louse, now placed in the genus Rostrinirmus Złotorzycka, 1964, whereas the latter is an uncommonly wide-headed and large-bodied member of Brueelia s. str. Brueelia intermedia , by contrast, is a slender-headed species of Brueelia , quite unlike both N. ruficeps and N. limbatus . This issue is further confused by Giebel’s statement that N. intermedius is similar to N. merulensis Denny, 1842, differing only in the proportions of the antennae and the prothorax. Gustafsson and Bush (2017) placed N. merulensis in the genus Turdinirmus Eichler, 1951, a genus superficially similar to Guimaraesiella , but very different from species of Brueelia known from thrushes in size, head shape, and head structure. It is therefore not at all clear what specimens Giebel actually examined, and what he means by “similar”.

Apart from the specimens listed here, we have been unable to locate any specimens of Brueelia -complex lice from L. megarhynchos in any of the museum collections we have searched (see list in Gustafsson and Bush 2017). In particular, Giebel’s original specimen appears to have been destroyed in the war ( Clay and Hopkins 1955). Moreover, Balát’s (1955) report appears to be the only subsequent report of any species of louse in the Brueelia -complex from L. megarhynchos. Eichler [in Niethammer] (1937; not seen) and Séguy (1944) reported N. lais from Luscinia luscinia (Linnaeus, 1758); we have not seen these specimens. It is not clear from Séguy’s (1944) short description whether his specimens represent the same species as Giebel’s N. lais , or whether this identity is assumed based on the close relationship between the host species.

Złotorzycka (1977: figs 149-152) illustrated the head, ventral anterior plate, male genitalia, and pleurites of N. lais , but indicated that this species was not known from Poland (ibid.: 10). It is therefore uncertain where the material she based her illustration on originated, nor where this specimen is located today. Złotorzycka’s illustrations are rarely very informative, especially those of male genitalia. However, the specimens we have examined are largely concordant with the illustrations of Złotorzycka (1977).

To stabilize the nomenclature of the lice found on thrushes and flycatchers, we here designate a neotype for Nirmus lais Giebel, 1874, from Balát’s specimens. These specimens all belong to Guimaraesiella (sensu Gustafsson and Bush 2017), and our neotype designation thus conforms to the placement of this species in Guimaraesiella by Gustafsson and Bush (2017), in Allobrueelia [= Guimaraesiella ] by Balát (1955) and Mey (2017), and in Allonirmus by Złotorzycka (1977). More over, this conforms to Giebel’s (1866) earlier placement of Nitzsch’s material from L. luscinola [= L. megarhynchos ; but given as Sylvia luscinia by Giebel (1866)] with his material from E. rubecula , which represents Guimaraesiella tristis .

Figures

Figures 83, 84. Guimaraesiella lais (Giebel, 1874) ex Luscinia megarhynchos (Brehm, 1831) 83 Male habitus, dorsal and ventral views 84 Female habitus, dorsal and ventral views.

Figures 85 - 89. Guimaraesiella lais (Giebel, 1874) ex Luscinia megarhynchos (Brehm, 1831) 85 Male head, dorsal and ventral views 86 Male genitalia, dorsal view 87 Male mesosome, ventral view 88 Male paramere, dorsal view 89 Female subgenital plate and vulval margin, ventral view.

Figures 78 - 82. Guimaraesiella haftorni (Balat, 1958) ex Turdus iliacus Linnaeus, 1758 78 Male head, dorsal and ventral views 79 Male genitalia, dorsal view 80 Male mesosome, ventral view 81 Male paramere, dorsal view 82 Female subgenital plate and vulval margin, ventral view.