Osculonirmus Mey, 1982

Bush, Sarah E., 2017, Morphological revision of the hyperdiverse Brueelia - complex (Insecta: Phthiraptera: Ischnocera: Philopteridae) with new taxa, checklists and generic key, Zootaxa 4313 (1), pp. 1-443 : 82-83

Osculonirmus Mey, 1982

Brueelia Kéler, 1936a: 257 (in partim). Osculonirmus Mey, 1982a: 59 .

Type species. Osculonirmus limpidus Mey, 1982a: 60 , by original designation.

Diagnosis. Osculonirmus is superficially similar in general habitus to Brueelia s. str., but does not appear to be closely related to any other genus treated here. As in Anarchonirmus n. gen. ( Fig. 116 ) s3 is a mesoseta and the antennae are sexually dimorphic in Osculonirmus ( Figs 124–125 ), with flagellomeres II–III modified in males of both species. In both genera psps are present on tergopleurites II–III of both sexes ( Table 2), but aps are absent in Osculonirmus , and the pss is not contiguous with the aperture of psps II–III in Anarchonirmus ( Figs 114–115 ). The two genera can be told apart based on the following characters: in Anarchonirmus ( Fig. 116 ) clypeo-labral suture does not reach anterior margin of the head, ventral carinae and ventral anterior plate are continuous with marginal carina, and there is no dorsal preantennal suture ( Fig. 116 ), whereas in Osculonirmus ( Fig. 124 ) the clypeo-labral suture reaches the frons and widens there, marginal carina is displaced dorsally at osculum, there is no ventral anterior plate, but there is a dorsal preantennal suture. In Anarchonirmus ( Fig. 114 ) there are tps on tergopleurites II–VIII in males, but these are absent in Osculonirmus ( Fig. 122 ). The male ( Figs 126–128 ) and female ( Fig. 129 ) genitalia of Osculonirmus are different from those of all other genera treated here.

Description. Both sexes. Head flat-dome shaped with broad, slightly concave, frons ( Fig. 124 ). Marginal carina uninterrupted, but displaced posteriorly and dorsally at osculum. Dorsal preantennal suture present, following lateral margin of head to near dsms and then obliquely to reach ads. Ventral carinae continuous with marginal carina but often diffuse anterior to pulvinus. Clypeo-labral suture widens anteriorly. Head setae as in Fig. 124 ; vsms2 not on lateral margin of clypeo-labral suture; pos, pns, and mts 1 absent; s3 mesosetae. Coni small, blunt. Antennae sexually dimorphic, with male scapes ( Fig. 124 ) swollen and twice as long as female scapes ( Fig. 125 ); flagellomeres II–III modified in male as in Fig. 124 . Temporal carinae not visible; mts 3 only macrosetae. Gular plate small, oblong.

Prothorax rectangular ( Figs 122–123 ); ppss on postero-lateral corner. Proepimera slender; median ends hookshaped. Pterothorax pentagonal; lateral margins widely divergent; posterior margin convergent to median point. Meso- and metasterna not fused; 1 seta on postero-lateral corner on each side of each plate. Metepisterna broad, median ends blunt. mms widely separated medianly. mths absent. Leg chaetotaxy as in Fig. 25 , except cI-v3, cI-d1, fI-v1, fI-v4, fIm2–4, cII-a3, cIII-a3, fIII-v2 absent; cI-v2, cII-v2, tII-v1, cIII-v2, tIII-v1 short

Abdomen oblong ( Figs 122–123 ). Tergopleurites rounded rectangular, more oblong in males; tergopleurites II– IX+X in male and tergopleurites II–VIII in females moderately divided medianly ( contra Mey 1982a : fig. 1). Large fenestrae surround spiracle openings. Sternal plates rectangular, not approaching pleurites. Pleural incrassations narrow. Re-entrant heads absent. Male subgenital plate trapezoidal, but diffuse posteriorly; whether it reaches posterior margin of abdomen is not clear. Abdominal chaetotaxy as in Table 2. Female subgenital plate obovate, does not approach vulval margin. Vulval margin ( Fig. 129 ) narrowly convex.

Male genitalia ( Fig. 126 ) distinct. Basal apodeme slender and elongated. Proximal mesosome slender, rectangular, overlapping with basal apodeme. Gonopore ( Fig. 127 ) open distally. Mesosomal lobes small, fused distally, with irregular distal and lateral margins; 2 pmes visible on each side of mesosome. Parameral heads ( Fig. 128 ) large, bulbous, bifid. Parameral blades elongated, slender; pst1 sensilla, near distal tip; pst2 microseta, lateral near distal tip.

Host distribution. Osculonirmus is known only from Eremophila alpestris ( Linnaeus, 1758) , where it appears to be widely distributed on four different subspecies (see below). All other material we examined from larks (species of Alaemon Keyserling & Blasius, 1840 , Alauda Linnaeus, 1758 , Ammomanes Cabanis, 1851 , Calandrella Kaup, 1829 , Eremopterix Kaup, 1836 , Galerida Boie, 1828 , Lullula Kaup, 1829 , Melanocorypha Boie, 1828 , and Mirafra Horsfield, 1821 ) belong to Brueelia s. str. In addition, material examined from Eremophila alpestris ammophila (Oberholser, 1902) and E. a. flava (Gmelin, 1789) belong to Brueelia s. str., similar to other species of Brueelia s. str. known from larks. Alström et al. (2013) showed that Eremophila is deeply nested inside the Alaudidae , being closely related to Calandrella , and host phylogeny thus does not appear to offer any clues to the relationships of Osculonirmus , nor suggestions for where other members of the genus may occur.

Geographical range. Holarctic.

Remarks. Males of Osculonirmus limpidus appear to be very rare; among the 61 individuals we examined, only 5 were males and all from North American host subspecies. Mey (1994b) appears to have collected several individuals from most of the hosts he examined, but did not examine any males prior to his description of Os. limpidus . Osculonirmus was not included in the phylogeny of Bush et al. (2016), hence its exact placement within the Brueelia -complex is unknown.

Included species

* Osculonirmus limpidus Mey, 1982a: 60

Figures

FIGURES 25. Dorso-ventral views of coxae I – III, trochanters I – III, and femora I – III, showing terminology of the leg setae used here. Other parts of the thorax removed for clarity. Setae situated marginally are illustrated and named on both dorsal (lefthand) and ventral (right-hand) sides. Terminology for individual seta as used in the text obtained by combining the leg segment (larger font) and the setal name (smaller font). Abbreviations: a 1 – 5, anterior setae 1 – 5; cI – III, coxae I – III; d 1 – 3, dorsal setae 1 – 3; dm 1 – 4, distal marginal setae 1 – 4; fI – III, femur I – III; p 1 – 3, posterior setae 1 – 3; s 1 – 6, sensilla 1 – 6; tI – III, trochanter I – III; v 1 – 4, ventral setae 1 – 4.

FIGURES 116 – 121. Anarchonirmus albovittatus n. gen. & n. sp. ex Pomatostomus temporalis strepitans: 116, male head, dorsal and ventral view; dorsal sensilla and pts not visible in the material examined. 117, female antenna, ventral view. 118, male genitalia, dorsal view. 119, male mesosome, ventral view. 120, male paramere, dorsal view. 121, female subgenital plate and vulval margin, ventral view (anterior dotted line outline pigmented part of subgenital plate, posterior dotted line extent of marginal thickening).

FIGURES 124 – 129. Osculonirmus limpidus Mey, 1982 a ex Eremophila alpestris utahensis: 124, male head, dorsal and ventral views. 125, female antennae, ventral view. 126, male genitalia, dorsal view. 127, male mesosome, ventral view. 128, male paramere, dorsal view. 129, female subgenital plate and vulval margin, ventral view.

FIGURES 114 – 115. Anarchonirmus albovittatus n. gen. & n. sp. ex Pomatostomus temporalis strepitans: 114, male habitus, dorsal and ventral views. 115, female habitus, dorsal and ventral views. (dotted lines on sternites outline densely pigmented areas).

FIGURES 122 – 123. Osculonirmus limpidus Mey, 1982 a ex Eremophila alpestris utahensis: 122, male habitus, dorsal and ventral views. 123, female habitus, dorsal and ventral views.