Couala Gustafsson & Bush

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: 307-308

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Couala Gustafsson & Bush

new genus

Couala Gustafsson & Bush  , new genus

Nirmus Nitzsch, 1818: 291  (in partim).

Degeeriella Neumann, 1906: 60  (in partim). Brueelia Kéler, 1936a: 257  (in partim).

Type species. Couala dodekopter  new species

Diagnosis. Couala  n. gen. is not particularly similar to any other genus in the Brueelia  -complex, but was placed as a sister to Buerelius  in the phylogeny of Bush et al. (2016). This placement was strongly supported, as was its placement as one of several sister lineages to the core Brueelia  -complex. The male genitalia of these two genera share the following characters ( Figs 515–516View FIGURES 514 – 517, 521–522View FIGURES 520 – 523 for Couala  ; male genitalia of Buerelius  illustrated by Clay & Tandan (1967: figs 5–7): mesosome at least partially fused to basal apodeme; gonopore terminal but elongated; parameres widest at head; pst1–2 near distal end of parameres; basal apodeme much elongated. Couala  ( Figs 514View FIGURES 514 – 517, 520View FIGURES 520 – 523) is primarily separated from Buerelius  ( Fig. 509View FIGURES 509 – 511; Clay & Tandan 1967: figs 1–4) by the following differences in head structure: preantennal area gently rounded in Couala  , but elongated in Buerelius  ; dorsal preantennal suture absent in Couala  , but present and uniquely shaped in Buerelius  ; marginal carina uninterrupted in Couala  , but interrupted medianly in Buerelius  ; antennal canal present in Couala  , but absent in Buerelius  ; mts  2 thorn-like in Couala  , but microsetae in Buerelius  ; ventral anterior plate absent in Couala  , but present in Buerelius  ; temples angular in Couala  n. gen, but gently rounded in Buerelius  ; coni folded ventrally in Couala  , but not folded in Buerelius  . Abdominal chaetotaxy ( Table 2) is similar between the two genera, however tps  are absent on segments II –VIII in Buerelius  ( Fig. 510View FIGURES 509 – 511) but present in Couala  ( Figs 512–513View FIGURES 512 – 513, 518–519View FIGURE 518 – 519). Females of both Buerelius  ( Fig. 511View FIGURES 509 – 511) and Couala  ( Figs 517View FIGURES 514 – 517, 523View FIGURES 520 – 523) have highly convex vulval margins, subgenital plates that are roughly trapezoidal, lack cross-pieces, and have some long vos on distal margin median to the vss. However, the vms are thorn-like and the vss microsetae in all Couala  , whereas the vms are microsetae and the vss are mesosetae in Buerelius  .

Description. Both sexes. Head bell-shaped ( Figs 514View FIGURES 514 – 517, 520View FIGURES 520 – 523). Marginal carina uninterrupted, displaced posteriorly and dorsally at osculum. Ventral carina broad, continuous with marginal carina, but may be diffuse anteriorly. Dorsal preantennal suture, dorsal anterior plate, and ventral anterior plate absent. Head chaetotaxy as in Figs 514View FIGURES 514 – 517, 520View FIGURES 520 – 523; as3 absent. Coni very large, folded ventral to scapes, and typically pointing directly or obliquely to the posterior. Preantennal nodi prominent. Antennae monomorphic. Pre- and postocular nodi very large, especially in Couala angulata  ( Fig. 520View FIGURES 520 – 523). Preocular nodi, if long, ventrally divided by the “antennal canal” (AC in Fig. 520View FIGURES 520 – 523). Ventral side of the preocular nodi continues posteriorly as ridge that ends at posterior margin of head. Antennae in many mounted specimens fit through the AC and along this ridge. Temporal and occipital carinae not visible; mts  3 only macrosetae, mts  2 spine-like or hooked, ventral. Gular plates large, shape varies between species.

Prothorax rectangular ( Figs 512–513View FIGURES 512 – 513, 518–519View FIGURE 518 – 519); ppss on postero-lateral corners. Proepimera broad, hookshaped medianly. Pterothorax roughly pentagonal; lateral sides widely divergent; posterior margin convergent to median point; mms widely separated medianly. Meso- and metasterna not fused; 1 seta on postero-lateral corner on each side of each plate. Metepisterna broad, blunt but diffuse medianly; large nodi laterally. Leg chaetotaxy as in Fig. 25View FIGURES 25, except cI-v3, fI-p2, fI-v4, fII-v2, fIII-v2 absent; fI-p3 absent in Couala dodekopter  n. sp. ( Figs 405–406View FIGURES 401 – 405View FIGURES 406 – 407).

Abdomen oval, broad ( Figs 512–513View FIGURES 512 – 513, 518–519View FIGURE 518 – 519). Terminal segment in females very short, and tergopleurite IX+X may project median to tergopleurites XI ( Fig. 519View FIGURE 518 – 519). Tergopleurites rectangular; tergopleurites II –IX+X in male and tergopleurites II –VIII in female narrowly divided medianly. Female tergopleurites III –VIII with increasingly slanted posterior margins; tergopleurite IX large, shield-like. Sternal plates wide, rectangular, not reaching pleurites, often pale or diffuse. Pleural incrassations wide. Ventral sections of tergopleurites wide, angular. Re-entrant heads elaborate. Male subgenital plate triangular, reaching to terminal end of abdomen. Abdominal chaetotaxy as in Table 2 and Figs 512–513View FIGURES 512 – 513, 518–519View FIGURE 518 – 519. Female subgenital plate broadly triangular, may approach vulval margin ( Figs 517View FIGURES 514 – 517, 523View FIGURES 520 – 523), but does not flare into cross-piece. Vulval margin ( Figs 517View FIGURES 514 – 517, 523View FIGURES 520 – 523) highly convex, with spine-like vms, minute vss; vos follow lateral margins of subgenital plate; distal vos at or near vulval margin.

Male genitalia variable ( Figs 515–516View FIGURES 514 – 517, 521–522View FIGURES 520 – 523), but mesosome, basal apodeme, and parameres are all fused at least partially. Basal apodeme elongated, anterior margin rounded. Proximal mesosome fused to basal apodeme, and not distinguishable. Gonopore terminal ( Figs 516View FIGURES 514 – 517, 522View FIGURES 520 – 523), prominently located in anterior portion of mesosome; distal ends of gonopore elongated. Mesosomal lobes large, distally fused with parameres, and in Couala dodokopter  ( Fig. 516View FIGURES 514 – 517) not distinguishable from parameral heads. Lobes may be smooth ( Figs 515–516View FIGURES 514 – 517) or densely papillate and rugose ( Figs 521–522View FIGURES 520 – 523); 2 ames sensilla on each side in translucent grooves antero-lateral to gonopore; 2 pmes sensilla or microsetae on each side postero-lateral to gonopore. Parameral heads ( Figs 515View FIGURES 514 – 517, 521View FIGURES 520 – 523) fused to mesosomal lobes. Parameral blades attenuating, divergent ( Fig. 408View FIGURES 408 – 412) or convergent ( Fig. 413View FIGURES 413 – 414); pst1 sensilla, central near distal end of paramere; pst2 microsetae, marginal near distal end of paramere.

Host distribution. Known only from species of the Malagasy cuckoo genus Coua Schinz, 1821  . Hughes (1996, 2000) suggested that the genus Coua  is close to other ground-living cuckoos, such as Centropus Illiger, 1811  , but no similar lice are known from these host genera.

Geographical range. Madagascar.

Etymology. Couala  refers to the generic name of the host with the arbitrary ending – la. Also, Couala  is a pun suggesting similarities to the koala, Phascolarctos cinereus (Goldfuss, 1817)  , as both are somewhat chubby, largely rounded in all parts, and live their lives clinging to something much larger, which they also eat. Gender: feminine.

Included species

* Couala angulata ( Piaget, 1880: 134)  n. comb. [in Nirmus  ]

* Couala dodekopter  new species

* Couala goniodes ( Piaget, 1880: 665)  n. comb. [in Nirmus  ] Nirmus goniocotes Piaget, 1885: 33  new synonymy [in Nirmus  ] [1]

[1] Nirmus goniocotes  was described from “ Dacelo gigas  de Madagascar (Museum de Leide)”. This species is today known as the laughing kookaburra Dacelo novaeguineae (Hermann, 1783)  and is endemic to Australasia ( Fry et al. 1999). There are no large kingfishers on Madagascar, and it appears that either the type host identity, its geographical origin, or both are erroneous. The syntypes of Nirmus goniocotes  in the Piaget collection at NHML are indistinguishable from those of N. goniodes  , although Piaget’s material of both taxa is poorly preserved. Therefore, we place N. goniocotes  as a junior synonym of Cl. goniodes  , implying that the type locality of Nirmus goniocotes  is correct, but that its type host was misidentified.












Couala Gustafsson & Bush

Bush, Sarah E. 2017


Nitzsch 1818: 291


Keler 1936: 257
Neumann 1906: 60

Couala angulata ( Piaget, 1880: 134 )

Piaget 1880: 134

Couala goniodes ( Piaget, 1880: 665 )

Piaget 1885: 33
Piaget 1880: 665