Brueelia bicurvata ( Piaget, 1880 )

Gustafsson, Daniel R., Zou, Fasheng, Oslejskova, Lucie, Najer, Tomas & Sychra, Oldřich, 2019, Four new species of Brueelia Kéler, 1936 (Phthiraptera: Ischnocera) from African hosts, with a redescription of Nirmus bicurvatus Piaget, 1880, European Journal of Taxonomy 507, pp. 1-48 : 16-20

Brueelia bicurvata ( Piaget, 1880)

Figs 16–22

Nirmus bicurvatus Piaget, 1880: 159 , pl. 13, fig. 8.

Degeeriella bicurvata – Harrison 1916: 109.

Brueelia bicurvata – Hopkins & Clay 1952: 53. — Gustafsson & Bush 2017: 38.

Type host

Vidua paradisaea (Linnaeus, 1758) – long-tailed paradise whydah ( Ploceidae ).

Type locality

Original material from the Leiden Museum, but no type locality given by Piaget (1880).

Material examined

ZAMBIA • 2 ♂♂, 2 ♀♀, ex Vidua paradisaea obtusa ; North Rhodesia [= Zambia], Luanshya; 26 May 1955; British Museum; NHML 1955-486 , ML /121 .

Description

Head rounded trapezoidal ( Fig. 18 ), lateral margins of preantennal area slightly convex proximally, but slightly concave distally, frons broadly flattened to slightly concave. Marginal carina slender, deeply displaced and much widened at osculum, and with median margin slightly undulating. Ventral anterior plate oblong, with rounded posterior margin. Head chaetotaxy and pigmentation pattern as in Fig. 18 . Preantennal nodi elongated. Preocular nodi larger than postocular nodi. Marginal temporal carina slender, with slightly undulating median margin. Gular plate slenderly lanceolate. Thoracic and abdominal segments and pigmentation patterns as in Figs 16–17 .

Male

Male subgenital plate does not reach terminal end of abdomen ( Fig. 16 ). Thoracic and abdominal chaetotaxy as in Fig. 16 . Basal apodeme broad, with concave lateral margins ( Fig. 19 ). Proximal mesosome broad, convergent to median point, and with lateral extensions, making entire structure somewhat arrow-shaped ( Fig. 20 ). Mesosomal lobes long and broad, with almost parallel lateral margins, rounded postero-lateral corners, and extensive rugose area along distal margin. Gonopore roughly semioval, about as long as wide. Penile arms long, reaching beyond distal margin of mesosome. Parameres long and broad, distal section elongated, with pst1–2 as in Fig. 21 . Measurements (n = 2): TL = 1.48– 1.51; HL = 0.36; HW = 0.30; PRW = 0.20; PTW = 0.29–0.31; AW = 0.40–0.41.

Female

Thoracic and abdominal chaetotaxy as in Fig. 17 ; psps present on tergopleurites IV–VII. Subgenital plate shaped as in Fig. 22 , with broad connection to cross piece. Vulval margin somewhat convergent to median point, with 3–5 short, slender vms and 5–8 short, thorn-like vss on each side; 2–4 short, slender vos on each side of subgenital plate; distal 1 vos median to vss. Measurements (n = 2): TL = 1.76–1.81; HL = 0.37–0.39; HW = 0.31–0.34; PRW = 0.20–0.21; PTW = 0.30–0.33; AW = 0.44–0.47.

Remarks

The presence of psps on the female tergopleurites IV–V is unusual in Brueelia . No examples of females with psps on these segments were included in the list of variation in abdominal chaetotaxy of Brueelia published by Gustafsson & Bush (2017: table 3). We know of no other species of Brueelia in which psps are present on the female tergopleurite IV, but psps are present on the female tergopleurite V in several species of Brueelia found on icterid hosts ( Cicchino & Castro 1996). Carriker (1963) illustrated setae on female tergopleurites III–VII in the position of psps in B. mirabile Carriker, 1963 , but did not illustrate any sts. It is therefore doubtful whether these setae represent psps or sts translocated to the dorsal side; we have not examined Carriker’s material. In females of most genera in the Brueelia complex, psps are absent on tergopleurites IV–V, and the general absence of these setae in Brueelia (except in B. bicurvata ) is unusual for the complex ( Gustafsson & Bush 2017: table 2).

A specimen of Brueelia from Vidua macroura was included in the phylogeny of Bush et al. (2016), but its placement as sister to the remaining Brueelia s. str. received no statistical support. As psps are

commonly found on female tergopleurites IV–V in many other genera of the Brueelia complex (see Gustafsson & Bush 2017), it is possible that this represents the ancestral condition in the Brueelia complex, and that this placement as sister to the remaining Brueelia is correct.

Notably, these setae are present in both Formicaphagus Carriker, 1957 (see Price & Clayton 1996) and Formicaricola Carriker, 1957 (see Price & Clayton 1995), two of the genera most closely related to the Brueelia complex in the phylogeny of Bush et al. (2016). In the closest relative, Neopsittaconirmus Conci, 1942 , the distribution of psps varies, e.g., present on III–VII in N. albus (Le Souëf & Bullen, 1902) ( Price & Emerson 1978) , but present only on IV–V in many species ( Guimarães 1974) and only on IV in N. gracilis Guimarães, 1974 (see also Sychra 2005).

Figures

Figs 16–17. Brueelia bicurvata (Piaget, 1880) ex Vidua paradisaea (Linnaeus, 1758) (NHML 1955- 486, ML/121). 16. ♂, habitus, dorsal and ventral views. 17. ♀, habitus, dorsal and ventral views.

Figs 18–22. Brueelia bicurvata (Piaget, 1880) ex Vidua paradisaea (Linnaeus, 1758) (NHML 1955- 486, ML/121). 18. ♂, head, dorsal and ventral views. 19. ♂, genitalia, dorsal view. 20. ♂, mesosome, ventral view. 21. ♂, paramere, dorsal view. 22. ♀, subgenital plate and vulval margin, ventral view.