Marcenendius fortunatus ( NavÁs, 1917 ) Lienhard & Baz & Ch-, 2011

Lienhard, Charles & Baz, Arturo, 2011, Redescription of the genus Marcenendius Navás (Psocodea: ‘ Psocoptera’: Amphientomidae) with a key to western Palaearctic amphientomids, Revue suisse de Zoologie 118 (3), pp. 451-466 : 459-461

Marcenendius fortunatus ( NavÁs, 1917) comb. nov. Figs 6 a-d; 5c, d

Perientomum fortunatum NavÁs, 1917: 20 .

Nephax fortunatus ( NavÁs, 1913) : Meinander, 1973: 143 (redescription based on holotype, male, figs); Lienhard, 1988: 369 (further description, male and female, figs); Lienhard, 1998: 141 (diagnosis, figs).

DISTRIBUTION: M. fortunatus is a Macaronesian endemic known from the following islands. Canary Islands: Tenerife ( NavÁs, 1917; Meinander, 1973; Lienhard, 1988; Baz & Zurita, 2001, 2004); La Palma (Domingo-Quero et al., 2003); unpublished records from Tenerife, La Palma, La Gomera, El Hierro, Gran Canaria, Fuerteventura, Lanzarote (leg. C. Lienhard, material in the MHNG). – Cape Verde Islands: island of Santiago ( Lienhard, 1988; Lienhard & Garcia, 2005).

DISCUSSION: Based on general morphology of adults and nymphs, this brachypterous species is closely related to M. nostras (see key, below). Macropterous specimens of M. fortunatus have never been observed, but the most significant morphological difference between this species and M. nostras is the strong reduction, in the latter, of the T-shaped sclerite of the female subgenital plate.

M. fortunatus lives usually under stones at places incompletely covered by xerophytic shrub vegetation, often also in stone walls built by humans ( Fig. 5d ). Adults are rather well camouflaged by their mottled wing pattern due to scales ( Fig. 5c ) and Marcenendius fortunatus (NavÁs) , female (a-d): (a) Mandibles. (b) Three pronotal "corkscrew" hairs. (c) Maxillary palp. (d) Hindmargin of subgenital plate with T-shaped sclerite, pilosity not shown. – Nephax sofadanus Pearman , female (e-h): (e) Hindmargin of subgenital plate with T-shaped sclerite, pilosity not shown. (f) Labrum, pilosity not shown. (g) Maxillary palp, with spur sensillum and macrochaetae shown in black. (h) Mandibles.

nymphs usually carry some loosely arranged dust particles on dorsal side of thorax (including wing pads) and of abdomen (personal observation by C. Lienhard). This nymphal camouflage is probably due to the presence of corkscrew hairs on these parts of the body (see genus discussion). Environmental dust particles probably adhere much more easily to such curled hairs than to straight hairs. However, the effectiveness of these hairs seems to be less than in the case of glandular hairs, where covering with dust particles is more complete and nymphal camouflage much more impressive (e. g. nymphs with glandular hairs of Protroctopsocidae or Psocidae ; see Lienhard, 1998).

Figures

FIG. 6

FIG. 5. Marcenendius nostras NavÁs: (a) Biotope (dry river bed) of the Alicante specimens (Peñas Roset). (b) General view of Peñas Roset. – Marcenendius fortunatus (NavÁs): (c) Female from Fuerteventura island (Canary Islands), near Lajares, 15.xi.1998, habitus in dorsolateral view, body length 2.5 mm. (d) Biotope of this specimen (stone wall built by humans). Photographs: V. M. Ortuño (a, b), C. Lienhard (c, d).