Nevrorthus reconditus Monserrat & Gavira

Monserrat, V. J. & Gavira, O., 2014, A new European species of Nevrorthus in the Iberian Peninsula (Insecta, Neuropterida), Zootaxa 3796 (2), pp. 349-360 : 352-355

Nevrorthus reconditus Monserrat & Gavira n. sp.

Diagnosis. The new species is characterized by pale-greyish tegumentary coloration and strongly contrasting brownish-blackish patches. Antennae brownish, slightly darker at the distal third. Transversal venation of fore wings strongly black, this coloration is clearly extending over the adjacent membrane. Male presents the parameres strongly curved to midline and the ninth sternite is narrow, with lateral margins sub-parallel at the base and the caudal margin lightly curved against the midline but without presenting a notable cleft.

Description. External morphology. General color of the tegument very pale brown-greyish, with notable darker brown-blackish patches all over the surface ( Fig. 1 ), especially on thorax and abdomen.

Head very pale brown, eyes black, vertex scarcely sclerified with a slightly more sclerified Y-shape area from the base of antennae to hind midline and carrying abundant brownish setae with dark base. Antennae with circular base poorly sclerified, scape sub-cylindrical and pedicel globular, both brownish, basal two thirds of flagellum pale brownish, flagellomeres sub-cylindrical, carrying two rings of dark setae, and progressively darker towards the apical third. Labial and maxillary palps brownish. Middle area of clyppeus and labrum poorly sclerified and pigmented at central region. Distal margin of labrum slightly emarginate in the center.

Thorax with pronotum semicircular with abundant brownish setae, strongly brownish pigmented at the base. Pronotum very pale brownish and irregularly darker brownish pigmented; notably, a slight midline dark brownish and two transverse lines also dark brownish and parallel to fore and hind margins. Meso and metanotum pale brownish with a slight midline dark brownish and dark brown triangular patches over the meso and metascutellum, and circular patches over the meso and metascutum ( Fig. 1 ). Also darker and very contrasting patches over epimera and episternum. Both segments carry a very hairy semispherical formation around the area of wing insertion. Legs pale brownish, somewhat darker at the base of coxa, especially on the second and third pair of legs. Femur-tibia joint area also somewhat darker. Male with hind femurs no broader than the femurs of fore and mid legs. Tarsomeres pale, somewhat darker at the distal part, and the last tarsomere entirely dark. Claws strongly curved at a right angle.

Fore wings length (♂: 6.1 mm; ♀: 6.7–6.4 mm). Longitudinal veins pale brownish, somewhat darker from the first bifurcations to the marginal veins, and with setae distinctly brownish at the base. Costal cross-veins very dark brownish, more pale towards the pterostigma ( Fig.1, 2 , 17 ). Transverse vein between Sc and R and remaining transverse veins very dark, extensively darkening the adjacent membrane ( Fig. 1, 2 , 17 ). Wing membrane in both sexes with a dark circular patch on anal field ( Fig. 2 , 17 ) carrying numerous conical micro-trichia that could have a stridulatory/hearing function as described in other families by Riek (1967).

Hind wings length (♂: 5.1 mm; ♀: 6.0–5.8 mm) with very similar pigmentation pattern but the transverse veins dark brownish, somewhat less contrasting and less extended over the adjacent membrane than on fore wings. Notably, the beginning of SR, transverse veins between this and R, and external gradate veins markedly darker but less so than on fore wings ( Fig. 2 , 17 ).

Abdomen with tergites and sternites irregularly brownish pigmented ( Fig. 1 ). Fore tergites bent at a right angle at the fore margin.

Genital elements. Female: Tergite 9 with a small circular emargination on the caudal margin. Subgenital plate broad, with external margins straight. Lateral gonapophysis narrow and fusiform, somewhat more sclerified and brownish pigmented on the fore half. Ectoproct ovoid, poorly sclerified.

Male: Pleuritocavae present, forming two internal bags with granular aspect, and apparently open ventrally between the sixth and seventh sternites ( Fig. 3 ). Seventh tergite and sternite with a triangular region more sclerified and broader towards the caudal margin. Eighth tergite and sternite narrow, not fused but forming a ring ( Fig. 3 ); tergite with a small narrow V-shape emargination, open towards the caudal margin; eighth sternite with similar emargination but comparatively larger, broader and more open. Ninth tergite narrow at middle dorsal part and rectangular in lateral view ( Fig. 3 ). Ninth sternite hairy at the basal part ( Fig. 8 ), narrow in lateral view ( Fig. 3, 7 ), lateral margins sub-parallel, not sinuous, and at the distal part with caudal margin very slightly sinuous and concave at the midline but without becoming a notable cleft ( Fig. 5, 8 , 10 ). Ectoproct semicircular-ovoid ( Fig. 3, 7 ), cercal callus with 7 trichobothria. Gonarcus with globular appearance in lateral view ( Fig. 3, 7 ), with caudal process that is spatulated in lateral view ( Fig. 3, 7 ) and tri-lobated in dorsal or ventral view ( Fig. 4 ). Paremeres strongly curved towards the midline and carrying three distal bended denticles ( Fig. 4–6 ). Coxopodite weak, hairy and digitiform ( Fig. 4–7 ). Hypandrium weak and triangular.

Larva: The external appearance of the larva of this new species was noted by Gavira et al. (2012) and is now shown in Figure 9 . Notable features in these larvae are their size at the end of development (8.5–9.5 mm); their coloration—brownish-amber head, cervix and pronotum, the rest of the body being extremely pale brownish in color, almost translucent in the live specimens; their extremely long and widely spaced bristles; and, on the legs, the powerful spines on the distal part of the femur and tibia ( Fig. 9 ). In the live specimens observed, marked characteristics were their agility and great mobility; they moved about rapidly while oscillating the head and prothorax looking for prey, using the end of the abdomen as a lever and thereby contributing to their movement. It is likely that they could move forwards as well as backwards, between detritus and submerged vegetation. Lastly, it is also interesting to note their capacity to hide in submerged hollow stems.

Figures

FIGURE 9. Nevrorthus reconditus Monserrat & Gavira n. sp., general appearance of the larva.

FIGURES 1 – 8. Nevrorthus reconditus Monserrat & Gavira n. sp. 1: General appearance; 2: Wings; 3: Abdominal end of male, lateral view; 4: Ditto, dorsal view; 5: Ditto, ventral view; 6: Paramere and coxopodite, ventral view; 7: Gonarcus-paramerecoxopodite complex, lateral view; 8: Ninth sternite, ventral view (c: coxopodite, e: ectoproct, g: gonarcus, pa: paramere, pl: pleuritocava, S: sternite, T: tergite). At different scales.

FIGURES 15 – 25. Fore wings and general appearance of Nevrorthus spp. 15, 19, 23, 24: Nevrorthus apatelios; 16, 21, 22: Nevrorthus hannibal; 17: Nevrorthus reconditus Monserrat & Gavira n. sp.; 18: Nevrorthus fallax; 20, 25: Nevrorthus iridipennis. 15,16,18 – 25: Photograhs by R. A. Pantaleoni.

FIGURES 10 – 14. Schematic diagram of the ninth sternite in ventral view of: 10: Nevrorthus reconditus Monserrat & Gavira n. sp.; 11: Nevrorthus fallax; 12: Nevrorthus hannibal; 13: Nevrorthus apatelios; 14: Nevrorthus iridipennis. Scale: 0.2 mm.