Ochterus unidentatus Chen & Nieser, 1992

Cianferoni, Fabio, 2012, The Ochteridae of Ecuador, with new records and an identification key (Hemiptera: Heteroptera: Nepomorpha), Zootaxa 3260, pp. 62-68 : 63-65

Ochterus unidentatus Chen & Nieser, 1992

Material examined. Ecuador, Pichincha province, La Unión del Toachi, Toachi river right tributary, 850 m amsl, 28.VI.2009, 3 3, legit F. Cianferoni, C. Monte & F. Zinetti, coll. CFC.

Notes. A rather narrow, elongate species, with the hemielytra variable in pattern ( Fig. 1 ): the two yellowish spots on the corium can range from being almost invisible (in dark specimens) to developing in stripes (in light specimens). The latter can also be present on the rest of the corium and on the clavus (cfr. Nieser & Chen 1992).

The anterior tibiae are strongly curved in males ( Fig. 1 ) on the apical part (a characteristic not reported in the original description).

The central section of the frontal plate (sensu Kormilev 1971) is smaller than the width of one eye, surpassing the ventral border of the eyes, with numerous faintly impressed ridges on the surface, varying from horizontal in the middle to almost vertical in the upper part; in the lower part they follow the margin of ventral shape of the frons ( Fig. 2 ).

The species can only be positively identified by the shape of the right paramere. The general shape of the right paramere is strongly curved as in O. barberi Schell, 1943 (from the USA and Mexico). Nieser (in verbis) indicates that in O. bidentatus Schell, 1943 from Peru (cfr. Nieser & Chen 1992) this structure emerges from the genital capsule in a similar way ( Fig. 3 ; cfr. Schell 1943). Despite this, the knowledge of taxonomy and distribution of the New World Ochteridae is still too low to support any hypothesis of relationships between species. The whole apical part of the right paramere is enlarged, turning around its axis, the tip of the apical part rounded, turned toward the internal side, and the rest of the apical part is wider in the middle and ends with a little hook. It should be noted that the general shape, curvature and structures strongly change when rotating the paramere ( Fig. 4 ), so is extremely important to observe it from different positions.

This species was not included among Ochteridae of South America by Heckman (2011).

Figures

FIGURE 1. Variability of hemielytral pattern in Ochterus unidentatus Nieser & Chen, 1992 (photo P. Magrini). Length of specimens (from left to right): 4.1, 4.0, 4.2 mm.

FIGURE 2. Frontal plate of Ochterus unidentatus Nieser & Chen, 1992 (drawing F. Cianferoni). Scale bar: 1 mm.

FIGURE 3. Genital capsule of Ochterus unidentatus Nieser & Chen, 1992 (photo P. Magrini). Length: 0.97 mm.

FIGURE 4. Right parameres of Ochterus unidentatus Nieser & Chen, 1992 in two different positions (photo P. Magrini). Length: 0.46 mm.