Procryphocricos perplexus Polhemus

Sites, Robert W. & Arango, Luisa Fernanda Álvarez, 2010, Description of the female of Procryphocricos perplexus Polhemus (Hemiptera: Heteroptera: Naucoridae), Zootaxa 2562 (1), pp. 66-68 : 66-67

Procryphocricos perplexus Polhemus

( Figs. 1–3 )

Procryphocricos perplexus Polhemus, 1991 : Pan-Pac Entomol. 119.

Description: Only differences from the description of the male are given here. Brachypterous female (n=1): Length 5.28 mm, maximum width 2.84 mm. Abdominal terga III–VI fused with only weak indication of segmentation becoming more pronounced laterally ( Fig. 1 ). Tergum VI broadly rounded posteriorly, extending over terminal segments. Left margin of abdominal tergum IV shallowly concave, almost straight. Metaxyphus (unreported in original description) broad; posterolateral margins concave, deflected ventrad; produced to rounded apex medially ( Fig. 2 ). Posterior margin of mediosternite III nearly straight, IV–V shallowly concave, VI distinctly concave. Mediosternite VI asymmetrical, with right anterolateral corner expanded laterad ( Figs. 2, 3 ). Subgenital plate 0.8 x as long as greatest width, lateral margins convergent posteriorly, lateral carina delimiting dorsal reflexion, apex broad with shallow medial concavity, posterolateral corners rounded, dense pad of golden setae on each side of concavity near posterior margin, line of elongate golden setae along posterior third of lateral carina ( Fig. 3 ).

Material examined: COLOMBIA: Puerto Triunfo - Antioquia, Río Claro , 24 July 2006 (1 male, 1 female) .

Discussion. In addition to the female specimen, we examined one male specimen which measured 5.12 x 2.80 mm and is close to the measurements given for the male holotype of Procryphocricos perplexus . Our specimens are from the Rio Claro and, thus, are topotypes of P. perplexus ; however, we were unable to compare them with either the type or paratype specimens, both of which are housed in the private collection of J. T. Polhemus. Nevertheless, there appears to be no question of the conspecificity of our specimens with P. perplexus . We noted only a few minor differences with the original description. Specifically, although the original description indicates that the head is "produced anteriorly 0.5 x eye length," our specimens are at most 0.3 x eye length when measured carefully in strict dorsal view. Further, the original description indicates that the head is "produced behind eyes 0.75 x eye length"; however, in our specimens, these lengths are subequal. Deviation from a strict perpendicular angle for measurement could account for these differences. The left margin of tergum IV is very shallowly concave in our specimen and not in continuation with the curvature of III and V, unlike that of the right side. Because we have only a single female, it is unknown whether this concavity is a consistent attribute of this taxon or an abnormality unique to this specimen. We suspect the latter is true. In addition, abdominal mediosternite VI is distinctly expanded to the right, an attribute not previously noted in the tribe. We examined females of eight species of Cryphocricos and noted subtle asymmetry only in C. obscuratus Usinger , but did not detect it in C. barozzii Signoret , C. breddini Montandon , C. hungerfordi Usinger , C. latus Usinger , C. mexicanus Usinger , C. peruvianus De Carlo , or C. vianai De Carlo.

The sexes of Procryphocricos perplexus are dimorphic in abdominal terga. Although both exhibit fusion of the terga, terga III–V are fused in the male, whereas terga III–VI are fused in the female. The sexes of the closely related genus Cryphocricos also are dimorphic with respect to the abdominal terga. In Cryphocricos , segment V of males is greatly expanded posteriorly and extends shelf-like over the remaining posterior segments, whereas females lack abdominal tergite specialization. Further, Cryphocricos exhibits alary polymorphism ( Usinger 1947, Sites 1990). Although macropterous specimens of Procryphocricos are not known, we consider their existence likely, particularly in streams with unstable hydrologic regimes. Because these insects appear to be closely related to Cryphocricos and also are brachypterous, it follows that Procryphocricos probably also uses plastral ventilation.

Figures

FIGURES 1–3. Procryphocricos perplexus Polhemus female. (1) dorsal habitus, (2) ventral habitus, (3) posterior segments of abdominal venter showing subgenital plate and asymmetrical mediosternite VI.