Harpagobaetis Mol, 1986

Falcão, J. N., Salles, F. F. & Hamada, N., 2010, The adults of Harpagobaetis Mol and Tomedontus Lugo-Ortiz and McCafferty (Ephemeroptera: Baetidae) with notes on the nymphal stage, Zootaxa 2530 (1), pp. 39-46 : 40

Harpagobaetis Mol

( Figs. 1–5, 10–12, 15–17)

Harpagobaetis Mol 1986: 63 ; Orth et al. 2000: 35; Salles & Lugo-Ortiz 2002: 155; Domínguez et al. 2006: 159.

Male Imago. Head. Turbinate eyes oval, length 1.6× width; stalk height 0.5× width of dorsal portion; inner margin slightly divergent anteriorly ( Figs. 1, 2, 4, 5).

On thorax, anteronotal protuberance rounded ( Fig. 2). Forewing ( Fig. 10a) with paired marginal intercalary veins; length of each intercalary vein about 0.7× distance between adjacent longitudinal veins; length of forewing about 2.6× width; stigmatic cross veins reaching Sc. Hind wing ( Figs. 10b, 11) present, with two complete longitudinal veins; costal projection pointed, placed in basal third of anterior margin, cross veins absent. Metascutellar protuberance weakly developed ( Fig. 2).

Genitalia ( Fig. 12) with forceps three-segmented. Forceps segment I without projections, 0.2× length of segment II; distance between segments about 1.1× width of segment I. Forceps segment II with bulbous base. Forceps segment III long, about 3× longer than wide and about 0.3× length of segment II. Posterior margin of subgenital plate straight.

Comments. Adults of Harpagobaetis can be distinguished from the other genera of Baetidae by the following combination of characters: forewing with paired marginal intercalary veins ( Fig. 10a); hind wing present, with two complete longitudinal veins ( Figs. 10b, 11); costal projection of hind wing pointed, placed in the basal third of anterior margin, cross veins absent ( Figs. 10b, 11); forceps three-segmented, segment I with bulbous base, segment III long, about 3× as long as wide ( Fig. 12).

In the key proposed by Domínguez et al. (2006) the genus Harpagobaetis would key out as Camelobaetidius Demoulin. However , these genera can be differentiated by the shape of the second segment of forceps, which has a bulbous base in Harpagobaetis , but not in Camelobaetidius .

The nymph of Harpagobaetis ( Figs. 15–17) was adequately characterized by Mol (1986) and later by Domínguez et al. (2006). The habitat where the nymphs were collected is also in agreement with that described by Mol (1986), except that besides being on Podostemaceae , they can also be encountered living on other organic material, such as leaves and plant stems. The water flow, in turn, seems to be an important factor, with nymphs collected exclusively in areas with moderate current. As indicated by mouthpart morphology ( Figs. 15−16, also see Mol 1986, Figs. 14 −27) and analyses of gut contents performed by Mol (1986), nymphs were observed in the field preying larvae of Diptera.