Key to the species of Huarpea Pate, 1947

A new key is provided as an attempt to shift the focus of identification criteria from coloration to morphological characters. Due to the unfortunate lack of material to examine, the defining steps for H. colombiana, H. burmeisteri and H. paranensis are based on Pate (1947) and Fernández & Sarmiento (2015) and maintain the coloration bias. The later study states that H. wagneriella presents a yellow stripe on S1 while H. colombiana does not. However, the examined material of H. wagneriella do not present this character and therefore this trait is removed from the key.

1. Head mostly red............................................................ H. burmeisteri (Gerstäcker, 1861)

- Head mostly black.................................................................................... 2

2. Head with two ferruginous spots behind the ocelli; scutellum mostly yellow............. H. paranensis (Gerstäcker, 1861)

- Head without ferruginous markings, scutellum mostly black................................................... 3

3. Large, fore wing length longer than 10 mm; clypeus medially bisected by a carina (Fig. 15); head densely hirsute with erect setae of similar height (Fig. 16); T1 with strongly protruding spiracles (Fig. 17).................................... 4

- Moderate-sized, fore wing length shorter than 8 mm; clypeus without median carina (Fig. 18); head covered by short erect setae, with two or three longer, darker and thicker setae on dorsal margin of the upper eye lobe that stand out (Fig. 19); T1 spiracles not protruding or at most very slightly so (Fig. 20)................................................... 5

4. Clypeus with yellow markings; T2 without subapical yellow bands........... H. colombiana Fernández & Sarmiento, 2015

- Clypeus without yellow markings; T2 with subapical yellow bands................... H. wagneriella (du Buysson, 1904)

5. Metapleura nearly interrupted midway ventro-dorsally by propodeum (Fig. 8); female clypeus wider, less than half as high as wide (Fig. 4); frontal carina stronger, higher above frontal lobes; depression above antennal socket abrupt, nearly forming a right angle and with sculpture sparser and shinier than surroundings (Fig. 9); male with last flagellomere round (Fig. 7)............................................................... H. rotundicornis Lopes, Moleiro & Lucena, sp. nov.

- Metapleura continuous ventro-dorsally, only slightly narrower midway (Fig. 21); female clypeus narrower, more than half as high as wide (Fig. 22); frontal carina weaker, with short and regular height throughout (Fig. 23); depression above antennal socket more regularly curved with sculpture similar to surroundings (Fig. 24); male with last flagellomere stylate and apically capitate (in Torretta 2014: Fig. 1A).................................................. H. fallax (Gerstäcker, 1861)