Key to the Genera and Species of (Modified from Cazier 1937) by Katherine A. Swoboda, 2002

1. Pronotum basomedially strongly produced posteriorly (Fig. 1). Female without pygidial spine ………………………………………... Homovalgus seticollis (Beauvois)

1'. Pronotum basomedially weakly produced posteriorly (Fig. 2). Female with pygidial spine …………………………………………………………………………….…….… 2

Figure 1. Pronotum of Figure 2. Pronotum of Homovalgus seticollis. Valgus minutus.

2(1). Posterior tarsus with first segment slightly longer than second segment and subequal in length to fifth ………………………………………….…… Valgus mexicanus Cazier

2'. Posterior tarsus with first segment as long as segments two and three combined or as long as two, three, and four combined .……………………………………………..…… 3

3(2). Lateral edges of pronotal disc not serrate. Female with short, scoop-like pygidial spine (Fig. 3), spine moderately concave on dorsal surface ….. Valgus californicus Horn

3'. Lateral edges of pronotal disc serrate. Female with acuminate pygidial spine (Fig. 4, Fig. 5), spine straight or moderately convex on dorsal surface ……………………….... 4

Figure 3. Valgus californicus. Figure 4. . Figure 5. Valgus canaliculatus.

Figures 3-5. Dorsal view of pygidial spine of: Valgus californicus, Valgus hemipterus, and Valgus canaliculatus.

4(3). Male with tufts of long, white setae at apex of pygidium. Pygidial spine of female with irregular, lateral serrations (Fig. 4). Color piceous. Size greater than 8.0 mm …………………………………………….…………….….. Valgus hemipterus Linnaeus

Figure 4. Dorsal view of pygidial spine of Valgus hemipterus.

4'. Male without tufts of long, white setae at apex of pygidium. Pygidial spine of female without lateral serrations. Color reddish-brown. Size smaller than 5.0 mm ……….……. 5

5(4). Longitudinal, medial ridges on pronotum well-developed. Occurs from northeast Texas to Pennsylvania.……………………………………………. Valgus canaliculatus (Olivier) 5'. Longitudinal, medial ridges on pronotum not well-developed. Occurs in Louisiana .…………………………………..………………………………. Valgus minutus Casey