Fig. 1
Placomerus micans La Rivers 1956: Ent. News 67: 240.
Discussion. This species was described by La Rivers (1956) from a type series that included specimens from Paraguay (the type locality), Bolivia, and Brazil. The specimens are hindwing brachypterous and thus have features typical of brachyptery in other genera, including a poorly defined clavus and angulate or produced posterolateral corners of the pronotum. The macropterous form of this species is unknown. Since the original description, the species also has been recorded from Argentina (Lopez Ruf & Bachmann 1991) and additional localities have been presented for Brazil (Souza et al. 2006, Moreira et al. 2011) and Argentina (Mazzucconi et al. 2008). Nymphal instars 3–5 were described by Lopez Ruf (1996).
In the original description of P. micans, La Rivers (1956) reported the antenna to be "short, undistinctive, three-segmented." Actually, P. micans has a four-segmented antenna with the proportions 4: 8: 11: 7. It is probable that La Rivers did not see the very small basal segment.
During a recent visit (February 2011) to the type locality of P. micans in Paso-Yobay, Villarica, Paraguay, William Shepard and Cheryl Barr were unable to find any specimens despite diligent searching. They collected several ponds as well as the local stream; however, substantial agricultural activities now occur in the area and the species might be locally extirpated (W. D. Shepard, pers. com.).
Material examined. HOLOTYPE ♂: PARAGUAY: Paso-Yobay, Villarica, II- 52 / micans La Rivers holotype ♂ / California Academy of Sciences Type No. 7180 (CAS). PARATYPES: PARAGUAY: Paso-Yobay, Villarica, II- 52 / micans La Rivers paratype (EMEC, 1 ♂; SEMC, 1 ♂; USNM 1 ♀; BMNH, 1); BOLIVIA: S.A., Santa Cruz, J. Steinbach / Snow Collections Univ. of Kansas / micans La Rivers paratype (SEMC, 2 ♂); BRAZIL: S.A., Itaquaquecetaba, July 1933, W. O. Townsend / Snow Collections Univ. of Kansas / micans La Rivers paratype (SEMC, 1 ♂).