Key to US Forelius species

Key to workers of Forelius species known from the United States, after Ward (2005).

1

 * Standing hairs present on scapes, posterior margin of head, and external face of tibiae => Forelius mccooki


 * Standing hairs absent or very sparse on scapes, posterior margin of head, and external face of tibiae => Forelius pruinosus

Note There is a third distinct (and apparently undescribed) species of Forelius in the United States. It is small and dark with a conspicuously shiny mesepisternum, short scapes (SL 0.40-0.48), and sparse standing pilosity. This species ranges from southern Texas to Colombia, and has been found sympatrically with a larger Forelius species—apparently F. pruinosus—in Mexico, Guatemala and Costa Rica, without showing any sign of intergradation. [Ward, 2005]