The adult male of Allokermes galliformis (Riley, 1881) (Hemiptera: Coccomorpha: Kermesidae) is described for the first time in Colorado, United States of America. This scale insect species recently emerged as a significant pest of red oaks in Colorado through its causative role in drippy blight disease. A description and illustration of the adult male characterize its key external morphological characteristics.
Keywords: Quercus sp.; drippy blight disease; kermes scale insect; pin oak kermes; scanning electron microscopy.