Libelloides coccajus, the "owly sulphur", is an owlfly species belonging to the family Ascalaphidae, subfamily Ascalaphinae. This rare insect is present in France, Czech Republic, Germany, Italy, Spain and Switzerland. The adults reach 25 millimetres (0.98 in) of length, with a wingspan of 45–55 millimetres (1.8–2.2 in) and can be encountered from April through July in areas with tall grass.