A new species of entomopathogenic nematode, Steinernema phyllophagae n. sp., was isolated from a white grub (Phyllophaga sp.) in a live oak (Quercus virginiana) nursery. The new species is characterised by morphometrics of the infective Sjuvenile (IJ) with body length 1289 (1133-1395) μm, distance from anterior end to the excretory pore 99 (84-120) μm, tail 89 (77-109) μm, ratio a = 31 (27.6-35.5), H% = 57 (51-60) and E% = 110 (70-139). The pattern of the lateral field of IJ of the new species is 2, 5, 6, 8, 6, 2. The male of the first generation can be recognised by the length and shape of the spicule and gubernaculum, position of the excretory pore, D% = 75 (68-80), and GS% = 71 (61-77). The female can be recognised by the vulva having low epiptygma and by the presence of several papilla-like structures near the tail tip. Steinernema phyllophagae n. sp. differs further from other species of Steinernema by characteristics of ITS and D2D3 regions of rDNA.