In laboratory tests moderate dosages of the nematode DD136 caused high mortality of larvae of 5 leaf-eating insect pests of apple: winter moth, Operophtera brumata (L.) ; fall cankerworm, Alsophila pometaria (Harris); fall webworm, Hyphantria cunea (Drury); eastern tent caterpillar, Malacosoma americanum (F.); and pale apple leaf roller, Pseudexentera mali Freeman. Most of the nematodes applied to foliage were killed by desiccation within 1hour after application in the laboratory. The high mortality of the nematode by desiccation was believed to be the cause of its ineffectiveness against larvae of O. brumata in an orchard test.