Preventing Vine Weevil Larvae Vine Weevil Larvae: Control with Parasitic Nematodes (Heter) BC07 This pest feeds underground on roots & stem-bases from mid/late summer through winter, severely weakening or killing plants. Mainly a problem in container plants, but can cause serious damage to some plants in borders & to strawberries. Larvae are C" shaped, cream coloured with a brown head. Control with Parasitic Nematodes (Heterorhabditis sp.)BC07: Microscopic transparent worms which feed & multiply inside the larva, not visible with a hand lens. Dilute with water before use. Must be applied to moist compost/soil between August & October. a follow up treatment may be applied between April & May. Having trouble with garden pests? These biological control products will ensure that pests stop killing your plants."