Weevils Female weevils excavate cavities Intercropping with maize, yam, cowpea, other crops Neem extract and create egg-laying punctures. Cylas spp Crop rotation The eggs are laid below the Elimination of crop residues Imidacloprid surface of the roots and are Deter infestation by preventing soil cracking, irrigating frequently or covered with dark color. hilling a small area around the sweet potato Hatched larvae are tunneling Mulching materials such as rice straw and plastic film reduce the inside tubers. Mining of sweet infestation of sweet potato weevils by spreading them over the potato tubers by larvae is the planting site principal cause of sweet potato damage. The tuber becomes spongy in appearance, riddled Reridging at tuber formation stage with cavities, and dark in color Practice proper field sanitation Using entomopathogenic nematodes and fungi Pheromone traps and use of natural enemies where available Write grub (larvae of White grub larvae gouge out Avoid planting in fields that follow pasture None Approved broad, shallow areas on the root Scarab beetles) Stemborers Larvae boring into the main stem Use treated planting materials Use of insecticides, is difficult and and sometimes penetrates costly because the insect remains Omphisa anastomosalis Crop rotation storage roots largely concealed throughout its life Hilling-up to cover the holes that provide the adults with an exit Thiamethoxam from the stem Lambda-cyhalothrin Earwigs and ants may attack the larvae developing within sweet potato vines. Undetermined hymenopteran species (family Encyrtidae) have been observed attacking this pest Use resistant varieties where available
Weevils Cylas spp Female weevils excavate cavities and create egg-laying punctures. The eggs are laid below the surface of the roots and are covered with dark color. Hatched larvae are tunneling inside tubers. Mining of sweet potato tubers by larvae is the principal cause of sweet potato damage. The tuber becomes spongy in appearance, riddled with cavities, and dark in color Intercropping with maize, yam, cowpea, other crops Crop rotation Elimination of crop residues Deter infestation by preventing soil cracking, irrigating frequently or hilling a small area around the sweet potato Mulching materials such as rice straw and plastic film reduce the infestation of sweet potato weevils by spreading them over the planting site Reridging at tuber formation stage Practice proper field sanitation Using entomopathogenic nematodes and fungi Pheromone traps and use of natural enemies where available Neem extract Imidacloprid Write grub (larvae of Scarab beetles) White grub larvae gouge out broad, shallow areas on the root Avoid planting in fields that follow pasture None Approved Stemborers Omphisa anastomosalis Larvae boring into the main stem and sometimes penetrates storage roots Use treated planting materials Crop rotation Hilling-up to cover the holes that provide the adults with an exit from the stem Earwigs and ants may attack the larvae developing within sweet potato vines. Undetermined hymenopteran species (family Encyrtidae) have been observed attacking this pest Use resistant varieties where available Use of insecticides, is difficult and costly because the insect remains largely concealed throughout its life Thiamethoxam Lambda-cyhalothrin
50298.docx