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Preventive Control

Natural enemies


  1. Braconids
  2. Native parasitic wasps



Management and cultural practices

  1. Practice proper field sanitation. After harvest remove all plant residues especially the discarded and un-harvested tubers.
  2. Remove Ipomea weeds, especially the morning glory, as this weed is the weevils' alternate host.
  3. Plow the field after harvest to expose the pests to predators.
  4. If there is access to irrigation water, submerge the field for at least a day. The weevils do not like being in wet areas and on rotten and decayed materials.
  5. Practice crop rotation, if possible, to disrupt the lifecycle of the pest. Rice, sorghum (AVRDC, 2001), yam, edible sunflower, and ornamental trees for flower arrangement (FFTC, 2000) are found to be good rotation crops.
  6. Properly select your planting material. The tender vine which is about 25-30 cm long is ideal and is usually free from eggs and larvae. The female lays its eggs on the vine near the base of the plant, and the larvae are found feeding on this plant part.
  7. Practice hilling-up to prevent soil from cracking. Cracked soil is an entry point for the weevils to feed and reproduce on the tubers.
  8. Storage containers and other facilities are possible source of new infestations. Clean and fumigate them.
  9. Complete eradication of the pest is a collective effort among the farmers in a given community (e.g. village, barangay) and involves not planting sweet potato, and removing Ipomea weeds regularly for a period of at least 6 months.
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