Main aphids in Africa: Black bean aphid ([i]Aphis fabae[/i]), Cabbage aphid ([i]Brevycoryne brassicae/Myzus persicae[/i]), Groundnut aphid ([i]A.craccivora[/i]), Cotton aphid ([i]A.gossypii[/i]), Russian wheat aphid ([i]Diuraphis noxia[/i]), Cypress aphid ([i]Cinara cupressi[/i])
Aphids (Aphis gossypii)
Colonies of green to blackish aphids are found on tender shoots, mainly on the lower leaf surface, where they suck sap. Under heavy attack the growth of attacked shoots is stunted and leaves are curled and twisted. Aphids excrete honeydew, which leads to growth of sooty mould, and may also attract fruit flies. Aphids transmit virus diseases such as the watermelon mosaic virus to pumpkins.
- Use reflective mulch (e.g a polyethylene sheet covered with a thin layer of aluminium that is spread out on the growing bed at planting time). Covering the ground with a material like aluminium foil repels winged aphids, delay aphid colonisation and may delay virus infection
- Place sticky traps to detect arrival of winged aphids into the crop.
- Conserve natural enemies. Aphids have a wide range of natural enemies which usually keep them under control.
- If necessary spray with botanicals (e.g. neem extracts). Spray only attacked plants (spot spraying).