Colorado potato beetle
Yellow-and-black striped beetles and their reddish larvae that strip the leaves of potatoes, aubergines and tomatoes.
Also known as: Potato bug, Leptinotarsa decemlineata
Symptoms and identification
Leaves are eaten down to the stems. Striped adults, clusters of orange eggs under leaves, and plump reddish larvae with black spots are easy to see.
Causes
Adults overwinter in the soil and emerge in spring to feed and lay eggs. They quickly develop resistance to insecticides.
Organic treatment
Hand-pick adults and larvae into soapy water and crush egg clusters. Spray Bt products for beetles (tenebrionis strain) or spinosad on young larvae.
Prevention
Rotate crops far from last year's potato bed, use straw mulch, and cover young plants with row covers.
Chemical treatment (use with care)
Use an insecticide labelled for Colorado potato beetle, rotating products to reduce resistance.