Caterpillar Brassicas Problems and Cures

Caterpillar Brassicas Problems and Cures

Small Cabbage White Caterpillar (pic)

Large Cabbage White Caterpillar are yellow with black markings

Caterpillar Problems

  • There are a large variety of caterpillar from different species of moths, butterflies and saw flies.
  • Brassicas are particularly susceptible to three common types the large cabbage white butterfly, the small cabbage white butterfly and the cabbage moth respectively Pieris brassicae, Peiris rapae and Mamestra brassicae.
  • Butterflies lay their eggs on the outer leaves of the brassica which hatch in 4 days to become voracious feeding larvae.
  • In addition to eating irregular shaped holes in leaves they often burrow into the hearts of cabbages.
  • Damage to plants will occur in April and October as the butterfly produces two generations per year.

Caterpillar Control

  • Avoid the butterflies by netting the brassicas.
  • Pick off any caterpillars by hand.
  • Squash any eggs that are found under the leaves before they develop.
  • Try a biological control from a parasitic wasp that lays its eggs in the caterpillars eg Cotesia glomerata
  • Grazers natural formula is sprayed directly on to the foilage which helps protect the plant from damage.
  • Spray with the contact pyrethroid insecticides but remember you plan to eat the brassica.
  • Distract the butterflies by planting nasturtiums as an alternative breeding ground.
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