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.