Dealing with the diamondback moth

Not for nothing is this species also called the cabbage moth. Just about every cabbage grower has encountered it at some point

-  Bill Kerr

The diamondback moth (DBM; Plutella xylostella), which breeds prolifically and whose larvae are highly destructive, is the number one pest of brassicas in South Africa.

Young plants are particularly vulnerable. DBMs lay their eggs in small clusters on the young leaves and the larvae later hatch and eat holes in the leaves. These holes expand as the leaves grow, reducing the leaf area and, consequently, the yield.

The larvae prefer to feed on the underside of the leaves, leaving the upper epidermis in place; this gives the appearance of little translucent ‘windows’.

Because they feed under the leaves, especially when these leaves are just above the ground, it is extremely difficult to reach DBMs with insecticides.