Pest insects in brassica crops

There are several types of pest insect to be aware of if you grow brassica crops in the UK. This section describes the activity of fly pests, beetles, caterpillars, aphids and cabbage whitefly and presents our findings on various approaches to managing them.

Brassica crops can be infested by up to 49 different species of pest insect, but most of these frequently appear on horticultural brassicas. They include flies, beetles, caterpillars, aphids and whiteflies. Pests can reduce yield and crop quality through direct feeding damage, the transmission of plant viruses and contamination.

Understanding pest insect life cycles

As 'cold-blooded' organisms, the rate at which pest insects complete their life cycle is driven by the temperature of their surroundings. They will develop more rapidly when the weather is warm, which means that they become active earlier in the year following a warm spring. They are usually active earlier in the South of the UK than in the North. The life cycles of these pests are very different, but there are periods when more than one species is active. Control programmes should take this into account.    

Fly pests

Learn about the life cycles of the cabbage root fly and turnip fly and the damage these pests can cause to brassica crops. Find out how to monitor fly pest populations and chemical-free ways of managing infestations.

Discover more about fly pests


Brassica plants can suffer damage from flea beetles, pollen beetles and cabbage stem weevils. Find out what to look out for and discover ways to limit infestation levels.

Read about beetles in brassica crops


Caterpillars feed on brassicas and can also contaminate harvested crops. Find out about caterpillar life cycles, using pest traps for monitoring, and mitigating damage with crop covers.

More on managing caterpillars in brassicas


Cabbage, peach-potato and potato aphids are all pest insects of brassica crops. They also act as contaminants and can reduce crop yield. Read our findings about chemical-free solutions to keeping on top of aphid populations.

Learn to manage aphids in brassicas

Cabbage whitefly

The cabbage whitefly is a pest insect that appears in kale and Brussels sprout crops and is mainly a contaminant. Find out more about its life cycle and activity in UK brassica crops.

More about managing cabbage whitefly

Whole crop IPM strategy for pest insects in brassica crops

Read about wholecrop IPM strategy for protecting brassica crops against pest insects in general. Learn about maintaining beneficial insects and insecticide resistance.

More about integrated pest management

Useful links

Download our factsheet: Pest insects infesting brassica crops

Read our Brassica Crop Walkers’ Guide

Originally authored Rosemary Collier, University of Warwick