Insecticide resistance in pests found in UK crops is not new, but an increasing number of insect species are now able to tolerate some of the chemistry used to control them.

Experts believe this is largely due to overuse of insecticides and applications at lower rates than those recommended on the product label. Hard-to-control pests are now becoming a problem in a variety of crops, including cereals, oilseeds, potatoes, peas, beans, field vegetables and in grain stores.

Here, Crops identifies which pests have developed resistance, which chemical group or groups they are resistant to and which crops they affect. It should be noted that three of the pests only have suspected resistance and cases of control failures are being investigated.

Resistant crop pests
Peach potato aphid	Grain aphid	Cabbage stem flea beetle
Crops affected: Oilseeds Potatoes Sugar beet Vegetable brassicas	Crops affected: Cereals Potatoes	Crops affected: Oilseeds Vegetable brassicas
Resistant to: Pyrethroids Carbamates	Resistant to: Pyrethroids	Resistant to: Pyrethroids
Pollen beetle	Pea and bean weevil	Cabbage seed weevil
Crops affected: Oilseeds Vegetable brassicas	Crops affected: Peas Field beans	Crops affected: Oilseeds
Resistant to: Pyrethroids	Resistant to: Pyrethroids	Resistant to: Pyrethroids (suspected)
Bruchid beetle	Saw-tooth grain beetle
Crops affected: Field beans	Crops affected: Stored grain
Resistant to: Pyrethroids (suspected)	Resistant to: Pyrethroids (suspected)