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Mint leaf beetle

Symptoms

Holes in leaves, made by iridescent green beetles and their and fat, black grubs.

Find it on: mint, pennyroyal
Time to act: May-September

Overview

The mint leaf beetle, Chrysolina herbacea is a native, iridescent green beetle that feeds on the leaves of the mint family in the south of the UK. Both the adults and their fat, black larvae feast on the foliage.


Solution

Holes in leaves, made by iridescent green beetles and their and fat, black grubs.

Organic

Mint is a prolific plant, so there's no need to control the beetles. If you're worried, you could try growing pennyroyal, Mentha pulegium as a sacrificial crop, or simply remove beetles and larvae by hand and squish them. You could also spray with organic pesticides based on pyrethrum in spring and summer.




Discuss this problem

Talkback: Mint leaf beetle
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Diana Reynolds 10/08/2012 at 20:12

a pest but a serious investation on a neighbours mint was beautiful, glittering all over

Dusha 20/08/2012 at 15:18

Er right... so GW presenters spend much time teaching us how to attract bees to our garden and then the GW website tells us how to kill them with neonicotinoid insecticides. Does GW really think some guy with a pesticide sprayer is really going to carefully remove all flowers from the mint that he has sprayed when they open? Also the neonicotinoids are not only present in pollen and nectar but also in the plant's roots, leaves and stems, where they will continue to kill bees and beneficial organisms that are upwards from them in the food chain. The BBC should stop promoting pesticides.

Frankly, mint can look after itself. Slugs and snails are the big problem this year for the organic gardemer.

sotongeoff 20/08/2012 at 15:25

Dusha wrote (see)

Er right... so GW presenters spend much time teaching us how to attract bees to our garden and then the GW website tells us how to kill them with neonicotinoid insecticides. Does GW really think some guy with a pesticide sprayer is really going to carefully remove all flowers from the mint that he has sprayed when they open? Also the neonicotinoids are not only present in pollen and nectar but also in the plant's roots, leaves and stems, where they will continue to kill bees and beneficial organisms that are upwards from them in the food chain. The BBC should stop promoting pesticides.

Frankly, mint can look after itself. Slugs and snails are the big problem this year for the organic gardemer.


You may or may not be aware that Monty Don on a programme pointed out that the only way to get rid of lily beetle was to squash them -this upset the pesticide industry because there are chemical preventatives

I don't think that the BBC are promoting pesticides in this article- just pointing out that this is an option

slaphead08 24/08/2012 at 22:07

So if your mint gets leaf beetle go and buy a jar from the shop and try again next year. Don't ingest the chemicals.