Plutella

Contributor: CABI
Date Compiled: 2024
Creative Commons "Attribution-Share Alike"
Diamondback moth damage on cabbage Image copyright: Francis Nduati, Kenya

Prevention

Solution
Avoid continuous cropping of brassicacae vegetables in a larger range, because they may all host the pest.
After harvest, immediately clean stubble and leaves because of residual pest eggs.
Plough in autumn, because pupae are in the soil.
Irrigate in winter to reduce overwintering pupae.
Apply botanicals against larvae (such as extracts from staff vine, staff tree or bittersweet Celastrus angulatus)

Monitoring

Solution
The first peak of diamondback moths occurs in mid-May to late June in northern-central provinces; the second peak occurs in late August to late October.
For early detection of tiny longish moths use 3 sex pheromone traps/667m2 field
Look for larvae feeding holes and notches on leaves once a week
Older larvae feed on the underside of leaves. At heavy infestation, feeding windows are seen on the leaves
When many larvae, leaves are eaten up and veins left.
Act quickly when larvae or holes or notches are visible especially at early stage of plant growth.
Thresholds: 1 to 2 larvae every second plant at the seedling stage or rosette stage, 2 to 3 larvae or damaged leaves / every second plant at the early heading period, 5 to 7 larvae or damaged leaves at heading stage.

Control

Solution
Solar powered light traps to capture adult moths (3 traps /667m2) at night, on the edge of the field.

Solution Product Category Production stage (if possible with reference to BBCH scale) Max nb. of a. i. application/year Chemical Group IRAC Code
Bacillus thuringiensis subsp. kurstaki
Microbiological insecticide
Bacillus thuringiensis subsp. aizawai
Microbiological insecticide
Spinosad
Biological insecticide
Maximum 3 interventions between Spinosad and Spinetoram
Spinosine
Release parasitic wasps (100-300/667m2) (for example Diadegma semiclausum 尾姬蜂 from Taiwan; Oomyzus sokolowskii 菜蛾啮小蜂 from Guangdong; Cotesia plutellae 菜蛾绒茧蜂 from Guangdong
Avermectin products
Synthetic insecticide
Treat at the first appearance of parasites. Suspend treatments 3 days before harvest
Avermectins
6
The information made available here has been obtained from or is based upon sources believed by CABI to be reliable but is not guaranteed as to accuracy or completeness. Anyone acting or relying on such information does so entirely at their own risk. The efficacy of the IPM methods included above will depend on local conditions and might not always be suitable everywhere within the specified country.