Control
Check susceptible plants frequently so action can be taken before a damaging population has developed. When choosing control options you can minimise harm to non-target animals by starting with the methods in the non-pesticide control section. If this is not sufficient to reduce the damage to acceptable levels then you may choose to use pesticides. Within this group the shorter persistence pesticides (that are usually certified for organic growing) are likely to be less damaging to non-target wildlife than those with longer persistence and/or systemic action.
Non-pesticide control
- Some damage can be tolerated without adverse effects on plant health. Populations of caterpillars, as butterflies and moths are an important part of the garden ecosystem
- Light populations can be controlled by squeezing the bound leaves to crush the concealed caterpillars and pupae
- Encourage predators and other natural enemies in the garden such as birds, wasps and ground beetles
- Carnation tortrix and light brown apple moths can be monitored and may be kept in check by using pheromone traps. These consist of an open-sided cardboard box with a sticky sheet in its base. A pellet which releases a pheromone is placed on the sheet; this is the same chemical produced by females to attract males. In a confined space, such as a glasshouse, these traps may capture enough males to reduce the mating success of the females. These traps are available from some suppliers of biological controls
Pesticide control
Early treatment is best since young caterpillars are more susceptible than the older larva.
- Organic sprays, such as natural pyrethrum (e.g. Bug Clear Gun for Fruit & Veg, Neudorff Bug Free Bug and Larvae Killer), can give some control of tortrix moth caterpillars. These pesticides have a very short persistence and so may require reapplication to keep caterpillar numbers in check.
- More persistent contact-action insecticides include the synthetic pyrethroids lambda-cyhalothrin (e.g. Westland Resolva Bug Killer), deltamethrin (e.g. Provanto Ultimate Fruit & Vegetable Bug Killer, Provanto Sprayday Greenfly Killer) and cypermethrin (e.g. Py Bug Killer)
- The systemic neonicotinoid insecticide acetamiprid (e.g. Bug Clear Ultra) is also available
Follow label instructions when using pesticides. On edible plants make sure the food plant is listed on the label and follow instructions on maximum number of applications, spray interval and harvest interval. Plants in flower should not be sprayed due to the danger to bees and other pollinating insects. Inclusion of a pesticide product does not indicate a recommendation or endorsement by RHS Gardening Advice. It is a list of products currently available to the home gardener.
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Pesticides for gardeners (pdf document)