The damage from leafrollers is usually not severe. It can start as a minor problem on fruit trees, just a few curled leaves maybe, spoiling the look of the plants. After a time, the fruits may look scarred and deformed, and the leaves have a ragged appearance.
An examination will reveal small leaf rolling caterpillars wrapped up inside the leaves, tied up neatly with silk. These are the larvae of certain tortricid moths , busily feeding.
Apart from fruit trees, leaf rollers commonly go after ornamentals and some flowering plants. These include box elder, canna, oak, birch, maple, rose, and willow.
Here’s how to get rid of leafrollers naturally.
1. Bacillus Thuringiensis (B.t.)
This is a naturally occurring soil bacterium. B.t. strains are often used in commercial products as organic pesticides.
Bacillus Thuringiensis delivers a fatal toxin to leaf roller worms and certain other pests. However, it will not harm beneficial insects and plants.
Spray onto leaves before the leaf roller larvae begin feeding on them. Once they are rolled up and sealed in, sprays cannot reach the pests.
Additionally, Bt becomes less effective in sunlight. As a result, you may need to reapply in a spell of hot sunny weather. Also, do not store it for more than one season.
Similar to Bt as a natural soil bacterium but has a different and possibly quicker action.
Spinosad works on the nervous system and causes paralysis, disrupting the feeding pattern. Thus, the death of the larvae occurs in 1-2 days.
It is widely available in commercial pesticides as powders, granules, and sprays and is often used in organic gardening.
3. Scrape Off the Eggs
An excellent home remedy is getting rid of the eggs before they hatch.
At the beginning of summer or late spring, batches of light green to light brown eggs may be visible on the upper side of leaves.
This is a good time to prevent destructive larvae from developing. Simply scrape off the eggs and dispose of them, preferably by burning them.
4. Lacewing Eggs
Around the same time as removing moth eggs, or in early spring, scatter green lacewing eggs onto the leaves of fruit or nut trees.
These natural predators will hatch out and devour moth eggs and leafroller caterpillars. You can purchase lacewing eggs online or from some local farm stores.
5. Trichogramma Wasps
These very tiny wasps will also help prevent an infestation of leaf-rolling insects. They parasitize the eggs of many varieties of moths, thwarting development and destroying the host.
Female wasps lay eggs in each of the moth eggs, potentially killing large numbers of pests each season.
You can also buy these beneficial wasps online or from various gardening suppliers.
Some farmers use this commercial product in the biological control of many pests affecting food crops. The 2 powerful active ingredients of Azera are Pyrethrins and Azadirachtin.
Neem oil is a popular natural insecticide that comes from neem trees. Pyrethrins are also famous for their insecticidal properties.
However, exercise caution when using Azera. Spray in the evening and not directly onto blooming flowers or ripe fruits as this may be harmful to pollinators like bees.
If you use the product according to the instructions, Azera is effective against leaf roller insects and other harmful pests like wireworms and aphids.
7. Bonide Spray
Bonide is a specially prepared concentrated lightweight mineral oil spray for winter application to control pests in the dormant time.
Diluted as per instruction, use it in stages over the colder months to prevent the eggs of pests hatching out or larval forms from developing.
Spray all parts of the trees including bark, branches, and leaves thoroughly. Additionally, you can use this leafroller control product at other times of the year if needed.
The environmental importance of bees and declining populations is due in part to the overuse of chemical pesticides. As a result, a return to biological control is helping to restore the balance.
Organocide is one such product that deals with insects, mites, and fungus without harming pollinators, particularly bees, although evening spraying is advised.
The main components of the spray are sesame and fish oils with soybean extracts. These are supplied in a ready-to-use form or a concentrate.
One application should clear existing infestations of leaf rollers. However, repeat once a month if any further damage is visible. Also, do not use this product for indoor purposes.
9. JMS Stylet Oil
You can use this product all year round. Besides, it is suitable for greenhouse use as well as for fruit trees and crops.
Stylet is a highly refined white-grade mineral oil principally used to control powdery mildew and other fungal plant diseases. A spray solution of Stylet and water is also effective against mites and pests including leaf rollers.
This pesky insect in the larval form of the leaf roller moth can affect fruit trees such as pear, peach, and apple. A perfect harvest may be ruined by discoloration, stunting, or deformity. Moreover, because there are so many garden pests, it is often difficult to assess the culprits.
Leaf rollers, however, are easy to identify as they hide within rolled-up leaves secured by silken threads. Once spotted, you can control them by one or more of these natural means.