European Gypsy Moth
European gypsy moth (EGM) is a defoliating insect that can severely weaken or kill trees. It is a major pest in North America.
City Control Programs
In conjunction with various ground-based methods of control, the City of Toronto will be conducting an aerial spray this spring. The spray is to help manage high levels of European gypsy moth caterpillars that are expected in certain areas of the city and prevent severe canopy damage and tree loss. The spray dates are yet to be determined but are set to occur sometime between May 16 and June 15, 2019. The spray dates are dependent upon weather conditions at the time and insect/leaf development. View the Public Notice of Pesticide Use For The Control of Gypsy Moth regarding the aerial spray program and the map of the areas that will be affected by aerial spraying operations. Stay up to date by subscribing to our mailing list.
The City has prepared this informational presentation for residents to help them understand the details surrounding the upcoming Aerial Spray Program.
What the Insect Looks Like
- As larva they are caterpillars that quickly mature to develop five pairs of blue dots followed by six pairs of red dots along their back. In addition, they are darkly-coloured and covered with tufts of hairs. This is the damaging stage of the life cycle for this pest as larva have insatiable appetites for tree leaves.
- As adults they are moths. The females are larger than the males and have white to cream coloured wings. Males are smaller than their female counterparts and are dark-brown in colour with feathery antennae. Adult moths do not feed on tree leaves. The males quickly die off after they have mated and the females have laid their eggs.
What the Damage Looks Like
- Young larvae eat small holes in the leaves of trees.
- Older larvae will eat the entire leaf except for the main veins.
- Trees can lose their foliage and appear bare.
What You Can Do
- Remove and destroy egg masses.
- Burlap Banding
- Wrap and secure a piece of burlap cloth with twine/rope around the stem(s) of your trees.
- Drape the burlap cloth over the twine/rope so there is an overhang where the caterpillars can crawl underneath to seek shelter during the day.
- Lift the burlap cloth overhang every afternoon and collect any hiding caterpillars and destroy them.
- Attract birds and other creatures that eat these insects by planting attractive flowers, herbs or shrubs in your garden.
- For severe infestations, apply Bacillus thurigiensis var. kurstaki (Btk), at the early stage of caterpillar development – visit your garden centre for details and ask for Btk availability.
The objective of the EGM management program is to control outbreak levels of EGM in areas with trees that are under the risk of defoliation. Eradication of EGM is no longer a possibility as it is well established throughout North America is not a realistic management objective.