European Gypsy Moth
European gypsy moth (Lymantria dispar dispar) is an invasive forest pest that was introduced accidentally in the United States in 1869. Since then, gypsy moth has expanded its range over much of the eastern United States and Canada. It was first detected in Ontario in 1969 and has quickly spread across southern Ontario over the next decade. It is now well established throughout southern Ontario and as far north as Sault Ste. Marie.
Gypsy moths spend the winter as partially developed larvae in eggs. The eggs hatch in the spring and the young larvae begin feeding by cutting small holes in the surface of leaves. As the larvae develop, they feed on the edge of leaves. Larvae have five pairs of blue and six pairs of red spots along their backs (Figure 1). Feeding is normally completed by early to mid-July.
Pupation occurs in a cocoon which can be found on a variety of surfaces including trees, rocks, houses, boats, trailers, fences, picnic tables, and firewood. In 13 – 17 days, the moths emerge. Both sexes have wings, but only the males can fly. The male moth is dark brown to beige, medium-sized, and is a very erratic flyer. The female is mostly white and has a wingspan between 60 – 70 mm. The female lays eggs in masses of 100 to 1000 on tree trunks, branches, houses, fences, etc. as well as under rocks and forest floor debris. The eggs are covered with fine brown hairs from the female’s abdomen (Figure 2). The egg masses will remain all winter and caterpillars will hatch in the spring, from late April to mid-May.
Gypsy moth larvae or caterpillars will feed on tree leaves. If the larvae population is high, they can defoliate whole trees and forests in a short amount of time. Gypsy moth prefer oak trees, but will feed on a variety of hardwood tree species. Under normal circumstances, defoliation caused by gypsy moth won’t kill a tree. However, trees can decline to the point of death in some cases when defoliation is coupled with dry hot summers, or impacted by other forest pests like Spring or Fall Cankerworm.
Recent signs have pointed to the possibility that gypsy moth activity may be on the rise in certain parts of the City of Hamilton. Residents in the Dundas and Ancaster areas became concerned in 2016 about an increase in defoliation, which was attributed in part to gypsy moth activity, prompting surveys of the pest.
Gypsy Moth surveying has been underway since the winter of 2016 with the completion of egg mass surveys. An increase in egg masses suggests a coming season of increased pest activity. The monitoring initiated in late 2016 was focussed within the Dundas Valley and into Ancaster, with some areas investigated in west Hamilton. Results of the Gypsy Moth survey suggest that the population will increase in coming years. High impact areas are expected to be within Dundas’s downtown, the Dundas Driving Park, Pleasant Valley, and suburbs within Ancaster. The results also suggest that expanded monitoring is warranted to see if this is a trending increase in the population.
In 2017, the City of Hamilton will continue to monitor the population of Gypsy Moth populations through the installation of sticky bands and pheromone traps on trees as part of an Integrated Pest Management program. These installations will be focussed throughout Dundas and Ancaster, and will be monitored daily. Surrounding areas will be visually inspected on a weekly basis by Forestry staff, including Flamborough, rural Ancaster, and west Hamilton.
In addition, individual trees within Dundas Driving Park (Dundas), and Somerset Park (Ancaster) will be treated with a naturally occurring bio-pesticide, Bacillus thuringiensis kurstaki (Btk). This pesticide does not affect people, pets, birds, or bees.
Homeowners are encouraged to monitor their hardwood trees like oaks, maples, beech and walnut for the presence of gypsy moth larvae (figure 1). Please help save trees by:
- Installing Sticky bands to monitor and control caterpillar populations.
- Installing Pheromone Traps in trees to lure and trap male moths to prevent them from mating with female moths
- Contacting an Arborist if you think a tree on your property is being heavily defoliated by Gypsy moth.
- Contacting the City of Hamilton at 905-546-CITY (2489) if you think a tree on city property is being heavily defoliated by Gypsy moth.
- Watering your tree and trees near your home in the public right-of-way once every 3 to 5 days during periods of high heat or drought
Consult your local Nursery or Hardware store for Sticky Bands and Pheromone Traps.
Emerald Ash Borer
The Emerald Ash Borer is a highly destructive invasive beetle that infests ash trees. It has killed millions of ash trees in North America and poses a major environmental threat to urban and forested areas in Hamilton. It has the potential to destroy Hamilton’s entire Ash tree population by the year 2020.
Mountain Ash is not in the same family and is not affected by the Emerald Ash Borer.
For Ash Tree & EAB identification view What is an Emerald Ash Borer (EAB)?
Ash trees are an important part of Hamilton’s urban and rural landscape. They are commonly found on city streets, woodlots, windbreaks and forests.
An Ash tree typically has:
- Opposite branching, so leaves and twigs are in opposite positions on the stem, not staggered.
- Compound leaves – leaves that have more than one leaflet, while the entire leaf has one bud at its stem base. The leaflets are positioned opposite with one at the top. Ash trees typically have five to nine leaflets per leaf.
- Rigid bark with diamond-shaped ridges (on a mature tree).
- Seeds that hang in clusters and are dry and oar-shaped.
The Emerald Ash Borer spreads naturally through beetle flight; the beetle is capable of flying distances of 5 km in search of a host tree. The Emerald Ash Borer is also spread by people moving material infested with the beetle such as firewood and nursery stock. The Canadian Food Inspection Agency regulates the movement of material outside the quarantined area.
In Road Allowance
The City will remove an infested ash tree from your property if it is located within the road allowance. If the tree in your front yard is showing signs of being infested with the emerald ash borer, call 905-546- 2489 to have your tree assessed. The City will plant a replacement tree once the infested tree and stump is removed.
On Your Property
You are responsible for all trees that are not on the City’s road allowance. This includes the treatment, removal and disposal of dying or dead Ash trees. Contact an arborist to discuss your options.
If you elect to have your tree removed, ensure that the materials are not moved outside the CFIA quarantined area. The wood and mulch can be utilized for firewood and landscape use within this area.
Contact the Canadian Food Inspection Agency at 1-866-463-6017 or Phytosanitary Requirements to Prevent the Introduction into and Spread within Canada of the Emerald Ash Borer for further information.