Box tree moth
The box tree moth, Cydalima perspectalis (Walker), was detected three times near Toronto, Ontario in 2018. It was first reported on iNaturalist by a citizen scientist. Hosts include: Buxus balearica (Balearic boxwood), Buxus bodinieri, Buxus harlandii (Harland boxwood), Buxus megistophylla, Buxus microphylla (Little-leaf box), Buxus rugulosa, Buxus sempervirens (Common boxwood) and Buxus sinica (Chinese box).
Control is with hand picking and pheromone traps.
It was detected in Germany and the Netherlands around 2006 probably arriving in Europe on plants. Since then it has spread to 30 countries as live plants have a free market in the EU.
Unlike Europe, Canada has no native boxwoods so it is expected to be a serious threat to landscaping but not to native areas.
There are two colour forms. The most common has white wings with thick dark brown borders. To date this is the only form detected in Canada. The other form is darker with brown wings and a small white streak on the forewing. Eggs are on the underside of leaves.
Detections should be reported to the CFIA, or EDDMapS .
Boxwood web worm
Boxwood web worm, Galaxa nigrinoda is being seen in association with other boxwood pests. This native species is not to be confused with invasives. It feeds on dead foliage and not living leaves. It is not a pest.
European cherry fruit fly
The European cherry fruit fly ( Rhagoletis cerasi L .) consumes fruit pulp in Europe resulting in 100 per cent loss of crop. It was first reported in Canada in June 2016 in an urban park located in Mississauga, Ontario.
Hosts include: Prunus spp ., including sweet cherry ( P. avium ), sour cherry ( P.cerasus ), black cherry (P. serotina) and mahaleb cherry ( P. mahaleb ). Honeysuckle hosts documented in Europe include Lonicera xylosteum , L. tartarica and L. alpigena . In Ontario, adult detections have been in association with Lonicera spp ., including L. morrowii , L. tartarica and L. xbella . This species attacks the fruit of its host plants but no other part of the plant.
The European cherry fly overwinters 1-13 cm deep in the soil and must experience cold temperatures to develop. The adults are small, black with clear wings and a yellow thorax. Attacked cherry fruits are pitted with oviposition puncture marks and exit holes. The tissue surrounding these punctures will appear soft and brownish.
It is not considered a human health hazard but it is an extreme threat to the cherry fruit industry.
Sightings of the pest should be reported to CFIA or EDDMapS Ontario
Emerald ash borer

Emerald ash borer, Agrilus planipennis continues to hitch hike across the country. It is now in Edmundston, New Brunswick and Quebec City. It is expected to fill in the areas in between. The extreme cold in the prairies this winter is expected to knock it back but not out. Chilly 2019 will only be a temporary setback. The larvae will have survived under the snow line even when temperatures dipped below minus 40. In the Maritimes, this pest will continue to expand its range. Like the Prairies, Quebec City is expected to have a slower rate of expansion due to its climate. Feasibility studies are being conducted for release of a parasitoid in New Brunswick and Nova Scotia similar to what is being done in Ontario and Quebec.
The fringe tree is now considered a secondary host of EAB.
The US is lifting some of their quarantine restrictions on this pest to allow harvesting of high value trees before their economic value is lost.
Taylor Scarr of NR Canada urges tree workers to remember treatment options are available for high value trees.
Hemlock Woolly Adelgid
Hemlock Woolly adelgid, Adelges tsugae is established in Southern Nova Scotia. It is widespread and well adapted to the climate. The US has several treatment options and they are releasing predator beetles as a long term control option. Using predator beetles as an option in Canada is under study.
The HWA in eastern Canada is closely related but not be confused with the established HWA in the west. The western species is not considered a pest; the insect is adapted and beneficial west of the Rockies.
Sticky traps and rubber balls covered with Velcro are being used to identify infestations in the east. Treatment options are available for high value trees.
Mountain Pine Beetle
The mountain pine beetle Dendroctonus ponderosae is now only 50 to 100km from the northern Saskatchewan border to Manitoba. This is a direct gateway to Manitoba and Ontario’s boreal forest and is a concern as the beetle will soon be entering an area with no host barriers. Alberta’s aggressive control program using a technique of surveys, felling and burning has shown effect. Ontario is doing active surveys.
Oak Wilt
Oak wilt or Ceratocystis fagacearum is now common in the lake states and through Michigan. It is considered likely already in Windsor but to date there is no confirmation. Surveys are ongoing. It is a lot like Dutch elm in the way it blocks the tree’s transportation system. The highest risk time for pruning is two weeks before bud flush to full flush. In response to the large appeal, hydro companies are altering their schedules to avoid pruning oaks during the high risk time.
Quebec and Manitoba are monitoring the situation closely. Forest fire compacts are being expanded on both sides of the border to include forest health sharing of resources.
Reports of possible sightings can be made to Ontario Anglers and Hunter’s hotline, OMNR or EDD Maps.
Forest Tent Caterpillar
Forest tent caterpillar or Malacosoma disstria is a native species expected to continue to expand its range in 2019. Areas in their second to third year of defoliation should start seeing collapse. The parasitic fly, “the friendly fly,” that parasitizes forest tent caterpillar is expected to increase this year and bring on full population collapse.
Jack Pine bud worm
The Red Lake district of Ontario has started public consultation for the use of aerial spraying of Btk for jack pine bud worm or Choristoneura pinus pinus Freeman .
Spruce bud worm
Spruce bud worm, Choristoneura occidentalis is expected to be low in Ontario this season while in Quebec it will be high. New Brunswick has started and early intervention program with intensive surveys. They are using Btk and a growth hormone that causes the insect to moult and not complete its maturation. This insect has two main parasitic enemies that control the population. The treatments are to work mainly with the one parasite and keep its levels high. Less than one per cent of the stands will be treated and the rest will be allowed to run their natural course.
Orange striped Oakworm & two-lined chestnut borer

Orange striped Oakworm
Orange striped Oakworm, Anisota senatoria and two-lined chestnut borer, Agrilus bilineatus are expected to be a concern in northeastern US and southern areas of Ontario where the gypsy moth has done back to back defoliation events. The two insects are coming in as secondary pests, attacking newly planted trees and trees already weakened by repeated defoliation.
Fall web worm
Fall web worm, Hyphantria cunea was a problem in the south east last year. Parasitoids are expected to kick in this year and bring it under control. Watch for regional problems in July and later in the summer.
Spotted lantern fly
Spotted lantern fly, Lycorma delicatula is now established in 14 counties in the US. Eggs hatch in May and the adults emerge in July. The egg masses are very hard to see and can be on anything including any plant material, concrete, stone — anything. The early nymph stage is black and white. It later matures to red with black spots before transforming to the adult form. It looks like the green stink bug nymph, tiger moth and leopard tiger moth.
A parasitoid is currently under study in the US in quarantine. In China, this beneficial organism parasitizes 80 per cent of the population of spotted lantern fly. At this time, there is no proposed release date as testing is not complete.
Norway Spruce Shoot Gall midge
Norway Spruce Shoot Gall midge, Piceacecis abietiperda is causing distorted growth in Norway Spruce. Galls are visible at the base of twigs among old bud scales. If you cut the galls open in the spring you will see a larvae. Later in the season, these spaces will be hollow.
Spruce bud scale has much larger swellings. These swellings will dislodge easily with your finger and are not a pest or concern.
Little is known about the Norway spruce shoot gall midge, and tree workers are encouraged to note when the adults are emerging (likely in late April or May). The adults have a reddish abdomen.
— Pat Kerr