Spongy Moth - Tree Canada

introduced from Europe to North America (Massachusetts) in 1869 for possible silk production
now well-established in the eastern US as well as small populations in western US
in Canada, it is most abundant in Ontario and Quebec
also occurs in small numbers in New Brunswick, Nova Scotia, and British Columbia
in BC, aggressive monitoring and control have prevented the moth from becoming established but introductions of egg masses from the east occur regularly

the female moth is mostly creamy-white with some dark markings and a wingspread of up to 62 mm (2 ½ in)
the male is darker and smaller with a wingspan of 37-50 mm (1 ½-2 in)
the female cannot fly so lays a single egg mass close to where she has emerged after pupation
each egg mass contains up to 1500 eggs
egg masses are laid on trees, rocks, or manmade objects, such as tires, trailers, or firewood
the species is easily spread when these objects are moved prior to the eggs hatching
eggs hatch in early spring and the caterpillars feed until mid-summer
the caterpillars are hairy with two rows of large spots on the back: red spots at the head end and blue spots at the tail end
caterpillars grow to 60 mm long (2 ½ in) when mature
Gypsy moths have one brood per year and overwinter as eggs
populations tend to cycle over the course of several years, going from abundant to rare and back

in BC, an aggressive program of trapping adults and spraying trees with a biological insecticide (Btk) in areas where the moth has been found has prevented establishment
aerial and ground-based spraying of Btk as well as chemical insecticides to kill the larvae have been used in eastern Canada
there are several parasites and birds that attack the larvae

Tree Killers: Spongy Moth