What attacks spruce: pests and diseases the sources name

This page reports what the named sources say. It is not a diagnosis of any tree and does not say what should be done with one. Each row names its source, all read on October 9, 2026. Where this site has a full profile, the row links it, and the regulated status tables are on the linked pages and are not repeated here. Spruces are covered species by species in tree species in the agency records, including black spruce, red spruce and Sitka spruce, and the spruce Forest Research ties to the eight-toothed spruce bark beetle in Britain is on the Norway spruce page.

The register

Agent	What the sources record
Spruce budworm, Choristoneura fumiferana. Full profile	Kind: Native moth whose caterpillars eat buds and needles Hosts: The Maine Forest Service says white spruce and balsam fir are the main hosts in Maine and other spruces are readily attacked. The USDA Forest Service Alaska Region leaflet names white and Sitka spruce in Alaska. Where: Maine; the Lake States in 2014 (Michigan Upper Peninsula, northeastern Minnesota, northern Wisconsin); Alaska. Symptoms as listed: Reddish-brown upper crown from dead and chewed needles, and in the Alaska leaflet top-kill and reduced growth after consecutive years of heavy feeding.
Eight-toothed spruce bark beetle, Ips typographus. Full profile	Kind: Bark beetle Hosts: Forest Research says it is present especially in Norway spruce across most of continental Europe, and that Ips beetles can also inhabit larch and fir. The Canadian Food Inspection Agency calls it one of the most destructive pests of spruce in Europe and says that besides damaged trees it also attacks healthy ones. Where and status: Forest Research lists it as present in the United Kingdom and notifiable. It says one outbreak was discovered in a Kent woodland in December 2018, and that its Norway spruce entry records a further discovery in 2021 and spread through southern England under official action. Season: No season given on the pages read. The Canadian agency says the beetle can breed in very fresh bark and keeps feeding in the bark after development is complete.
Cooley spruce gall adelgid. Full profile	Kind: Aphid-like insect that makes galls, needing spruce and Douglas-fir to complete its normal life cycle Hosts: Colorado State University Extension says the galls are common and conspicuous on blue spruce and do little or no harm to the tree. Where and status: The page gives no regulated status. It says only extremely heavy infestations may slow tree growth a little and distort it, and that old galls are covered by new growth within a year and become almost unnoticeable a few years later. Season: Galls appear early in the season as cucumber-shaped growths 2 to 4 inches long, light green in late spring and early summer, drying and turning brown from mid-July. They are often mistaken for seed cones.
Green spruce aphid, Elatobium abietinum	Kind: Aphid Hosts: Forest Research says it can damage Norway spruce in severe outbreaks. Where and status: Britain, in the species entry. No regulated status. Season: The same entry says it can be noticeable after mild winters.
Conifer root and butt rot, Heterobasidion annosum. Full profile	Kind: Decay fungus Hosts: Forest Research says Norway spruce is susceptible to it and to other decay fungi such as Stereum. Where and status: Britain, in the species entry. No regulated status is given there. Season: No season given on the page read.
Eastern dwarf mistletoe, Arceuthobium pusillum	Kind: Tiny parasitic plant Hosts: Natural Resources Canada says black spruce is the preferred host. It also infects white spruce, red spruce, eastern larch and eastern white pine, and rarely jack pine, red pine, balsam fir and blue spruce, typically only near other infected spruce. Where and status: Native, with a range through eastern Canada from Saskatchewan to Newfoundland and Labrador and the eastern United States. No regulated status is given. Season: No season given in the text read. The page says infections stimulate excess branching that forms witches' brooms, and that seeds are expelled explosively and can travel up to 15 metres.

How the sources describe the effects

Forest Research says that in Europe the eight-toothed spruce bark beetle is a significant pest on Norway spruce and kills trees through mass beetle attack. At the other end, Colorado State University Extension says Cooley spruce galls usually do not cause serious harm. Natural Resources Canada says eastern dwarf mistletoe takes the bulk of its nourishment from its host and, in Canada, causes most economic damage in stands valuable for pulp, paper and lumber, where heavily infected trees are deformed and stunted. The agency adds that yellow witches' broom, a fungal disease, causes similar brooms on spruce, which can lead to confusion, and that the brooms of that fungal disease lose all their needles in winter and are yellow-orange in spring and summer.

Profiles on this site

The full profiles linked in the table are eight-toothed spruce bark beetle, Cooley spruce gall and Heterobasidion root and butt rot. Green spruce aphid and eastern dwarf mistletoe have only the rows above, because the pages read give too few separate facts for a page each. The other Ips beetles of spruce and pine are on the engraver beetles page.

Who the sources say to report to

Forest Research asks that suspected eight-toothed spruce bark beetle in mainland Britain be reported through TreeAlert. The Canadian page on the beetle names no report line, and the pages read for the other four rows name none either. The reporting offices for each country are on the report a pest in the United Kingdom and report a pest in Canada pages.

What attacks spruce: pests and diseases the sources name

The register

How the sources describe the effects

Profiles on this site

Who the sources say to report to

Sources