On this page
How to identify it
- The full-grown caterpillar is only about 9 mm long, pale yellow to reddish pink above the line of spiracles and creamy yellow below, with diffuse orange-brown to orange-red stripes down the middle and sides of the back that show best on pale specimens. The head is brown and unmarked.[1]
- The moth's forewings are ashy gray with rusty markings, and the wingspread is 13 to 15 mm. Adults emerge in August and September.[2][1]
- Eggs are laid singly at the base of the needles; fresh eggs are pale green and turn yellowish orange after a few days. The first two larval stages resemble Zeiraphera bud moths.[1][2]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Spruce budworm | The spruce tip moth feeds in the opening buds much as the spruce budworm does and often occurs with it, but no economically important outbreak of the tip moth is recorded, whereas the western spruce budworm is the most destructive forest defoliator in western North America. The tip moth caterpillar is also much smaller, about 9 mm when grown.[2][1] |
| Spruce bud moth | Zeiraphera bud moths share the same spruce buds, and the first and second instars of the spruce tip moth resemble them; the older tip moth caterpillar shows its pink-and-orange striping.[2][1] |
Where it lives
It is transcontinental: throughout British Columbia, with records in Yukon and Prince Edward Island, east to Newfoundland and south to California; the USDA manual gives its western range as California to British Columbia to Manitoba.[1][2]
Biology and life cycle
The principal hosts are Engelmann spruce, white spruce and Douglas-fir, with subalpine, grand and amabilis fir and Sitka and black spruce as other hosts. In the East the main hosts are white spruce and balsam fir.[1][2][3]
The egg overwinters at the base of a needle. Caterpillars appear in late May and feed on the current year's foliage until early July, passing through five instars.[1][2]
Grown caterpillars either drop to the ground to spin cocoons and pupate or stay in the tree and pupate under the bud caps. The pupal stage lasts about three weeks; the moths emerge in August and September and lay eggs about seven days later.[1]
Damage and signs
Health risk
The sources treat it only as a conifer bud and needle feeder and mention no effect on people.[1][2][3]
Control
Prevention
No control is called for. The sources record no outbreaks and no economic damage from this moth; if your spruce or fir is losing new growth in early summer, the spruce budworm it often accompanies is the likelier culprit to check for.[1][2]
Common questions
- What is the small pinkish striped caterpillar in my spruce buds?
- A caterpillar under 1 cm long, pale yellow to reddish pink with orange stripes, in opening spruce, fir or Douglas-fir buds in June is the spruce tip moth or red-striped needleworm.[1]
- Is it the same as spruce budworm?
- No, though the two feed in the same buds at the same time and often occur together. The tip moth is smaller and has never been recorded in outbreak numbers.[2][1]
- Where does it pupate?
- Either in a cocoon on the ground or under the bud caps in the tree; the pupal stage takes about three weeks before the moths emerge in August and September.[1]
Sources
- Natural Resources Canada, Canadian Forest Service, “Spruce tip moth; redstriped needleworm, Trees, insects and diseases of Canada's forests.” tidcf.nrcan.gc.ca/en/insects/factsheet/11014 (accessed 2026-11-10)
- USDA Forest Service, “Western Forest Insects, Miscellaneous Publication 1339 (R. L. Furniss and V. M. Carolin, November 1977; scanned copy).” archive.org/details/CAT78702369 (accessed 2026-11-10)
- USDA Forest Service, “Eastern Forest Insects, Miscellaneous Publication 1175 (W. L. Baker, 1972; scanned copy).” archive.org/details/easternforestins1175bake (accessed 2026-11-10)
- iNaturalist, “Epinotia radicana taxon page (order and family).” www.inaturalist.org/taxa/219343 (accessed 2026-11-10)