On this page
How to identify it
- The first sign is the color of the current year's needles, which come in light olive green and shorter than normal. The olive slowly turns light yellow and finally brick red, on individual branches first and then across the whole crown. A tree dies soon after its foliage starts turning red.[1]
- Look under the discolored branches for masses of male cocoons that look like small fluffs of cotton. The bark on branches and trunks of heavily infested trees is swollen and cracked, with dead tissue under each feeding scale.[1]
- Adult females are brownish red, wingless, roughly pear-shaped and coarsely wrinkled, 1/16 to 3/16 inch long, and carry their minute amber-yellow eggs in a white, loosely woven waxy sac attached to the abdomen. Preadult males look like small females; the true adult males are two-winged and midge-like with a prominent brush of long white waxy filaments at the tip of the abdomen.[1]
- The settled feeding stage is an elliptical, legless nymph without antennae tucked under a bark scale. All stages live on the branches and stems, where nymphs and adult females feed through the bark on the phloem.[1][3]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Pinyon needle scale | A related Matsucoccus species. The red pine scale lives under bark scales on the branches and stems of red pine and a few Asian pines in the Northeast, feeding through the bark on the phloem.[1][3] |
| Pine needle scale | The red pine scale's only white sign is the cottony male cocoons on the undersides of branches; its feeding stages hide under bark scales, and the needles discolor from olive to yellow to brick red.[1] |
| Pine bark adelgid | Red pine scale's cotton-like masses are male cocoons on the undersides of branches of red pine, Japanese red, Japanese black and Chinese pine; the trees' bark swells and cracks and the crown turns brick red before the tree dies.[1] |
Where it lives
The Forest Service found it in Connecticut, New York (Long Island and Westchester County) and New Jersey, all south of red pine's natural range, in plantations, nurseries and ornamental trees. ScaleNet records it from Connecticut, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania and Rhode Island. The species also occurs in western China, where it attacks Masson and Japanese black pine.[1][2][3]
Biology and life cycle
Hosts in the Northeast are red pine, Japanese red pine, Japanese black pine and Chinese pine. In Forest Service trials the scale would settle on jack, pitch, Scotch, white, Austrian and mugo pine growing among heavily infested red pine but failed to complete development on them. The infested area lies south of the natural range of red pine, and the trees it kills are planted ones.[1]
There are two generations a year in Connecticut. Summer-generation eggs are laid in May; the first-stage nymphs appear by early June, wander briefly, then settle under a bark scale and never move again while feeding. They become the legless intermediate stage by mid-July. Preadult males emerge in August and spin loosely woven, white, spindle-shaped waxy cocoons in which they become winged adults, while female intermediates develop straight into adults that lay the fall generation's eggs in late August or early September.[1][2]
The fall generation overwinters as partly grown first-stage nymphs under the bark, resumes feeding in spring, reaches the intermediate stage in April, and produces adults in early May to start the cycle again.[1]
The scale is apparently spread by wind: first-stage nymphs have been carried at least a quarter of a mile. Native predators, including an anthocorid bug, a lady beetle, a brown lacewing and green lacewings, attack it but have not stopped its buildup and spread.[1]
Damage and signs
- Feeding under the bark kills tissue beneath each scale, stunts and discolors the new needles, and progresses from single branches to the whole crown; the tree dies soon after the foliage turns red. The Forest Service counted thousands of trees killed, from nursery stock to mature red pine, and many more so weakened that bark borers finished them.[1]
- EFSA describes the same syndrome in Asia: yellowing and browning needles, early needle drop, drying shoots and bark necrosis, with the most serious infestations in trees 8 to 25 years old and some tree death.[3]
- Because the known infestation sat outside red pine's native range, the scale was considered a serious threat to natural red pine stands should it spread north.[1]
Health risk
None of the sources mention any effect on people or pets; the insect is a plant feeder confined to pine bark.[1][3]
Control
Keep them out
New Jersey's 1960 infestation of about 160 acres of watershed plantings was eradicated by 1966, though two small infestations were found again in the same area in 1970, so early detection and removal matter.[1]
Sanitation
No effective chemical spray was found for plantations. The Forest Service's recommendation is to cut infested trees during the winter months to prevent spread, peel the logs, and burn the branches and bark.[1]
Pesticides
On ornamental pines, two applications of a 2 percent oil emulsion, the first in early June and the second in early September, gave some protection in the Forest Service's 1971 leaflet; current product registrations should be checked with extension before treating.[1]
Common questions
- My planted red pines are turning yellow then rusty red, one branch at a time. Could it be this scale?
- That progression, olive-green new needles that fade to yellow and then brick red while cotton-like male cocoons collect under the branches and the bark swells and cracks, is the classic picture of red pine scale in Connecticut, New York and New Jersey plantings.[1]
- Is Matsucoccus resinosae a different insect?
- That is the name given to the Connecticut population in the 1950s. ScaleNet lists it as a junior synonym of Matsucoccus matsumurae, an Asian species, based on pheromone cross-attraction and later morphological and molecular work.[2]
- Can I spray my infested red pines?
- For plantations the Forest Service found no effective spray and advises cutting infested trees in winter and burning the bark and branches. Ornamentals got partial protection from oil sprays in early June and early September.[1]
Sources
- USDA Forest Service, “Red Pine Scale, Forest Pest Leaflet 10 (J.L. Bean and P.A. Godwin, revised June 1971).” www.fs.usda.gov/foresthealth/docs/fidls/FIDL-10-RedPineScale.pdf (accessed 2026-11-10)
- ScaleNet (scale insect database begun at the USDA ARS Systematic Entomology Laboratory), “ScaleNet catalogue: Matsucoccus matsumurae (Kuwana).” scalenet.info/catalogue/Matsucoccus%20matsumurae/ (accessed 2026-11-10)
- European Food Safety Authority (EFSA Journal), “EFSA Panel on Plant Health. Pest categorisation of Matsucoccus matsumurae. EFSA Journal 22(7):e8970 (2024) (abstract).” doi.org/10.2903/j.efsa.2024.8970 (accessed 2026-11-10)
- iNaturalist, “Matsucoccus matsumurae taxon page (order and family).” www.inaturalist.org/taxa/1397315 (accessed 2026-11-10)