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Adelges laricis

Adelgid on Japanese larch, assumed to be Adelges laricis, according to host plant records. Photo: Tawny Simisky
Scientific Name: 
Adelges laricis
Common Name: 
Larch Adelgid
Growing Degree Days (GDD's): 
None available at this time.
Host Plant(s) Common Name (Scientific Name): 
Black spruce (Picea mariana) *Primary host.
Japanese larch (Larix kaempferi) *Secondary host.
Larch (Larix spp.) *Secondary host.
Red spruce (Picea rubens) *Primary host.
Spruce (Picea spp.) *Primary host.
Insect Description: 

This insect was originally found in central Europe, but is now widespread throughout Europe and is believed to have been introduced into North America. The larch adelgid has a late spring generation on larch that may be so abundant that trees may look as if they are dusted in snow. Overwinters as an immature at the base of buds. While spruce is the primary host for this insect, research suggests that the larch adelgid can complete its development and remain solely on larch hosts, without spruce present in the nearby area. On larch, the adelgids overwinter as nymphs near the buds. Once buds begin to swell in the spring, nymphs begin feeding on the opening buds. Once mature, the females will secrete a white, powdery wax over their bodies. By mid-late April, females lay several hundred eggs over a period of approximately two weeks. Females are parthenogenetic, and males are not needed for viable eggs to be laid. When eggs hatch, the nymphs settle on new leaves and produce a white, waxy material. A nymphal stage that will become the stem mother overwinters on spruce hosts. The offspring of the stem mothers will produce galls on the newly developing shoots of spruce hosts. Galls from the larch adelgid on spruce hosts may look similar to the eastern spruce gall adelgid, however the galls often have a pink color and may form over the entire tip of the spruce shoot. Spruce galls of the larch adelgid may mature by June or July. Adults and nymphs are black or dark in color. Some alate (winged) adults are present and can migrate to spruce where they lay eggs that hatch into sexual males or females. The larch adelgid is known from New England and Ontario south to Maryland.

Damage to Host: 

Severe damage to larch as a result of the feeding of these insects has not been observed. Larch adelgid feeding may cause needle distortion, reduced growth, and ample production of honeydew (liquid, sugary excrement). When the insects are producing a white, waxy, woolly material, they may be very visually apparent on larch. On spruce, small galls similar to those of the eastern spruce gall adelgid are produced near the tips of shoots. Feeding by the larch adelgid may provide an entry route for certain fungal pathogens of larch. The fungus Meria laricis has been observed invading needles infested with larch adelgid, leading to premature needle drop. 


Scout and monitor larch for the late spring generation (April-May) that makes the host plant look as if it is coated in snow. Monitor spruce hosts for small, possibly pink-tinged, galls near the tips of spruce shoots. Galls may be seen during much of the season, but after July the insects may have emerged from the galls.

Cultural Management: 

If possible, avoid planting spruce near larch. However, because this insect can complete its life cycle and remain on secondary larch hosts in the absence of the primary spruce host, it is questionable whether or not planting these species separately would impact the population of this insect. Spruce galls can be pruned out and destroyed prior to insect emergence in June or July.

Natural Enemies & Biological Control: 

Two predators of the larch adelgid are known in the literature. Cnemodon and Aphidoletes abietis have both been observed feeding on the larch adelgid. Both feed on the adelgid when it is in the gall stage on spruce hosts.

Chemical Management: 

Abamectin (NL)

Acephate (NL)

Acetamiprid (L)

Bifenthrin (NL)

Chlorpyrifos (N)

Chromobacterium subtsugae (NL)

Clothianidin (NL)

Cyantraniliprole (NL)

Dinotefuran (NL)

Flonicamid+cyclaniliprole (N)

Tau-fluvalinate (NL)

Horticultural oil (L)

Imidacloprid (L)

Insecticidal soap (NL)

Pyrethrin+sulfur (NL)


Contact insecticides should be applied to needles and twigs of larch to target these insects. On the spruce host, the larch adelgid may be protected within its gall from contact insecticide applications.

When used in nursery settings, chlorpyrifos is for quarantine use only.

Active ingredients that may be applied systemically include: Abamectin (injection), acephate (injection), acetamiprid (injection), clothianidin (soil drench), cyantraniliprole (soil drench, soil injection), dinotefuran (soil drench), and imidacloprid (soil drench).

Make insecticide applications after bloom to protect pollinators. Applications at times of the day and temperatures when pollinators are less likely to be active can also reduce the risk of impacting their populations.

Note: Beginning July 1, 2022, neonicotinoid insecticides are classified as state restricted use for use on tree and shrub insect pests in Massachusetts. For more information, visit the MA Department of Agricultural Resources Pesticide Program.

Read and follow all label instructions for safety and proper use. If this guide contradicts language on the label, follow the most up-to-date instructions on the product label. Always confirm that the site you wish to treat and the pest you wish to manage are on the label before using any pesticide. Read the full disclaimer. Active ingredients labeled "L" indicate some products containing the active ingredient are labeled for landscape uses on trees or shrubs. Active ingredients labeled "N" indicate some products containing the active ingredient are labeled for use in nurseries. Always confirm allowable uses on product labels. This active ingredient list is based on what was registered for use in Massachusetts at the time of publication. This information changes rapidly and may not be up to date. If you are viewing this information from another state, check with your local Extension Service and State Pesticide Program for local uses and regulations. Active ingredient lists were last updated: January 2024. To check current product registrations in Massachusetts, please visit: .