Back to top

Neodiprion sertifer

European pine sawfly larvae. Photo: Erik Christiansen, Agricultural University of Norway, Bugwood.
Scientific Name: 
Neodiprion sertifer
Common Name: 
European Pine Sawfly
Growing Degree Days (GDD's): 
Ranges noted differ: 90–420 GDD's, Base 50F, March 1st Start Date (Source: Robert Childs, UMass Extension) or 78-220 GDD's, Base 50F, March 1st Start Date (Source: Cornell Cooperative Extension.)
Host Plant(s) Common Name (Scientific Name): 
Austrian pine (Pinus nigra)
Eastern white pine (Pinus strobus)
Jack pine (Pinus banksiana) *Preferred host.
Japanese red pine (Pinus densiflora) *Preferred host.
Mugo/Swiss mountain pine (Pinus mugo) *Preferred host.
Pine (Pinus spp.)
Pitch pine (Pinus rigida)
Ponderosa pine (Pinus ponderosa)
Red pine (Pinus resinosa) *Preferred host.
Scots pine (Pinus sylvestris) *Preferred host.
Shortleaf pine (Pinus echinata)
Table mountain pine (Pinus pungens) *Preferred host.
Insect Description: 

At minimum, 17 different species of sawfly may be found feeding on various pine species (Pinus spp.). The European pine sawfly (Neodiprion sertifer) is noted here as this insect is a native of Europe and was accidentally introduced into the US around 1925. It is now widespread and invasive in New England. Mature larvae are gray-green, 0.7-1 inch long caterpillars. They have 3 pairs of thoracic legs and 7 pairs of fleshy abdominal prolegs. Mature larvae also have shiny black heads and five stripes that run parallel along the length of their bodies. Stripes vary in color, from dark green or black to gray-green, with a light green stripe running directly along the middle of the back of mature larvae. Eggs are laid evenly spaced along pine needles, looking like rows of light brown spots. Adult European pine sawflies are wasplike, brown or black in color, and approximately 0.4 to 0.5 inches in length. Females are active in September and October and lay their eggs in slits they cut in pine needles using sawlike ovipositors (egg laying structures). They prefer current year's needles for egg laying. Females typically lay eggs in groups of 6-8 in a single needle and repeat this at least 10-12 times, laying approximately 60-96 eggs per female (a range of 30-140 eggs per female is reported in the literature). The egg stage overwinters, and only one generation occurs per year. Egg hatch may occur roughly between late-April and early May, with larvae feeding on previous year's needles until approximately late-May or early June, at which time they drop to the ground to pupate. By late-August, following a summer diapause, pupation has occurred and adults emerge in September.

Damage to Host: 

Needles may appear dry and straw-like from the feeding activity of young larvae, who eat the surface of the needle. Older larvae may eat entire needles from their tip to the base. Aesthetic damage may be most apparent on mugo pine in landscapes and nurseries. Since larvae rarely attack new foliage and most trees are seldomly entirely defoliated, host plants typically survive the activity of this insect. On occasion, larvae may also feed on the bark of new shoots causing shoot deformation and twig mortality. However, this pest is not typically considered a serious threat to the overall health of a tree. Compare with the redheaded pine sawfly and introduced pine sawfly.


Monitor for the presence of European pine sawfly eggs in the needles between September (current season's) and mid-April (previous season's).  By late April and early May, begin to look for dry, straw-like needles on the previous year's growth. This is a sign that young larvae might be feeding and if that is the case, it is a great time to try to manage this insect.

Cultural Management: 

Remove larvae by pruning infested branches if this is practical. Otherwise, remove and dispose of clusters of caterpillars with a gloved hand. Northern cultivars of Scots pine are known to be more resistant to attack than southern ones, so selectively plant those cultivars in areas where this insect has historically been a problem.

Natural Enemies & Biological Control: 

N. sertifer is attacked by several hymenopteran and dipteran parasitoids, and many predators including ants, bugs, beetles, lacewings, spiders, small mammals and birds. Pathogenic fungi, bacteria, and a species-specific nuclear polyhedrosis virus also attack it. The species of natural enemies involved depends upon which portion of this insect's native or introduced range is being considered. A lethal species-specific nuclear polyhedrosis virus frequently infects caterpillars of the European pine sawfly. The disease is caused by Borrelinavirus diprionis (NeseNPV). It is often one of the main factors causing the abrupt collapse of outbreaks of this species, with larvae becoming infected either by ingesting the virus with food, or via an infected parent.

Larvae of this species also have a special defense strategy against predators and parasitoids, including by being found in the environment in groups. The larvae will perform alarm reactions and defensive displays, including "U-bending", jerking, and stretching. European pine sawfly caterpillars will also regurgitate a droplet of resinous liquid when harrassed. This behavior has been shown to repel ants, other predaceous insects, spiders, and birds, as well as parasitoids.

Chemical Management: 

Acephate (NL)

Azadirachtin (eggs) (NL)

Bifenthrin+imidacloprid (L)

Carbaryl (L)

Chlorpyrifos (N)

Cyfluthrin (NL)

Deltamethrin (L)

Dinotefuran (NL)

Flonicamid+cyclaniliprole (N)

Gamma-cyhalothrin (L)

Horticultural oil (L)

Imidacloprid (L)

Indoxacarb (L)

Insecticidal soap (NL)

Lambda cyhalothrin (L)

Pyrethrin+sulfur (NL)

Spinetoram+sulfoxaflor (N)

Spinosad (NL)


To entomologists, the term caterpillar refers to the immature or larval life stage of the Lepidoptera - butterflies and moths. However, the public and some entomologists included sometimes use this term interchangeably to refer to the immature or larval life stage of certain Hymenoptera - in particular, sawflies. 

This can cause confusion when selecting management options for pests collectively referred to as caterpillars. The larvae discussed here will mature into an adult sawfly. This means that the active ingredient Bacillus thuringiensis Kurstaki (Btk) will not be effective at managing this insect. Btk will only kill the caterpillars of moth (or butterfly) pest insects. It will not kill sawfly larvae. 

Sawfly larvae can be distinguished from moth or butterfly caterpillars by the presence of or absence of 6 or more prolegs. Some sawfly species will have 6 or more pairs of fleshy abdominal prolegs, whereas some sawfly larvae will have 0 pairs of fleshy abdominal prolegs. Caterpillars that mature into butterflies or moths will have 5 or fewer pairs of fleshy abdominal prolegs. Prolegs are soft, and found behind the hardened 3 pairs of thoracic legs on the insect. In butterfly or moth caterpillars, the prolegs will also have tiny hooks or crochets on the very bottom.

Active ingredients that may be applied systemically include: acephate (injection), azadirachtin (injection, soil drench), 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: .