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Heterocampa guttivitta

Saddled prominent caterpillar. Photo: Bruce Watt, University of Maine, Bugwood.
Scientific Name: 
Heterocampa guttivitta
Common Name: 
Saddled Prominent
Growing Degree Days (GDD's): 
None available at this time.
Host Plant(s) Common Name (Scientific Name): 
Apple (Malus spp.) *Preferred host. (Johnson and Lyon, 1991)
Beech (Fagus spp.) *Preferred host. (Johnson and Lyon, 1991)
Blueberry (Vaccinium spp.) (Wagner, 2005)
Buckeye (Aesculus spp.) (Wagner, 2005)
Chestnut (Castanea spp.) (Wagner, 2005)
Dogwood (Cornus spp.) (Wagner, 2005)
Hazel (Corylus spp.) (Wagner, 2005)
Hickory (Carya spp.) (Wagner, 2005)
Hophornbeam (Ostrya spp.) (Wagner, 2005)
Oak (Quercus spp.) (Wagner, 2005)
Sugar maple (Acer saccharum) *Preferred host. (Johnson and Lyon, 1991)
Sumac (Rhus spp.) (Wagner, 2005)
Walnut (Juglans spp.) (Wagner, 2005)
Witchhazel (Hamamelis spp.) (Wagner, 2005)
Yellow birch (Betula alleghaniensis) *Preferred host. (Johnson and Lyon, 1991)
Insect Description: 

The saddled prominent is a native insect that is occasionally a severe defoliator of its host plants in parts of New England and eastern Canada. A single generation is noted to occur per year (Johnson and Lyon, 1991), however other sources indicate that two generations per year are possible over much of the east with mature caterpillars present from late May to November in some locations (Wagner, 2005). The overwintering life stage of this moth species are the pupae, which can be found in the leaf litter near host trees. Most of the adult moths will emerge from these locations by the last week in May over a two week period. During this time, they fly frequently in the twilight, normally resting on the trunks of trees (well camouflaged) during the day time. Egg laying by the adult female moths occurs over a 4-5 week period, starting by approximately the second week in June. Eggs are 1 mm in diameter, round, and pale green when first deposited and laid on the undersides of host plant leaves. Each female moth can lay up to 500 eggs, but on average 200-250 are laid. Fecundity may depend upon the host plant the female caterpillar had fed upon. Eggs turn a reddish color as they develop, unless they have been parasitized. Parasitized eggs turn gray with black spots. When first hatched from the egg, the caterpillars are dark red in color with a pair of black horn-like projections directly behind the head, and eight pairs of black abdominal spikes. After the first molt of the caterpillar, the horns and abdominal spikes are lost. The first three instar caterpillars feed as skeletonizers on leaf undersides. Skeletonized patches of the leaves will allow more light to pass through, and if seen this can be an early indication of saddled prominent activity. The fourth and fifth instar larvae begin to feed from the leaf margin of the foliage. This species is a late-season defoliator, typically stripping host plants of their leaves in late July and August. This feeding activity typically is more noticeable in forested locations. Fully grown caterpillars are approximately 1.5 inches long, smooth, variable in color (pale to lime green or reddish brown) with a creamy colored subdorsal stripe. A red/brown/purple-ish pattern often forms a V-shaped saddle over abdominal segments A3 and A4 which are counted beginning with the first segment after the third pair of hardened thoracic legs. This is a common species of caterpillar that is often easily sampled on its hosts during any given growing season. Pupae are stout, shiny, dark brown, and 0.75 inches long and enclosed in a thin, loose, cocoon made of leaf fragments and silk. Adults are inconspicuous moths, varying in color from greenish gray to brownish gray to olive with white and black markings. This coloration helps them to blend in with their surroundings. Moths are also approximately 0.75 inches long.

Damage to Host: 

This caterpillar is mostly a forest pest. Luckily, because these caterpillars feed so late in the season, not too much time photosynthesizing is lost, and host plants (if otherwise healthy) can withstand the activity of this insect. However, several seasons of feeding during an outbreak can cause some branch mortality or crown loss. Drought conditions may make things worse, and in some years up to 10-15% host plant mortality may be reported during saddled prominent outbreaks. Feeding by this insect can also make trees more vulnerable to secondary pests. Sugar maple and American beech are common hosts, with foliage first being skeletonized by young caterpillars, and eventually eaten from the leaf margins by the larger, older caterpillars. Older caterpillars may also shred the leaves, littering the area below infested host plants with leaf fragments. The population of saddled prominent in any given area of its native range is occasionally irruptive (outbreak phase) and capable of defoliating large expanses of forest in the Northeastern US and parts of eastern Canada. During these outbreaks, forested American beech, sugar maple, and yellow birch are often most severely impacted. Paper birch may also be defoliated. During outbreak phases, frass (excrement) may be heard falling from host plant trees while these caterpillars are feeding. Outbreaks may occur cyclically, and are often reported every 10 years. Outbreaks may last 1-3 years prior to collapsing naturally on their own. (Ex. 1.5 million acres were defoliated in Maine, Massachusetts, New Hampshire, New York, Pennsylvania, and Vermont from 1968-1971. Rush and Allen, 1987)


Traps and pheromones for monitoring saddled prominent moth activity exist. In studies, pherocon 1C wing traps were significantly more effective than green Unitrap bucket style traps. Capture of moths is not affected by position when traps were ≥20 meters from a road or other opening in the forest, and lures were specific to saddled prominent. The lure noted for this species is: 90/10 blend (ratio of EAD activity) of the 16-carbon acetate Z13-hexdadecen-11-yn-1-yl aldehyde (Z13Y11-16:Ald) and hexadec-11-yn-1-yl aldehyde (Y11-16:Ald) (Spear-O'mara and Allen, 2014).

Cultural Management: 

Not many cultural management options are suggested for this insect, in particular because it typically is primarily a pest of forested trees. During an outbreak, presumably caterpillars could be excluded from small ornamental plants grown near forests with fine netting such as cheesecloth. 

Natural Enemies & Biological Control: 

Birds, mammals, and other insects feed upon saddled prominents. Birds such as bronzed grackles are reported to be predators of this insect, feeding on the larvae. At least two species of shrews are reported to feed on the pupae. Insect predators include Calasoma frigidum (a species of ground beetle) and Podisus modestus (a species of stink bug). Additionally, starvation, fungal pathogens such as Cordyceps spp. and Entomophthora spp. as well as an unidentified virus impact their populations. Two species of parasitic wasps may have notable impacts on saddled prominent populations- including Trichogramma minutum and Telenomus coelodasidis, which, when combined, may contribute to 40-78% egg mortality during an outbreak. Pupal parasitism by Cratichneumon sublatus may reach 1-17% and sometimes up to 57% before outbreaks collapse. None of these factors prevent the population from building entirely, but once an outbreak occurs, they all contribute to the eventual collapse of the saddled prominent population (Rush and Allen, 1987). Additional, but sometimes less impactful, insect natural enemies include but are not limited to: Phobocampe pallidaEulophus anomocerusPatelloa spp., and additional Ichneumonidae and Sarcophagidae (Allen, 1972).

Chemical Management: 

Abamectin (NL)

Acephate (NL)

Acetamiprid (L)

Azadirachtin (NL)

Bacillus thuringiensis subsp. kurstaki (NL)

Beauveria bassiana (NL)

Bifenthrin (NL)

Carbaryl (L)

Chlorantraniliprole (NL)

Chlorpyrifos (larvae) (N)

Chromobacterium subtsugae (NL)

Cyantraniliprole (NL)

Cyfluthrin (NL)

Flonicamid+cyclaniliprole (N)

Gamma-cyhalothrin (L)

Horticultural oil (L)

Lambda-cyhalothrin (L)

Methoxyfenozide (NL)

Neem oil (NL)

Pyrethrin+sulfur (NL)

Spinetoram+sulfoxaflor (N)

Spinosad (NL)

Tebufenozide (NL)

Tau-fluvalinate (NL)


Chemical management of the saddled prominent is often not necessary due to the natural enemies that eventually reduce the population on their own. If chemical management is deemed necessary during an outbreak, select reduced risk options that preserve natural enemies.

Active ingredients that may be applied systemically include: abamectin (injection), acephate (injection), acetamiprid (injection), azadirachtin (injection, soil drench), chlorantraniliprole (soil drench), cyantraniliprole (soil drench, soil injection), and neem oil (soil drench).

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

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: .