Caterpillars might have red heads to appear more dangerous. Red is a coloring that may associate them with a potentially poisonous species.
A red head might also be an adaptation to the coloring of the environment. These types of caterpillars are present in different areas of the United States.
Most are located in the Eastern part of the country and many can be found in gardens where they might need to be removed to stop them from eating your plants.
Here are some of the most common types of caterpillars with red heads you can find in North America.
1. Azalea Caterpillar
Azaleas are the typical hosts of the Azalea Caterpillar (Datana major). This is a colorful species that grows into a caterpillar with a red head, even if it looks different at first.
Caterpillars go through different growth stages known as instars. The first instar of the Azalea Caterpillar is marked by an orange or orange-to-brown color.
It’s only in the following instars that this species shows a red head and red prolegs.
The rest of its body is marked by stripes. Black and yellow alternating stripes are seen across its dorsal side.
Contrasting colors make the species look poisonous to most of its predators, especially birds.
If you have azaleas in your garden, this is the species most likely trying to eat and kill your flowers.
2. Red-humped Caterpillar
Similar body coloring is also specific to the Red-humped Caterpillar (Oedemasia concinna) as it matures.
It starts life as a yellow species and slowly changes its size and coloring as it goes to its last instar.
This species has a yellow and black body as it matures with its head being completely red. A bright red nuance is specific to this caterpillar even if some can show red to brown nuances on their heads.
Removing these caterpillars immediately is recommended as they can be highly damaging to the ecosystem.
Complete tree defoliation is possible years after a Red-humped Caterpillar outbreak occurs.
Using pesticides and other types of chemicals might be recommended in case you see these types of caterpillars feeding on tree leaves too high to be manually removed.
3. Western Red-Humped Caterpillar
Another caterpillar with a bright red head is the Western Red-Humped Caterpillar (Oedemasia salicis).
This is a species that only shows a red head into its late instars, as it’s born as a yellow to the orange caterpillar.
It triples in size and it becomes yellow and black or orange and black in its late growth stages.
This is also the point when its head becomes red. Black spines are also seen across its body.
Both its spines and its red head are used to steer predators away by looking poisonous.
A red hump-like structure is also seen at the back of its head, also believed to make the species appear more threatening than it is.
4. Common Buckeye Caterpillar
The Common Buckeye Caterpillar (Junonia coenia) is one of the species with evolving coloring. It has a rather dark appearance at first.
As it grows, it becomes a species with a black body, tiny white spots, and a brown or red head. Other spots on the sides of its body may also become red or brown.
Scarce black spines cover the body of this species as well. The Common Buckeye Caterpillar is a species that has very specific host plant needs.
While you may spot it around the garden on various plants, it tends to prefer narrowleaf plantain.
This species eventually becomes a brown butterfly known for its very large eyespots along its wings.
5. Fir Tussock Moth Caterpillar
This caterpillar species (Orgyia detrita) has a red head throughout its life stages. It’s one of the caterpillars known for its fuzzy look and its possible skin irritation reactions when handled.
A large red head is seen on this species while orange spots decorate its dorsal side which has base green and black coloring.
Multiple glandular formations on the central dorsal area close to the head make the Fir Tussock Moth Caterpillar look poisonous.
This species also shows long black tufts which make it stand out with multiple distinctive physical traits.
Apart from fir, this colorful caterpillar can also be seen on oak, maple, and hackberry.
Like other caterpillars that feed on tree leaves, this species may also be seen on willow.
6. White-lined Sphinx Caterpillar
These types of caterpillars (Hyles lineata) are known for their colorful bodies and long history in North America.
Once used as food by natives, this is a species also recognized as a pollinator as a moth.
The caterpillar, on the other hand, is widely detrimental. It’s a known pest on crops and in gardens.
Years, when outbreaks are noted, are the periods when the species can lead to complete host plant defoliation.
You might find this colorful caterpillar feeding on the tomatoes and tomato plant leaves in your garden.
Grapes are also impacted to complete defoliation if left unmanaged in periods of the outbreak.
7. Horace’s Duskywing Caterpillar
Caterpillars of this species (Erynnis horatius) may also be detrimental in parks, gardens, and woodlands as they feed on tree leaves.
Live oak, red oak, and white oak are among its common hosts.
Since it only feeds on these leaves, the species takes on the green colors of the broad leaves it feeds on, except the head.
Its head is red or it can also be brown-red.
The species only have faint light green to white narrow bands across its body which mimic oak leaf veins.
8. Long-tailed Skipper Caterpillar
Similarly to Horace’s Duskywing Caterpillars, the Long-tailed Skipper Caterpillar (Urbanus proteus) is a species with a mostly green body.
Its thick green body is only contrasted by its black and red head. This is a species with large red eyes and which may show faint yellow dots across its dorsum in its late instars.
Some caterpillars of the species also show yellow stripes on its body as they grow.
You may only find this caterpillar on wild pea family plants and not on cultivated beans.
However, Long-tailed Skipper Caterpillars can sometimes be spotted feeding on the leaves of wisterias in your garden.
Up to 3 broods per year are common in Southern parts of North America.
9. Silver-spotted Skipper Caterpillar
Silver-spotted Skipper Caterpillars (Epargyreus clarus) are a species that feed on vines and vine leaves. They are often spotted climbing plants in the garden.
This is a species marked by its contrasting colors both in its caterpillar stage and in its adult moth stage.
A base yellow color is specific to the caterpillar which also shows a brown-red head with large yellow-orange eyes.
Caterpillars of this family are further known to maintain their yellow color into their emerged moth stage.
The Silver-spotted Skipper is a species that has a mostly brown color with contrasting yellow marks.
10. Dull Firetip Caterpillar
This contrasting-looking caterpillar (Apyrrothrix araxes) is only seen in one brood per year across North America.
You may only see this caterpillar in the summertime while adults start to emerge at the end of the summer.
Dull Firetip Caterpillars are among the species that only feed on oak tree leaves.
A common sight in oak woodlands, these types of caterpillars are only found in Southwestern territories of the United States.
Once emerged as adults, they have a camouflaging brown color which makes them more difficult to spot.
11. Hieroglyphic Moth Caterpillar
This species (Diphthera festiva) has a very contrasting body and it only shows contrasting colors throughout all of its growth stages.
The white base color with contrasting black bands is specific to this caterpillar. The species shows a distinct red or red-to-brown head color.
Contrasting colors are also specific to the white-cream and black moth.
This is one of the species established in most parts of peninsular Florida with a high presence across Central America as well.
Insecticides are often used on these caterpillars directly to control possible outbreaks.
12. Interrupted Dagger Caterpillar
A large red head is also specific to the Interrupted Dagger Caterpillar (Acronicta interrupta).
This is a species with a black central dorsal coloring which shows tiny orange to brown spots.
Wide white bands contrast the sides of its body. Its head and body are also covered in scarce long white hairs.
Interrupted Dagger Caterpillars are some of the most detrimental species in gardens, parks, and woodlands.
They feed on tree leaves, sometimes affecting fruit trees. You may spot them feeding on apple trees in the garden.
This is also a species seen on oak and birch.
Gardens with apricot might also suffer from low-level invasions in some years, so management techniques are recommended against the species.
Once an adult, this moth turns gray and black, losing its contrasting red coloring specific to the head of the caterpillar.
13. White-marked Tussock Moth Caterpillar
This species of caterpillars (Orgyia leucostigma) has multicolored bodies, long white hairs, and long black tufts that look like antennae.
A large and bright red head is spotted on the caterpillar. The red coloring is also distinguished on its body, typically in the form of small red dots in the mid-dorsal area closer to the anal plate.
The dorsal area closer to its head is known for its glandular formations.
Black is the main color of its body while the dorsal area shows contrasting yellow stripes.
A combination of fruit and hardwood trees is among the hosts of the species.
It feeds on apples but it may also feed on oak. You may also see this species feeding on rose leaves and flowers in the gardens.
White-marked Tussock Moth Caterpillar outbreaks are frequent. But all end in a type of transmittable disease.
14. Lily Caterpillar
Lily Caterpillars (Spodoptera picta) are among the few species that show similar coloring both in their caterpillar stage and in their emerged moth stage.
These caterpillars have a distinct bright red head. The body is mostly black, with white and yellow stripes.
The prolegs of the caterpillar have darker yellow coloring.
Adults show all of these colors as well, including red markings on the wings.
Various species of lilies are the hosts of these caterpillars. The long thin green leaves of these hosts are eaten by the caterpillar.
15. Splendid Dagger Caterpillar
Splendid Dagger Caterpillars (Acronicta superans) may have a red or brown head. Green is the main color seen across their body.
A wide brown mid-dorsal band with yellow margins is further contrasting its appearance.
This species also grows long hairs in this area.
Plum and apple trees are among the hosts of the caterpillar. You might also spot the species on ash trees.
Splendid Dagger Caterpillars are a constant presence in the Northeastern parts of the United States.
16. Bedstraw Hawkmoth Caterpillar
Bedstraw is one of the typical hosts of the Bedstraw Hawkmoth Caterpillar (Hyles gallii). This is a species that may show a red head throughout its growth stages.
A red-brown body or even a black body is also specific to this caterpillar.
Bedstraw Hawkmoth Caterpillars are among the few species present both West and East of The Rocky Mountains.
However, its’ range mostly includes the Northern US and Southern Canada territories.
Once emerged into an adult moth, this species maintains red coloring on the hindwings.
17. Rosy Maple Moth Caterpillar
This colorful moth (Dryocampa rubicunda) has a colorful caterpillar stage.
Green is the dominant color across its body. Yellow decorative marks appear on its green body once it matures.
The head of the Rosy Maple Moth can be brown, red, or red-brown. The first 2 instars mark the period when the species shows the brightest red head coloring.
18. Tetrio Sphinx Caterpillar
This rare type of caterpillar (Pseudosphinx tetrio) is characteristic of Southern and Central Peninsular Florida.
It’s one of the rare black caterpillars in the United States. Its body shows contrasting yellow bands while its head is red.
The species also show different proleg colors, unlike most other caterpillars.
Its 3 pairs of front prolegs are also red, like the head. The following prolegs are yellow while the hind prolegs are orange-red.
This species only choose the most fragrant hosts. This is why it can only be seen on frangipani or jasmine in the garden.