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What is a brown caterpillar with a stripe down its back?

What is a brown caterpillar with a stripe down its back?

There are many different types of caterpillars that can be found throughout North America. Caterpillars are the larval stage of butterflies and moths before they form their pupa and undergo metamorphosis into their adult form. Identifying caterpillars can be tricky, but looking for key physical characteristics can help narrow down the possibilities. One distinct caterpillar has a brown body color with a prominent stripe running down its back. Let’s explore some of the common brown caterpillar species with this distinguishing stripe pattern.

Physical Description

The caterpillar in question is described as having an overall brown body coloration with a noticeable stripe along the length of its back. The stripe is usually a darker color than the base brown of the body. The stripe may be black, dark brown, orange, or reddish in tone. The body shape is typical of most catepillars – generally tubular and segmented, with six small legs towards the head and fleshy prolegs along the abdomen. The size can range considerably depending on age, but fully mature caterpillars are usually 1-2 inches in length.

Beyond the brown color and dorsal stripe, other physical characteristics to note include type of hairs or spines, head shape, patterns on the sides, and presence of additional colors or markings. However, the brown body and single stripe feature are the key consistent identifiers across the likely caterpillar species.

Potential Species Identification

There are several types of caterpillars that match this brown and striped description. Here are some of the most common possibilities:

Tobacco Hornworm

The tobacco hornworm (Manduca sexta) is a very large, plump brown caterpillar with white diagonal lines along its sides and a reddish-orange stripe down its back. It has a distinctive horn on its rear end which gives it its name. Hornworms feed on plants in the Solanaceae family including tobacco, tomato, potato, and pepper plants. They can defoliate these plants very quickly when an infestation occurs.

Tomato Hornworm

Closely related to the tobacco hornworm is the tomato hornworm (Manduca quinquemaculata), which has a similar appearance but with blue spots along its sides rather than white lines. It also has a reddish stripe along its back and feeds primarily on tomato, tobacco, and potato plants. The tomato hornworm can be a major agricultural pest.

Walnut Caterpillar

The walnut caterpillar (Datana integerrima) has a brown body with black stripes along its back and sides. Mature larvae have reddish-orange heads with black dots. This species feeds mainly on trees in the family Juglandaceae including walnuts, pecans, and hickories. Heavy infestations can defoliate trees.

Red-lined Panapoda

The red-lined panapoda (Panapoda rufimargo) is a brown caterpillar with orange or tan stripes along its length. It has tufts of branched black spines. This species feeds on a variety of broadleaf trees and is widespread in the eastern half of North America.

Fall Webworm

The fall webworm (Hyphantria cunea) builds messy web tents in trees. Its caterpillars are variable in color but often have dark striping – the middle stripe may be orange or yellow. This pest feeds on over 600 species of trees and shrubs. Two subspecies occur in North America.

Distinguishing Features

While the brown and striped caterpillars on this list share some similarities, there are also distinguishing characteristics that can help differentiate the specific species:

Size – Hornworms are much larger than other caterpillars when fully grown. Fall webworms are on the smaller end of the size range.

Type of stripe – Hornworms have a reddish stripe compared to the black or orange stripes of other species. The stripe may be continuous or broken into dashes.

Extra markings – Look for extra dots, spots, tufts, or other markings like the tomato hornworm’s blue dots that can aid identification.

Host plants – Knowing where a caterpillar is found feeding can help pin down the species based on its dietary preferences.

Range – Consider the geographical location and check range maps to see if a particular species occurs in that area.

Behavior – Web-making, movements, and posture while resting can be characteristic to each species. Hornworms have a distinct arching posture.

Life Cycle

These brown and striped caterpillars share a similar life cycle, typical of Lepidoptera. The adult female butterfly or moth lays eggs on or near the caterpillar’s host plant. After hatching from the egg, the caterpillar feeds and grows through a series of instars (growth stages between molts). Once fully developed, it pupates, undergoing metamorphosis within a protective cocoon or chrysalis. The adult moth or butterfly emerges from the pupa to begin the cycle again. Life cycle duration depends on variables like climate and food availability. Most of these species produce one or two generations per year.

Pest Status

Most of the brown caterpillars with a stripe are considered agricultural or horticultural pests, especially the hornworms and fall webworm. They can occur in large numbers and quickly defoliate crops and ornamental plants. Heavy damage can lead to reduced yields for farmers and loss of aesthetic value or tree health for gardeners and landscapers. Some ways to control caterpillar pests include:

  • Manual removal – picking off and destroying egg masses and caterpillars
  • Natural predators – encouraging beneficial insects like parasitic wasps
  • Pesticides – using microbial or chemical insecticides targeted at caterpillars
  • BT toxin – applying formulations of Bacillus thuringiensis bacteria
  • Resistant plants – selecting plant varieties bred to tolerate defoliation

Integrated pest management employs a combination of control tactics for sustainable, effective caterpillar control.

Species Food Plants Range
Tobacco hornworm Tomato, tobacco, potato, pepper North America
Tomato hornworm Tomato, tobacco, potato North America
Walnut caterpillar Walnut, hickory, pecan Eastern North America
Red-lined panapoda Various trees Eastern North America
Fall webworm 600+ tree/shrub species North America

Moth or Butterfly Stage

After pupating, the adult form that emerges from these striped caterpillars can help confirm their identity:

– Tobacco hornworm moths are large sized, heavy bodied moths with wing spans up to 5 inches. They have brown and grey color patterns on their wings.

– Tomato hornworm moths are similar and closely related, with more distinct wing markings in white, brown, and black.

– Walnut caterpillar moths have bright orange and brown wings with white bands and splotches. Wingspans reach 1.5 inches.

– Red-lined panapoda moths are orangey-brown with faint gray lines across the wings. Wingspans are around 1.25 inches.

– Fall webworm moths are mostly white with brown or black spot patterns. They have bushy abdomens with wing spans under 1.5 inches.

So if a brown and striped caterpillar is found, the moth or butterfly that emerges from it can confirm which species it belonged to. Hornworm moths are the largest, while fall webworm moths have the most white coloration.


While some of these caterpillars are considered pests, others may provide ecological benefits:

– Many are important prey items for birds and other insectivorous animals. Hornworms especially contain large amounts of fat and protein to nourish developing nestlings.

– As part of the Lepidopteran life cycle, caterpillars support the adult moths and butterflies that are important pollinators for flowering plants.

– Frass and damaged plant materials from caterpillar feeding contributes organic matter and nutrients back into the soil.

– Outbreaks of species like forest tent caterpillars provide pulses of resources that may help synchronize breeding cycles or mast fruiting events.

– Some species like the walnut caterpillar may preferentially feed on stressed trees, thinning weaker individuals in the long run.

– Native caterpillars help sustain populations of native insect predators, supporting healthy ecosystem function.

So even the striped caterpillars perceived as pests can provide energy, nutrition, and ecological roles that contribute to local food webs.


There are several common caterpillars that fit the description of having a brown body and a single stripe along the back. This includes some notorious agricultural pests like hornworms and fall webworms, but also native species that utilize a diversity of woody plant hosts. Specific characteristics like the stripe color, size, markings, and food plants provide clues to distinguish the different brown striped caterpillars found across North America. While they occasionally need control to limit damage, these caterpillars are important components of natural ecosystems and the Lepidopteran life cycle. With their roles as pollinator larvae and nutritious prey items, brown striped caterpillars occupy necessary niches across many habitats.