A Comprehensive Guide to White Caterpillars

White caterpillars stand out against the green foliage of trees and plants, making them easier to spot than other colored caterpillars. These worm-like larvae are the immature stage of moths and butterflies in the insect order Lepidoptera. There are many different species of white caterpillars, each with their own unique characteristics. This guide will provide an overview of common white caterpillars, how to identify them, what plants they feed on, and whether they can sting or irritate skin.

Why Are Some Caterpillars White?

The white coloration of some caterpillars serves as camouflage to blend in with their surroundings Species like the hickory tussock moth and fall webworm are pale white or yellowish, which helps them blend in with light-colored leaves as they feed The furry or hairy appearance of many white caterpillars also helps camouflage them among foliage.

In some cases, white caterpillars use coloration as a warning signal. Their bright color tells predators they may have a bad taste or toxins, making them less appealing as a food source. The puss caterpillar, for example, has venomous spines along with its white furry coat.

Do White Caterpillars Sting or Irritate Skin?

Some white caterpillars have stinging or irritating defenses, while others are harmless. Handling fuzzy white caterpillars often leads to skin irritation, redness, and itching due to their detachable hairs. The hairs can get lodged in the skin, causing discomfort.

More dangerous are venomous caterpillars like the puss caterpillar and saddleback caterpillar. Their spines can inject toxins that feel like bee stings, sometimes needing medical treatment. Smooth-bodied white caterpillars, on the other hand, don’t have irritating hairs or venom.

It’s wise to avoid touching any white hairy caterpillars Teach children not to handle them. Seek medical attention if you experience a severe reaction from contact

Identifying Types of White Caterpillars

Here are some of the most common white caterpillars you may encounter:

Hickory Tussock Moth Caterpillar

The hickory tussock moth caterpillar is covered in tufts of black and white hairs. It has a hairy black stripe down its back and long black pencil hairs on the sides. The head is solid black. This caterpillar feeds on trees like hickory, oak, and elm. Its hairs can irritate skin.

Sycamore Tussock Moth Caterpillar

This hairy yellow-white caterpillar has long white and orange pencil tufts at both ends of its body. It eats leaves of sycamore, maple and other deciduous trees, sometimes causing defoliation. Its hairs may be irritating.

Fall Webworm Caterpillar

Fall webworms create messy nests on branches of trees. The caterpillars are pale yellow or white with long hairs, red or black heads, and black spots down the back. They eat leaves of over 600 species of trees. Their hairs do not sting.

American Dagger Moth Caterpillar

This fuzzy yellow-white caterpillar has many long, black pencil hairs along its body. It has a shiny black head and green stripes. Found in forests feeding on trees like oak, maple and hazelnut, its hairs can irritate skin.

Woolly Bear Caterpillar

Woolly bear caterpillars are very hairy with black ends and a reddish-brown or white band in the middle. They feed on herbaceous plants and are often seen in late summer and fall wandering in search of an overwintering spot. Their hairs may cause skin irritation.

Silkworm Caterpillar

Silkworms are smooth white caterpillars with yellowish undersides and faint black dots on each segment. They feed only on mulberry leaves. Completely harmless to handle, silkworms are cultivated for their silk cocoons.

Sphinx Moth Caterpillar

Large, smooth white sphinx moth caterpillars have black dots and stripes that turn to bands as they grow. They have a horn on the rear end. Found on ash, elm, grapevines and other plants, their skin secretions may irritate.

Spotted Apatelodes Caterpillar

These hairy caterpillars start out white and turn yellow as they mature. They have black spines along the body and long black tufts at the head. The larvae feed on oak, maple, hickory and other trees. They do not sting.

What to Do If You Find White Caterpillars

Caterpillars play an important role in the ecosystem as food sources for birds and other wildlife. But some can damage ornamental plants, trees and agricultural crops if their population grows too large. Here are a few options if white caterpillars become a problem:

• Manually remove and kill isolated caterpillars on small plants. Wear gloves to avoid skin irritation.

• Use Bacillus thuringiensis (Bt) insecticide on larger infestations. It specifically targets caterpillars but is safe for humans.

• Encourage natural predators like birds, wasps and flies that help control caterpillar populations.

• Check with a local extension office for specific recommendations if dealing with agricultural pest caterpillars.

• Identify the species to better understand its life cycle and habits. This can help with control efforts.

• Be patient, as their presence is usually temporary. Most damage occurs while caterpillars are actively feeding.

With some basic knowledge about white caterpillars, you can identify them in your own landscape and make smart decisions about control methods if needed. A few harmless furry critters can be tolerated, but large infestations may call for action if they impact the health of trees or crops. Handle irritating species with care.