Orgyia leucostigma, commonly known as the white-marked tussock moth, is one of the few known examples of a flightless moth. The females of this species are brachypterous, which means that they have tiny, vestigial wings that are completely non-functional; in fact, their wings are barely even visible at all.

Above: close-up of a female white-marked tussock moth

As this article describes:

The adult form of Orgyia leucostigma exhibits strong sexual dimorphism. The males are small, grayish-brown moths with a wingspan of about 25-35 mm. They have feathered antennae that they use to detect pheromones released by females from a considerable distance.

In contrast, the females are wingless and remain on or near their cocoons after emerging. They are larger than the males and have a plump, cylindrical body covered with dense hairs. Since they are flightless, females rely on releasing pheromones to attract males for mating.

Above: the photo at the top depicts a female white-marked tussock moth, while the photo on the bottom shows a male of the same species

After mating, the females lay their eggs atop the remnants of their own cocoons, then cover them with a frothy substance that quickly hardens to form a protective barrier around the eggs.

Above: Orgyia leucostigma in the process of laying its eggs

According to this article:

The white-marked tussock moth is native to eastern North America and parts of Canada. This species of tussock moth overwinters in the egg stage. Eggs are laid by females in groups of approximately 300 in a white frothy mass on the cocoon from which the female moth emerges.

Above: Orgyia leucostigma

Flightlessness occurs in several other tussock moths of the genus Orgyia; it can also be found in some species of bagworm moth (family Psychidae) and footman moth (subfamily Arctiinae).

Above: these photos show female clouded footman moths, Anestia ombrophanes, which are also flightless/wingless

Sources & More Info:

North Carolina State University: White-Marked Tussock Moth Factsheet

UMass Amherst: Orgyia leucostigma

iNaturalist: Photos of White-Marked Tussock Moths

Ohio State University: Sneaky White-Marked Tussock Moth Caterpillars

Ozark Bill: Orgyia leucostigma

PINK GLOWWORM Microphotus angustus ©Ken-ichi Ueda

Females of this species never morph into winged firefly beetles, but morph instead into ‘larviform’ reproductive adults; not really worms at all. However, the males of this species do morph into non-glowing winged fireflies ready to embark on the hunt of their night-lives: the bright glows of their instinct’s desire.

The female Pink Glowworm is not a blinking firefly like those back east; but rather shines forth with a bright steady neon-green glow waiting for her suitor to see her glow and come down for a visit. The adult female has only about ten days before her light producing abilities cease. If a male does not find her by then her lineage comes to an end.

But happily, most Pink Glowworms do meet up; the eggs are laid in the soil under moist leaf litter, and the larvae hatch and begin their secretive lives by munching on small soft bodied invertebrates such as earthworms, snails, and other insect larva.

Photo by Sara Stephens-Huddleston, at Northerm Rivers, NSW.

Yeah! Trilobite beetles are those in the genus Platerodrilus. The females are larviform - meaning they never pupate into an adult-looking beetle. After their final molt, they look the same, but they will then have sexual organs. Here’s either a larva or an adult female:

Platerodrilus sp., Malaysia by Matthieu Berroneau (All rights reserved - shared with permission)

Scientists actually had no idea what adult males looked like for nearly 100 years. Because they look nothing like females, they were almost impossible to locate. And even now, it’s difficult to match an adult male and adult female of the same species without DNA testing or catching them in the act of mating. Turns out, though, males are pretty typical-looking net-winged beetles, and about one tenth the size of the females. I couldn’t find any photos of males to share legally but you can google it to get an idea of what they look like.

Trilobite beetles aren’t the only beetles that have larviform females! A lot of firefly beetles do as well. There are even some moths with larviform females.

Some more trilobites to admire, though:

Platerodrilus paradoxus by txex

Platerodrilus ngi by naufalurfi

Platerodrilus foliaceus by squiresk

Absolutely! Not any caterpillars that I know of, but there are a bunch of species of beetle where the females remain in their larval state for their entire life. I think the most well-known of those are glowworms.

Here’s an adult male western banded glowworm:

And here’s a larva OR could be an adult larviform female:

Photos by kueda and wildlife_seeker

My favorite though are trilobite beetles like this female Platerodrilus paradoxus:

Photo by csanchezj7

I couldn’t find a creative commons photo of the male to share but you can google it - they just look like a regular beetle.

It’s not really the same because they still pupate, but there are some species of moth where the female is wingless! Here’s an adult female rusty tussock moth: