Evergreen bagworm

Thyridopteryx ephemeraeformis

The evergreen bagworm, commonly known as bagworm, eastern bagworm, common bagworm, common basket worm, or North American bagworm, is a moth that spins its cocoon in its larval life, decorating it with bits of plant material from the trees on which it feeds.
Evergreen Bagworm Moth - Thyridopteryx ephemeraeformis Bagworms are not really worms, but are caterpillars - they are the immature stage of a moth. They're called "bagworms" because they construct bags/cases that are covered with pieces of twigs and/or leaves. In this species, the larvae emerge from the carcass of their mother in her pupal case. These newborn larva emerge from the bottom of the hanging case and drop down on a strand of silk. The wind will then blow them to a nearby plant where they can build their own cases made of silk, fecal material, and plant bits. Adult males transform into moths in about four weeks and immediately seek out females for mating. The females never leave the cocoon, but wait for a male to stick its abdomen through the opening at the end of her case so they can mate. Females do not have eyes, legs, wings, or antennae...and, they can't eat. After her death, her offspring hatch and then pass through her body and leave the case. This case was pretty big - around 5 cm long. I cut it open, and found remnants of a female carcass, other debris, and frass. I'm not sure what kind of tree it was on, but it was some kind of arborvitae. If you look closely, you can see the hole in the top right of the case. https://www.jungledragon.com/image/61550/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html Evergreen Bagworm,Geotagged,North American bagworm,Spring,Thyridopteryx,Thyridopteryx ephemeraeformis,United States,bagworm,bagworm moth,common bagworm,common basket worm,eastern bagworm,moth week 2018

Appearance

The evergreen bagworm's case grows to a length of over 6 cm, tapered and open on both ends. Newborn larva are blackish and turn brown to tan as they grow, mottled with black. The heads and thorax develop a yellow tint as they grow to a full length of 24 to 32 mm. Adult males resemble bees, having a 25 mm wingspan with transparent wings and black furry bodies. Adult females are maggot-like with yellowish-white soft bodies 19 to 23 mm long and small tufts of hair near the end of the abdomen. The cream-colored eggs are 0.75 mm in diameter.
Evergreen Bagworm Moth - Thyridopteryx ephemeraeformis Bagworms are not really worms, but are caterpillars - they are the immature stage of a moth. They're called "bagworms" because they construct bags/cases that are covered with pieces of twigs and/or leaves. In this species, the larvae emerge from the carcass of their mother in her pupal case. These newborn larva emerge from the bottom of the hanging case and drop down on a strand of silk. The wind will then blow them to a nearby plant where they can build their own cases made of silk, fecal material, and plant bits. Adult males transform into moths in about four weeks and immediately seek out females for mating. The females never leave the cocoon, but wait for a male to stick its abdomen through the opening at the end of her case so they can mate. Females do not have eyes, legs, wings, or antennae...and, they can't eat. After her death, her offspring hatch and then pass through her body and leave the case. There are many of these bagworms on an arborvitae where I live. I never see the caterpillars during the day, so I decided to check at night, and actually found one peeking its head out! This is the case that it is living in. This case was 5 cm long. https://www.jungledragon.com/image/64188/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html https://www.jungledragon.com/image/64191/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html https://www.jungledragon.com/image/64189/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html Evergreen Bagworm Moth,Evergreen bagworm,Geotagged,Summer,Thyridopteryx ephemeraeformis,United States,bagworm

Distribution

The evergreen bagworm thrives in the eastern United States as far west as Nebraska, north into New England and bordering the Gulf of Mexico south throughout Texas. It has been found in other countries, such as South Africa, Croatia, and in the north-east of Iran.
Evergreen Bagworm (dead female, full of eggs) - Thyridopteryx ephemeraeformis I frequently find tons of these bagworm cases hanging on arborvitae, buildings, and trees in my neighborhood. Today, I was examining some and noticed that many of them did not have openings in them (meaning that the larvae hadn't hatched out). I took three home and dissected them to find that they contained dead females, two of which had viable eggs). Here's how it works: Female bagworms never leave their cocoon. They require a male to mate with her through her case. She has no eyes, legs, wings, antennae, and can't even eat! After mating, she dies, and her body contains hundreds to thousand of eggs. The eggs overwinter, and then hatch, chewing their way through her body and case to emerge and start their own cases. Habitat: Rural area Eggs: https://www.jungledragon.com/image/87170/evergreen_bagworm_eggs_bursting_out_of_female_-_thyridopteryx_ephemeraeformis.html https://www.jungledragon.com/image/87168/evergreen_bagworm_eggs_-_thyridopteryx_ephemeraeformis.html Female: https://www.jungledragon.com/image/87169/evergreen_bagworm_dead_female_containing_eggs_-_thyridopteryx_ephemeraeformis.html Check out my other bagworm spottings: https://www.jungledragon.com/image/64192/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html https://www.jungledragon.com/image/64188/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html https://www.jungledragon.com/image/65151/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html https://www.jungledragon.com/image/76356/evergreen_bagworm_case_-_thyridopteryx_ephemeraeformis.html Evergreen bagworm,Fall,Geotagged,Thyridopteryx ephemeraeformis,United States,female bagworm

Behavior

Large populations in forested areas are rare. With scarce predators in urban areas, evergreen bagworms often thrive in urban habitats. When disturbed, the larva will retract its head into its case and hold the front opening closed. Mature larva may remain in the host tree or drag its case nearby before attaching itself for the pupa stage.
Evergreen Bagworm Case - Thyridopteryx ephemeraeformis Bagworms are not really worms, but are caterpillars - they are the immature stage of a moth. They're called "bagworms" because they construct bags/cases that are covered with pieces of twigs and/or leaves. This case had a big hole in the top, and I'm not sure if it was made by a caterpillar/moth or parasitoid. In this species, the larvae emerge from the carcass of their mother in her pupal case. These newborn larva emerge from the bottom of the hanging case and drop down on a strand of silk. The wind will then blow them to a nearby plant where they can build their own cases made of silk, fecal material, and plant bits. Adult males transform into moths in about four weeks and immediately seek out females for mating. The females never leave the cocoon, but wait for a male to stick its abdomen through the opening at the end of her case so they can mate. Females do not have eyes, legs, wings, or antennae...and, they can't eat. After her death, her offspring hatch and then pass through her body and leave the case. Evergreen bagworm,Fall,Geotagged,Thyridopteryx,Thyridopteryx ephemeraeformis,United States,bagworm moth

Reproduction

Eggs hatch from early April to early June and larvae emerge from the carcass of their mother in her case. Newborn larva emerge from the bottom of the hanging case and drop down on a strand of silk. The wind often blows the larva to nearby plants where it begins its new case from silk and fecal material before beginning to add leaves and twigs from its host. When mature in mid-August, the larva wraps silk around a branch, hangs from it, and pupates head down.

The silk is so strong that it can strangle and kill the branch it hangs from over the course of several years as the branch grows. Adult males transform into moths in four weeks to seek out females for mating. The female never leaves the cocoon, requiring that the male mate with her through the open end at the back of the case. She has no eyes, legs, wings, antennae, and can't eat, but she emits a strong pheromone to attract a mate.

After her death with hundreds to several thousand eggs still inside, her offspring hatch and pass through her body, pupal shell and case over several months emerging to start their own cases. Later, her pupal case can be found, full of the yellow remains of eggshells.
Evergreen Bagworm Moth - Thyridopteryx ephemeraeformis Bagworms are not really worms, but are caterpillars - they are the immature stage of a moth. They're called "bagworms" because they construct bags/cases that are covered with pieces of twigs and/or leaves. In this species, the larvae emerge from the carcass of their mother in her pupal case. These newborn larva emerge from the bottom of the hanging case and drop down on a strand of silk. The wind will then blow them to a nearby plant where they can build their own cases made of silk, fecal material, and plant bits. Adult males transform into moths in about four weeks and immediately seek out females for mating. The females never leave the cocoon, but wait for a male to stick its abdomen through the opening at the end of her case so they can mate. Females do not have eyes, legs, wings, or antennae...and, they can't eat. After her death, her offspring hatch and then pass through her body and leave the case. There are many of these bagworms on an arborvitae where I live. I never see the caterpillars during the day, so I decided to check at night, and actually found one peeking its head out! This case was 5 cm long. *Note - the colors in this photo are not authentic. My camera lens was fogged up from humidity, and I tried to remove the haze on the shot in photoshop, but it ended up making the shot really reddish. https://www.jungledragon.com/image/64188/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html https://www.jungledragon.com/image/64191/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html https://www.jungledragon.com/image/64192/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html Evergreen Bagworm Moth,Evergreen bagworm,Geotagged,Summer,Thyridopteryx ephemeraeformis,United States,bagworm

Food

Arborvitae and red cedar are the favored host trees of the evergreen bagworm, but cypress, juniper, pine, spruce, apple, birch, black locust, elm, maple, poplar, oak, sycamore, willow, and over 100 other species are also attacked. Leaves and buds are both fair game for food.
Evergreen Bagworm (Eggs Bursting out of Female) - Thyridopteryx ephemeraeformis I frequently find tons of bagworm cases hanging on arborvitae, buildings, and trees in my neighborhood. Today, I was examining some and noticed that many of them did not have openings in them (meaning that the larvae hadn't hatched out). I took three home and dissected them to find that they contained dead females, two of which had viable eggs). *In this photo, all I did was poke the female's dead body with my forceps and she literally burst open. I was shocked to see how many eggs were inside! I'm going to try to rear them. Here's how it works: Female bagworms never leave their cocoon. They require a male to mate with her through her case. She has no eyes, legs, wings, antennae, and can't even eat! After mating, she dies, and her body contains hundreds to thousand of eggs. The eggs overwinter, and then hatch, chewing their way through her body and case to emerge and start their own cases. Habitat: Rural area Here's the female that I extracted these eggs from: https://www.jungledragon.com/image/87166/evergreen_bagworm_dead_female_full_of_eggs_-_thyridopteryx_ephemeraeformis.html Eggs: https://www.jungledragon.com/image/87168/evergreen_bagworm_eggs_-_thyridopteryx_ephemeraeformis.html Check out my other bagworm spottings: https://www.jungledragon.com/image/64192/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html https://www.jungledragon.com/image/64188/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html https://www.jungledragon.com/image/65151/evergreen_bagworm_moth_-_thyridopteryx_ephemeraeformis.html https://www.jungledragon.com/image/76356/evergreen_bagworm_case_-_thyridopteryx_ephemeraeformis.html Evergreen bagworm,Fall,Geotagged,Thyridopteryx ephemeraeformis,United States,bagworm eggs,eggs

Predators

Bagworms are commonly parasitized by ichneumonid wasps, notably "Itoplectis conquisitor". Predators include vespid wasps and hornets. Woodpeckers and sapsuckers can feed on the larva from their cases.

References:

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Taxonomy
KingdomAnimalia
DivisionArthropoda
ClassInsecta
OrderLepidoptera
FamilyPsychidae
GenusThyridopteryx
SpeciesT. ephemeraeformis
Photographed in
United States of America