Megalopyge opercularis
Encyclopedia
The moth Megalopyge opercularis has numerous common names, including southern flannel moth, pussy moth, puss caterpillar, tree asp, and, asp caterpillar. It is visually striking in both larva
l and adult forms. The inch-long larva is generously coated in long, luxuriant hair-like setae, making it resemble a tiny Persian cat, the characteristic that presumably gave it the name "puss." It is variable in color, from downy grayish-white to golden-brown to dark charcoal gray. It often has a streak of bright orange running longitudinally. The 'fur' on early-stage larvae is sometimes extremely curly, giving the larva a cottony, puffed-up look. The body tapers to a tail that extends well beyond the body, unlike its relative M. crispata . The middle instar
has a more dishevelled, 'bad-hair-day' appearance, without a distinctive tail.
The adult moth is also very bizarre in appearance, covered in long fur in colors ranging from dull orange to lemon yellow, with hairy legs and fuzzy black feet.
The 'fur' of the larva contains venomous spines that cause extremely painful reactions in human skin upon contact. The reactions are sometimes localized to the affected area but are often very severe, radiating up a limb and causing burning, swelling, nausea, headache, abdominal distress, rashes, blisters, and sometimes chest pain, numbness, or difficulty breathing . Additionally, it is not unusual to find sweating from the welts or hives at the site of the sting. Ironically, the resemblance of the larvae to soft, colorful cotton balls encourages people to pick them up and pet them.
M. opercularis can be found on oak
s, elm
s, citrus
and other trees, and many garden plants such as rose
s and ivy
. It is distributed throughout the southern United States
, Mexico
, and parts of Central America
. The larva does not spin a real cocoon, rather, it separates from its furry skin and uses it as a protective covering while it pupates.
Other remedies, which are reported to have varying degrees of success, include ice pack
s, oral antihistamine
, baking soda, hydrocortisone cream, juice from the stems of comfrey
plants, or calamine lotion .
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
l and adult forms. The inch-long larva is generously coated in long, luxuriant hair-like setae, making it resemble a tiny Persian cat, the characteristic that presumably gave it the name "puss." It is variable in color, from downy grayish-white to golden-brown to dark charcoal gray. It often has a streak of bright orange running longitudinally. The 'fur' on early-stage larvae is sometimes extremely curly, giving the larva a cottony, puffed-up look. The body tapers to a tail that extends well beyond the body, unlike its relative M. crispata . The middle instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
has a more dishevelled, 'bad-hair-day' appearance, without a distinctive tail.
The adult moth is also very bizarre in appearance, covered in long fur in colors ranging from dull orange to lemon yellow, with hairy legs and fuzzy black feet.
The 'fur' of the larva contains venomous spines that cause extremely painful reactions in human skin upon contact. The reactions are sometimes localized to the affected area but are often very severe, radiating up a limb and causing burning, swelling, nausea, headache, abdominal distress, rashes, blisters, and sometimes chest pain, numbness, or difficulty breathing . Additionally, it is not unusual to find sweating from the welts or hives at the site of the sting. Ironically, the resemblance of the larvae to soft, colorful cotton balls encourages people to pick them up and pet them.
M. opercularis can be found on oak
Oak
An oak is a tree or shrub in the genus Quercus , of which about 600 species exist. "Oak" may also appear in the names of species in related genera, notably Lithocarpus...
s, elm
Elm
Elms are deciduous and semi-deciduous trees comprising the genus Ulmus in the plant family Ulmaceae. The dozens of species are found in temperate and tropical-montane regions of North America and Eurasia, ranging southward into Indonesia. Elms are components of many kinds of natural forests...
s, citrus
Citrus
Citrus is a common term and genus of flowering plants in the rue family, Rutaceae. Citrus is believed to have originated in the part of Southeast Asia bordered by Northeastern India, Myanmar and the Yunnan province of China...
and other trees, and many garden plants such as rose
Rose
A rose is a woody perennial of the genus Rosa, within the family Rosaceae. There are over 100 species. They form a group of erect shrubs, and climbing or trailing plants, with stems that are often armed with sharp prickles. Flowers are large and showy, in colours ranging from white through yellows...
s and ivy
Ivy
Ivy, plural ivies is a genus of 12–15 species of evergreen climbing or ground-creeping woody plants in the family Araliaceae, native to western, central and southern Europe, Macaronesia, northwestern Africa and across central-southern Asia east to Japan and Taiwan.-Description:On level ground they...
. It is distributed throughout the southern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, and parts of Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
. The larva does not spin a real cocoon, rather, it separates from its furry skin and uses it as a protective covering while it pupates.
Dangers and Treatment of Stings
Exposure to the caterpillar's fur-like spines will lead to an immediate skin irritation. The caterpillar is regarded as a dangerous insect because of its venomous spines. Medical advice may be sought in case of contact with one. It is best if the venom from the spines are treated within hours of first contact. For first aid, it is recommended that you remove the spines (if present) using cellophane tape .Other remedies, which are reported to have varying degrees of success, include ice pack
Ice pack
An ice pack or gel pack is a plastic sac of ice, refrigerant gel or liquid, or, in an emergency, even frozen vegetables. The refrigerant, usually non-toxic, can absorb a considerable amount of heat, since its enthalpy of fusion is high...
s, oral antihistamine
Antihistamine
An H1 antagonist is a histamine antagonist of the H1 receptor that serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions...
, baking soda, hydrocortisone cream, juice from the stems of comfrey
Comfrey
Comfrey is an important herb in organic gardening. It is used as a fertilizer and also has many purported medicinal uses...
plants, or calamine lotion .