Bag-Shelter Moth

Known widely as the Bag Shelter Moth or the Processionary Caterpillar, this Australian native is the ultimate team player of the insect world. They are most famous for their "follow-the-leader" parades, where hundreds of larvae link up head-to-tail to find a new place to pupate. While their synchronized walking is a marvel of nature, they are an insect that demands a respectful distance.

🔍 How to Identify

• 🐛 The Caterpillar Parade: Larvae are dark, stout, and covered in a dense coat of long, brownish-grey hairs. They are almost always found in a single-file line (a "procession") on the ground or tree trunks.
• 🎒 Silken Shelters: They retreat into large, tough, brown silken bags or nests, usually located at the base of a tree or nestled in the forks of branches. These bags are filled with shed skins, silk, and waste.
• 🌙 The Adult Moth: The adult moths are thick-bodied with dark brown wings. They feature a distinct pale, crescent-shaped spot (the "lunifer" or "moon-bearer" mark) on each forewing and a tuft of orange/bronze hairs at the tip of the abdomen.

🌲 Habitat & Ecology

• 🌳 Wattle Specialists: They are primarily found across Australia, specifically favoring Acacia (Wattle) species and occasionally Eucalyptus. They feed on the foliage at night and hide in their communal bags during the day to avoid birds.
• 🛤️ Silk Trails: As they move, each caterpillar leaves a fine strand of silk behind. The individual behind it uses its sensitive palps to detect this silk, allowing the colony to stay connected even over uneven forest floors or through tall grass.

⚠️ Safety & Toxicity

• 🚫 Extreme Irritant: Do not touch the caterpillars or their silken bags! They are covered in thousands of microscopic, barbed hairs (setae) that contain a potent irritant.
• 🧴 Human & Pet Risk: Contact with the hairs causes "Urticaria"—a painful, itchy skin rash that can last for weeks. If the hairs become airborne, they can cause severe eye inflammation and respiratory distress.
• 🐴 Livestock Warning: These insects are a major concern for horse owners. If a pregnant mare accidentally ingests the hairs (even from old, abandoned nests), it can cause Equine Fetal Loss Syndrome, leading to miscarriages.

✨ Fun Fact

If you were to pick up the lead caterpillar and place it at the end of the line to form a circle, the group would continue walking in a loop for hours, or even days, blindly following the silk trail of the one in front until they eventually collapse from exhaustion!