Yellow Flat-Footed Fly

Often called the "Yellow Flat-footed Fly," this tiny insect is more famous for its architecture than its appearance. It has a highly specialized relationship with a specific bracket fungus, making it a favorite for naturalists and foragers to track in the wild. While the fly itself is rarely seen, it leaves behind unmistakable "chimneys" on the underside of mushrooms, acting like a tiny, forest-dwelling engineer.

🔍 How to Identify

• 🪰 Visual Appearance: A very small fly (about 4-5mm) with a golden-yellow to orange-brown body and large, prominent reddish eyes that take up most of its head.
• 🦵 The "Flat Foot": True to its family name (Platypezidae), its hind legs are noticeably widened and flattened, looking somewhat like tiny oars.
• 🏗️ Nipple Galls: The easiest way to identify its presence is by looking at the underside of the Artist’s Bracket fungus (Ganoderma applanatum). The fly triggers the mushroom to grow small, volcano-like bumps or "nipple galls" where its larvae reside.

🌲 Habitat & Ecology

• 🍄 The Specialist: This fly is a "host-specific" insect. It spends its life cycle almost exclusively around the Artist’s Bracket fungus. The female lays her eggs on the white pore surface of the mushroom, which reacts by growing a protective woody chamber around the larvae.
• 🍂 Forest Home: You will find this fly in damp, deciduous woodlands where old beech or oak trees are present, as these are the primary homes for its host mushroom. It plays a neutral role in the ecosystem, neither harming the tree nor significantly damaging the fungus.

⚠️ Safety & Toxicity

• 🛡️ Completely Harmless: Agathomyia wankowiczii is a "friend" to humans. It does not bite, sting, or transmit any known diseases.
• 🐾 Non-Toxic: It is safe to have in your garden or local park. It poses no threat to curious pets or children, though the fungus it lives on is generally too tough and woody to be edible.

✨ Fun Fact

The Artist's Bracket fungus is famous because you can draw on its white underside with a stick to create permanent brown art. When this fly moves in, it adds a "3D effect" to the artist's canvas by creating dozens of tiny, raised towers across the drawing surface!