Horse Stomach Bot Fly vs Microcaddisfly

Side-by-side species comparison

Attribute Horse Stomach Bot Fly Microcaddisfly
Scientific Name Gasterophilus intestinalis Hydroptila sparsa
Order Diptera Trichoptera
Family Oestridae Hydroptilidae
Size 12-16 mm 3-4 mm
Habitat Farmland Rivers & Streams
Diet Omnivores Omnivores
Regions Cosmopolitan wherever horses are kept Europe, North America
Conservation Least Concern Least Concern

Horse Stomach Bot Fly

A bee-like fly that glues eggs to horse leg hairs where they are ingested during grooming. Larvae attach to the stomach lining and develop for months before passing out.

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Did You Know?

Larvae survive the acidic horse stomach by secreting a protective alkaline buffer around themselves.

Microcaddisfly

One of the smallest caddisflies, with adults only 3-4 mm long. Larvae build tiny purse-shaped cases from silk and algae on submerged rocks.

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Did You Know?

Microcaddisfly larvae build a new case for each instar, and their final pupal case is so small it is barely visible to the naked eye.