Nose Bot Fly of Horses vs Giant Case-Builder Caddis

Side-by-side species comparison

Attribute Nose Bot Fly of Horses Giant Case-Builder Caddis
Scientific Name Gasterophilus haemorrhoidalis Phryganea bipunctata
Order Diptera Trichoptera
Family Oestridae Phryganeidae
Size 10-14 mm 18-25 mm
Habitat Farmland Ponds & Lakes
Diet Omnivores Omnivores
Regions Europe, North America, Asia, North Africa Europe
Conservation Least Concern Least Concern

Nose Bot Fly of Horses

A dark-bodied bot fly that deposits reddish-black eggs around the lips of horses. Larvae penetrate the lip mucosa and migrate to the stomach, then before pupation they reattach to the rectal mucosa, causing irritation and inflammation. The name refers to the reddish rectal inflammation it causes.

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Did You Know?

Before pupation, larvae reattach to the horse's rectum, causing such irritation that affected horses may rub their tails raw.

Giant Case-Builder Caddis

A large caddisfly with spotted wings found in northern and central Europe. Larvae construct conspicuous helical cases from plant material in weedy waters.

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Did You Know?

Its larvae are among the few caddisflies known to actively prey on other aquatic invertebrates.