Bot Flies in Oregon? No — They're Tropical/Subtropical

Bot flies (family Oestridae) do not live in Oregon or anywhere in the Pacific Northwest.

Where They Actually Live

• Primary range: Tropical and subtropical regions of Africa, Central & South America, parts of Asia (e.g., Dermatobia hominis in Neotropics; Gasterophilus spp. in equids worldwide but require warm climates for larval development).
• US presence: Rare, mostly in southern Florida, Texas, Arizona, California — usually travel-associated or in livestock/equines. No established populations in Oregon.

Why Not Oregon?

• Climate: Cool, wet winters; insufficient year-round warmth for larval development in hosts.
• Host specificity: Many bot flies require specific tropical hosts (e.g., Dermatobia uses mosquitoes as vectors; not present in Oregon).
• Surveillance: Oregon Department of Agriculture & CDC monitor; no endemic cases.

What You Might See Instead

• Cuterebra (rodent bot flies): Native to North America, including Oregon. Larvae parasitize rodents/rabbits; rarely infect pets (dogs/cats) as accidental hosts. Not the human bot fly.
• Warble flies (Hypoderma): Cattle grubs; historically in US, largely eradicated.
• Other myiasis flies: Blow flies (Calliphoridae), flesh flies (Sarcophagidae) — opportunistic, not true bot flies.

If You Travel to Endemic Areas

• Use insect repellent (DEET, picaridin).
• Wear long sleeves/pants.
• Sleep under treated nets.
• Iron clothes dried outdoors (kills eggs).

Oregonians need not worry about bot flies at home — but check your dog for Cuterebra lumps in summer.