Promachus yesonicus

Promachus yesonicus · Order: Diptera · Family: Asilidae

No source yet on danger. We have no source yet on whether it bites, stings or damages anything.
Promachus yesonicus
Photo: BrianAdler, CC BY-SA 3.0

Adults are 23 to 30 mm long (about 0.9 to 1.2 in). They live throughout Japan, from Hokkaido down to Okinawa. They are seen from June through September.

Source: Wikipedia

Size

Adults measure 23 to 30 mm in length.

Source: Wikipedia

Where it lives

Found across Japan from Hokkaido to Okinawa.

Source: Wikipedia

When you see it

Active and visible from June to September.

Source: Wikipedia

Where it comes from

Its range covers the whole of Japan, from Hokkaido to Okinawa.

Source: Wikipedia

More photos

Promachus yesonicus photo 3
Photo: Alpsdake, CC BY-SA 3.0
Promachus yesonicus photo 4
Photo: KKPCW, CC BY-SA
Promachus yesonicus photo 5
Photo: KKPCW, CC BY-SA
Promachus yesonicus photo 6
Photo: harum.koh from Kobe city, Japan, CC BY-SA 2.0

Same family (Asilidae)

Northeastern HammertailNortheastern HammertailEfferia aestuansHarmlessStripe-legged Robber FlyStripe-legged Robber FlyDioctria hyalipennisPlain-tailed Hanging ThiefPlain-tailed Hanging ThiefDiogmites neoternatusKite-tailed robberflyKite-tailed robberflyTolmerus atricapillusGolden-tailed BeebanditGolden-tailed BeebanditMallophora fautrixSand HammertailSand HammertailEfferia albibarbis

Sources

  • Wikipedia: https://en.wikipedia.org/wiki/Promachus_yesonicus

Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia

Text written 2026-10-23 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.

How this page works

This is one bug's fact sheet. The colored box at the top says whether it is dangerous. Sections below cover how to recognize it, whether it is a pest, and how to deal with it. The US map shows which states have records; tap a state to see other bugs there.

Every fact on Bug FAQ comes from a named source (university extension sites, government agencies, GBIF, iNaturalist, Wikipedia). The source is linked next to each section. If we have no source for something, we leave it out.