Keyhole Wasp vs Black Headed Birch Sawfly

Side-by-side species comparison

Attribute Keyhole Wasp Black Headed Birch Sawfly
Scientific Name Pachodynerus nasidens Craesus alniastri
Order Hymenoptera Hymenoptera
Family Vespidae Tenthredinidae
Size 10-15 mm 7-9 mm
Habitat Underground Woodlands
Diet Nectar Feeders Herbivores
Regions Americas, introduced to Australia Europe
Conservation Least Concern Least Concern

Keyhole Wasp

A mud-nesting wasp notorious for building nests inside aircraft pitot tubes. It has caused aviation incidents by blocking airspeed sensors.

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Did You Know?

Brisbane Airport installed covers on aircraft sensors specifically because of this species.

Black Headed Birch Sawfly

A medium-sized sawfly with a dark head and orange body. Larvae are greenish-blue with black heads and feed communally on birch and alder leaves.

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Did You Know?

When a predator approaches, the entire colony of larvae simultaneously rears up and thrashes, making the group appear larger and more threatening.