Mountain Ash Sawfly vs Red-winged Spider Wasp

Side-by-side species comparison

Attribute Mountain Ash Sawfly Red-winged Spider Wasp
Scientific Name Pristiphora geniculata Tachypompilus ferrugineus
Order Hymenoptera Hymenoptera
Family Tenthredinidae Pompilidae
Size 5-7 mm 18-28 mm
Habitat Mountains Deserts & Drylands
Diet Herbivores Predators
Regions Europe, introduced to North America North America
Conservation Least Concern Least Concern

Mountain Ash Sawfly

A small blackish sawfly with pale legs whose green larvae can completely defoliate mountain ash (rowan) trees. Larvae have dark heads and feed gregariously.

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Did You Know?

Introduced to North America in the early 1900s, it quickly became the most damaging pest of ornamental mountain ash trees across the continent.

Red-winged Spider Wasp

A large rusty-red spider wasp that hunts wolf spiders and other large ground spiders. It drags paralyzed prey across the ground to its burrow.

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Did You Know?

Females can drag spiders many times their own weight across rough terrain to reach their nesting burrows.