Tenthredo xantha

Adults can be distinguished from other Hymenoptera by the absence of a narrow petiole (wasp waist), triangular face, and reticulated wing venation. Within Tenthredo, species-level identification is problematic due to extensive variation in color patterns and the large number of species in the genus. Tenthredo xantha may be distinguished from other Tenthredo species by geographic distribution and collection timing, though specific diagnostic features are not well documented.

Associated with deciduous forest edges. Adults have been observed on aspen leaves. Larval host plants are poorly known.

Recorded from northern Canada: Yukon, Northwest Territories, British Columbia, and Alberta.

Adults active in late summer and early autumn; larvae present during growing season.

Adults are known to consume pollen, nectar, and smaller insects. Larval feeding habits are poorly documented for this species, though Tenthredo larvae generally feed on foliage.

Complete metamorphosis with egg, larval, pupal, and adult stages. Females use a saw-like ovipositor to insert eggs into plant tissues. Larvae resemble caterpillars with seven pairs of prolegs.

Adults frequently visit flowers. Larvae typically feed on leaves and may occur in groups. Adults are susceptible to capture in yellow pan traps.

Adult predation on small insects may provide minor biological control. Larval herbivory contributes to nutrient cycling in forest ecosystems.

Females lack a stinger and pose no sting risk to humans. May be mistaken for stinging wasps due to mimicry of yellowjackets and spider wasps. No significant economic impact documented.

• Diprion similis (Imported Pine Sawfly)Larvae may be confused due to similar caterpillar-like appearance, but D. similis feeds on conifers and has different adult morphology.
• Other Tenthredo speciesExtensive color pattern variation and large number of species make visual identification difficult; geographic and seasonal data may assist separation.
• Lepidoptera caterpillarsLarvae resemble caterpillars but possess seven pairs of prolegs versus five or fewer in Lepidoptera.

Despite wasp-like appearance, females cannot sting. The absence of a narrow waist distinguishes sawflies from most other wasps.

• sawfly
• Symphyta
• northern Canada
• late season
• flower visitor
• mimicry

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Bug Eric: Wasp Wednesday: Tenthredo