Tenthredo

Linnaeus, 1758

Common Sawflies

Species Guides

23

Tenthredo is a large of comprising over 700 with Holarctic distribution. exhibit -mimicry with long and lack the narrow petiole ('wasp waist') characteristic of true wasps. Larvae are herbivorous and feed on diverse plants, with most species showing host specificity. Adults are predatory or , feeding on smaller insects as well as pollen and nectar at flowers. The genus is notable for its complex wing venation and soft-bodied, delicate adults.

Tenthredo olivacea by (c) Martin Scheuch, some rights reserved (CC BY), uploaded by Martin Scheuch. Used under a CC-BY license.Tenthredo grandis by (c) Dan MacNeal, some rights reserved (CC BY), uploaded by Dan MacNeal. Used under a CC-BY license.Tenthredo angulifer by (c) Owen Strickland, some rights reserved (CC BY), uploaded by Owen Strickland. Used under a CC-BY license.

Pronunciation

How to pronounce Tenthredo: //tɛnˈθriːdoʊ//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from true (Vespidae, Sphecidae) by the broad connection between and —no narrow 'wasp waist.' Forewing with characteristic lance-shaped and straight cross-nervure distinguishes from other . Triangular with bulging separates from many other Tenthredinidae. Larvae distinguished from lepidopteran caterpillars by seven pairs of versus five or fewer. -level identification is problematic due to high species count (>700) and extensive variation in color patterns.

Images

Habitat

Associated with diverse including montane meadows, semi-open forests, and edges of deciduous forests. Tenthredo maxima specifically occurs in montane zone habitats of the Rockies, Cascades, and Sierra Nevada.

Distribution

Holarctic distribution. Approximately 118 in the United States and Canada. Documented in Europe including Austria, and across North America from Vermont to the southwestern United States (Arizona).

Seasonality

active primarily in late summer and early autumn, though some appear in spring. Tenthredo maxima larvae observed in August–September.

Diet

are predatory and : they prey on flies and other small insects, and consume pollen and nectar at flowers. Larvae are herbivorous, feeding on foliage of plants.

Life Cycle

are inserted into plant tissues using the saw-like ovipositor. Larvae develop on plants, feeding externally on foliage. Larvae of some nearly full-grown by August–September. occurs in soil or plant litter; specific details vary by species.

Behavior

frequently observed on flowers. Females do not sting despite -mimicry; the ovipositor is modified for sawing plant tissue, not defense. Some appear susceptible to yellow pan traps. Larvae often feed in groups on leaves.

Ecological Role

Larvae function as herbivores, with some documented feeding on plant rarely used by (e.g., Gentianaceae). serve as of small insects and as potential when feeding on nectar and pollen.

Human Relevance

No significant direct economic impact. may be encountered by naturalists and photographers due to conspicuous -mimicry. Larvae may cause minor defoliation of ornamental or native plants but are not considered major pests.

Similar Taxa

  • Vespidae (true wasps)Constricted petiole (' waist') present; Tenthredo lacks this constriction with broad - attachment.
  • Diprionidae (conifer sawflies)Larvae superficially similar but associations differ; Diprionidae specialize on conifers while Tenthredo use broad-leaved plants.
  • Other Tenthredinidae generaDistinguished by forewing venation (lance-shaped with straight cross-nervure) and triangular with bulging .

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Sources and further reading