Tenthredo verticalis

Adults in the genus Tenthredo can be recognized by their triangular faces with slightly bulging eyes and complex wing venation that gives the wings a reticulated appearance. Unlike many wasps, they lack a constricted petiole between the thorax and abdomen. Females possess a saw-like ovipositor used to insert eggs into plant tissues but lack a stinger. Species-level identification within Tenthredo requires specialized taxonomic expertise.

Associated with deciduous forest edges and areas where host plants occur. The genus Tenthredo has been observed in mountainous regions, including near the summit of Mt. Lemmon in the Santa Catalina Mountains of southern Arizona.

Recorded from Canada (New Brunswick, Nova Scotia, Ontario, Prince Edward Island). Distribution within the United States is not well-documented in available sources, though the genus occurs across North America.

Adults in the genus Tenthredo tend to appear in late summer and early autumn, later than many other sawfly genera which are most abundant in spring.

Adults feed on pollen and nectar from flowers, and have been observed consuming smaller insects. Larvae are herbivorous, feeding on plant foliage.

Females use their saw-like ovipositor to insert eggs into plant tissues. Larvae feed on foliage and possess seven pairs of prolegs, distinguishing them from caterpillars which have five or fewer pairs. Larvae are frequently mistaken for lepidopteran caterpillars due to similar appearance and feeding behavior.

Adults are often seen on flowers. Larvae typically feed in groups on leaves. Adults in the genus are known to mimic stinging wasps such as yellowjackets and spider wasps, though they cannot sting.

Adults may contribute to pollination through flower visitation. Larvae function as herbivores in forest and woodland ecosystems.

Not known to be economically significant. Adults pose no sting risk despite wasp-like appearance. Larval feeding on foliage is generally not severe enough to cause notable damage to plants of human concern.

• Other Tenthredo speciesApproximately 118 species occur in the U.S. and Canada; species-level identification requires examination of morphological characters not visible in field observations.
• Caterpillars (Lepidoptera larvae)Sawfly larvae resemble lepidopteran caterpillars in appearance and foliage-feeding behavior, but can be distinguished by having seven pairs of prolegs versus five or fewer in caterpillars.
• Stinging wasps (Vespidae, Pompilidae)Adult Tenthredo species mimic the appearance of stinging wasps with similar color patterns, but lack the constricted waist and stinger; they also have distinctive triangular faces and reticulate wing venation.

• sawfly
• Tenthredinidae
• Hymenoptera
• North America
• herbivore
• mimicry

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• Bug Eric: January 2011
• Sphecidae | Beetles In The Bush