Synanthedon mellinipennis

Distinguished from other clearwing moths by association with Ceanothus hosts and specific wing venation and scaling patterns. Most similar to other Synanthedon species, particularly those in the mellinipennis species group. Accurate identification often requires examination of genitalia or molecular confirmation. Resembles wasps in flight, but perching behavior and wing posture differ.

Associated with habitats containing Ceanothus species, including chaparral, scrubland, and open woodlands. Larval habitat is within living stems or roots of host plants. Adults found in vicinity of host stands.

Nearctic region. Records indicate presence in western North America where Ceanothus occurs.

Adults active during warmer months; specific flight period varies with latitude and elevation. Diurnal activity pattern.

Larvae bore into and feed on tissues of Ceanothus species. Adult feeding habits unknown; may take nectar or not feed as adults.

• Ceanothus - larval hostLarvae are stem or root borers in living plants

Complete metamorphosis. Eggs laid on or near host plant. Larvae tunnel into stems or roots, feeding internally and causing gall-like swellings or visible frass. Pupation occurs within tunnel or in soil. Adults emerge and are active during day.

Diurnal flight activity. Adults rarely attracted to artificial light sources. Males may be attracted to pheromone lures. Flight rapid and wasp-like, contributing to mimicry. Perching behavior observed on vegetation.

Larval boring creates entry points for other organisms and may influence host plant vigor. Contributes to wasp mimicry complex in diurnal Lepidoptera. Pollination role, if any, unstudied.

Minor economic concern when Ceanothus is cultivated as ornamental. Larval boring can damage or kill cultivated plants. Occasionally encountered by collectors using pheromone lures.

• Other Synanthedon speciesShare clearwing morphology and wasp mimicry; require detailed examination or host association for separation
• Euhagena nebraskaeSimilar clearwing appearance and diurnal behavior, but distinct wing pattern and different host associations
• Melittia speciesAnother sesiid genus with wasp mimicry, but generally larger with different wing shape and abdominal patterning

• clearwing moth
• wasp mimic
• borer
• diurnal
• Ceanothus

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Euhagena nebraskae… again | Beetles In The Bush