Euproserpinus euterpe

Distinguished from other Euproserpinus species and small sphinx moths by combination of: small size (wingspan ~25 mm), gray forewings with black and brown patterning, off-white hindwings with black marginal banding, and diurnal activity. Day-flying behavior in late winter to early spring is unusual among sphinx moths. Larval coloration changes dramatically through instars, with mature larvae showing distinctive red heads and green/rust-red bodies with black markings. Restricted to specific California localities with sandy wash habitats and evening primrose host plants.

Sandy washes with proper compaction and moisture content for burrowing larvae; banks of washes in open, disturbed areas. Also recorded from road shoulders and abandoned agricultural fields where evening primrose host plants occur. Requires sandy soils suitable for pupation.

Endemic to California with highly restricted, disjunct distribution: Walker Basin, Kern County (privately owned ranch) and Carrizo Plain National Monument, San Luis Obispo County. Distribution pattern influenced by glacial history.

Adult flight season mid-January to first week of April, peaking mid-February through mid-March. Timing varies with regional climatic conditions. Adult eclosion from pupae occurs in morning hours.

Larvae feed on flowers and young leaves of evening primrose (Camissonia contorta epilobiodes or Camissonia campestris). Adults nectar on filaree (Erodium species), goldfields (Lasthenia gracilis), and baby blue eyes (Nemophila menziesii).

• Camissonia contorta epilobiodes - larval food plantevening primrose
• Camissonia campestris - larval food plantevening primrose
• Erodium species - adult nectar sourcefilaree; not consumed by larvae despite egg deposition
• Lasthenia gracilis - adult nectar sourcegoldfields
• Nemophila menziesii - adult nectar sourcebaby blue eyes

Eggs laid on various plants near host species; larvae hatch after approximately one week. First instar larvae feed on evening primrose flowers and young leaves; larvae from eggs laid on non-host plants wander to locate suitable food. Pupation occurs in sandy soils. Pupae can remain dormant for extended periods. Adults emerge late winter to early spring (February-March peak), with eclosion typically in morning hours.

Diurnal (day-flying) activity pattern unusual for sphinx moths. Females deposit eggs haphazardly on plants near host species rather than directly on food plants; larvae actively wander to locate evening primrose hosts. Pupae burrow in sandy soils with specific compaction and moisture requirements. Population size shows dramatic natural fluctuations in response to climatic conditions, particularly rainfall patterns.

Specialist herbivore on evening primrose; adult pollination services through nectar feeding on diverse wildflowers. Population dynamics may serve as indicator of habitat quality and climatic conditions in California's Central Valley and Carrizo Plain ecosystems.

Federally threatened species (U.S. Endangered Species Act). Subject to conservation concern due to extreme rarity and habitat restriction. Threats include habitat loss and alteration, pesticide and herbicide application, and collection pressure from insect collectors. Populations monitored by Bureau of Land Management at Carrizo Plain National Monument. Recovery plan developed by U.S. Fish and Wildlife Service (1984). Once considered extinct until rediscovered in 1974.

• Other Euproserpinus speciesLack specific gray and black-brown forewing pattern with off-white hindwings; different geographic ranges and host associations
• Other small SphingidaeMost are nocturnal rather than diurnal; lack the specific wing pattern and late winter-early spring flight period

Previously believed that Erodium (filaree) posed a serious threat due to larval mortality from mistaken egg deposition. Research has shown females deposit eggs indiscriminately near hosts, and larvae actively wander to find evening primrose; Erodium is never fed upon and does not cause mortality. Species was considered extinct until 1974 rediscovery.

• federally threatened
• endemic
• diurnal
• specialist herbivore
• glacial relict
• California endemic
• evening primrose feeder
• sandy soil pupation
• population fluctuation
• conservation concern
• insect collecting threat
• habitat specialist
• disjunct distribution
• late winter emergence
• morning eclosion
• agricultural disturbance tolerance
• Bureau of Land Management
• recovery plan species
• presumed extinct rediscovery
• climate-sensitive population dynamics

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Ghosts of glaciers and the disjunct distribution of a threatened California moth ( Euproserpinus euterpe )
• Observations of Pupal Biology and Adult Eclosion in the Federally Threatened Kern Primrose Sphinx Moth, Euproserpinus euterpe (Sphingidae: Macroglossini)