Riparian-specialist
Guides
Battus
Pipevine Swallowtails and Allies
Battus is a New World genus of swallowtail butterflies in the family Papilionidae. The genus comprises approximately 9 species distributed across the Americas, with the most well-known North American representatives being Battus philenor (pipevine swallowtail) and Battus polydamas (Polydamas swallowtail). All members share a specialized ecological relationship with pipevine plants (Aristolochia), which serve as their exclusive larval host plants. The genus is notable for its aposematic coloration and chemical defense system derived from sequestered toxins.
Battus philenor philenor
Pipevine Swallowtail, Blue Swallowtail
Battus philenor philenor is a subspecies of the pipevine swallowtail butterfly found in North America. Adults display iridescent blue hindwings against a black background, serving as aposematic warning coloration derived from sequestered aristolochic acids from their host plants. The subspecies is univoltine to bivoltine with flight periods from late winter through autumn, peaking before July. Populations have shown resilience to drought conditions in California's Central Valley, in contrast to montane butterfly declines.
Desmocerus aureipennis piperi
valley elderberry longhorn beetle, VELB
Desmocerus aureipennis piperi, commonly known as the valley elderberry longhorn beetle (VELB), is a federally threatened subspecies endemic to California's Central Valley. Adults are active for only a few weeks annually, making detection difficult. The subspecies breeds exclusively in living stems and roots of elderberry plants (Sambucus spp.). Males are attracted to a sex pheromone, (R)-desmolactone, which has proven effective for monitoring populations.
Euura californica
Willow Apple Gall Sawfly
Euura californica, the willow apple gall sawfly, is a tenthredinid sawfly that induces distinctive galls on arroyo willow (Salix lasiolepis). Females oviposit into leaf tissue, triggering the formation of rounded, apple-like galls that enclose developing larvae. The species exhibits multivoltine breeding with up to six generations annually in favorable climates. Adults emerge through exit holes chewed in mature galls.
Ufeus plicatus
Folded Satyr
A small noctuid moth endemic to northeastern North America, closely tied to large poplars—especially eastern cottonwood—growing in riparian habitats with loose, rotting bark. Adults exhibit an unusual bimodal activity pattern with spring emergence followed by summer aestivation and renewed fall activity. The species is notably scarce at light traps despite occurring in suitable habitats.