Cactobrosis fernaldialis

The species can be distinguished from other Cactobrosis species by its geographic restriction to the southwestern United States and its specific association with Ferocactus wislizeni as a larval host. Adults are active during two distinct periods (March–April and July–November), which may aid in identification. Wing measurements overlap broadly between sexes, limiting their utility for sex determination.

Adults have a wingspan of 36–47 mm in males and 34–50 mm in females. The common name 'blue cactus borer' suggests blue coloration, though specific details of wing patterning are not documented in available sources.

Desert environments in the southwestern United States, specifically regions supporting populations of the barrel cactus Ferocactus wislizeni.

Found from Texas to southern California.

Adults are active from late March to April, and again from July to November. This bivoltine pattern suggests two generations per year.

Larvae feed on Ferocactus wislizeni (barrel cactus). Adult feeding habits are not documented.

• Ferocactus wislizeni - larval food plantThe sole documented host for larval development.

As a specialist herbivore on Ferocactus wislizeni, the species may influence cactus population dynamics and serve as a food source for predators in desert ecosystems.

• Other Cactobrosis speciesCongeneric species may overlap in distribution and share similar morphologies; host plant specificity and flight timing are key distinguishing features.

• desert fauna
• cactus specialist
• herbivore
• Pyralidae
• Lepidoptera
• North America
• United States
• Texas
• California
• Arizona
• New Mexico

• BugGuide
• Wikipedia
• GBIF taxonomy match
• NCBI Taxonomy