Eupackardia

Adults are distinguished from other Saturniidae by the combination of black wings with white post-median lines, red thoracic collar, and relatively large size. The white lines are notably wider in females than males. The presence of triangular white spots (when present) further aids identification. Caterpillars are recognizable by their bright green coloration with contrasting white stripes and black scoli with blue-orange bases. The genus is monotypic, so all individuals encountered belong to the single species E. calleta.

Inhabits thorn scrub vegetation, foothills, and canyons of desert mountain ranges in arid and semi-arid regions. Associated with dry desert environments and riparian corridors within these systems.

Mexico, Guatemala, and the southwestern United States (Arizona, New Mexico, Texas). Within Arizona, occurs in the Chiricahua Mountains, Santa Rita Mountains, and Huachuca Mountains.

Activity varies by region and elevation. In southeastern Arizona mountains, adults are present July–August. In central Arizona to Mexico, adults occur October–January. In South Texas, adults are present September–November and March–April.

Larvae feed on Fraxinus (ash), Leucophyllum frutescens (ceniza), Sapium biloculare (Mexican jumping bean), and Fouquieria splendens (ocotillo). Adults do not feed.

• Fraxinus - larval food plantash species
• Leucophyllum frutescens - larval food plantceniza; primary host in some regions
• Sapium biloculare - larval food plantMexican jumping bean
• Fouquieria splendens - larval food plantocotillo

Eggs are deposited in clumps on surfaces of host plant leaves, with females beginning to lay at dusk on the day of emergence. Adults emerge in the evening and may mate by early morning (as early as 7:30 am). Males are diurnal, females nocturnal. Young caterpillars (instars 1–3) feed gregariously; older caterpillars (instars 4–5) are solitary feeders. Larvae possess integumental glands that secrete defensive chemicals. Pupation occurs in cocoons spun near the ground in shaded locations.

Adults exhibit sexual dimorphism in activity patterns: males are diurnal, females nocturnal. Larvae display ontogenetic shift in social behavior, feeding gregariously when young and solitarily when mature. Caterpillars actively spray defensive secretions from integumental glands when disturbed.

Larvae function as herbivores on woody desert plants. The species serves as prey for various predators; larvae possess chemical defenses that deter most predators except certain wasps. Cocoons are subject to predation by raccoons, opossums, and rodents. Parasitoid pressure appears relatively low compared to other large Saturniidae, though some wasp parasitoids have been reported.

Cocoons have been traditionally used by Yaqui and other American Indian peoples of Arizona and Mexico for ankle rattles ("tenabares" or "tenevoim") and medicinal necklaces in ceremonial contexts. The species is occasionally encountered by entomologists and naturalists in its desert mountain habitats.

• RothschildiaSimilar large Saturniidae with black-and-white wing patterns, but lacks the distinctive red thoracic collar of Eupackardia and has different wing venation and pattern elements.
• EaclesRelated Saturniidae genus with large size and bold coloration, but Eacles species typically display green, yellow, or orange coloration rather than black-and-white with red accents, and have different body proportions.

• Saturniidae
• silkmoth
• desert moth
• monotypic genus
• aposematic coloration
• chemical defense
• ethnobotanical use
• Southwestern United States
• Mexico
• Guatemala

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Sphecidae | Beetles In The Bush
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