Dasymutilla sackenii

Females can be distinguished from similar species Dasymutilla albiceris by the specific pattern of cream dorsal and black ventral setae. Superficially resembles D. albiceris, with which it shares a similar geographic distribution. The combination of wingless females with cream-colored dorsal fuzz and black ventral fuzz is diagnostic for this species within its range.

Females have dense cream-colored to pale yellow fuzz (setae) covering the dorsal surface of the body, with black fuzz on the ventral side and legs. Males possess two pairs of wings and are capable of flight. Body covered in velvety hair characteristic of the family Mutillidae.

Found in Oregon, California, Nevada, Baja California, and Baja California Sur. Western North American distribution spanning the Pacific Coast and adjacent interior regions, extending south into the Baja California peninsula.

Most commonly observed from May through October. Observations from December through February are very rare, indicating a pronounced seasonal activity pattern with peak abundance in warmer months.

Females run rapidly across the ground in search of host nests. Both sexes have been observed feeding on sweet, sticky secretions of plants such as Common Sunflower (Helianthus annuus). When disturbed or captured, individuals may produce an audible squeaking sound (stridulation) by rubbing abdominal segments together, serving as an additional defensive warning signal.

As with other velvet ants, females are likely parasitoids of ground-nesting bees and wasps, though specific host records for this species have not been documented. The aposematic coloration serves as warning advertisement of defensive capabilities, contributing to Müllerian mimicry complexes with other velvet ant species.

Females possess a potent sting and should not be handled. The specific epithet honors Carl Robert Osten-Sacken, a notable 19th-century entomologist who contributed significantly to North American dipterology.

• Dasymutilla albicerisSuperficially similar in appearance and shares overlapping geographic distribution in western North America; distinguished by subtle differences in setal coloration and pattern

• BugGuide
• Wikipedia
• iNaturalist taxon
• NCBI Taxonomy
• Insect FAQs | Entomology Research Museum
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• Mutillidae | Beetles In The Bush