Cremastocheilus armatus

One of about thirty-five species of myrmecophilous Cremastocheilus. The host ant is presumed to be a species in the genus Formica.

Distribution
California, Idaho, Oregon, Washington; Canada (British Columbia);Mexico (Guerero Mill)

Habitat
Common host is Formica obscuripes.

Nomenclature
Type should be in the Natural History Museum, London.
 * Cremastocheilus cribripennis Casey 1915 Syn
 * Cremastocheilus densicollis Casey 1915 Syn.
 * Cremastocheilus maritimus Casey 1915 Syn.
 * Cremastocheilus montanus Casey 1915 Syn.
 * Cremastocheilus obliquus Casey 1915 Syn.
 * Cremastocheilus pilosicollis Horn, 1879