Apomorphies of the internal reproductive organs relevant to production and utilization of spermatophores, biologic traits associated with anthophily, and presence of afferent peg sensilla on the antennae suggests that a presumed monophyletic assemblage of genera of subfamily Clerinae are descendants of an ancient monophyletic stock linked to early angiosperm evolution. The species examined include all suprageneric categories of Cleridae proposed to date. The ground plan of the internal reproductive organs of Cleridae for the male involved a pair of multifollicular testes, tubular vas deferens, unichambered seminal vesicle, one pair of accessory glands, highly muscular ejaculatory duct, and for the ancestral female, a pair of multifollicular ovaries, non capsular spermatheca, well-developed spermathecal gland and spermathecal gland duct, and a spacious vagina. Based on presumed homologies of the male accessory glands across generic lines, and to a lesser extent on extraction of contents of the vagina of gravid females, the following clerines are thought to utilize the “mating plug” type of spermatophore as a method of sperm transference: Trichodes, Aulicus, Chilioclerus, Opilo, Dieropsis, Phlogistus, Phlogistomorpha, Scrobiger, Trogodendron, Zenithicola, and Balcus. Many species of several of the noted genera are anthophilic; histological work involving the alimentary canal, and examination of midgut contents, confirm their pollen feeding habits, and their opportunistic predatory nature on flower-visiting insects. The abovementioned genera are morphologically diverse externally, but nine share a peculiar microsetose character of the antennal club that is presumed synapomorphic. Investigations involving electron microscopy show that some of these microsetae are peg sensilla, which in other beetles are known to function as thermoreceptors. It is hypothesized that these thermoreceptors present on the antenna of spermatophoral clerines are afferent structures that enable the beetles to avoid fire-death in xeric environments. The widespread distribution, peculiar structure of the internal reproductive organs, substantial diversity of external structure, and anthophilous character invite the speculation that the spermatophoral clerines represent a monophyletic group evolved from an ancient Gondwanan ancestor tied to early Angiosperm diversification. Then, due to tectonic, climatic, and ecological events, the spermatophoral clerines became vicariously distributed onto the North American, Eurasian, African, and Australian plates on which they underwent an extensive radiation in part due to Angiosperm proliferation.
