From Frederick Smith   26 August 1869

My dear Sir

The bee to which you allude from Australia—the male of which of a bright brassy colour and clothed with rich fulvous pubescence—the female being of a steel-blue colour—is the Lestis bombylans.¹ The female is as brilliant as Musca vomitoria²—the common blue-bottle—having—frequently bright tints of vivid green—

Your conjecture as to the Male of Anthophora being of a rich fulvous brown— the female is quite black.—³

The Males in the genus Bombus vary as you say—and the same may be said of their parasites the Apathi— the Males of A. campestris vary extremely—so much so—that M^r. Kirby has described three or four as distinct species;⁴ some males are gaily coloured black and yellow being banded and tufted with the latter colour—others are clothed principally with yellow—with narrow bands of black intermixed on the abdomen—and from these standards—every shade of colouration occurs between them and a totally black variety— The female varies from a black and yellow banded insect to a totally black one—and this species does not confine its parasitism to one species— it has been obtained from nests of two or three species of Bombus.

The greatest sexual differences in coloration certainly obtains among the solitary bees—as in Anthophora and Xylocopa— in the latter genus many species consist of black females and bright yellow males

believe me | Yours very truly | Fred^k. Smith

Cha^s. Darwin Esq^re.