Histology of the Compound Eye of the Boll Weevil1,2,3

Abstract

A histological study of the compound eye of the boll weevil, Anthonomus grandis Boheman, with a light microscope showed that each eye is composed of about 500 ommatidia 100–140 µ long, 27 µ in diameter at the lens, and 7 µ in diameter at the basement membrane. A single ommatidium consists of a hexagonal lens, a crystalline cone, 4 Semper cells, 2 primary pigment cells, 6 secondary pigment cells, 6 retinula cells which contribute to the formation of a central rhabdom that extends from the Semper cells to the basement membrane, and 2 basal pigment cells that surround the base of the retinula cells. The 6 axons, 1 from each of the 6 retinula cells, join and penetrate the basement membrane as a bundle. Each bundle of primary nerves converges with other bundles to form larger bundles that enter the optic ganglion.