Effect of dark rearing on the eye of Gryllus bimaculatus crickets

Studies of the visual fields of six species of crickets have shown that the extent of these visual fields is related more to the nature of their habitat than to the phyletic proximity of the species. The present experiments were conducted to determine the influence of light itself on the development of the eye in young Gryllus bimaculatus. When these insects were maintained in total darkness from the first stages of ontogenetic development, they exhibited morphogenetic changes which seem to result in better light energy reception (more numerous ommatidia, smaller interommatidial angles). However, electron microscopic studies revealed fine structural modifications, which are likely to affect vision adversely. We discuss these changes in terms of the visually guided locomotion of the insects in their natural habitat. © 1994 Wiley-Liss, Inc.