Pterygote Insects

IN CONTRAST to the Myriapoda and the apterygote insects, the pterygote insects have been the focus of a large amount of embryological research for almost a century. During this time, more than 400 hundred significant papers have been published on the descriptive embryology of the group.) The reasons for this arc not difficult to discern. Many pterygote species are of economic significance in human affairs and their embryology has been closely studied as part of the investigations underlying control methods. The easy availability of pterygotes, their often short life-cycles and their favorable response to laboratory culture have also made them attractive to embryologists. Furthermore, the pterygotes display a fascinating diversity in their embryonic development, ranging from the large yolky embryos of the more primitive orders to instances of specialized polyembryony and viviparity in orders of more recent origin. Comprehension of this diversity is a continuing challenge