The Circadian Clocks of Insect Eclosion

Abstract

Understanding the circadian timing of eclosion in insects is a pretty big undertaking. A lot of technical detail is essential and a lot of close reasoning from meticulous experiments stands in the place of direct observations on the “clock’s” unknown physiological mechanism. In that respect clockology has some of the intellectual delight of the earlier years of genetics. However, (as of the 1978 writing) the whole argument has never been spelled out for publication in one place. This chapter once again attempts only an outline of the essentials. The story presented here seems to be generally valid for butterflies and moths, flies and mosquitoes, wasps and bees (i.e., Lepidoptera, Diptera, and Hymenoptera), but I emphasize my own experimental beast, the fruitfly. For a review of insect eclosion systems from the viewpoint of physiology and ecology, see Remmert (1962).

... indeed what reason may not go to Schoole to the wisdome of Bees, Aunts, and Spiders? what wise hand teacheth them to doe what reason cannot teach us? ruder heads stand amazed at those prodigious pieces of nature, Whales, Elephants, Dromidaries and Camels; these I confesse, are the Colossus and Majestick pieces of her hand; but in these narrow Engines there is more curious Mathematicks, and the civilitie of these litde Citizens more neatly sets forth the wisedome of their Maker.

Sir Thomas Browne, physician, regular correspondent of Henry Power