The Inherited Basis of Variation in the Hatching-response of Aëdes Eggs (Diptera: Culicidae)

Abstract

A stimulus is necessary for the hatching of eggs of Aëdes mosquitos, but, while many different kinds of change in the external environment may be adequate as hatching-stimuli, there is variation in the response of the eggs to any given one of them.Not only is there variation between species as regards behaviour of the eggs, but batches of eggs laid by different females in a single species may vary one from another and there is even variation of behaviour between the eggs laid in a single batch.The response of the eggs of A. aegypti (L.) has been studied here and evidence produced that both parents contribute to their hatching-behaviour. Egg behaviour has also been studied in two populations of this species, one originating from West Africa and the other from East Africa. In the former, only a very low proportion of the mature eggs (0–9%) responded to the daily application of a suitable stimulus over a short period, whereas in the latter the proportion of responders in the same period with the same stimulus was very much higher (46–100%). The next generation reared from each of these gave very similar results (0–11 and 65–100%, respectively), while reciprocal crosses between them gave a wide range of scatter (16–100 and 4–99%, respectively).