The physiology of hatching of aedine mosquito eggs: Carbon monoxide stimulation and ethyl chloride inhibition of hatching of Aedes aegypti (L.) eggs

Abstract

Hatching of eggs of Aedes aegypti (L.), which is normally stimulated in nature by a reduction of the ambient oxygen concentration, is induced by carbon monoxide without a reduction of pO 2. This stimulatory effect of carbon monoxide is photoreversible, demonstrating an inhibition of the terminal respiratory enzyme cytochrome oxidase and is considered to be analogous to natural stimulation. Illumination of the anterior halves (head and thorax) of larvae reduces the amount of hatching due to carbon monoxide to significantly ( p = 0·001) lower levels than occurs when the posterior halves (abdomen) are illuminated. The anaesthetic ethyl chloride reversibly inhibits hatching of these eggs in response to both low pO 2 and to carbon monoxide, demonstrating the participation of the embryo's nervous system in the process. These results locate the stimulus receptor within the anterior portion of the larva and suggest the involvement of the nervous system in stimulus reception.