The occurrence of periodic or continuous discharge of carbon dioxide by male desert locusts (Schistocerca gregariaForskål) measured by an infra-red gas analyser

Abstract

Newly emerged adult Schistocerca discharge their CO$_{2}$ periodically. This method of discharge helps to conserve water. Once they start to feed and when they have built up their fat reserve they discharge their CO$_{2}$ as a continuous stream. Prior to death there is a return to the periodic method of discharge. During the process of ecdysis the quantity of CO$_{2}$ produced is high but, as the locusts recover from the exertion of ecdysis, there is a decrease in the quantity of CO$_{2}$ produced. This decrease continues until the adults start to feed when there is a sharp rise in their metabolic rate. This results in a rapid increase in the quantity of CO$_{2}$ produced which reaches a maximal output on the 4th or 5th day. The quantity of CO$_{2}$ produced starts to drop after the 5th day. There is also a rapid increase in weight after the adults start to feed. This reaches a peak on the 8th day and remains fairly constant until the 27th day when it also starts to drop. A high percentage of the increase in weight is due to a build up of fat reserve. The fat content of the body is closely related to colour change, sexual maturation and migration. As the locusts approach senescence the fat reserve drops rapidly.