Why Do Wasps Need Oxygen?
WouterUnlike humans, wasps do not have lungs or a circulatory system. Instead, they breathe through spiracles, tiny holes in the abdomen. They need a good source of food to stay alive.
As a result, wasps have a low metabolic rate. This may help them survive in arid environments. However, it is not clear how wasps obtain their energy. In this study, the metabolic rate of the Polistes dominulus was investigated in temperature ranges from 2.4 to 40.6 degC.
Three to five individuals were exposed to each temperature category. The temperature was controlled with an electronically controlled water bath. The lid was insulated with Styrofoam. The wasps were then weighted with a balance to the nearest 0.1 mg. This was calculated to provide a VCO2 per temperature estimate.
The metabolic rate of the wasps decreased with the increase of the ambient temperature. This was confirmed by the presence of minimal T th – T ab during rest. However, gas exchange patterns were not represented in analysis.
When the wasps were handled, their metabolic rate increased. However, handling also caused increased body movement. As a result, gas exchange patterns became erratic. In most cases, wasps remained at rest for long periods of time at temperatures below 10 degC. However, they were agitated at higher temperatures.
When wasps were at rest, they did not produce any CO2. This was confirmed by analyzing the CO2 recordings. However, four of the eight individuals showed slight endothermy.
