Respiration patterns of resting wasps (Vespula sp.)

We investigated the respiration patterns of wasps (Vespula sp.) in their viable temperature range (2.9–42.4 °C) by measuring CO(2) production and locomotor and endothermic activity. Wasps showed cycles of an interburst–burst type at low ambient temperatures (T(a) < 5 °C) or typical discontinuous gas exchange patterns with closed, flutter and open phases. At high T(a) of >31 °C, CO(2) emission became cyclic. With rising T(a) they enhanced CO(2)-emission primarily by an exponential increase in respiration frequency, from 2.6 mHz at 4.7 °C to 74 mHz at 39.7 °C. In the same range of T(a) CO(2) release per cycle decreased from 38.9 to 26.4 μl g(−1) cycle(−1). A comparison of wasps with other insects showed that they are among the insects with a low respiratory frequency at a given resting metabolic rate (RMR), and a relatively flat increase of respiratory frequency with RMR. CO(2) emission was always accompanied by abdominal respiration movements in all open phases and in 71.4% of the flutter phases, often accompanied by body movements. Results suggest that resting wasps gain their highly efficient gas exchange to a considerable extent via the length and type of respiration movements.