Physical constraints of shallow water on acoustic communication by aquatic insects

Frequency responses of shallow, freshwater ponds in northern Mississippi were measured. The response has a highpass characteristic with a sharp cutoff frequency due to the modal properties of the system. The cutoff frequency of the system is inversely related to the depth of water at the shallower transducer (projector or receiver). Frequencies below the first mode are nonpropagating, and the overall effect of this environment on propagation is about 50 dB. Several species of aquatic insects communicate in these shallow‐water ponds using acoustic signals, and they must contend with the physical constraints imposed by the system. Data on the calling song (long range) of a common aquatic beetle (Tropisternus collaris, Hydrophilidae) are presented and discussed in relation to the propagation characteristics of their shallow pond habitats. [Work supported by USDA.]