Termites live in a material world: exploration of their ability to differentiate between food sources

Abstract

Drywood termites are able to assess wood size using vibratory signals, although the exact mechanism behind this assessment ability is not known. Important vibratory characteristics such as the modal frequencies of a wooden block depend on its geometry and boundary conditions; however, they are also dependent on the material characteristics of the block, such as mass, density and internal damping. We report here on choice experiments that tested the ability of the drywood termite Cryptotermes secundus to assess wooden block size using a solid wooden block paired with a composite block, the latter made of either wood and aluminium or wood and rubber. Each composite block was constructed to match mass or low-frequency vibratory modes (i.e. fundamental frequency) of the solid wooden block. The termites always chose the blocks with more wood; they moved to the solid wooden blocks usually within a day and then tunnelled further into the solid wooden block by the end of the experiment. Termites offered composite blocks of wood and rubber matched for mass were the slowest to show a preference for the solid wooden block and this preference was the least definitive of any treatment, which indicated that mass and/or damping may play a role in food assessment. This result clearly shows that the termites were not fooled by composite blocks matched for mass or frequency, which implies that they probably employ more than a single simple measure in their food assessment strategy. This implies a degree of sophistication in their ability to assess their environment hitherto unknown. The potential importance of alternative features in the vibrational signals is discussed.

Communication and Social Regulation in Termites

“…The vibrations produced by foraging and feeding can also be used as signals. Drywood termites of the genus Cryptotermes choose optimal food sources based on the substrate-borne vibrations produced by their own activity, which are modulated by the size and the other properties of the wood upon which they are feeding (Evans et al 2005;Inta et al 2007). At the same time, they are attracted by vibrations produced by their nestmates, and thus the social cohesion of the colony is maintained as a result of the perception of passive signals produced by foraging and wood-chewing ).…”

X-ray tomographic analysis of the initial structure of the royal chamber and the nest-founding behavior of the drywood termite Incisitermes minor

“…The drywood termite has the ability to assess physical properties of the wood such as mass, density, and internal damping [23] through the reception of vibratory signals [24]. Indrayani et al [25] also observed that I. minor touches the surface of the timber with its antennae before penetrating the timber by engaging in cutting, pulling, and collecting activities.…”

Quantitative observation of the foraging tunnels in Sitka spruce and Japanese cypress caused by the drywood termite Incisitermes minor (Hagen) by 2D and 3D X-ray computer tomography (CT)

“…This is a chance for their early detection. This can be explained by the working modus of termites (Evans et al 2005Inta et al 2007) as they send vibration signals to determine the wood Brought to you by | UCL -University College London Authenticated Download Date | 4/24/17 10:06 AM thickness. Though the vibratory characteristics of materials are strongly dependent on its properties (Thomson 1993), the termites are able to cope with these different parameters.…”