Howard Berg

to test whether termites of the Cryptotermes domesticus species might be able to discriminate between different sizes of wood. The team constructed experiments that presented termites with blocks of wood with a standard crosssectional diameter of 20x20 mm but of either 20 mm or 160 mm length. The insects were placed in a gap between the two faces of the timber blocks so that they were not able physically to assess the length of each block. The team found that the termites, when presented with a choice, preferred the shorter 20 mm block. To test whether the termites might be using vibration signal to assess the blocks, the researchers carried out two experiments. They recorded the vibration signals produced by termites placed in a hole in blocks of wood of lengths varying from 20 to 160 mm long. They then examined the influence of some of the recorded signals on termites faced with wood blocks of different sizes along with the influence of two artificially synthesized signals. The team found that when they played the vibration signals recorded from the larger block into the smaller block, the termites’ preference for the smaller block disappeared, but when the signal from the smaller block was played the preference was maintained. The termites did not change their behaviour in response to artificial noise signals. The researchers believe the demonstrated preference for smaller pieces of wood may be a mechanism to avoid competition with larger species of termite attracted to larger pieces of wood. But while individual termite species might be fussy, the news is not good for those whose home timbers have been deemed an ideal feast by whatever species finds this source and size of wood attractive. Magazine R189