External stimuli in searching for favourable habitat, overwintering sites and refugia of ground beetles: a short review
Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences,Kreutzwaldi St. 64, 51014 Tartu, Estonia; e-mail: email@example.com
More than 10 morphological types and subtypes of sensilla have been found on the antennae of ground beetles. On the basis of their external features and similarity with the antennal sensilla of other insects, it is suggested that they may function as mechano-, olfactory, taste, thermo- and hygroreceptors. In ground beetles, however, a thermoreceptive cell located in antennal campaniform sensilla, and three chemoreceptive cells of four, innervating large antennal taste bristles have been electrophysiologically identified. These cells are the salt, pH and sugar cell. Their probable role in searching for favourable habitats, overwintering sites and refugia is discussed. It is concluded that the strength of external chemosensory stimuli to which antennal taste cells do not fire, or fire at very low frequency, represents chemical conditions in the ground beetles’ preferred habitats and microhabitats. In the future, a good knowledge of external stimuli crucial in the searching behaviour of ground beetles’ could allow more effective manipulation of these predatory beetles in agricultural lands..