Sensilla on maxillary and labial palps in a helicophagous ground beetle larva (Coleoptera, Carabidae)

Sensilla on the labial and maxillary palp of Carabus lefebvrei Dejean, 1826 larvae were investigated using scanning and transmission electron microscopy. Two identical sets of sensilla were present on the tips of both palp pairs, and four morphological types of sensilla were identified: sensilla basiconica types 1 and 2, sensilla coeloconica and sensilla digitiformia. Ultrastructure indicates that the sensilla basiconica type 1 and coeloconica have a chemical role as gustatory and olfactory receptors, respectively, while sensilla basiconica type 2 are mechanoreceptors and the sensilla digitiformia are probably thermo- and hygroreceptors. Their function is discussed in relation to specialized prey detection and habitat adaptations.