Sense organs on the antennal flagella of earwigs (Dermaptera) with special reference to those of Forficula auricularia.

Abstract

AbstractFive types of sense organs have been found on the antennal flagellum of Forficula auricularia Linnaeus: (1) tactile hairs; (2) long, thick‐walled chemoreceptors; (3) short, thick‐walled chemoreceptors; (4) thin‐walled chemoreceptors and (5) coeloconic chemoreceptors. Earlier workers have placed the first three of these in a single class. The structural characteristics and distribution of these five kinds of sensilla on the antenna are described. All of the types except the third have been reported previously for other species but short, thick‐walled chemoreceptors have not been described before. They are remarkable for the presence of (1) a broad pad‐Like structure that absorbs dyes readily at the distal end of the peg and (2) a spheroid body, over a micron in diameter, on the dendrite of each olfactory neuron at the point where it narrows to assume the structure of a cilium. The antennal sense organs of a few specimens of Chelisoches morio (Fabricius), Labidura riparia (Pallas) and Euborellia annulipes (Lucas) were also examined.