A comparison between the adult antennal sensilla of the cavernicolous stonefly Protonemura gevi and other epigean Protonemura species (Plecoptera: Nemouridae) in a biological context.

In the present paper we study the antennal sensilla of the unusual hypogean stonefly Protonemura gevi Tierno de Figueroa & López-Rodríguez, 2010 (Plecoptera: Nemouridae), comparing them with those of two epigean species of the genus Protonemura, P. alcazaba (Aubert, 1954) and P. meyeri (Pictet, 1842), with the aim to describe possible peculiarities. No differences exist in the types and morphology of antennal sensilla among the studied species and neither between sexes. The types of sensilla identified are long aporous trichoid sensilla with a tactile function, uniporous gustatory sensilla chaetica, multiporous sensilla basiconica (porous pegs) and sensilla coeloconica (digitated pegs), with a supposed olfactory function, and domes probably hosting aporous thermohygroreceptive pegs. These sensilla are very similar to those observed in other Plecoptera families and described in detail in Dinocras cephalotes (Curtis, 1827), thus suggesting a quite conserved sensory function for the antenna in the whole order, as it happens in other aquatic insects, such as Ephemeroptera and Odonata.