Vergleichende Morphologie des Schmetterlingsrüssels und seiner Sensillen — Ein Beitrag zur phylogenetischen Systematik der Papilionoidea (Insecta, Lepidoptera)

Comparative morphology of the butterfly proboscis and its sensilla — a contribution to the phylogenetic systematics of Papilionoidea (Insecta, Lepidoptera) The morphology of the proboscis was investigated in more than 70 European representatives of Papilionoidea using light microscopy and scanning electron microscopy. The composition of the proboscis wall, its surface structures, as well as the shape and distribution of the different types of sensilla are compared. Special attention is given to the tip region and the diversity of the sensilla styloconica. Plesiomorphic features of the proboscis of Papilionoidea were found to include vertically extended exocuticular ribs composing the galeal wall, cuticular spines restricted to the ventral side of the proximal galea, and two rows of fluted sensilla styloconica restricted to the tip region. Apomorphic features of the proboscis in Papilionidae are three rows of small sensilla styloconica. The presence of cuticular spines all over the galeae was identified as an autapomorphy of Pieridae. Possible apomorphies of Nymphalidae are oblique exocuticular ribs of the galeal wall and the great number and length of the sensilla styloconica (significant at p < 0.01, t-test). A possible synapomorphy of Lycaenidae and Riodinidae are cuticlar spines up to the distal galeae. Distinct transformation series of sensilla styloconica give evidence that divergent evolutionary trends led from fluted shafts to a multitude of other shapes in Papilionidae, Nymphalidae (sensu lato), and Lycaenidae. Long smooth-shafted, club-shaped sensilla styloconica, bearing apical spines, are found in Nymphalinae, Apaturinae and Limenitidinae. Highly derived sensilla styloconica evolved in Heliconiinae and Melitaeini, which are arranged in only one row in both taxa. Their shafts are smooth, flattened and bear an excentral sensory cone. Further apomorphic character states are dented flutes which evolved several times, independently from each other in Satyrinae, Lycaeninae and Riodinidae. The results are discussed in a systematical context and provide the basis for a better understanding of the function of different morphological structures of the proboscis in feeding.