Systematic Implications of Butterfly Leg Structures that Clean the Antennae

The foreleg tibial epiphyses of Lepidoptera are used to clean the antennae Jander 1966, ODe!! et al. 1982 and included references. Among butterflies, the skippers Hesperiidae and swallowtails Papilionidae possess a tibial epiphysis Evans 1949, Ehrlich 1958, but other butterfly families do not. The absence of a tibial epiphysis in these families raises the question of how they clean their antennae. Jander1966 addressed this question and reported three kinds of cleaning behavior in butterflies. Hesperiids use their foreleg tibial epiphyses to comb antennae. Lycaenids and most nymphalids pull each antenna between a midleg tibia and femur. Satyrine nymphal ids clean antennae by sliding each against a midleg tarsus as they walk. Jander did not mention any special structures for cleaning antennae besides the tibial epiphysis. There is a hypothesized correlation between Jander's behavioral observations and midleg morphology in lycaenids, riodinids, liby theids, and nymphalids. Eliot 1973 reported that there are scale "brushes" on the midleg tibia and femur of virtually all lycaenids, that the function of these brushes is unknown, and that the brushes allow the midleg to be distinguished from the hindleg. Sorensen 1980 hypothesized that the midleg brushes are used by lycaenids to clean the antennae. Scott 1985 accepted this hypothesis, noted that Ehrlich 1958 had discovered a midleg tibial brush in the monarch Danaus plexippus Linnaeus, a danaiine nymphalid, and reported that similar brushes occur in many riodinids and nymphalids. The behavior of cleaning the antennae with the legs has been used in determining phylogenetic relations among the butterfly families. Kristensen 1976 proposed that the Nymphalidae including Liby theidae and Lycaenidae including Riodinidae form a monophy letie lineage, in part because both families use the midleg for