ARE EYESPOTS HONEST INDICATORS OF FECUNDITY IN BICYCLUS ANYNANA?

Abstract

Males of the dry season form of Bicyclus anynana butterflies show a preference to mate with females with intact forewing eyespots centres on dorsal and ventral wing surfaces. Female forewing eyespots are sexual ornaments which may be honest signals of female condition and aid in male choice. A mate choice experiment was carried out to deduce if a particular set of eyespots in females are preferentially preferred by males. The white, UV-reflective center of female forewing eyespots were blocked by applying black paint to artificially create ‘dorsal’ and ‘ventral’ females. There was no preference of any particular set of eyespots and hence, both dorsal and ventral eyespots may be equally important for sexual signalling or species recognition. It was then tested whether eyespots are honest signals, i.e., whether individuals with larger eyespots have more fat bodies and heavier ovaries and may thus be more fecund. Larval diet was manipulated to create females of low and high condition and then tested whether eyespot size was variable and condition-dependent and whether eyespot size correlated with ovary or fat body size. Our study showed that the forewing eyespots are not condition dependent traits and, thus, conclude that they are not honest indicator traits.