Effect of female body size on courtship preferences of males in two Pierid butterfly species: <scp> <i>Pieris melete</i> </scp> and <scp> <i>P. napi</i> </scp>

Abstract Reproductive interference has been reported in many organisms and has been observed in all aspects of the reproductive process. In some organisms, heterospecific females are preferred due to their larger body size. However, no studies have conducted mate choice experiments involving manipulation of female body size in species with smaller females than males. This study examined differential responses of males to female body size to determine the direction of reproductive interference in the butterflies Pieris melete and Pieris napi (Pieridae) by investigating whether female body size affects courtship partner recognition. In individuals of normal body size, both larger P. melete males and smaller P. napi males courted larger P. melete females with high frequency. However, when body size was manipulated by regulating temperatures during larval growth, smaller P. melete males courted smaller P. melete females, whereas larger P. napi males courted larger P. napi females. These results imply that an interspecies difference in the effect of female body size on courtship partner recognition caused reproductive interference between P. melete and P. napi .