Relationship between body size and ovariole number in three cerambycids inhabiting mulberry orchards

Abstract

Natural selection operates on a suite of life-history traits. Those traits are under constraints and trade-offs which often differ among species. Thus, there are an array of suites found in insects. Studies conducted to date predict two reproductive strategies in the family Cerambycidae: body-size dependent ovariole number and pro-ovigeny versus body-size independent ovariole number and synovigeny. To investigate these relationships, we examined the elytral length, the body mass, the number and development of ovarioles, and the content of alimentary canals for adult females of three cerambycid species captured in mulberry orchards. The results confirmed synovigeny in two lamiines Apriona japonica Thomson (Coleoptera: Cerambycidae) and Psacothea hilaris (Pascoe) (Coleoptera: Cerambycidae) and no adult feeding in the cerambycine Xylotrechus chinensis (Chevrolat) (Coleoptera: Cerambycidae). We also found the dependence of ovariole number on body size and pro-ovigeny in X. chinensis, whereas invariable numbers of ovarioles irrespective of body size and synovigeny were found in A. japonica and Ps. hilaris. Two likely different suites of reproductive traits including size dependence of ovariole number and ovigeny are discussed by comparing life-history traits of nine cerambycids reported by the present and previous studies.