Phenotypic plasticity of the reproductive system of female Leptinotarsa undecimlineata

The effect of a non-host plant, Solanum myriacanthum, on ovarian dynamics and longevity of Leptinotarsa undecimlineata (Stål) (Coleoptera: Chrysomelidae) was studied under laboratory conditions. Females reared on the natural host, S. lanceolatum, served as controls. Female beetles did not accumulate eggs on the non-host. After continuous exposure to S. myriacanthum, the production of basal oocytes was diminished and oocytes were reabsorbed. Oocyte size, however, was not affected when compared to females fed with S. lanceolatum. In control females, the first mature eggs appeared at 34 days old. No eggs matured in females fed with the non-host in the 54-day duration of our experiment. Continuous exposure to the non-host resulted in significantly less resorption of reproductive resources than a stress period of 20 days on the non-host. Egg resorption was completely reversible after the preferred host was re-offered for another 20 days. Further studies under field conditions will be necessary to understand why this Leptinotarsa species uses only one of two sympatric Solanum species. © 2005 The Netherlands Entomological Society.