Phenotype “Explosion” in Hercinothrips femoralis (O. M. Reuter 1891) (Thysanoptera: Thripidae): A Particular Phenomenon for Successful Introduction of Economic Species

Intraspecific trait variability, produced by genetic variation and phenotypic plasticity within species, allows the optimization of individual’s fitness in different conditions, ultimately enhancing survival and reproduction. We investigated variability in morphological traits of invasive thrips species Hercinothrips femoralis (O. M. Reuter, 1891) during simulated introduction and establishment in a novel environment. Six generations of this species were reared in laboratory for eight months. The initial phase of introduction was simulated by the transfer of thrips generations to environments with different environmental conditions varying in temperature and humidity. The statistical evaluation of seven measured morphological attributes (e.g., body length, wing length) was performed to analyse the morphological variability. Species phenotypic “explosion” in several morphological characters (especially total body length) was observed during the initial phase of introduction in generations brought from the primary site into novel environments with different conditions. Probable phenotypic specialization was observed during the generations following introduction under the same ecological conditions. Furthermore, the most variable morphological features were specified. This study goes beyond the taxonomic level, because its results and main idea can be applied to any invasive species.