Notes on sex ratio and reproductive modes in field populations of two pest thrips species (Thysanoptera, Thripidae) in Italy

Two important Italian pest thrips species, Frankliniella occidentalis and Thrips tabaci, reproduce arrhenotokously in field populations with high female-biased sex ratios. However, in the laboratory in F. occidentalis male numbers approached these of females (0.7:1 — males:females), but in T. tabaci no males were produced. The presence of Wolbachia could not be detected in unmated females of laboratory strains of the two thrips species.