Comparisons of developmental and reproductive biology between parthenogenetic and sexual Echinothrips americanus (Thysanoptera: Thripidae)

Echinothrips americanus Morgan, an invasive pest on various ornamentals and greenhouse crops, was introduced into mainland China recently, posing a potential threat to ornamentals and greenhouse crops. It exhibits two different reproductive modes: arrhenotokous parthenogenesis and sexual reproduction. Laboratory studies were conducted to compare the developmental and reproductive biology of E. americanus in these two reproductive modes. Results showed that the oviposition period, and longevity of female adults using sexual reproduction were longer than those using parthenogenesis. Furthermore, sexual female adults had higher fecundity and survival rates. However, no significant differences were found among immature stages in the durations of first and second instars, prepupae, and pupae between the two reproductive modes, with the exception of the duration of the egg stadium. The survival rates for eggs and first and second instars were higher in sexual E. americanus whereas there were no survival differences for prepupae and pupae. These results provide valuable insights into the mechanisms of parthenogenesis and sex determination in Thysanoptera.