2022 Volume 64 Pages 63-68
The biological control agent Haplothrips brevitubus (Karny) (Thysanoptera: Phlaeothripidae) exhibits female reproductive diapause, and the incidence of diapause under short-day conditions differs among geographical populations. The influence of storage at 5°C for 50 days on mortality in both diapausing and non-diapausing females and the number of eggs laid at 20°C were investigated in a strain with a higher diapause incidence. In addition, the inheritance of diapause was examined by crossing strains with higher and lower incidences of diapause. The survival percentage during cold storage in diapausing females was higher than that in non-diapausing females. However, the total number of eggs laid per survivor after cold storage did not differ between the diapausing and non-diapausing females. The crossing experiments showed that diapause is under polygenic control, and diapause-suppressing factors exist in both the autosomal genome and cytoplasm. Being able to keep diapausing females in cold storage might contribute to the achievement of low-cost, mass-produced, and high-quality H. brevitubus individuals for controlling pest thrips.
