Biological attributes of Hadronotus pubescens (Motschoulsky) (Hymenoptera: Scelionidae) reared on refrigerated eggs of Riptortus pedestris Fabricius (Hemiptera: Alydidae)

Hadronotus pubescens (Motschoulsky) (Hymenoptera, Scelionidae) is a solitary egg parasitoid that lays its eggs in the eggs of Riptortus pedestris Fabricius (Hemiptera: Alydidae), which is a major pest for legume crops in Korea, Japan, and Bangladesh. This study assessed the quality of refrigerated R. pedestris eggs in relation to host-accepting behaviors and biological characteristics, including parasitism rate, development duration, emergence rate, sex ratio, and longevity. The hatchability of the refrigerated eggs was evaluated. R. pedestris eggs that were refrigerated for over 30 days failed to hatch entirely. The refrigeration influences the average duration of each host acceptance behavior (i.e., drumming, drilling, oviposition, and marking) on host eggs. The number of parasitized host eggs per female, the male proportion, and the emergence rate of H. pubescens were unaffected by chilling for up to 30 days in comparison to fresh eggs. Moreover, the refrigerated host eggs did not influence the reproduction of the emerged adult parasitoids or the growth of their offspring. The longevity of H. pubescens was not influenced by the refrigeration of R. pedestris eggs. The refrigeration of host eggs for up to 30 days did not adversely affect any biological features of the second generation of H. pubescens. So, keeping H. pubescens eggs in the fridge can be a good way to produce a lot of the parasitoid, and the host eggs that are no longer alive after being stored in the cold can be used in the field to increase parasitism.