Parasitic behaviour and developmental morphology of reared on the factitious host .

The egg parasitoid is a key natural enemy in the biological control of various agricultural and forestry pests. It is particularly used against the brown marmorated stink bug and the emerging defoliator pest in East Asia. It has been proved that the eggs of can be used as a factitious host for the mass production of . This study systematically documented the parasitic behaviour and developmental morphology exhibited by on the eggs of . The parasitic behaviour of encompassed ten steps including searching, antennation, locating, digging, probing, detecting, oviposition, host-feeding, grooming, and resting. Oviposition, in particular, was observed to occur in three stages, with the parasitoids releasing eggs during the second stage when the body remained relatively static. Among all the steps of parasitic behaviour, probing accounted for the longest time, constituting 33.1% of the whole time. It was followed by digging (19.3%), oviposition (18.5%), antennation (9.6%), detecting (7.4%), and the remaining steps, each occupying less than 5.0% of the total event time. The pre-emergence of adult involves four stages: egg (0 to 2nd day), larva (3rd to 9th day), pre-pupa (10th to 13th day), pupa (14th to 22nd day), and subsequent development into an adult. Typically, it takes 25.60 ± 0.30 days to develop from an egg to an adult at 25℃. This information increases the understanding of the biology of and may provide a reference for optimising reproductive devices.