Behavior and Extra-Oral Digestion of the Wasp Sclerodermus guani (Hymenoptera: Bethylidae) Parasitizing

For many decades, the parasitic behavior of wasp Sclerodermus guani (Hymenoptera: Bethylidae), a typical generalist gregarious ectoparasitoid, was described as paralyzing the hosts by stinging with venom for egg-laying, and then their offspring larvae after hatching feed on hosts' hemolymph for the development until emergence. However, this paper reported a new mechanism of the wasp to parasitize the host borer Monochamus alternatus (Coleoptera: Cerambycidae). Observation on their parasitic behavior and their offspring growth discovered that the wasp needs 6 steps to complete its parasitic process, i.e. host-biting and-fighting, host-subduing and-nursing, host-liquefying and-feeding, wasps' berried and oviposition, larval sucking and developing, cocooning and wasps' emerging. Host-biting and host-liquefying are the key steps which would evolve an amazing array of mechanisms to create a liquid nutrient reservoir inside the borer body cavity for the parasitoid larvae's sucking and developing. This mechanism suggests that S.guani is a species of ectoparasitoid