none The granular cells of the host Pseudaletia separata were associated with the initial recognition of foreign materials. When the host was parasitized by Microplitis mediator , the filopodial elongation of the haemocytes was strongly suppressed. An inhibition of filopodial elongation was also observed following injection of the calyx and venom fluids of M. mediator . The inhibitory mechanisms of Microplitis mediator and Apanteles kariyai against the cellular defence reactions of the host seemed to depend on different strategies. Circulatory system; Blood; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Host parasite relationships; Immunology and repair mechanisms Pseudaletia separata (Noctuidae); Blood cells; Haemocyte morphology, changes in response to hymenopteran parasites; Hymenopteran parasites; Apanteles kariyai & Microplitis mediator; Haemocyte morphology relations, effect on encapsulation capacity; Reaction of host to parasite; Haemocyte morphological changes in response to hymenopteran parasites; Immune like reactions; Haemocyte filopodial elongation, effect of hymenopteran parasitism Apanteles kariyai; Microplitis mediator (Braconidae ); Lepidopteran hosts; Pseudaletia separata; Host haemocyte response; Reaction of host to parasite; Lepidopteran host haemocyte response to parasitism