none no species Arylphorin (Ap) is the principal protein of the last larval instar hemolymph of Trichoplusia ni . It was shown to be homologous with the Aps of Manduca sexta and Lymantria dispar by Western blot and quantitative immunoelectrophoresis. Another hemolymph storage protein in T. ni of lesser titer was shown to be homologous with larval hemolymph protein (LSP) of M. sexta . Ap titer increased dramatically in the last larval instar of T. ni , as in other holometabolous insects studied. Parasitization by Chelonus sp. caused the Ap titer to rise prematurely in the penultimate larval instar of T. ni . This rise in Ap in the fourth instar is one of the earliest diagnostic signs of parasitization. Among the suite of behaviors of the Chelonus larva on exiting the host is depletion of the host cadaver of most remaining protein. Circulatory system; Blood; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Host parasite relationships Trichoplusia ni (Noctuidae); Blood and serum proteins; Haemolymph; Arylphorin characterization & parasite induced precocious increase; Hymenopteran parasites; Chelonus; Host arylphorin, precocious increase induced by parasite; Reaction of host to parasite; Arylphorin, precocious increase induced by Hymenoptera Chelonus (Braconidae); Lepidopteran hosts; Trichoplusia ni; Host arylphorin, precocious increase induced by parasite; Reaction of host to parasite; Arylphorin in lepidopteran host, precocious increase induced by parasites