none Integument; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Host parasite relationships; Diseases and disorders; Diseases; Microbial diseases Cydia pomonella (Tortricidae); Cuticle; Penetration by hymenopteran parasite; Hymenopteran parasites; Ascogaster quadridentatus; Cuticle penetration by parasite; Penetration of host; By Ascogaster (Hymenoptera), effect on susceptibility to fungus; Fungal diseases; Beauveria bassiana; Susceptibility, effect of cuticle penetration by hymenopteran parasite Ascogaster quadridentatus (Braconidae); Lepidopteran hosts; Cydia pomonella; Host cuticle penetration, effect on susceptibility to fungal disease; Penetration of host; Cydia pomonella (Lepidoptera), effect on host susceptibility to fungus Parasitism of Ascogaster quadridentatus promotes cuticle penetration in diapausing last instar larvae of Cydia pomonella by the fungus Beauveria bassiana . This cuticular weakness of parasitized host larvae corresponds with its reduced capability of wound repair reactions against invading hyphae, i.e. development of melanin spots in the outer cuticle layers. Further growth of the fungus in the endocuticle, however, is considerably checked. Dissemination of the disease in the hemocoel, destruction of tissues, paralysis and death are delayed in parasitized caterpillars. Even postmortal development and fructification of B. bassiana are adversely affected. Physiological pathologies of host cuticle, as induced by A. quadridentatus , are thought to be the first reason of the abnormal progress of Beauveria disease. It is not yet clear, whether this mechanism for its alone can be responsible for the delayed development of B. bassiana .