Responses by Diprion Hercyniae (Hymenoptera: Diprionidae) to Its Food Plant and Their Influence on Its Relationship With Its Parasite Drino Bohemica (Diptera: Tachinidae)

The sawfly Diprion hercyniae (Htg.) prefers the old to the new growth of its preferred food plant, Picea glauca (Moench) Voss. The similarity between the responses by the sawfly and those by one of its parasites, the tachinid Drino bohemica Mesn., and the significance of this similarity are discussed.