Relationship between the Population Dynamics of the Gypsy Moth (Lymantria dispar L., Lymantriidae: Lepidoptera) and the Genetic Polymorphism of the Nuclear Polyhedrosis Virus

The population dynamics of the gypsy moth and the genomic DNA of the nuclear polyhedrosis virus (NPV) pathogenic for this insect were simultaneously studied using nucleic acid molecular hybridization (NAMH). It was demonstrated that population outbreaks of the gypsy moth were accompanied by an increase in its sensitivity to NPV and in the genetic polymorphism of NPV strains circulating in the insect populations. The hybridization activity of the virus strains isolated at the phase of gypsy moth population growth was significantly higher (p < 0.001) than the activity of the strains isolated at the phase of population decrease.     

The response of gypsy moth (<Emphasis Type="Italic">Lymantria dispar</Emphasis> L.) larvae infected with nuclear polyhedrosis virus to induced resistance in birch (<Emphasis Type="Italic">Betula pendula</Emphasis> Roth.)

The effects of birch resistance induced by its artificial defoliation on the development of gypsy moth larvae and their sensitivity to viral infection and on the state of the antioxidant and detoxification systems of the insect midgut were studied. The dynamics of larval body weight; larval mortality and its etiology; glutathione-S-transferase (GT), nonspecific esterase (NE), and catalase (CAT) activities; and the ratio between the concentrations of oxidized and reduced thiol-containing compounds (RSSR/RSH) were estimated. In larvae feeding on the leaves of a previously defoliated plant, body weight was decreased, NE was inhibited, and the RSSR/RSH ratio was increased.