The proof of vertical transmission of the nucleopolyhedrovirus in many generations of the gypsy moth Lymantria dispar L

Introduction. Insect viruses can play an important role in population dynamics of their hosts. That is why the problem of permanent viral infection support among virus-positive insects is associated with one of the intriguing problems of general biology and virology.

Materials and methods. Under laboratory conditions, the modeling of the vertical transmission of the nucleopolyhedrovirus (NPV) gypsy moth was implemented at relatively high level of mortality among insects of parental generation (60%). The diagnostics of the occult virus was executed by the PCR method among insects before their infection under laboratory conditions, as well as among insects that survived after inoculation. results. The NPV-caused mortality among insects that survived after infection in generations F₁, F₂, and F₃ was 14 ± 4%, 10 ± 4%, and 5 ± 0.5%, respectively. In the following three generations NPV-induced mortality was not noticed.

Discussion. The level of the virus-positive individuals among the gypsy moth embryos in all occasions was higher than the NPV-induced mortality of insects. Thus, the given results show that the presence of virus among insect does not mean inevitable mortality of their hosts. Perhaps, the viral DNA can completely or partly lose its infectivity but may exist in the analyzed insect samples.

Conclusions. The viral infection can be formed among progeny surviving after inoculation of insects. It can be actuated during three generations of the gypsy moth. The level of the virus-positive individuals among the gypsy moth embryos determined by the PCR method in daughter generations was higher than the NPV-induced mortality of insects.