Polymerase chain reaction assay for Cydia pomonella granulovirus detection in Cydia pomonella population.

The polymerase chain reaction (PCR) assay was successfully used to identify Cydia pomonella granulovirus (CpGV) in larvae of Cydia pomonella L. (codling moth). PCR with the primers CpGV-2A/CpGV-2B and CpGV-3A/CpGV-3B was found suitable for detection of CpGV. The primers Cp-I/Cp-II and Cp-III/Cp-IV were able to identify the transposable element TCp3.2 in C. pomonella larvae. The presence of CpGV in the larvae from orchards,which had been infected with CpGV was tested during 2 years post infection. (p.i.). CpGV was found in as many as 15% of the surviving larvae 1 year p.i. in one location. The virus was not detected in CpGV-infected orchards 2 years p.i. or in natural C. pomonella populations. This result suggests a poor persistence of CpGV in surviving C. pomonella individuals and its slow spread in a natural host population. One the other hand, the presence of a transposable element, transposon TCp3.2 may correlate with virus redistribution in this insect population.