The pathogenisity of stored polyhedrosis virus of the red palm weevil, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae)

The laboratory bioassays showed the frozen stored Rhynchophorus polyhedrosis virus (FSRPV), and newly extracted one from died Red Palm Weevil (RPW) collected from the field. The FSRPV was stored for 36 months under -4oC. The newly extracted Rhynchophorus polyhedrosis virus (NERPV) was used for contamination of laboratory reared larvae of RPW at different ages as a comparison in the pathogenicity between FSRPV and NERPV. The infected larvae were bioassayed and LC50 and LT50 values were computed. The range of LC50 for NERPV was from 2.6x107 to 4.0x107 Polyhedra Inclusion Bodies (PIBs) /100 g diet, while the LC50 for FSRPV ranged between 3.3 to 3.8x107 PIBs/100 g diet. The range of LT50 for NERPV was from 2.4 to 24.3 days while it was from 3.2 to 25.9 days for FSRPS.