Biological Control Of The Coconut Palm Rhinoceros Beetle (Oryctes Rhinoceros L.Coleoptera: Scarabaeidae) Using Rhabdionvirus Oryctes Hüger In Sultanate Of Oman

• M. M. Kinawy
• Royal Court Affairs, Directorate General of Agriculture & Veterinary Services, P.O. Box : C.P.O. 17, Code : 111, Muscat Sultanate of Oman.

Abstract

The virus Rhabdionvirus oryctes Hüger was initially released against the coconut palm rhinoceros beetle Oryctes rhinoceros L. in Sultanate of Oman, by means of releasing virus-infected beetles, which act as vectors to spread the virus into natural breeding sites. Total of 900 virus-infected beetles were released in six locations in Dhofar province. Two months after release, we could confirm the incidence and spread of that virus to local population of Oryctes rhinoceros L. using the rapid smear technique, we could confirm that out of 123 beetles collected from the local population there were 50 beetles infected with the R. oryctes virus, i.e. 40.7 % of the local population became infected with that virus. After 16 months of virus introduction, dramatic reduction in beetle damage occurred whilst high levels of damage existed at the outset. Two years after virus introduction, marked reduction in rhinoceros beetle damage to palms was recorded, since percent of fronds damage (DS) ranged from 24 % to 37 % (with an average of 30.8 % ± 4.6) and palm damage (RSD) ranged from 19 % to 43 % (with an average of 27.7 % ± 8.8). Later on after three years of virus introduction, the damage was highly reduced dramatically to about half the percentage of the previous year. The lowest levels of damage started from the fourth year after virus introduction, since the mean percent of fronds damage (DS) reached 10.3 % ± 4.8 and the mean percent of palm damage (RSD) reached 6.5 % ± 4.2. The really lowest percent levels of damage recorded in the fifth and the sixth years after virus introduction, since the mean of fronds damage (DS) were 5.7 % ± 2.2 and 4.2 % ± 2.0, while the mean percentage of palm damages (RSD) were 5.8 % ± 3.5 and 3.5 % ± 2.1, respectively.