Damage assessment of Oryctes rhinoceros Beetle (Oryctes rhinoceros Linn) and its host range in selected sites in the Philippines

Abstract

The study was conducted to determine the extent of damage and host range of O. rhinoceros in different coconut areas in the Philippines. Using the five criteria based on Bedfort assessment, at least 50 coconut palms in one hectare were randomly selected and replicated three times from selected provinces in Luzon, Visayas and Mindanao. Results revealed that there were at least considered alternate host of O. rhinoceros; such as buri (Corypha elata), anahaw (Saribus rotundifolius), oil palm (Elaeis guineensis), nipa palm (Nypa fruticans), betel nut (Areca catechu), banana (Musa spp.), pineapple (Ananas comosus), papaya (Carica papaya), and Colocasia (Colocasia spp). Moreover, the most affected other host plant were African oil palm, particularly in Palawan and Davao del Sur sites where this is periodically planted as replacement for sugarcane, banana, coconut palm and forest areas. The percentage of infested coconut palm based on the leaf damage caused by beetle was found ranging from 6.47 to 10.67%. Among the coconut fields surveyed, Goa, Camarines Sur site got the highest percentage of damage with 10.67% followed by San Francisco, Quezon (8.79%) Ragay, Camarines Sur, Baler and Dingalan, Aurora, Lopez, Quezon with 8.68%, 8.45%, 8.19%, and 7.53% respectively. In contrast, relatively low percentage of damage was recorded in Buenavista, Marinduque with 6.47%. In terms of leaf damage category, the highest was also observed in Goa, Camarines Sur with 2.01 followed by Baler Aurora and Padada, Davao del Sur with 1.89. The same category were observed in Dingalan, Aurora and Aborlan, Palawan with 1.87 while the lowest damage category was recorded from Valencia, Negros Oriental with 1.83. Attacks on coconut palms were not shown any danger on the plants.