Biologically-based control of the red palm weevil, Rhynchophorus ferrugineus olivier (Coleoptera: Curculionidae) in Amadeo, Cavite, Philippines

• Main Author: Sanchez, Joanna Sababan
• Format: text
• Language: English
• Published: Animo Repository 2022
• Subjects: Rhynchophorus > Philippines > Cavite; Natural pesticides; Biology
• Online Access: https://animorepository.dlsu.edu.ph/etdm_bio/9; https://animorepository.dlsu.edu.ph/cgi/viewcontent.cgi?article=1009&context=etdm_bio
• Institution: De La Salle University

The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) native to Southeast Asia, is one of the most destructive pests of palm in the world. It is widely known from Southeast Asia as an important pest of coconut. Baseline information such as the life cycle is beneficial in determining the appropriate management strategy specific to RPW’s developmental stages. RPW reared on apple and coconut pith diet in the laboratory had a life cycle of 263.52±21.26 days. The average developmental period for each life stage are as follows: egg (4.28±0.19d), larvae (158.30±13.54d), pupa (19.29±1.44d), and adult (81.65±6.09d). Pheromone trapping was used to determine seasonal monthly abundance during the rainy and dry seasons commencing in October 2020 to October 2021 using three trapping tool designs, namely, inverted flower pot, chicken feeder and bucket. Results showed no significant difference in the RPW trap catches among the three trap designs (p-value 0.56>0.05). However, the chicken feeder trap captured the highest number of RPW adults. A significant difference (p-value 0.01B. subtilis, (2) B. amyloliquefaciens (3) Azadirachtin was conducted with water and Prevathon® as the negative and positive control, respectively. The 1st instar RPW larvae were used as the test insects for the biological assay. The results showed no significant difference (p-value 0.55>0.05) but B. subtilis was most lethal recording 80% mortality in RPW larvae, thus it showcased the strong potential of B. subtilis in the biological control of RPW. The results from the different studies are important information in the establishment of the bio-based Integrated Pest Management (IPM) Program for RPW in the Philippines. However, it is recommended to conduct follow-up experiments on these studies to verify the results and consider the modifications as follows: (a) for rearing: assess artificial diet compared to the apple and coconut pith food substrates; (b) trapping system: consider the addition of ethyl acetate in the food bait to enhance capture capacity, and (c) biopesticides trial: evaluate different concentrations of B. subtilis to determine the LC50 values, which is fundamental in the calculation of field formulation. Key words: biological control agent, biopesticides, coconut, laboratory rearing, life cycle, pest, pheromone, polymorph [6], trap designs, trapping, Rhynchophorus ferrugineus