TWO months after the government declared the Southern Luzon provinces of Cavite, Laguna, Batangas, Rizal and Quezon (collectively known as Calabarzon) in a state of emergency for coco-scale insect (CSI) infestation, the Philippine Coconut Authority (PCA) is currently mass-producing friendly insects at its Biological Control Laboratory in Lucena to help reduce the population of the coconut-eating insects, known as Aspidiotus rigidus.
“In preparation for the expected drop in CSI population, as a result of the initial procedure employed by the government such as pruning of infested fronds, trunk injection with systemic insecticide and application of organic sprays, the PCA is now mass-producing insects that are known to be natural predator of the Aspidiotus rigidus or cocolisap,” the agency said in a statement on Monday.
According to the PCA, “the scale insect infestation reduces or even stops photosynthesis in an infected coconut tree, producing yellow and dry fronds and unnaturally thin nut meat, and after few months of infestation, the tree dries.”
These natural enemies of an insect pest considered as kaibigang kulisap of our farmers, are actually biological control agents (biocon) by entomologists and crop protection specialists, the statement said. “Biocons include predators, parasitoids and even microbial pathogens.”
Predators, such as the Coccinellid beetle, consume large number of prey, including coconut-scale insects, while parasitoids like wasps, enter their host (usually insects), feed on it and, eventually, kill it in the process.
“The positive identification and origin of the pest [cocolisap] by Dr. Celia Medina and Dr. Barbara Caoili, both members of the research and development task force from the University of the Philippines at Los Baños [UPLB], in March paved way for the precise selection of biocon agents to be collected for augmentation,” PCA Administrator Romulo N. Arancon Jr. said.
Telsimia nitida, Chilocorus nigritus, Chilocorus circumdata, Pure Black and Orange Head (still-unidentified species of Coccinellid beetles) are predators, while the Aphytis sp. are parasitoid insects being mass-reared by PCA, while the Department of Agriculture’s Regional Crop Protection Center Laboratory in Los Baños is also mass-producing the same predatory insects, according to the statement.
The PCA said the friendly insects will be released in areas with low or reduced CSI infestation, to augment the natural population of these natural enemies of both the native (Aspidiotus destructor) and the invasive (A. rigidus) species of scale insects.
Arancon said “the release of biocontrol agents reared by PCA-certified laboratories will be done in two weeks after the application of organic sprays in an affected area, and when the degree of infestation has reached a manageable level, as assessed by UPLB and PCA scientists.”
Apart from regular monitoring, PCA will conduct follow-up studies to determine the successful establishment of the biocons at the site of release and to evaluate the long-term benefits of the strategy,” Arancon said.
The scale insect, although still mostly limited to the Calabarzon area, “could affect the entire 325 million fruit-bearing coconut trees across the country” if not immediately reduced, according to the PCA. In the past a number of similar infestations, such as the deadly cadang-cadang disease and the foliage-eating Brontispa, have threatened the coconut industry.
The PCA estimates that at present, some 3.5 million farmers work and around 25 million Filipinos are either directly or indirectly dependent on the coconut industry.
