Science and Environment

The Coconut Scale Insect (CSI) Outbreak in the Philippines

STAR SCIENCE - Ruben L. Villareal, Ph.D. - The Philippine Star

The coconut industry faces perhaps the worst problem it has encountered in many decades. The coconut scale insect (CSI) infestation has affected more than 1.2 million coconut trees in the CALABARZON. The pest infestation starts with yellowing of the lowermost leaves, followed by drying of all leaves leaving only the youngest leaf green and ultimately the death of the palm. The CALABARZON area, especially Batangas province, has been reported to be the most severely hit by the insect pest. The CALABARZON area supplies 42 percent and 14 percent of Luzon’s and the country’s total coconut production, respectively. The infestation of more than 6,000 trees in 15 barangays in Isabela City, Basilan has also been reported.

Thus, this infestation has had a huge damaging effect on the livelihood of many farmers and on the coconut industry. The Philippine Coconut Authority of the Department of Agriculture (PCA-DA) estimates that 25 million Filipinos rely upon the industry, 3.5 million of whom are coconut farmers. Twenty-seven (27) percent of the country’s agricultural land are planted to coconut. Sixty-eight (68) out of 79 provinces in the country grow coconuts (PCA 2010). As one of the top five exports of the country earing US$1 billion in 2011, coconut and its products contribute an annual average of 5.79 percent to the country’s gross value added (GVA) and 1.14 percent to gross national product (GNP).

The CSI’s presence in the CALABARZON area was first reported in 2010 in Tanauan, Batangas and has been spreading to nearby towns and provinces as far as Marinduque and Mindoro. The infestation is expected to spread to other areas of the country due to temperature, relative humidity, wind direction, and planting density.

The National Academy of Science and Technology Philippines (NAST PHL), the country’s highest advisory body on science and technology, recognizing the importance of the coconut scale infestation, with the Coalition for Agriculture Modernization in the Philippines (CAMP) and the Department of Science and Technology (DOST), conducted a round table discussion on April 29, 2014, to gather all science-based information on this economically important pest and with stakeholders concerned, discuss and establish the most appropriate strategies to address the problem.

What is the coconut scale insect?

The common coconut scale insect is Aspidiotus destructor.  The CSI infestation is not new in the Philippines.  It had attacked coconut trees in Mindanao before but did not cause any significant damage.

However, the destructive species infesting the CALABARZON area has been identified as Aspidiotus rigidus and not Aspidiotus destructor, based on morphological and DNA analysis by the University of the Philippines Los Baños faculty member-researchers Dr. Ireneo Lit, Jr., Dr. Barbara Caoili and Dr. Celia Medina.  A. rigidus was first described as a subspecies of A. destructor by Reyne in 1947 (with the name A. destructor rigidus) based on biological and morphological features and its status changed to A. rigidus in 1966 based on more rigorous scientific evaluation. It was a serious pest of coconut palm reported in 1947 in Sangi Island which is between Sulawesi, Indonesia and Mindanao, Philippines.

Thus, A. rigidus CSI is a more recent introduced species. Its rapid spread can be attributed to two possible reasons: changing wind pattern because of climate change, and/or unintentional introduction because of human economic activities. 

Activities to stem the CSI infestation

To address the rapid spread and wide scale damage of the CSI, PCA-DA created the Scale Insect Comprehensive Action Program (SICAP) Task Force on Aug. 28, 2013. The SICAP provided PCA-DA researchers with the opportunity to work with other scientists and institutions to craft strategies to address the CSI problem. The task force is composed of experts from the PCA-DA, the University of the Philippines Los Baños, Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD)  of the Department of Science and Technology and the Department of Trade and Industry.

Earlier, PCA-DA tried leaf pruning and mass releases of biocontrol agents coupled with spraying of banole oil and cochin. The use of detergent (four percent dishwashing soap) has also been utilized. However, it was found that leaf pruning and mass releases of biocontrol agents are not as effective as expected since the CSI outnumbered the biocontrol agents. Moreover, spraying of banole oil and cochin is labor- and cost- intensive.

The biocontrol agents which have been utilized are the coccinellids or ladybird beetles. However, their effectiveness has been erratic and difficulty in their rearing has been encountered. PCA-DA scientist Raul Alfiler had reported the release of thousands of the predator in selected towns in Batangas, Quezon and Laguna.

Other scientists at the National Crop Protection Center led by Mario Navasero have reported that a local parasitoid (Comperiella unifasciata Ishii Encyrtidae, Hymenoptera) can cause 80 percent parasitization of A. rigidus. They also oppose the proposed importation of natural enemies as these introduced species could displace the native species.

The general strategy adopted by the SICAP Task Force is as follows: (1) As an interim measure, the program seeks to manage the outbreak and its spread so that it will not cause more economic damage to farmers and the industry. (2) In the medium-term, research on and implementation of sustainable control measures using biological control agents will be conducted.

In the course of implementing these strategies, SICAP Task Force faces problems such as uncooperative and absentee farm-owners; limited support from LGUs and availability of manpower; limited supply and lack of water in some areas particularly in high elevation areas; total dependence on government support and the wait-and-see attitude; spraying of tall and senile trees with low production is not cost effective; and difficulty in spraying residential and intercropped farms.

Lessons learned from this devastation include the following: (1) Need for promptness and regular monitoring of pest infestation and accurate identification of the pest; (2) proactive quick response action and cooperation among key players; (3) strict implementation of the Bureau of Plant Industry (BPI)-Quarantine Special Order # 1 to restrict movement of infested plant parts; (4) basic research and development (R&D) studies on invasive pests should be well-established;  (5) intensive efforts of awareness drives should be effectively implemented and (6) less bureaucracy in the operationalization of massive pest management action plans.


Near term

In the near term, the spread of the CSI has to be slowed down and population pressure is reduced to buy time for the insect’s natural enemies to proliferate and for other measures to be applied on large scale to contain the insect outbreak in the current locations.

For young, short, and accessible coconut palms, heavily infested old leaves should be trimmed and burned. Then, they should be treated with detergents, horticultural oils (cochin oil) and/or various contact pesticides.

For senile, old, unproductive very tall palms, infested trees should be cut down and their leaves burned. The trunk can be converted to coco lumber (note: this will require a PCA permit).

For still productive tall palms, old infested leaves should be trimmed and burned. The trees should be sprayed with detergent or horticultural oils (cochin oil) to reduce the CSI population to give natural enemies time to multiply and work.

Buffer zones will be created to slow down the spread of CSI to the Bondoc peninsula, then to Bicol and Eastern Visayas.  The feasibility of establishing a 5 km buffer at the narrowest part of Quezon province will be made.

The efficacy of Dinotefuran (a third generation neonicotinoid systematic insecticide which is considered category 4 and thus is more benign to humans, less  persistent in the environment, and effective at very low dosages) should be explored. Different modes of application should be tested, the residue levels should be monitored in coconut water and meat (endosperm), and the possible impact on non-target organisms especially honeybees should be monitored. The injection of the neonicotinoid insecticide into the trunk of the coconut has been recommended since in this manner, the insecticide will be able to destroy the insect pest and not affect nontarget organisms including humans as when spraying is done. 

The mass rearing and testing of candidate biocontrol agents at PCA-DA and UPLB should be continued and intensified.

Intermediate term

The researches on ecology, mass rearing, protocol or deployment/release etc. of  wasps, lady beetles, earwigs, lacewings, fungi, parasitoids and other potential bio-control agents at PCA-DA and UPLB should be intensified.

Entomologists/ecologists from other state universities and colleges, e.g., Visayas State University, Central Luzon University, Mariano Marcos State University, University of Southern Mindanao, Central Mindanao University, etc., should be mobilized to flesh out a national Integrated Pest Management (IPM) program for various insect pests.

Long term

The mandate of National Crop Protection Center (NCPC) at UPLB should be revisited. The NCPC should be revitalized and together with PCAARRD and DA, formalize the National Crop Protection Research Agenda.

More than adequate funds should be provided the NCPC at UPLB and the Regional Crop Protection centers of BPI to provide direction, coordination, and implementation of the national crop protection program.

A national cadre of scientists (entomologists, plant pathologists, systematists, ecologists) should be organized and trained to develop integrated pest management measures against various genera of insect pests and to anticipate future insect (and pathogen) outbreaks.

Coconut replanting and intercropping program

For the CSI-ravaged communities in CALABARZON, immediate replacement for lost income from the affected coconut trees can be derived from interplanting between the coconut rows various kinds of annual food/cash crops like corn, root crops, beans and vegetables. For the medium- to long-term, perennials like pineapple, papaya, coffee, cacao and black pepper can be established between the rows of coconut.

PCA-DA should launch an aggressive coconut replanting program in the CSI-ravaged communities with, if available, PCA hybrid seedlings, and mass-selected seedlings. The coconut seedlings will take a few years to grow tall and CSI can be easily controlled with benign and cheap detergent sprays. By then, the race to identify effective biocontrol agents would have succeeded and/or natural predators would have reached equilibrium with the CSI host.

Saving the coconut trees is saving the country

Only this June, the national government led by Secretary Francis Pangilinan, presidential assistant for food security and agricultural modernization, launched a six-month emergency measure to address the CSI infestation with a budget of PhP700 million. But this is not enough. To help the coconut industry, it is important that all stakeholders must work harmoniously together to come up with the best protocols to eliminate the CSI. We have the best minds from the universities to conduct the research and the PCA-DA to implement the laboratory and field activities but they need to closely work together and support each other to eradicate this pest.

While funds are already available to address the CSI outbreak, there is a need to find ways of eliminating the red tape in the government’s accounting and auditing rules so as not to hinder the research and operation activities. We must bear in mind that eliminating red tapes does not mean circumventing the law. All Filipinos must understand that we are not only saving the coconut trees, but we are saving our country as well.

The National Academy of Science and Technology PHL, with the Coalition for Agriculture Modernization in the Philippines (CAMP), PCA-DA, and PCAARRD, DOST will continue roundtable discussions on the coconut scale insect problem with a national consultation on intercropping coconut with annual/perennial crops. NAST PHL will constantly update and advise government and the general public regarding the coconut scale insect infestation and its control and management.

* * *

Dr. Ruben L. Villareal is an academician of the National Academy of Science and Technology Philippines, and member, CAMP board of trustees. He is former professor and chancellor of the University of the Philippines Los Baños and dean of its College of Agriculture.  Academician Villareal is the chair of the Agricultural Sciences Division of NAST PHL and the focal person for the Coconut Scale Insect roundtable discussions. He can be contacted at: [email protected].

Acknowledgement: The expert help of Academician Emil Q. Javier in the preparation of the report on the coconut scale insect on which this article is primarily based is gratefully acknowledged.


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