Bicol coconuts threatened by coconut scale insects—PCA

The Philippine Coconut Authority (PCA) has placed Bicol under watch against the possibility that the massive scale insect infestation wreaking havoc on the coconut industry in nearby southern Tagalog provinces may reach the region.

Harvesting coconuts in Camarines Sur
Harvesting coconuts in Camarines Sur

Recent reports said coconut scale insect (CSI) infestation in the Southern Luzon provinces of Batangas, Cavite, Laguna and Quezon has reached alarming levels which when not contained immediately might spread up to Bicol.

According to the Philippine Coconut Authority (PCA), CSI, also known as Aspidiotus destructor Signoret (Hemiptera: Diaspididae), are small insects which are plant parasites that usually cause problems not only in coconut nurseries and young palms but also in those that are already bearing nuts.

They have been observed underneath coconut leaves in young palms, and in affected bearing palms, the insects are found not only on the underside of the leaves but also on the surface of the fruits and petioles.

These insect pests cause yellowing or chlorosis, wilting, premature nutfall and low yield because it continuously siphons off the plant sap with their specialized mouth parts.

Thick sooty molds grow on the honeydew excreted by these insects, preventing photosynthesis, and in the process, coconut trees die because CSI block leaf pores, preventing leaves from producing nutrients for the tree.

The insect is dispersed by wind and its enigmatic nature, which is very small and remains undetected for long periods during which it rapidly multiplies before infested leaves show signs of yellowing, is a big problem being encountered by PCA.

Fortunately so far, coconut palms in Camarines Norte, the Bicol province closest to Quezon Province, have been tested negative to SCI, Mateo Zipagan, PCA regional manager for Bicol based here, on Monday said.

“While our wish is for these insects in its currently infested Tagalog provinces to be contained the soonest possible time and that the do not reach any part of Bicol, our office is not letting its guard loose so that in case they spread down to the region, we can readily act against them,” Zipagan said.

PCA has solutions in containing the pest that is now being applied in the Southern Tagalog provinces like the release of predatory coccinellids (Cryptolemus and Telsimia) beetles that eat scale insects in the affected areas.

The Albay Research Center, the research arm of PCA based in Guinobatan, Albay, in collaboration with Bureau of Plant Industry Plant Quarantine Service and National Crop Protection Center — all of the Department of Agriculture (DA), is looking for sustainable long-term solutions such as biological control, he said.

Biological control involves insects, earthworms and other species which may become predators of CSI.

It is a way that lets nature take its course on preventing the spread of the infestation, Zipagan said, citing an explanation from the National Academy of Science and Technology.

PCA is also pursuing the mechanical control wherein the scale insects and mealybugs in young coconut plants can be controlled manually by scraping them off or spraying them off with a jet of soapy water.

Washing infested plant parts or a brisk wash spray of water can be helpful in reducing insect populations, particularly in cases of small infestations and/or in young palms, Zipagan said.

Also part of this mechanical control is leaf pruning and disposal of pruned leaves by burning, reducing the reproducing population of the scale insects and mealybugs and prevents the spread to other areas.

Chemical control with contact or systemic insecticides can be used but is effective only for the "crawler" stage of the pest or the very young scale insect.

Furthermore, the use of insecticide spraying is also applicable but only for young palms and seedlings. DA’s Regional Field Unit for Bicol based in Pili, Camarines Sur, on the other hand, is intensifying its campaign to encourage coconut intercropping to sustain the livelihood of farmers that may be affected just in case (but not hoping) CSI infestation takes place in the region.

Abelardo Bragas, DA regional executive director, had earlier said that intercropping is among the palliative solutions the agency is pushing in any event of coconut farm infestation such as the present reign of brontispa in some parts of the region.

Brontispa or coconut leaf beetle, which is a flat and slender beetle that feeds on the soft tissues of coconut fronds enough to kill the tree, is one of the current problems that confront Bicol’s coconut industry and being dealt with by the PCA.

Control measures being initiated by PCA, which include pesticides and biological control agents such as parasitic wasps, are now in place, Zipagan added. (PNA)
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