[Headlines of The Connection] The coconut pest’s now named: What’s next?



BRGY. BOOT, TANAUAN CITY—Coconut farmer Juan Plete can’t contain the swarming of pests that have been pestering his care of over-100 coconut trees here that mother-in-law Elena Malabanan entrusted him. These pests took care of Plete instead, like thousands of other farmers here and in Batangas province.

Plete, with the biyenan’s blessing, cut off a hundred trees and sold those to a nearby coco lumber here in this city, the reported epicenter of a coconut scale infestation in 2010 that, until today, has posed threats to the world’s top supplier of coconuts.

Two related species of the Aspidiotus insect specie that has been pestering on Philippine coconut trees for four years have confused scientists. Now that the precise pest, with the scientific name Aspidiotus rigidus (not Aspidiotus destructor), has been named, the search is on for the pesticides that can exterminate this coconut insect. (Photo by Lyle Buss of the University of Florida)

Two related species of the Aspidiotus insect specie that has been pestering on Philippine coconut trees for four years have confused scientists. Now that the precise pest, with the scientific name Aspidiotus rigidus (not Aspidiotus destructor), has been named, the search is on for the pesticides that can exterminate this coconut insect. (Photo by Lyle Buss of the University of Florida)







If the tree that’s cut is long, Plete nets P1,000; shorter ones can rake P800. Not bad for a take-home profit, he says, but like the coconut fruits —sheltered under yellowish leaves— that have been dropping from the top, hopes to revive past bounties from coconut are falling.

Hindi na magamot (The tree can’t be cured anymore),” said Plete. “Hindi na mapakikinabangan ang niyog eh kapag nabulok na siya. May tama na din kasi iyung katawan ng puno pag nilagare mo siya (The rotten coconut fruit is of no use already. If you cut off the tree, you can see even the trunk’s affected).”

Plete admitted he doesn’t know how to precisely kill a coconut scale insect, as the Philippine Coconut Authority generically calls it. He had been told to use detergents like the local brand Joy and a globally-renowned insecticide called Furadan that’s commonly used in rice and corn.

In disgust over the coconut pests that won’t go away, Plete has nearly called it quits from planting those trees. “Kasi nga wala nang mahanap na solusyon sa sakit ng mga niyog (The precise cure to kill the coconut pests remains elusive).”

But in this fourth year of what PCA, says a flyer, calls the “new threat” to the Philippine coconut industry, there’s a new twist: the pest that was initially identified was wrong and its correct identity was established by Filipino scientists recently. Yet there seems to be uncertainty as to precisely naming the pesticide or other set of methods that can kill these pests.


That pest

Filipino entomologists (scientists who study insects) said the long-identified name of the pest, Aspidiotus destructor, was wrong. Dr. Celia Medina of the University of the Philippines-College of Agriculture in Los Baños, Laguna told The Filipino Connection the correct pest’s scientific name is Aspidiotus rigidus.

The first-identified name of the scale insect, Aspidiotus destructor, was first discovered by French pharmacologist Victor Antoine Signoret in 1869. Meanwhile, a 1948 paper by an entomologist named A. Reyne found a “sub-species” of the Aspidiotus destructor, the rigidus, so he called the subspecies Aspidiotus destructor rigidus. 

However, Medina points to a 1966 taxonomical paper by Russian entomologist Nikolai Borchsenius that raised Aspidiotus destructor rigidus into a species (not anymore a subspecies), hence becoming Aspidiotus rigidus.

Reyne had found the subspecies in Sangi island of the old Dutch East Indies, or what is now Indonesia –the world’s second-biggest producer of coconut behind the Philippines.

But while the PCA, through its Filipino-language flyers, referred to the pest as Aspidiotus destructor, Medina’s team advised the PCA on October 2013 “to refer to the outbreak species as ‘undetermined species of aspidiotus.’” This is because she, Caoili (an insect molecular biologist) and Dr. Sheryl Yap (an insect taxonomist) “were still verifying their initial findings”. 

This insect, prominently found at the bottom part of coconut leaves, makes the coconut’s green leaves turn yellow, leading these leaves to wilt and eventually die. The situation then leads to premature nutfall, and eventually coconut farmers reduce their harvests. Even fronds (or long, divided leaves) get colonized by these insects, and coconut seedlings and young palm trees are more likely to die, a PCA online primer on the CSI wrote.

Old papers on these two pests, like those done in Sangi from 1929-1933, wrote that the insects are spread generally by wind and less by mutual contact of the trees. However, the then-subspecies Aspidiotus rigidus was spread “by the agency of man, presumably by coconut seedlings or ornamental plants,” as Reyne wrote in 1948.

Medina and UPLB colleague Dr. Barbara Caoili, who are both from the College of Agriculture’s Crop Protection and Management Division, did say the said coconut pest “was said to have been reported first” in Sangi after collecting and preserving specimens from there. Morphologic and DNA analysis of sampled coconut leaves in Sangi island matched those found in Batangas province.

“We are 99-percent positive (of Aspidiotus rigidus),” Caoili told BusinessMirror. Medina, meanwhile told The Filipino Connection the two Aspidiotus species “can occur in the same place or in the same palm”.

For her part, Dr. Gillan Watson of US state of California’s Department of Food and Agriculture (CDFA) collaborated with Medina’s team in studying that armored scale insect. But since she wrote a paper on the insect for a scientific journal, and is not at liberty to disclose her paper’s details, Watson told The Filipino Connection the insect was “not identified correctly because the species is not well-known, although it has a past track record of causing occasional, very damaging outbreaks on coconut palms in Indonesia.”

Watson herself said identifying the pest “was a very difficult one”. She only recognized the pest in entomological papers she’d read during the 1980s.

“Morphologically, Aspidiotus rigidus and A. destructor have very subtle variation, not easily discernible without mounting in microscope slide,” Medina said. (Morphology is the study of the form and structure of organisms.) “Even other scientists say that they can be distinguished only using their biology but studying the biology of a species takes a very long time.”


What pesticide?

PCA’s survey on the extent of infestation, from 2012 to February this year, has identified about 1,010,517 coconut trees in the Calabarzon provinces of Batangas, Laguna, Quezon and even Cavite to be infested, says a March PCA report. About 733,491 trees in Batangas alone were infested. About 434,298 trees had been sprayed with pesticides, as some 466,071 others had been pruned (or some parts of the tree had been selectively removed).

Now that the pest’s been precisely named, what about the cure to arrest the current biggest threat to the coconut industry of the Philippines, the world’s biggest coconut producer?

When the pest was initially identified as Aspidiotus destructor, PCA’s flyer on the CSI recommended the cutting down and burning of affected leaves. Smaller palms’ leaves, meanwhile, may be cleaned with detergent.

For taller coconut trees whose leaves can go up to over-30 meters from the soil, PCA had recommended using pesticides through “foliar spraying” or directly spraying the leaves with fertilizer. And to contain the spread of the pests, PCA have put Batangas, Laguna, Quezon and Cavite provinces under quarantine to prevent the growth of coconuts that were hit by the pest.

Still, the precise pesticide to use pesks scientists, PCA personnel and coconut farmers. Medina said farmers “should be discerning because there is a proliferation of different products that are dubbed to be effective”. Even chemicals Medina’s team had tested thus far “can be effective depending on the dosage”.

PCA Batangas Field Office’s Acting Senior Agriculturist Alvin Ardeza told The Filipino Connection the specific pesticides cannot be provided to the coconut farmers given the old confusion over the pest’s name.

Ardeza said cochin oil is still the product PCA in Batangas is using for spraying. Cochin oil can only kill adult insects —not the eggs— if sprayed directly at the insects; two-to-three treatments should be done, Ardeza said.

However, a March report by the PCA wrote the spraying of cochin oil coupled with using detergents “was discontinued due to the low temperature” recorded last December 2013 and January this year. Another recommended insecticide, says the PCA report, is Neo Nicotinoid, which is injected into the trunk.

Crop Guard, a plant-oil based product, was used instead in Batangas and Laguna. Meanwhile, the Crop Protection Association of the Philippines (CPAP) recommended Dinotefuran (developed by the US-based Mitsui Chemicals Group). The DA-attached agency Fertilizer and Pesticide Authority (FPA) is set to grant Dinotefuran an emergency permit for its use.

But Medina called on farmers to avoid being fooled as there are “real concerns” to ensure effective pesticide use. “Is it logistically possible (equipment, manpower, water) to do the application [of the botanical spray] area-wide, within a short period of time, and [all together simultaneously]? How much will it cost? How do you deal with absentee or reluctant [farm] owners?”

Spraying of pesticides simultaneously altogether is important because there might be unsprayed coconut farms and the pests will just transfer to the sprayed pests, says Medina. “The untreated farm will be the constant source of re-infesting population, and we will be wasting money.”

Agriculture Secretary Proceso Alcala and PCA Administrator Euclides Forbes are both hoping that Task Force Scale Infestation Comprehensive Action Program (SICAP) can identify the “best solution” to pummel these pests.

vn mendoza tradingBut for farmers like Plete, what to precisely use is anybody’s guess. “Kanya-kanyang kuru-kuro na lang kasi iyung ginagamit naming na pamatay peste (It’s people’s own views now that prevail on what to use to kill those pests).”

Since there’s no use to the 100-or-so of her trees, and Plete’s nearly resigned to resurrecting the humble livelihood out of coconut, he has his own tips. “Subukan ho nila iyung Joy. Baka sakali. O kaya eh iyung isang dakot ng Furadan (They might want to try out the detergent Joy. It might work. Or they can try out Furadan).”



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