New pest attacking coconuts across Luzon

Some of the coconut trees along Manila’s famous Roxas Boulevard are wilting.

And if they are not saved from a new pest now attacking them and tens of thousands of palms across Luzon, they will eventually die.

Coconut palms are reeling under the attack of a pest named coconut hispine (leaf) beetle. As of last count, 38 coconut trees along Roxas Boulevard have been infested by the pest, which is known in the science world as Brontispa longissima Gentro.

The pest has also been wreaking havoc on coconut trees in other parts of Luzon, although no Brontispa cases have so far been monitored in the Visayas and Mindanao, according to the Brontispa Action Team (BAT), a group of government agencies now addressing the problem.

The BAT steering committee is composed of representatives of the Department of Agriculture-Philippine Coconut Authority, DA-Bureau of Agricultural Research (BAR), DA-Bureau of Plant Industry (BPI), DA’s Kasakalikasan Program, University of the Philippines Los Baños-National Crop Protection Center (UPLB-NCPC), and the Los Baños-based Philippine Council for Agriculture, Forestry and Natural Resources Research and Development (PCARRD).

In Cavite, Mateo Zipagan, chairman of the BAT technical working group, said 41,117 coconut trees are under "Brontispa siege" in the towns of Dasmariñas, Gen. Mariano Alvarez, Silang, Naic, and Amadeo and in the cities of Tagaytay and Trece Martires.

The presence of the coconut leaf beetle has also been noted in the Laguna towns of Sta. Rosa, San Pedro, Biñan and Cabuyao.

Its infestation in the towns of Los Baños, Alaminos, and Majayjay has yet to be confirmed.

At least 244 coconut trees in the Batangas cities of Lipa and Tanauan and in the towns of Sto. Tomas and Taal have been infested.

So are 100 trees in Rizal, mostly along the Manila East Road stretching from Pilillia to Montalban.

In Quezon, Brontispa has attacked an initial three young palms.

Farther south in Bicol, 38 royal palms have been infested in Naga City, Camarines Sur.

Experts believe that the pest reached the country in 2003 due to the importation of ornamental palms.

That year palms along the Coastal Road in Metro Manila showed almost total frond damage caused by the pest.

The coconut leaf beetle is native to Maluku, Indonesia and Papua New Guinea.

Brontispa spread

In the early part of the 20th century, it spread to other parts of Indonesia and some South Pacific islands and infested palms.

In the past few decades, it reached other Southeast Asian countries, China, and Australia, causing substantial losses in coconut yield and tourism revenues.

Cambodia presented a clear picture of the pest’s effect, when 58 percent of its 7.2 million coconut trees were affected, killing 16 percent of them.

In the Maldives, outbreaks occurred in several atolls, while in Thailand, the beetle spread so widely in its southern provinces that by 2004, it had become a very serious threat to the country’s $30-million coconut industry.

In a recent press briefing at the Sulo Hotel in Quezon City recently, Dr. Joy Eusebio, director of PCARRD’s crop research division, said the beetle feeds on young coconut leaves, which then appear scorched or burned.

The beetle causes grave damage to seedlings and mature coconut palms, killing the young spears (young blade or shoot) and eventually the whole palm.

Its destructive stages, larva and adult, damage the lamina (epidermis) of the young leaves, eventually providing easy entry for pathogens (disease-causing organisms).

"If the injuries caused by these feedings are close to one another so that all of the leaflets are overwhelmed, the entire frond dries up once it opens and photosynthesis is reduced to zero," the Brontispa Action Team said.

The beetle’s eggs are difficult to detect because they are inserted between leaflets. Thus, planting materials of coconuts and ornamentals that are intended for transport to non-infested areas should be inspected thoroughly.

Brontispa longissima is a flat and slender beetle. It is generally black, except for the yellow-orange to red color of its neck and the basal portion of its wings. It measures 7.5 to 10 millimeters long and 1.5 to two millimeters wide.

The most practical control measures against the pest are cultural methods such as pruning, clean culture, and proper disposal of infested coconut trees or parts thereof.

But the best method is biological control by using Metarrhizium and Beauveria (fungi) and Asecodes hispinarum (parasitoid).

"Chemical spraying is ineffective against Brontispa longissima; it is costly, not sustainable, and poses hazard to non-target organisms and the environment," the Brontispa Action Team said in a leaflet it has produced as part of its information campaign against the infestation.