Pests are 'globetrotters,' too, says study

Have you ever wondered why destructive pests find themselves in distant lands far from where they are endemic or from their places of origin?

For instance, the Dutch elm disease caused by a fungus called Ophiotoma ulmi found its way to Europe after World War I. By causing discoloration in the trees’ sapwoods, Dutch elm, which is also native to Asia, has eliminated most majestic American elms in Europe’s urban areas and continues to kill many trees each year.

The Asian long-horned beetle entered the United States in 1996 and wiped out many hardwood trees in New York and Chicago.

In the early part of the 1900s, the pine wood nematode, a microscopic worm carried by sawyer beetles, entered Japan and has since killed large tracts of pine trees. It entered Missouri (US) in 1979 and until now continues to decimate pine trees in mid-western and eastern states.

How did these pests manage to cross the seas, settle and wreak havoc in new lands?

The answer: Through wooden packaging materials that are used to move commodities around the world, according to the Los Baños-based Department of Science and Technology-Forest Products Research and Development Institute (DOST-FPRDI).

Addressing this worldwide problem of pest spread across the globe, the International Plant Protection Convention (IPPC) required, starting in 2002, that all wooden packaging materials be stamped with the IPPC mark after they have undergone methyl bromide (MB) or heat treatment.

But MB has been found to be hazardous to human health, it being 60 times more damaging to the ozone layer than chlorine and is responsible for five to 10 percent of worldwide ozone depletion. It also makes wood non-recyclable.

Thus, MB turned out to be a problem instead of a solution to a problem.

Now comes the good news. Three years ago, the DOST-FPRDI, in a joint project with Nippon Express Philippines Corp. (NEPC), found that heat treatment using the institute’s 1,000-board-feet capacity furnace-type lumber dryer (FTLD) can eliminate insect pests and diseases infesting wooden pallets — although re-infestation can occur under favorable conditions.

FPRDI’s forester Robert Natividad explained: “Heat treatment requires that the pallet’s wood core be treated at 56 degrees Celsius for 30 minutes. We found that the optimum MT time is five hours and average operation cost is P6.66 per pallet, 46 percent cheaper than MB fumigation. Today, six of the country’s top wooden pallets producers use the technology.”

Researcher Wency Carmelo added: “By doing away with MB fumigation, we help protect the environment. We also help the wooden industry, which makes about 14.5 million units a year, comply with the European and Japanese markets’ demand for heat-treated pallets.”

Carmelo concluded: “With heat treatment, the pallet industry has found a safer and cheaper way to get the IPPC mark on its products, something any exporter who relies on wooden packaging materials cannot afford not to have.”