CEBU CITY -- A caterpillar infestation that is devastating teak trees in Metro Cebu's watershed awaits the action of the Department of Environment and Natural Resources (DENR) and concerned citizens.

Thousands of teak trees (Tectona grandis), planted in more than 100 hectares within the Central Cebu Protected Landscape (CCPL) are losing foliage fast.

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The infestation has not affected agricultural crops within Barangay Toong, said a DENR representative.

But the loss of foliage raises the danger of faster soil erosion and landslides in the affected area. Rainfall is normally caught in the leaves of trees, before falling to the ground. The process decreases the likelihood of erosion and prevents siltation or sedimentation of the seas.

The 29,000-hectare CCPL, Metro Cebu's main source of water, consists of five watershed areas in Buhisan, Mananga and Kotkot-Lusaran and the national parks of Central Cebu and Sudlon.

Marili Ortiz, the DENR representative at the CCPL, said the infestation has stripped the wide leaves of teak trees that were planted in the area during reforestation efforts dating back to the 1950s.

She said the infestation started at the onset of the rainy season early last month and covers four barangays: Buhisan, Pamutan, Toong, and Sapangdaku.

"More than 100 hectares are affected," she told Sun.Star Cebu.

"We were able to observe the same phenomenon in the 1980s and we were not able to do anything about it because quite a large area was affected. A DENR forest ranger suggested that we use a helicopter to spray over the area but this was never done," she added.

Ortiz said they did not do anything at that time and after some months the trees recovered their foliage.

The caterpillars at the CCPL first appeared as short white worms that grow about three inches long. They eat the green part of the leaves, exposing a lace-like mesh of veins.

The clumps of teak trees affected by the infestation within the Buhisan Watershed look like dried-up wood with tiny brown-red branches.

"This time, we have to observe what will happen to the trees. Teak trees are considered strong species but these caterpillars are different from the last (infestation) that occurred," she said.

She added the trees might recover during the dry season, just like they did the last time.

"But we are not really sure about that. It was the ipil-ipil trees that were affected before. Kung dili maulian, kuyaw na (If they don't recover, that's going to be a problem)," said Ortiz.

"I still do not know the effect of this phenomenon on the watershed. This is just the second time this happened here," she said.

In a separate interview, Toong barangay councilor Hermes Abelgas said residents observed the caterpillars prefer to consume the fresh buds of the trees at night and early morning.

He said they also noticed an unusual proliferation of small moths in the area, especially at night.

The caterpillars were first observed by the villagers in the first week of July, as the leaves were falling off and being eaten away.

Abelgas said they informed the DENR about the situation in their village and are just waiting for advice on what to do.

In its website, the Goldteak project, which cultivates teak plantations to fight poverty in Indonesia, identifies moth caterpillars (Hyblaea puera) as one of the main pests that prey on teak trees. It said the migrant pest often attacks during the pre-monsoon rains, but then suddenly disappears. It is more commonly known as the teak defoliator. (Bernadette A. Parco of Sun.Star Cebu)