New rice pest called Rice Grain Bug (RGB)

By Danny O. Calleja

The Regional Crop Protection Center (RCPC) of the Department of Agriculture (DA) based here is vigilant against a new rice pest called Rice Grain Bug (RGB) that is far more notorious and damaging than any other rice bugs.

RCPC chief Evangeline de la Trinidad on Tuesday said RGB was first discovered in Bicol when it wreak havoc on rice fields in Dimasalang, Masbate in 2011 then, in Ragay, Camarines Sur during the onset of summer this year.

This new bug, she explained, is very agile thus can easily evade chemical spraying by staying on the upper side or underneath the leaves.

“They stay on upper portion of rice plants even in intense sunlight and can also thread on water or stay in stubbles,” De la Trinidad said.

Earlier findings reveal that these bugs are oval in body shape, shiny and lay reddish brown eggs along midrib of palay plant leaves that produce slender and brown-green nymphs that along with adult bugs feed on grains at the milking stage.

High RGB populations are influenced by factors such as nearby woodlands, extensive weedy areas near rice fields, wild grasses near irrigation canals and staggered rice planting.

The insect also becomes active when the monsoonal rains begin while warm weather, overcast skies and frequent drizzles favor its population buildup.

During surveillance and observation conducted by the RCPC along with national technical teams of the DA in Ragay rice fields last April, she said it was observed that RGB usually emerged between 10:00 a.m. and 12:00 noon and damaged mostly the rice panicles.

Palay grains sucked by RGB, De la Trinidad said were observed to have discolored, unfilled and become infested with molds.

An after-harvest report on the infested field submitted later by Ragay municipal agricultural technologist Teresita Bravo revealed disturbing facts: 40 to 80 percent reduction in palay yield.

In her report to the RCPC, Bravo shared the experience of a farmer in one rice producing barangay of the municipality who complained that following an RGB attack, he was able to harvest only 14 sacks of palay from his half-hectare farm where he previously harvested 70 sacks without the pest.

Worse, rice recovery from the remaining palay was also dismally affected as when milled, Bravo reported, only 10 to 12 kilos of rice were recovered from each sack that usually yields 25 to 30 kilos under a normal rice recovery rate of about 60 percent.

Moreover, the rice grains were cracked and tasted bitter when cooked owing to the molds developed by the infestation.

These mean, according to De la Trinidad, that rice farms in Bicol earlier attacked by RBG were practically rendered totally unproductive.

Those experiences have been properly documented and now being made basis of researches and studies by the DA that expect to find solutions to this new pest problem.

And while concrete solutions are yet to be developed by government pest control experts, De la Trinidad said the RCPC along with the DA Regional Field Unit (RFU) for Bicol headed by Regional Executive Director Jose Dayao and the Bureau of Plant Industry (BPI) is staying vigilant against it and ready with some damage mitigating measures.

Part of these measures is the recent conduct of the RGB awareness and management seminar-workshop held at the RFU training hall and participated in by farm technicians and farmers from the six provinces and seven cities of Bicol.

In the gathering, De la Trinidad said massive monitoring and information dissemination on this new rice pest was put in place with participation from all farm communities across the region.

“Prompt reporting of any sign of RGB build-up has been arranged in the seminar to be applied in the field so that immediate damage control measures are instituted,” she said.

Municipal Agricultural Offices have also been placed on alert and instructed to closely monitor rice fields in their areas and submit a specimen of pest they suspect as RGB as early detection is crucial to its control.

“We do this however without loosening our guard against other pests such as rodents, rice black bug, tungro, golden kuhol, armyworms and brown hoppers as the prevailing rainy season does not only brings more water but also these plagues,” De la Trinidad stressed.

Crop protection is a vital component in rice production as 35 percent of yield loss is attributed to insect pests and diseases occurrence, she said adding that often, the problem are not insects but the imbalance in the ecosystem which allow these insects to multiply.

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