THE Department of Agriculture (DA) on Friday recommended the use of biological control agents to fight rice black bug (RBB) and armyworms that have infested some areas in Mindanao.
The Bureau of Plant Industry (BPI), an attached agency of the DA, said a fungus called
Metharizium can be used to control RBB, while the Nuclear Polyhedrosis Virus (NPV) can control armyworms.
The Metharizium fungus is entomopathogenic which causes disease to the insects and seriously disabling or killing them. Meanwhile the NPV is a virus that destroys the cellular structure of the armyworm until it dies.
Corn is palatable to armyworms. As for RBBs, the BPI said in a statement that only three out of the 11 species of the bug are harmful to plants.
The BPI said that if armyworms attack rice plants during the tillering stage—when rice plants produce side shoots and multiple stems—recovery is possible. But if the worms attack during booting stage—when rice plants develop flowers—there may be a 100-percent yield loss.
In the case of the RBB, rice crops can still survive if the bugs attack during the tillering stage in a low population density.
However, if the bugs attack during reproductive stage—for example, at dough stage when green grains turn to yellow—a 60-percent yield loss is likely.
The BPI said it is coordinating with the DA Regional Crop Protection Centers (RCPCs) to mass produce Metharizium as a control agent against RBB. Metharizium has been tested to be effective when regularly applied in RBB-infested rice fields. The biopesticide is now distributed to farmers throughout the country.
Sanitation is the first strategy to avoid an armyworm outbreak, according to the BPI. This should be followed by synchronous planting. After harvest, all stubbles or straws in infested areas must be plowed under the ground to kill the remaining population of the pests.
On the onset of attack, the BPI said spraying of NPV would be needed to kill the feeding worms.
The bureau said most farmers who have been trained on integrated pest management at the DA’s RCPCs already manage the infestations by themselves.
The government urged farmers to avoid spraying inorganic pesticides to control RBB, as it will also kill its natural enemies and beneficial insects.
The BPI said farmers may also consider practicing intermittent irrigation.
From time to time the rice field must be drained then later flooded in a day to kill RBB nymph and eggs.
Herding ducks on paddies will also help in managing the population of RBB, the DA said.
The government said this will be beneficial to ducks as those feeding on RBB weigh heavier and have better meat quality.
Agriculture Secretary Proceso J. Alcala urged farmers to immediately report infestations to local agriculturists or to RCPCs so that appropriate measures for effective pest management or eradication can be immediately implemented.