RICE black bugs, a dreaded pest which has ravaged rice fields in Luzon, Palawan, Central Luzon, Mindanao, Leyte and Samar, can be controlled “the natural way,” according to the Philippine Rice Research Institute (PhilRice).
In a PhilRice-published bulletin titled, "Management of the Rice black bug," entomologists Gertrudo Arida and Dr. Hoai Xuan Truong said rice black bugs, locally known as itim na atangya, can be prevented at the start of the planting season.
The two authors advised farmers to plant rice varieties with same maturity within a month of the barangay's regular planting time as this breaks the pests' life cycle.
Should outbreaks happen, researchers at PhilRice's Crop Protection Division recommended the use of light traps because the bugs are strongly attracted to high intensity light.
"Light trapping of insects should start five days before and after the full moon. Use 2000-3000 watts or super light during outbreaks and set them up every night to obtain the most number of bugs. Effective light trapping is from 8 p.m. to 12 midnight," the rice experts recommended.
Flooding, herding of ducks in the field, and sanitation can also prevent pest infestation.
"We advise farmers to flood the field to submerge egg masses," Arida and Troung wrote. "Eggs that are submerged for more than 24 hours will no longer hatch. Ducks also feed on the bugs. However, herd the duck in the field a month after transplanting or when the plants are established."
Farmers are also advised to clean their field by removing the weeds as these serve as alternate hosts of the rice black bugs.
Arida and Troung warned farmers to reduce insecticide use in controlling rice black bugs. Insecticides, they suggested, should be used to a minimum so as not to kill the natural enemies of rice black bugs.
The natural enemies of black bugs are wasps; ground and coccinellid beetle; wolf, lynx, and long-jawed spider; red ant; and damsel bug.
A black bug is only as big as a "black bean" but it is very destructive. It sucks the juice from the midrib of leaves and panicles at the milk stage. In most cases, it feeds on the basal part of the tillers most often at night.
A report from the Department of Agriculture said that during the vegetative stage, plants attacked by this bug become stunted. The youngest leaf shoot of the tiller fold longitudinally, turns yellowish to reddish brown, and later dies.
When not properly controlled, 10 adult rice black bugs per hill can cause losses of up to 35 percent, PhilRice said.
Rice black bugs reportedly entered the Philippines from Sabah, Malaysia in 1972 and was later detected in Zamboanga and slowly spread in Mindanao then to Visayas. Incidence of rice black bug attack was first reported in Bonobono, Bataraza, in Southern Palawan in 1979. A major outbreak occurred in 1982.