Recognize the problem
Rice stem borers (RSB) can
be present in all rice growing areas. During tillering, the typical damage
symptom is deadheart, while in flowering stage, it causes whitehead. The larvae also produce tiny holes on the stem and deposit
faeces within it, which is seen when the stem is cut open. The adult
RSB is 1-1.5cm long and white, with one tiny black dot on each wing.
Eggs are laid in a cluster of about 200 white or brown
in size to soybean seeds. These are laid on
leaves and are covered with a yellow cottony layer,
about 5 mm wide. Larvae are creamy
white and between 2mm and 20mm long.
After hatching, larvae
are spread by wind. They enter rice stems, then live and feed inside the stem. A
larva can consume 3-4 stems and move from plant to plant. The larvae move
downwards in the stem and pupate in the lower part for
7-10 days, after which an adult emerges. The adult is more active at night and
normally shelters within the plant tillers during the
possible, plant early to avoid peaks of larval stage
harvesting, ploughing rice stubble into the soil to kill larvae and pupae and avoid
leaving unwanted ratoons
alternative hosts of the insect such as weeds
rotation with non-host crops
measures: For stems/stalks with deadhearts, cut at the base, and remove from
the field. Destroy the larva or burn the stalk. Remove egg masses manually in
the nursery and field.
Observe the field every 7 days and count the number of deadhearts per 10 plants
and whiteheads per 10 plants
planting time could be adjusted, apply chemicals if more than 10% deadhearts
during tillering or more than 5% whitehead during flowering are observed.
planting time could not be adjusted, apply chemicals slightly earlier
use chemicals containing one of these active ingredients: abamectin (e.g. Voliam
Targo 063SC), chlorpyrifos or fipronil
When using a pesticide, always wear protective clothing and follow the instructions on the product label, such as dosage, timing of application, and pre-harvest interval.