Crops Care

Rice Stem Borer

Scirpophaga incertulas is one of the major pests of rice . Attack of this insect is seen in all seasons of paddy, but this insect attacks more in Aush and Boro seasons. It attacks at all stages of the crop, but mostly at the bud and gamar (penical initiation) stages. Warm and humid weather i.e. 80-90% relative humidity is suitable for the growth of these insects.

Insect Introduction:

They are insects belonging to Crambidae family. There are three types of rice beetle attack in Bangladesh. 1. Yellow maggot 2. Black head spider 3. Pink spider mites. They are named according to the color of the insect. However, in Bangladesh, the attack of yellow caterpillar and black-headed caterpillar is more common.

Damage Type:

After hatching, the maggots slowly enter the stem and start eating and slowly eat the root of the plant and cut it off. As a result, the seed dies. If the worm eats inside the leaf sheath and does not completely cut the inner part of the stem, the rice plant is partially damaged and some of the rice at the base of the ear is crushed.

Symptoms:

• At the bud stage of paddy, the attack of maggots causes the middle leaf to die, which is called dead dig or deadheart. After the pods are damaged, the entire pods dry up if the caterpillars damage them. It is called white head, dead head or white head.
• Holes are seen in the stems of affected plants. Insects, their feeding patterns and feces are found in the stems. The outer color of the stem fades.
• The yellow caterpillar lays its eggs on the upper part of the leaf and the pink caterpillar lays its eggs on the inside of the leaf sheath.
• The egg mass of the yellow caterpillar is covered with a light gray coating. Blackhead moth eggs have a white coating that looks like fish scales, which gradually turns dark before hatching.
• These insects gather around light.

Management:
Biological means:

• Saplings should be planted at the right distance and of the right age. Soil should be tested and balanced fertilizer should be applied to the land.
• Immediately after planting, dig enough stakes in the ground to allow birds to perch and eat insects.
• Moths and eggs of maggots should be collected and destroyed during regular field monitoring. Moths can be collected and killed by placing light traps at a distance of 200-300 meters from the paddy field.

Chemical way:

"Prostar 40 WDG and Biplob 55 EC" should be mixed at the rate of 0.5 g per liter of water and sprayed at the bud stage and at the panicle initiation stage of rice.