Major Paddy Insect Pests and Thier Control Measures:
Today, let us talk about paddy insect pests and methods of controlling these rise crop pests.
Rice is the staple food for almost all parts of the world. Paddy cultivation is followed b most of the people. However, most of the paddy farmers face huge economic losses in paddy cultivation due to damage caused by insect pests. Following are the insect pests that damage the paddy crop. Among the following pests, severe economic losses are caused b few pests which are described below. In addition, we also gave the information on symptoms produced due to the damage caused by those insect pests along with the management practices of insects in Rice. Furthermore, we have also given information on Biological control of insects in Rice
- Planthoppers – Nilaparvatha lugens.
- Stem borer – Scirphphagaincertulus.
- Armyworm – Spodopterafrugipeda.
- Rice Hispa Beetle – Dicladispa armigera.
- Paddy leaf roller – Cnaphalocrocismedinalis.
- Gall midge – Orseoliaoryzae.
- Aphids – Aphidoidea.
- Leaf Miner – Agromyzidae.
- Meal bug – Pseudococciddae.
- Paddy swarming caterpillar – Spodopteramauritia.
- Rice bug – Leptocorisa.
- Ear cutting caterpillar – Mythimnaseperata.
- Stink bug–Ouebaluspugnax.
- Thrips – Thysanoptera.
- Whiteflies – Aleyrodidae.
Planthopper – Nilaparvatalugens:
There are two types of Planthopper species that attack the paddy crop. These are BPH (Brown Plant Hopper, Nilaparvatalugens and WBPH (White-backed Plant Hopper), Sogatellafurcifera.
- Yellowing of the plants.
- On the midrib or on leaf sheath, we can see crescent shaped white eggs that are inserted into the midrib.
- White to brown color nymphs are seen on the leaves.
- At the base of tillers, we can see brown to white adult hoppers feeding.
- At severe infestation or presence of high hopper population on the field, we can see hopper burn symptom that is leaves turn orange to yellow
- Sooty moulds are present at the base of the plant.
Management of BPH on Rice
- Removal of weeds from the surrounding fields.
- Avoiding indiscriminate use of chemical insecticides as it leads to destring of natural enemies.
- Use paddy cultivars resistant to this insect pests.
- Use light traps in the paddy field with an electric bulb as it inundates BPH insects prior to its attack on paddy
- Avoid the heavy use of Nitrogenous Fertilizers.
Physical or Mechanical control of BPH
- Avoid exposure of the seedlings on the seedbed completely and flood them with water once in a day so that only tips of the seedlings are exposed.
- Sweep the nursery seedling bed with a net to remove the BPH.
Biological control of Brown Plant Hopper
- Natural enemies like egg parasitoids, mired bugs, water striders and spiders prey on the BPH. Mass production of those natural enemies and release of them into the field during BPH incidence. Don’t spray any insecticides after releasing of the natural enemies on to the crop.
Chemical control of Brown Plant Hopper
- Apply the insecticides most at seedling stage in the nursery seedbed.
- Spray insecticides formulations like Buprofezin, Prometrozin or other alternative insecticides.
- Avoid spraying of insecticides like chlorpyrifos, pyrethroid combinations or lambda-cyhalothrin as it favors for the resurgence and resistance of the insect pest.
Paddy stem borer
There are around six species of stem borers that attack paddy crop. They are yellow stem borer, striped stem borer, white stem borer, gold fringed stem borer, dark headed striped stem borer and the last one is pink stem borer which is of less economic importance.
Symptoms of Paddy stem borer
- Stem borer can attack the paddy crop at a stage from seedling to the crop maturity
- A typical symptom of stem borer attack is the dead heart that means when the upon tillers, the central tiller dry during the vegetative stage and cause whiteheads at the reproductive stage of the crop.
- Emerging panicles become white color with unfilled grains or empty
- We can see tin holes on the tillers and stems.
- Inside the damaged stem, frass or faecal matter of the stem borer is seen,
- However, these symptoms of the dead heart may be confused with the damage caused b the black bugs, neck blast, and rats.
Management of Paddy stem borer
Preventive and cultural measures to control paddy stem borer
- Go for the cultivation of resistant cultivars.
- Apply the recommended nitrogenous fertilizers in split doses and times.
- As the stem borer lays eggs on the leaf tip, cut the tips before transplanting.
- Harvest the crops to ground level in order to remove the larvae I the stubble and burn the stubbles after harvesting.
Biological control of Rice Stem Borer
- There are various parasitoids and predators that kill the stem borer viz., Braconid, Europhid, Mymarid, Grillid, Staphylinid beetles, Chlopid, Vespid wasps, Dragon fliesandDamsflies.
- In addition, there are also Entomopathogenic Nematodes and Entomopathogenic fungi that kills or parasitizes the Stem Borer.
- Spray neem extracts @15ml/Lt water.
- Use light traps to attract the stem borer moths.
- Install the pheromone traps from 15 days after transplanting @3/acre or 8/acre based on the insect pest population.
- Soak the seedling roots in 0.02% Chlorpyriphos for 12 to 14 hrs before transplanting.
- Appl granular chemical insecticides like Fipronil 0.3G @25kg/ha or chlorpyriphos or chlorpyriphos-methyl 10G @ 10kg/ha.
- SprayChlorpyriphos 20 EC @2lt/ha or Fipronil 5SC @0.8t/ha or chlorantraniliprole3ml/lt water at threshold intervals.
Rice Armyworm – Spodoptera frugipeda
Armyworms are the caterpillars that attack paddy. There are around three armyworm species that attacks the paddy crop in Asia. They are rice ear cutting caterpillar, swarming caterpillar and common cutworm.
Symptoms of damage caused by armyworm
- The armyworm caterpillar feeds on paddy leaves and cuts the leaves and young seedlings at the basal region. Armyworm also cut the rice panicles from the bottom.
- Armyworms are nocturnal in habitat and feed on the upper portion of the rice canopy at night.
- In dryland or rainfed crops, the pupa of armyworm can be seen at the basal soil near the affected Whereas, in wetland rice cultivation, the armyworm undergoes pupation on the plants or on the weeds present along the crop borders.
- Armyworms feed along the leaf margins and tips. Whereas, the can also eat the complete leaf leaving the midrib. Sometimes, they also eat the complete leaf with midrib.
- During severe damage, we can see the armyworm roaming in the field.
Management of Armyworm in Rice
- Construct seedbeds was from the weeds or remove the weeds around the nursery seedbed.
- Go for following land ploughing.
- Rouging is done at regular
- Also, remove the stubbles before transplanting.
Cultural method to control armyworm
- Place branches of big trees around the field that helps in easy collection of armyworm
- Avoid spraying of chemical insecticides as it leads to the killing of natural enemies like predator wasps and spiders.
Biological control of armyworm
- Release Wasp parasitoids like Cotesmarginvenris, ChelonustexanusandChelonusremus. Also release predators like Ground beetles, spined soldier bugs and flower
- Spray the biopesticides containing neem extracts, Bt, BaculovirusSpodoptera or azadirachtin.
- Spray insecticides like esfenvelarate, chlorpyriphos, lambda-cyhalothrin and malathion in recommended
- Go for poison bait technique for the above insecticides to kill the grown larvae.
Paddy leaf roller – Cnaphalocrocismedinalis
It is also known as the leaf folder. The caterpillars of these insects fold the paddy leaf and attach to the leaf margin together with silk strands. The feed inside the leaf making longitudinal and transparent streaks on the leaf blade.
Symptoms of damage
- On the damaged leaves, we can observe transparent and longitudinal white streaks.
- The easiest way to observe its damage is tubular folded leaves.
- At severe damage, the whole field appears like scorched with a lot of folded leaves.
- We can see disc-shaped ovoid single eggs on the tillers.
- faecal matter is seen in between the damaged
- The larvae of the leaf folder most; feed on the young and unopened leaves.
Management of Rice leaf folder
Preventive and Cultural practices
- Use resistant cultivars of paddy.
- Go for crop rotation.
- Remove the weeds at regular intervals.
- Avoid high density
- April balanced dosage of fertilizers.
Biological control of Paddy leaf roller
- Release Trichogramma egg parasitoids likeTrichogrammachilonis @10,000 adults/ha.
- Spreading the neem leaves in the field deters the adult insects from laying eggs.
- There are also some entomopathogenic fungi and viruses that controls the Paddy leaf roller.
- Spray Chlorantraniliprole @0.3ml/lt water or firstname.lastname@example.org/lt water if the infestation of the insect is severe.
- You can also o for spraying of insecticides like chlorpyrifos, indoxacarb, azadirachtin, gamma or lambda-cyhalothrin. In addition, you can also spray Alpha-cypermethrin, 2%abamectin in order to kill the larvae of the leaf folder insect. However, care should be taken that the chemical may not lead to resistance and resurgence of the insect pest.
Rice Hispa – Dicladispaarmigera
Both the adult and larvae stages of the insects damage the paddy crop. The adult beetle scrapes the upper surface of the leaf leaving the lower epidermis. The adult lays the eggs inside minute slits on the tender leaves towards the tip most probably. The adult beetle measures about 3 to 5mm length and width. The hispa beetle is dark blue to black in color with spines on its body surface.
Symptoms of damage
- We can see the tunnels formed on the leaf d=blade dues to the damage of the beetle.
- Plants become less vigorous.
- Irregular and clear feeding marks of the beetle are seen on the leaf
- Presence of white streaks of unfaded epidermis between the leaf veins.
- Leaves turn whitish and membranous.
- Whithering of the damaged leaves.
Management of Rice Hispa beetle
Preventive and cultural practices
- Avoid over dosage of fertilizer application in the field.
- In addition, also avid close or dense planting.
- Cut the shoot tips with the eggs.
- Go for crop rotation to break or discontinue the life cycle of the Rice Hispa Beetle.
- Burn the infested leaves away from the paddy
Biological control of Rice Hispa beetle
- Larval parasitoid Eulophusfemoralis ma found to be useful to control the hispa
- There are some small wasps that pre on the Hispa beetles.
- In addition, we can use some entomopathogenic fungi species to reduce the insect population to some extent.
Chemical control of Rice Hispa Beetle
- A chemical formulation containing the active ingredient such as chlorpyrifos, malathion, permethrin, and phenthoate spraying control the rice hispa.
Read: Growing Pearl Millet.