PESTS OF RICE
More than 100 insect species are associated with the rice crop at one stage or the other and 20 of these are pests of major economic significance. Among the sucking pests, BPH, GLH, WBPH, rice earhead bug pose severe threat to rice production.
1. Thrips
2. Green Leafhopper
3. Brown Plant Hopper
4. White Backed Plant Hopper
5. Rice Earhead Bug
6. Mealy Bug
7. Rice Black Bug
MINOR PESTS
8. Earhead Stink Bug /
Shield Bug / Red Spotted Bug
9. Rice Striped Bug
10. White Rice Leafhopper
11. Blue Rice Leafhopper
12. Zigzag Striped Leafhopper
1. Thrips: Stenchaetothrips biformis (Thripidae: Thysanoptera)
Distribution and status: Bangladesh, India, Indonesia, Japan, Malaysia, Sri Lanka, Thailand and Vietnam. Minor but has potential to become major.
Host range: Echinochloa sp.'
Distribution and status: Bangladesh, India, Indonesia, Japan, Malaysia, Sri Lanka, Thailand and Vietnam. Minor but has potential to become major.
Host range: Echinochloa sp.'
Damage symptoms: Both nymphs and adults lacerate the tender leaves and suck the plant sap, causing yellow or silvery streaks on the leaves of young seedlings. Terminal rolling and drying of leaves from tip to base is the typical symptom of attack. It causes damage both in nursery and main field.
ETL: 60 Nos. per 12 wet hand sweeps in nursery.
Bionomics: Adults dark brown, female inserts the eggs singly within the leaf tissues in young leaves. Egg period 3-5 days, life cycle completed in 13-19 days.
Bionomics: Adults dark brown, female inserts the eggs singly within the leaf tissues in young leaves. Egg period 3-5 days, life cycle completed in 13-19 days.
Management:
- Spray endosulfan 35 EC 80 ml or monocrotophos 36 WSC 40 ml/800 m2 nursery.
- Spray Endosulfan 35 EC 1.0 L or Monocrotophos 36 WSC 1.0 L or Azadirachtin 0.15% w/w 1.5-2.5 L or Lambda-Cyhalothrin 2.5 EC 500 ml or Lambda-Cyhalothrin 5 EC 250 ml in 500 L water/ha
- Grow resistant cultivars like PTB 12, PTB 20, PT 321, H 4
2. Green leafhopper: Nephotettix virescens, N. nigropictus and N. cincticeps (Cicadellidae: Hemiptera)
Distribution and status: India, South Japan to oriental region, west of south Africa, Phillippines, Formosa, Sri Lanka
Host range: Rice, millets, grasses
Host range: Rice, millets, grasses
Damage symptoms:Both nymphs and adults desap the leaves and cause “hopper burn” due to heavy infestation. Yellowing of leaves from tip downwards is the typical symptom caused by this pest. However, it is more important as a vector forrice tungro virus, rice yellow dwarf and transitory yellowing diseases.
ETL: 60 Nos. / 25 sweeping – Nursery
10 Nos. / hill - Flowering stage
5 Nos. / hill - Vegetative stage
2 Nos. / hill - Tungro endemic area
Bionomics: Adults green with black spot and black patch on wings, gravid female inserts 200-300 eggs in batches of 8-16 in midrib of leaf blade. Egg period 6-7 days, nymphs undergo five instars and become adult in 25 days. Adult longevity 20-30 days. The population normally increases from August onwards, reaches maximum during September - October and declines from November.
10 Nos. / hill - Flowering stage
5 Nos. / hill - Vegetative stage
2 Nos. / hill - Tungro endemic area
Bionomics: Adults green with black spot and black patch on wings, gravid female inserts 200-300 eggs in batches of 8-16 in midrib of leaf blade. Egg period 6-7 days, nymphs undergo five instars and become adult in 25 days. Adult longevity 20-30 days. The population normally increases from August onwards, reaches maximum during September - October and declines from November.
Management
- Use resistant varieties like IR 20, IR 50, CR 1009, Co 46, PTB 2, PTB 18, IET 7301, IET 7302, IET 7303 and Vani, Vikra marka, Lalit, Nidhi.
- Nursery should not be raised near the lamp posts.
- Apply neem cake @ 12.5 kg/800 m2 nursery as basal dose.
- Apply carbofuran 3 G @ 3.5 kg or phorate 10 G @ 1.0 kg or quinalphos 25 EC 80 ml or endosulfan 35 EC 80 ml per 800 m2 nursery. Maintain the water level at 2.5 cm for 3 days after granular application.
- Spray any of the following insecticide in 500 L water/ha
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3.Mealybug:Brevennia rehi (Pseudococcidae: Hemiptera)
Host range: Rice, graminaceous weeds
Damage symptoms: Large number of insects remains in leaf sheath and suck the sap, affecting plants in circular patches. Plants become weak, yellowish and stunted. Presence of white waxy fluff in leaf sheath is a typical symptom of damage.
Bionomics: The mealy bug is small reddish white, soft-bodied, wingless insect covered with filamentous materials. It lays 126-139 eggs in the leaf sheath and reproduces parthenogenetically. The egg period 1-2 days; nymphal period 17-34 days, nymphs remain within the leaf sheath and suck the plant sap.
Management
4. Spray dimethoate 30 EC 500 ml/ha in initial stages of infestation.1. Parasitoids such as Adelencyrtus sp., Xanthoencyrtus sp. and Dolichoceros sp. and coccinellid predators can be utilized. 2. Remove the grasses and trim the bunds during the main field preparation before transplanting. 3. Remove and destroy the affected plants. |
