Tuesday, January 29, 2019
Monday, January 7, 2019
Marginal Notching |
Friday, January 4, 2019
American bollworm
Forewing grey to pale brown with “V” shaped speck. Hind wings are pale smoky white with a broad blackish outer margin.
PESTS ON RICE
ü Sporadic pest
appears during July- September.
Egg period: 7 days; Larval period: 20-25 days; Pupal period: 10-15 days
ü Larva:
Long, cylindrical, smooth and dark to pale green in color, with dull reddish
and yellowish dorsal and sub dorsal stripes.
ü Adult:
medium size, Grayish brown moth with black spot near the anterior margin and
irregular, wavy, black band along the lateral margin of forewing.. Hindwing
whitish brown
ü Cutting of seedlings in large scale, similar to cattle grazing by nocturnal feeding. Peduncles of ears bitten through in maturing crop.
Management
v Summer ploughing
v Collection and destruction of egg masses
v Flood the nursery to expose the hiding larvae
to the surface and thus they picked up by birds.
v Allow the ducks into the field to feed on the
larvae.
v Kerosinate the water while irrigation to
suffocate and kill the larvae.
v Set up light traps to attract adult moths.
v Drain the water from the nursery and spray Chlorpyriphos 20EC 80 ml or Endosulfan 35 EC 80 ml during late
evening.
v Dusting neem cake / pungam cake powder @ 10
kg/ac.
v Dusting of wood ash @ 10-12 kg/ac.
v Keep neem leaves in bunches at 10 different
places per acre.
Caseworm : Parapoynx stagnalis: Pyraustidae: Lepidoptera
ü It
is a sporadic pest, become serious in specific weather conditions.
ü It
is serious in young transplanted crop.
ü Female
moth lays about 50 eggs, singly on under surface of leaves, hatches in 2-6
days.
ü Larva
is pale green color, with a light brownish-orange head and thin hairs. It
initially scrapes the chlorophyll later cut the leaf into small bits and
construct tubular cases, live inside the cases. The case is replenished in each
molting.
ü The
grown up larva pupates inside the case, which is attached to the base of the
tiller.
ü The
adult moths are small, whitish in color with light brown, wavy markings on the
white wings.
Management
·
Nursery - Mix 100 ml
kerosene in standing water and spray
endosulfan 35 EC 30 ml / 8 cents nursery
·
The field should be
filled with water upto 6 cm. Add one litre of kerosene , Dislodge the cases by
running a rope over the young crop, so that the cases fall in the water and
then drain the water from the field.
·
Spray
Monocrotophos 36 WSC 500 ml / ha.
Whorl maggot: Hydrellia sesakii: Ephydridae : Diptera
ü The
pest become severe in water stagnated fields, when the plants are young.
ü Egg: Long, cylindrical, white pasted on the leaves.
ü Young
maggots are pale white in color later become yellow.
ü The
maggot bore into shoots of young plants and feed on the inner tissues.
ü Narrow
stripes of whitish area are seen on margins, near the leaf tips of unfurled
leaves. Leaves shriveled, plants stunted and maturity delayed.
ü It
pupates inside the shoot; adults are very small dull grey fly.
Management
v Remove the alternate hosts and adjust the time of
planting (early)
v Use early maturing varieties
v Optimum recommendation of potash fertilizer
v Spray Quinolphose 25 EC 1000 ml/ha.
Green leafhopper: Nephotettix nigropictus: N.cincticeps, N.virescens: Cicadellidae : Hemiptera.
ü Female hopper
inserts the cylindrical eggs inside the epidermal layer of the leaf sheath of
plants. Fecundity is 420.
ü Nymphs are pale
green in color, wingless, but are very active. Adults are green with black spot
and black patch on the wings.
ü Both nymphs and
adults suck the sap from the leaves an succulent stem portions.
ü The leaves of
infested plants show yellowing, with drying of leaf tips. In case of severe
infestation, the whole plant turns yellow, becomes stunted and finally dies.
ü It is the vector
of rice tungro virus disease and
rice yellow dwarf disease.
ETL: 60 nos./25 sweepings-Nursery , 10nos/hill-Flowering
stage,
5 nos/hill – Vegetative stage, 2 Nos/hill – Tungro
endemic areas
Management
·
Use resistant varieties
like IR 50, CR 1009, Co 46,Ptb 2,Ptb 18.
·
Remove wild grasses and
weeds from the field bunds and field.
·
Apply neem cake @ 12.5
kg/20 cent nursery as basal dose
·
The vegetation on the
bunds should also be sprayed with the insecticides
·
Set up light traps
·
Nursery should not be
raised near the lamp post.
·
Dip the seedlings in
neem seed kernel extract for 24 hrs before transplanting.
·
Apply neem cake as top
dressing @ 50-60 kg/ac.
Brown planthopper: Nilaparvata lugens: Delphacidae : Hemiptera.
ü It cause yield
loss upto 10-70 percent/
ü Eggs are inserted
into the tissues of leaf sheath. Fecundity is 650.
ü Nymphs are
whitish. Adults are yellowish brown with dull white streaks on the thorax and
black lines on the lateral side of the head.
ü Bothe nymphs and
adults congregate on the collar region of the plant and suck the sap.
ü Hopper burn:
Drying and browning of young plants. Circular patches of drying in the field,
lodging of matured plant.
ü Two forms namely,
Macropterous (long winged) and brachyterous (short winged) are found, of which
the former is responsible for migratory movement and colonization in other
neighboring rice crops.
ü Vector of Grassy
stunt, Ragged stunt and wilted stunt.
ETL: 5-10 insects/hill.
v Use resistant/tolerant varieties like Aruna, ADT
36, Co 42, Co 46 IR 36, IR 72, PY 3, Ptb 33, Ptb 21, Divya, Asha.
v Avoid close planting, provide adequate spacing.
v Provide 30 cm rogue spacing at every 2.5 m to
reduce the pest incidence.
v Avoid use of excessive nitrogenous fertilizers.
v Control irrigation by intermittent draining.
v Set up light
traps to monitor the pest population.
v Set up yellow
pan traps during day time
v Conserve natural enemies like Lycosa
pseudoannulata, Cyrtorhinus lividipennis
v Avoid synthetic pyrethroids, methyl parathion,
fenthion and quinalphos causing resurgence
v Drain the water before the use of insecticides
v Spray NSKE 5% or 2% neem
oil or Iluppai
oil 6%
v Apply any insecticide
Preflowering
·
Phosphomodan 85 WSC 200
ml or Monocrotophos 36 WSC 500 ml or Imidachloprid 200 SL 100 ml/ac
Post flowering
·
Caboryl 10 D @ 10 Kg/ac.
Note : Direct the spray and dust towards the base
of the plant
Earhead bug: Leptocorisa acuta:Coreidae : Hemiptera
ü It is commonly
known as gundhy bug
ü Nymph: Green to brown. Adult: Brown, slender with
long antennae and legs.
ü Both nymph and adult suck the sap from the milky grains; the individual grains become chaffy. Black or brown spots appear around the feeding puncture. PECKY GRAINS.
Management
·
Collection of adults
using net and killing them.
·
Remove the alternate
host
·
Dust any one of the following at 25 kg/ha twice, the first during
flowering and second a week later
1. Quinalphos 1.5 D
2. Carbaryl
10 D
3. Malathion
5 D
4. KKM
10 D
5. KKM dust formulation consists of 10% of Acorus
calamus rhizome powder and 90% of fly ash
6. This dust formulation repels the rice earhead
bug.
Spray
any one of the following twice as above
·
Fenthion 100 EC @ 500
ml/ha or Malathion 50 EC @ 500 ml/ha
·
Neem seed kernel extract
5% @ 25 kg/ha or Notchi or Prosopis leaf extract 10% .
Black bug: Scotinophara lurida: Podopidae :
Hemiptera
ü Adult: brownish black bugs with a prominent
scutellum and pronotum having a spine on either side.
ü Presence of bugs
at the base of the plants. Plants stunted with reduced number of tillers.
Leaves turns reddish- brown or yellow and dry
(bug burn).
ü Both nymph and
adult cause damage to the crop.
Red spotted bug: Menida histrio: Pentatomidae :
Hemiptera.
ü Orange colored
bugs make the individual grains as chaffy.
Striped bug/
Nama vandu: Tetroda histeroides:Pentatomidae : Hemiptera
ü Adult: Brown bug
with a prominent ‘V’ shaped mark on its back.
ü Infested leaves
become yellow.
Mealy bug: Brevennia rehi: Pseudococcidae:
Hemiptera
ü Both nymph and
adult cause damage to the crop.
ü Nymph: Pale
yellowish –white; Adult: Reddish- white, soft bodied and are covered by a
white, powdery waxy coatings.
v During main field preparation - remove the grasses from the bunds and trim the bunds
v Remove and destroy the affected plants.
v Spray any one of the following insecticides
in the initial stage of infestation
o Dimethoate 30 EC 500 ml/ha
o Methyl demeton 25 EC@ 500 ml/ha.
v Conserve the natural enemies like Scymnus sp.,Anatrichus
pygmaeus, and Mepachymerus ensifer
Source: TNAU Agritech portal