Cotton Insect Pest APHIDS
Aphid in Cotton
Common Name :
Aphids
Local Name :
Mawa
Scientific Name :
Aphis gossypii Glover
Family :
Aphididae
Order :
Homoptera
Pest Category: Sap feeder
Distribution and status: India, occasionally serious.
Host plants: Cotton, Bhendi, Brinjal, Chillies, Guava
ETL: 5% of Infested Plants.
Description of Insect Stages:
Nymph:
Nymphs
are small, yellowish
or brownish on the
undersurface of the
leaves and on the
![Aphids are Nymph Stage Aphids are Nymph Stage, Aphida, Mawa, Aphid ( Aphis gossypii ), Aphis gossypii, Cotton Crop Major Sap Feeder Insect Pest, Aphids On Cotton Crop, Aphids Live Video On Cotton Crop](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhxhvjJN_bYsCmZWmCH_MoIgz9QND1SAbduj0OZ8H32s2coxxqYI5vC_mL4HFiF8dKDYWM-hyNPeC3rg7sgIfFVRF7TtQ_4EAxmwLLhWz4I6h84PyU8xmUs-ucW2Ij4b679hN_HaOTQB2Xz/s1600/Aphids-Nymph-Stage.jpg) |
Aphids are Nymph Stage |
terminal shoots and
are mostly wingless.
Adult:
Adults are
yellowish-brown
to black, 1.25 mm
long with black cornicles and yellowish-green
abdominal tip. Both operate (0.9-1.8 mm) and alates
(1.1-1.8 mm) occur together.
Bionomics:
![Aphids On Cotton Plant Leaves in Nymph & Adult Stager Aphids On Cotton Plant Leaves in Nymph & Adult Stager, Aphida, Mawa, Aphid ( Aphis gossypii ), Aphis gossypii, Cotton Crop Major Sap Feeder Insect Pest, Aphids On Cotton Crop, Aphids Live Video On Cotton Crop](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQsjct_3GdPGvFftdBPcD6ka-VSh62U6ghIqscmrxRuPdn_MlB0DJxDkuhUwNvhmTzjD_MFYC-NvGrISKXi-VeyZLMXkNknwdv7YxSkmH0MW-FpBPwu4PubaN__ZisYuFayI9sxmg1uqxG/s1600/Aphids-On-Cotton-Plant-Leaves-in-Nymph-%2526-Adult-Stager.jpg) |
Aphids On Cotton Plant Leaves in Nymph & Adult Stager |
The
aphids are greenish-brown, soft-bodied and small insects. The alate, as well as apterous females, multiply parthenogenetically and viviparously. A
single female may produce 8-22 nymphs in a day which become adults in about 7-9
days. They are often attended by ants for the sweet honeydew secretion.
Winged forms may be seen under crowded conditions.
Nature of Damage:
Aphids are phloem feeders, causing direct leaf
c rumpling and
downward curling
with a severe attack.
Indirectly decreases
cotton fiber quality
as a result of sticky
cotton due to
deposits of
honeydew on open
bolls. Younger plants suffer more attack than older
plants. Aggregating populations are seen at the
terminal buds and largest populations are found below
leaves of the lower third of plants where they are partially
protected from sunlight and higher temperature.
![Aphids are Adult Stage Aphids are Adult Stage, Aphids On Cotton Plant Leaves in Nymph & Adult Stager, Aphida, Mawa, Aphid ( Aphis gossypii ), Aphis gossypii, Cotton Crop Major Sap Feeder Insect Pest, Aphids On Cotton Crop, Aphids Live Video On Cotton Crop](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiSCXLZuYu0j-1K-85pVMT3kAPbNO3wk9qNcgFm9nOy4t7ID-imvFRLaQOcgSTitp22SBU9lxw0P548-MnbwIndSSfzEWotxvo-dCkzHAl86AFh7uQYH0pjRKhLubJE_ULeAfjA3OfxR8ZB/s1600/Aphids-Adult-Stage.jpg) |
Aphids are Adult Stage |
Symptoms:
Leaves show downward crumpling. Leaves are shiny
with honeydew or darkened by sooty mold growing on the honeydew. Contamination of lint with
honeydew and associated fungi leads to poor quality
cotton. The activity of ants on the aphid-infested plants is
common
Life History:
Aphids live in colonies and the alate as well as apterous
females multiply
parthenogenetically
and viviparously. In
a day female may
give birth to 8-22
nymphs. Nymphal the period lasts for 7-9
days and the adults
live for 12-20 days.
In all, the pest has
12-14 generations
per year. It is a
polyphagous pest.
Aphids produce
sugary excretion
called 'honeydew'
on which sooty
mold grows. Ant
activity is
associated due to the
honey
![Aphids are Affected in Cotton Plant Leaves Aphids are Affected in Cotton Plant Leaves, , Aphids On Cotton Plant Leaves in Nymph & Adult Stager, Aphida, Mawa, Aphid ( Aphis gossypii ), Aphis gossypii, Cotton Crop Major Sap Feeder Insect Pest, Aphids On Cotton Crop, Aphids Live Video On Cotton Crop](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEipH8IH-Gi57HxI2Dl_eZvIL4YTKbajXjpaeGGLBpqe6dyOms8kHHyfqpUecOQaM8xdZfYndvyrNWba68dh-PG9wvxVIS5tIeYPbAjKeXA-qgnK5z5BsfdP898aMXtyLGZFxNSSge2uDM6R/s1600/Aphids-are-Affected-in-Cotton-Plant-Leaves.jpg) |
Aphids are Affected in Cotton Plant Leaves |
excretion by aphids. Ants transmit aphids from plant to plant. Aphids have a large host range with varying durations of development and reproductive rate.
Seasonal Dynamics:
Aphid infestations on cotton commence after the true
leaves emerge and their field distribution is often clumped Typically aphid infestations will develop along with areas
downwind from bunds and occasionally spotty within
fields. It is to be noted that fields receiving regular
insecticide treatments continue to have damage due to
aphids for a long period of time over the fields
without
insecticide applications wherein aphid cause damage
for a short period of time but quickly brought under
control by natural enemies. High levels of aphid
populations develop on late than early-planted cotton.
Excessive nitrogenous fertilizer
applications stimulate
faster development of aphids.
Pest Management Options:
Management of aphids during very early crop growth the stage should be attempted with a view to maintain
optimum plant stand. Assessment of overall field
conditions are necessary before opting for management
against aphids. Insecticides of neonicotinoid group
such as imidacloprid and thiamethoxam applied as
seed treatment is efficient in suppressing the population of aphids on the crop for a maximum period
of 45 to 50 days. However, 'prevention is better
than cure' approach of pre-sowing seed treatment with
systemic insecticides aids in attaining proper plant
stand however they also cause luxuriant plant growth
leading to a higher attack by thrips during pre-flowering
stage, especially when there are dry periods.
Therefore, keeping a close watch of crop growth and
weather conditions, post-emergence sucking pest
management should be done on a need basis. Crops
should not be sprayed with insecticides considering the
populations of aphids on plants. This is because aphids
occur in aggregations and distributed randomly in a
field, initially. As they breed, the population spreads to adjacent plants and the proportion of aphid infested
plants in the field increases. The aphidophagous
coccinellids and syrphids, and the generalist predator
Chrysoperla carnea offer significant control of aphids
during the early crop growth period. Under such
situations, even if the pest numbers are high,
insecticidal sprays need not be given. Spraying the
crop should be done only when cupping and curling of
rd the leaves on the top 1/3 portion of the plant and
aphids all over the plant are seen, and the active growth
of the plants is inhibited in at least 25 % plants of the field. Await and watch attitude is a must in cotton pest
management to succeed by doing nothing e.g. the
decision of spraying insecticides against the high
population of aphids would be no use when heavy rains
occur. The applied insecticide goes waste, but with
natural reduction of pests due to rain.
A spray of 5 %
neem seed kernel extract prepared on-farm or crude
neem oil spray @ 1% suppresses also the aphid
population in addition to other sucking pests during the pre
squaring crop stage. While using neem products,
detergent/soap powder @ 1 gm/liter of spray fluid is to
be added for getting uniform spray suspension.
Chemical insecticides such as
Imidacloprid 200 SL @
0.5 ml/lit and Thiamethoxam 25 WG @ 1-1.5 gm/lit of
water can be used only when there are symptoms,
indicative of a high aphid population. The conventional
systemic insecticides should be alternated if more than
one spray of systemic insecticides is to be sprayed.
Sprays should be undertaken when the population of
aphids is high. Aphid attack during late season
coinciding with the boll opening can be managed using
the conventional insecticides like Endosulfan @ two
ml/ lit of water. Pyrethroids cause resurgence of
aphids on the crop and hence care should be taken
against the control of pink bollworm. In such a situation a
spray of anyone organophosphorus insecticidal
compound is to be followed for aphid suppression.
Insecticidal control is more successful in late than the early population of aphids. The table of the spray
volumes for field use at different crop growth stages is
given below.
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- Fluvalinate 25EC 200-400 ml
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- NSKE 5% kg/ha or Azadirachtin 0.03% 500 ml
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- Imidacloprid 70 WG 30-35 g or 30.5 SC 60-75 ml or 17.8 SL 100 -125 ml
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- Diafenthiuron 50 WP 600 g
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- Thiacloprid 21.7 SC 100-125 ml
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