Pests of cotton_Sucking_Pests_Dr.UPR.pdf

Cotton crops are vulnerable to a variety of sucking pests, which can severely impact plant health, yield, and fiber quality. These pests primarily feed on plant sap, extracting nutrients directly from the plant's vascular system. Here's a breakdown of some of the most significant sucking pests in cotton cultivation:

Aphids: Cotton aphids or melon aphids can cause direct damage by sucking sap and indirect damage by secreting honeydew, which encourages sooty mold growth. This can interfere with photosynthesis and weaken the plant. Aphids can also transmit viral diseases.
Whiteflies: Two species, the silverleaf whitefly and the bandedwinged whitefly, are particularly troublesome. They not only suck sap from the underside of leaves, causing yellowing and leaf drop, but their honeydew excretion promotes sooty mold and they can transmit several plant viruses.
Thrips: While thrips can chew on plants, their primary damage to cotton is through sucking. They attack the cotton plant during its seedling stage, which can stunt growth and reduce vigor. Thrips are also capable of transmitting the Cotton Bud disease.
Spider Mites: These are not insects but arachnids. Spider mites, such as the two-spotted spider mite, suck cell contents from the leaves, leading to speckled discoloration and potentially significant leaf loss if infestations are severe.
Leafhoppers: Including various species, leafhoppers can cause direct damage through feeding, which results in leaf curling and stunted growth. They can also be vectors for plant diseases.
Mealybugs: These pests are less common but can be problematic, especially in clustered planting conditions. They suck sap and secrete honeydew, which leads to sooty mold. Mealybugs can also spread viruses.
Stink Bugs: Although primarily known for their chewing mouthparts, certain stink bugs can cause damage similar to sucking pests by injecting saliva into the plant and sucking out nutrients, leading to boll damage and stained lint.
Management Strategies:

Cultural Controls: This includes practices such as crop rotation, using resistant varieties, and managing planting and harvesting times to avoid peak pest populations.
Biological Controls: Beneficial insects like lady beetles, lacewings, and predatory mites can naturally control sucking pest populations. Parasitic wasps also play a role in controlling aphid and whitefly populations.
Chemical Controls: Insecticides may be used but should be chosen carefully to minimize resistance development and preserve beneficial insects. Systemic insecticides can be particularly effective against sucking pests.
Integrated Pest Management (IPM): Combining multiple control strategies based on monitoring and thresholds to apply the most effective and environmentally sensitive approach.
Effective management of sucking pests in cotton requires a thorough understanding of the pest species present, their life cycles, and the ecological balance of the field environment.

1. Sucking pests of cotton
By
Dr. U. Pirithiraj, P.hD.
Assistant Professor (Entomology)
JSACAT
Affiliated to Tamil Nadu Agricultural University

2. Leafhopper / Jassid, Amrascadevastans,
Cicadellidae, Hemiptera
1
Dr. U. Pirithiraj, P.hD. (Entomology)
Natureofdamage
Nymphsandadultsremainbetweentheveinson
theundersurfaceoftheleavesandsucksthe
sap
Symptomofattack
Yellowingofleaves,crinkling,backwardcurling
ofleaves,bronzingandhopperburn,plants
becomestunted
Distribution:Major pest in all cotton-growing region of India

3. Elongate, yellowish eggs are laid singly
within the leaf veins in the
parenchymatouslayer between the
vascular bundles and the epidermis on
the upper leaf surface
Light green, translucent, wingless and wedge shaped
Slender green insect, wedge shaped
Dr. U. Pirithiraj, P.hD. (Entomology)

4. ETL: 50 nymphs or adults / 50 leaves
Hairy varieties of cotton are resistant to jassids
Adopt synchronisedsowing
Treat seeds with Beauveriabassiana@ 10 g/kg.
Apply nitrogenous fertilizers judiciously

5. Cotton aphid, Aphis gossypii, Aphididae, Hemiptera
2
Dr. U. Pirithiraj, P.hD. (Entomology)
Natureofdamage
Nymphsandadultssucktheplantsap
andlowertheplantvitality.They
producehoneydew,whichresultsin
developmentofblacksootymould.The
damageismoresevereinyoungplants
Symptomofattack
Youngplantsbecomeweak,leafcurlup
andwither
Soft, yellow, exist both in winged and wingless
forms. Both forms reproduce
parthenogeneticallyand are viviparous
Tropical and temperate regions throughout the world

6. Management
ETL:15% of infested plant
Avoid late sowing
Treat seeds with Beauveriabassiana@ 10 g/kg
Apply nitrogenous fertilizers judiciously
Grow cowpea as intercrop or on the bunds to increase the natural enemy
build up

7. Thrips, Thrips tabaci, Scirtothripsdorsalis, Thripidae,
Thysanoptera
3
Dr. U. Pirithiraj, P.hD. (Entomology)
Natureofdamage
Nymphsandadultslaceratethetissueon
theundersurfaceoftheleavesandsuck
upthesap
Symptomofattack
Silverysheenontheundersurfaceofthe
leaves
Small slender insects, colourvary from yellow to
brown with fringed wings
Tropical and temperate regions throughout the world

8. ETL: 5 -10 /leaf
Avoid alternate cultivated host crops of the whitefly like brinjal, bhendi,
tomato, tobacco and sunflower in the vicinity of cotton crop
Removal and destruction of alternate weed hosts like Abutilon indicumand
Solanum nigrumfrom the fields and neighbouringareas and maintaining
field sanitation
Adoption of crop rotation with non-preferred hosts such as sorghum, ragi,
maize

9. Whitefly, Bemisiatabaci, Aleyrodidae, Hemiptera
4
Dr. U. Pirithiraj, P.hD. (Entomology)
Natureofdamage
Nymphsandadultsremaininclusteranddesap.
Italsoactsasvectorofcottonleafcurlvirus,
vein-clearingdiseaseinbhendi,tobaccoleafcurland
cassavamosaic
Symptomofattack
Whitechloroticspotsappearonleaves.Numberand
qualityofflowerssquaresandbollsgetsreduced.
Nymphsandadultssecretehoneydew,whichleadto
sootymouldformation
Origin inUganda, to the northern, central, eastern and coastal regions of Tanzania

10. Red cotton bug /cotton stainer, Dysdercuscingulatus
Pyrrhocoridae, Hemiptera
5
Dr. U. Pirithiraj, P.hD. (Entomology)
Natureofdamage
Nymphsandadultssucksthesapfromtheplant
andbolls,reducethevigouroftheplant,
producepoorqualitylint
Symptomofattack
Youngbollsareaffected,whichturndarkbrown
andfailtoburst,Lintstainedred.Seedsshrivel
Bacterium,Nematospioragossypiistainslint
Mainly found in the continents of Asia and Oceania

11. Ovoid, yellowish eggs are
laid in loose masses in
the soil and protected
with soil/ dry leaves
Reddish with
white band on
the abdomen
Red and black with white stripes ventrally on the
abdomen
Dr. U. Pirithiraj, P.hD. (Entomology)

12. Dusky Cotton Bug, Oxycarenushyalinipennis,
Lygaeidae, Heteroptera
6
Dr. U. Pirithiraj, P.hD. (Entomology)
Symptomofdamage
Sucksthesapfromdeveloping
seedsinopenbollsandstainsthe
lintblack
Seedsdiscoloredandshrunken
Asia, Europe, the Middle East, South America and the Caribbean

13. Cigar shaped, white eggs in
clusters of 2-10 within the
half opened bolls, on the
bolls, flower or buds
Dusky, greyish brown bug, with
pointed head and hyaline wings
Dr. U. Pirithiraj, P.hD. (Entomology)

14. Mealy bug, Ferrisiavirgata, Pseudococcidae,
Hemiptera
7
Dr. U. Pirithiraj, P.hD. (Entomology)
Natureofdamage
Nymphsandadultsremainin-groupandsuckthe
sap.Generallythedamageisnoticedtowardsthe
endandinplaceswhereratooningispracticed
Symptomofattack
Presenceofmealybugsontendershoots,leaves,
stemandbolls.Yellowingofleavesinitiallyandlater
theplantsdie.Leavesandbollsfallprematurely
It is a widely distributed and polyphagous pest species

15. Black scale, Saissetianigra,
White scale, Pulvinaria maxima, Coccidae, Yellow scale,
Cerococcushibisci, Asterolecanidae, Hemiptera
8
Dr. U. Pirithiraj, P.hD. (Entomology)
Natureofdamage
Nymphsandadultsremainingroupandsucksthe
sapfromleavesandshoots
Symptomofattack
Presenceofscalesonthetendershoots,leaves,
stemandbolls,stuntingoftheplantsandbears
onlyfewbolls.Movementofantsseen.Sootymould
developmentalsoseen
Widespread throughout the world

16. Black scale,
Saissetianigra
White scale,
Pulvinaria maxima
Yellow scale,
Cerococcushibisci
Dr. U. Pirithiraj, P.hD. (Entomology)