Thrips IPM in Cotton

 

Thrips (http://cottonbugs.tamu.edu/seedling-pests/thrips/)

Cotton is up on the coast of Texas and Thrips are the primary insect pest we will encounter until the plant gets 3-5 leaves.  Thrips are very small insects found on the underside of small leaves and in the plant terminal.  Thrips are slender, cigar shaped, straw colored insects about 1/15 inch long, with piercing and sucking mouthparts. Adults are winged and capable of drifting long distances in the wind. (Source)

Thrips are early-season pests of seedling cotton. In much of the state, thrips are a minor pest, but in areas prone to cool, wet conditions when plant growth is slowed, they are often a severe pest. Thrips are especially numerous in cotton grown near maturing small grains, near onion fields or seedling corn.

Thrips attack leaves, leaf buds and very small squares and may cause a silvering of the lower leaf surface, deformed or blackened leaves, terminal loss and square loss.  Affected plants will have leaves crinkled or cupped upward.  Severe infestations can cause terminal death and square loss.

Most cotton is planted with an insecticide seed treatment which will provide acceptable control the thrips.  The seed treatment combined with the warm temperatures and good soil moisture in the cotton fields should provide an environment where the thrips are unable to delay crop maturity or reduce yields.

Economic Thresholds for thrips is published at one thrips per true leaf through the 5th leaf stage.  However, with good growing conditions, the plants can often sustain higher numbers without having economic damage.  I suggest using an economic threshold of 2 thrips per true leaf this year.

Follow this link to a video on scouting for Thrips. (THRIPS VIDEO LINK)

Cotton Insect Management Guide LINK

 

 

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