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Texas Agricultural Extension Service The Texas A&M University System Plains Pest Management Newsletter |
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News about Integrated Pest Management in Hale-Swisher Counties. Greg Cronholm, Extension Agent - IPM, 122 East 6th, P.O. Box 680, Plainview, TX., 79073-0680, 806-291-5273 |
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Web Site: http://entowww.tamu.edu |
E-Mail:
g-cronholm@tamu.edu
June 20, 2001 |
Cotton continues to look very good at this time. Early planted fields are now at the 1/3 grown square stage, with other fields just starting to square. Temperatures have been very hot this past week, but cotton has not shown signs major stress. Thrips damage is declining with the new growth in the terminal showing little damage. A few fields continue to average over 8 thrips per plant. Beet armyworm infestations continue to be found in many area cotton fields. Populations have continued to decline due to predators and new growth in the terminal shows no skeletonized leaf tissue. Cotton aphids were found in more fields this past week. Counts continue to be low with only occasional plants infested. Lygus bug adults have been reported moving into cotton by several private consultants. Most of the movement has been from weedy areas or pastures. Most of the activity has been in early planted cotton with larger squares. The Lygus bug complex is difficult to deal with because the adult stage is very mobile. They can move in and out of fields over short periods of time and may go undetected. During the first week of squaring, the economic threshold is one lygus bug adult or nymph per 3 feet of row combined with less than 90% square set. |
During the second week of squaring, one lygus bug/three feet of row with less than 85% square set is the threshold. In the third week of squaring, the economic threshold is one lygus bug adult or nymph per 3 feet of row, with less than 75% square set. After the 3rd week the threshold is 2 lygus per 3 feet of row with less than acceptable fruit retention. A few cotton fleahoppers have also been reported. They tend to damage very small squares while the lygus bugs damages all sizes of squares and small bolls. Boll weevil trap collections remain very low over Hale and Swisher counties. Last year we had already treated many cotton fields for overwintered weevils. Lets hope this trend continues as we move toward eradication.
Southwestern corn borer have been found feeding in the whorl this past week. We have found 1st instar larvae to 5th instar larvae. The majority of larvae have been in the 3rd instar stage. As larvae reach the 3rd instar they move from the whorl to the stalk where they bore into the stalk behind the leaf collar. European corn borers remain light. Consultants have reported finding an occasional corn field infested. Emilio Nino, IPM agent in Castro and Lamb County has reported finding a larvae in two fields in his area. |
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April planted sunflowers
are now starting to bloom. The sunflower moth is a key pest of this
crop which can greatly reduce yield potential. Treatments for this pest
should begin when 20% of the heads start to bloom and sunflower moths
are present in the field. Count any head as blooming if the ray petals
can be observed. Confectionary flowers tend to bloom faster than oil
seed flowers. Last year we took bloom counts in a confectionary field
and found the following bloom pattern
As one can see
when confectionary sunflowers hit 5% bloom they should be treated the
following day. If one waits til the field is at 20% bloom and is delayed
by a day the field will be at 40% bloom. Many insecticides are labeled
for control of sunflower moth. Currently listed in our Sunflower Insect
Pest Guide are Furadan ®, Sevin ® ,Lorsban ®, Bacillus thuringiensis,
Baythroid ®, endosulfan, Asana ®, Karate,® methyl parathion
and Socut X-TRA ®. |
Sincerely, Greg Cronholm  Posted at this web site by: texagnet Internet Services.
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