Vol XXXIX, No. 14

September 14, 2000

LAST ISSUE OF 2000 NEWSLETTER

This is the last issue of FOCUS for this season. I can’t say it has been an all together enjoyable one for you or for me. On behalf of all the contributors to FOCUS this year I would like to thank you for your patronage. I hope you have benefited from this newsletter and will next year again become a loyal reader. We have tried to provide a first class, electronic newsletter with as many bells and whistles as we could add. We intend to continue in this vein, but also add a much shortened version on DTN for those that are still not buddies with a computer or comfortable surfing the internet.

I do intend to continue providing updates on the boll weevil situation based on Foundation reports and the GRID trapping program run as a partnership between the Extension Service and Plains Cotton Growers, Inc. This will continue for at least another 6 weeks. I will continue to provide e-mail notification of these updates to those on my list. The address for these boll weevil situation updates will be:

http://lubbock.tamu.edu/ipm/AgWeb/index.html

COTTON INSECTS

It Is Over. Let’s Call It Quits!

Open cotton is the rule as we finally have moved out from under the hothouse conditions unusual for September to more typical (but still warm) conditions for this time of year (80s for high temperatures). The record temperatures have stressed many fields with limited to no supplemental irrigation capabilities, but on a positive note have probably limited the rate of boll weevil population expansion and stopped our other pest problems in their tracks. This has been an especially tough summer with extended multiple pest problems, expensive insecticide programs and drought conditions. Those producers with lots of water will probably make exceptional yields but at what cost? And those producers without adequate water will make limited yields, often with too much money spent for insect control. Strippers are beginning to roll. We will soon know the outcome of the 2000 season.

While bollworm and beet armyworm moths continue their relentless egg bombing runs on the later or lusher irrigated fields, it is time to realize that these late attacks cannot cause yield losses to fruit we can mature for harvest, at least not enough to pay the spray bill.

Watch Out for Sticky Cotton

Cotton aphids persist in many fields but are no longer a threat to your yield. The only remaining concern with this pest is the potential for sticky cotton from their honeydew contamination of open boll lint. With insect control expenses at all time highs and yields for the most part not at desired levels, most producers will not be interested in controlling these late season aphids once their cotton opens. Remember that the threshold is a low 15 aphids per leaf. A good avoidance practice would be to terminate your crop with an appropriate harvest aid as soon as is it agronomically possible. The step up of eradication program spraying activity could exacerbate the aphid situation, so be prepared for that.

It is essential for our cotton industry to avoid a sticky cotton problem and the long term reputation that goes with it. For a thorough discussion of the problem and possible remedies, look at the publication, "Sticky Cotton Sources & Solutions". A printed version of this publication is available from me or your local Extension Ag or IPM Agent. It is a four-page color publication developed by Texas A&M University, the University of California, University of Arizona, USDA and Cotton Incorporated. A web version of the publication is available at: http://ag.arizona.edu/cotton/stickycss.pdf

Boll Weevil Trap Catches Continue Upward

Boll weevil numbers continue to rise in the GRID trapping system (Table 1). The decline in the dryland and limited irrigated acreage has forced many weevils on the move. Some of these weevils have been intercepted by our traps on the way to greener pastures. This is exactly the same pattern we have observed each year. While late squares and bolls are being hammered by this latest onslaught of weevils, their yield robbing capabilities are all but negated by the fact that boll weevil vulnerable fruit no longer have enough time left to mature and make an acceptable boll for harvest.

 

Table 1. Total boll weevils caught per week and percent of traps catching boll weevils since April 24, 2000 in the GRID trapping program.*

Week beginning
Total weevils caught
% of Traps Catching Weevils
April 24
948
30
May 1
887
34
May 8
5243
67
May 15
1112
34
May 22
2106
45
May 29
1651
46
June 5
4163
56
June 12
3391
47
June 19
5684
49
June 26
3346
53
July 3
3318
48
July 10
2057
32
July 17
1522
42
July 24
1772
41
July 31
4534
50
August 7
2960
45
August 14
6133
54
August 21
3258
52.3
August 28
15,562
54.5
September 4
20,209
51.4

*Includes three counties in the Rolling Plains.

The biggest increases in weevil numbers caught in traps remains in the two zones yet to support eradication (Tables 2 and 3). But the differences between 1999 and 2000 trap catches will be reduced in the active eradication zones from this point forward since the eradication effort was initiated with a full blown diapause program in September last year in these areas. However the differences in the inactive zones between 1999 and 2000 probably will continue to grow.

With a boll weevil referendum vote in progress in the Northern Plains Zone and scheduled for next month in the Southern High Plains/Caprock Zone, it is critical that producers objectively evaluate the information available and vote on the basis of facts and not fiction, innuendo or scare tactics. Scientifically it makes sense to vote for eradication. It has a proven track record, the Foundation has made adjustment to avoid the mistakes of the past and eradication has proven itself as being a cost-effective alternative to self management of the boll weevil. It is a long term investment in the future of a viable cotton industry for the High Plains of Texas, and for you. But maybe you are not looking for a long term investment? Only you can make that decision. But if you still have questions. Get answers! But please vote.

 

Table 2. Comparison of average weekly boll weevil trap catch in the Southern High Plains/Caprock Zone between 1999 and 2000.*

Week beginning
1999
2000
June 5
12.2
6.8
June 12
7.8
6.1
June 19
9.9
4.1
June 26
9.5
6.0
July 3
3.3
4.6
July 10
2.0
1.8
July 17
2.1
5.1
July 24
2.0
6.0
July 31
5.8
18.8
August 7
5.5
10.0
August 14
13.7
17.0
August 21
7.0
12.4
August 28
20.6
36.9
September 4
16.8
80.8

*These data represent the average number of weevils caught per trap catching weevils. Zeros are not counted.

 

Table 3. Week 36 (week beginning September 4)— Accumulative average number of boll weevils caught per trap in the GRID trapping program starting with week 18.

Location
1999
2000
Northwest High Plains
64.1
31.5
Northern High Plains
146.5
190.1
Southern High Plains
164.7
245.9
Western High Plains
320.7
41.1
Permian Basin
142.2
44.2
     
Andrews
438.2
43.6
Bailey
66.2
34.1
Borden
105.9
55.8
Briscoe
184.0
135.6
Castro
20.1
15.8
Cochran
108.1
83.6
Crosby
245.4
296.7
Dawson
213.9
60.4
Deaf Smith
13.0
3.0
Floyd
129.7
234.3
Gaines
423.2
34.9
Garza
285.0
253.4
Hale
147.1
220.6
Hockley
99.1
81.6
Howard
128.7
33.6
Lamb
76.2
29.8
Lubbock
151.0
438.0
Lynn*
124.9
67.3
Martin
73.6
23.0
Midland
55.9
26.3
Parmer
16.1
8.3
Swisher
113.4
128.8
Terry
181.3
32.5
Yoakum
233.0
38.3

This data represents the average number of weevils caught per trap catching weevils. Zeros are not counted. Refer to the Plains Cotton Growers, Inc. web page for actual total numbers caught and percent of traps catching weevils each week. The diapause phase of eradication has begun in the three active zones in 1999, reducing trap catches significantly for the first time.

*Includes traps both inside and outside active eradication zones.

 

It is time for producers to take one last step to help on the weevil problem for next season. Timely termination of the crop can deny boll weevils their last supper, essentially starving them to death over the winter. This practice is advocated for producers both in and outside of active eradication zones. Those inside active zones can help the Foundation save money by removing their fields from the list that needs to be sprayed. Those producers outside the program can add to the reduction by mixing an insecticide, such as methyl parathion, in with their harvest aid if weevils are still in their fields at the time of application.

Eradication Update

There are lots of planes flying in the three active eradication zones as the Foundation turns up the heat on boll weevils before they have a chance to disappear into their overwintering sites. This is a critical stage in the program. Success means a drastic reduction in spraying next year, which in turn means lower costs and a greatly reduced risk of secondary pest problems. Most weevils that successfully overwinter in the High Plains will leave cotton for good in the latter part of September and the month of October. Very few if any of the weevils that have left thus far are a threat to cotton next year. Help the Foundation by terminating your crop as soon as possible and remove it from the list of fields that need to be sprayed. Hopefully we will have a more typical freeze date this year.

Table 4 provides the statistics on the eradication program for last week. Trap catches went up slightly as weevil movement increased but beet armyworm trap catches decreased significantly indicating to me that the threat is over for this pest.

 

Table 4. High Plains Eradication Program weekly report for week ending September 3.

Zone
Accumulative acre applications
Avg. # boll weevils per trap
Avg. # beet armyworms per trap
Northwest
1,235,370
1.0 (3.8)*
372
Western
1,941,675
0.32 (14.7)
205
Permian Basin
1,308,297
0.20 (8.7)
25

*( #) = 1999

 
Focus on Entomology is published by the

Texas Agricultural Extension Service

Route 3, Box 213AA

Lubbock, TX 79403

For more information call or e-mail:

806-746-6101 or

m-coffman@tamu.edu

Editor: James F. Leser

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