The cotton crop is mostly in the ground up to the 5 true-leaf stage. Soil moisture was greatly improved this past weekend by several thunderstorms. These storms dropped between 0.5 and 3+ inches of much needed rainfall. And most fields are not currently under any drought stress.

COTTON INSECTS

Thrips, where found, do not seem to be effecting the cotton crop and aphid numbers seem to be falling; field populations range from 0 to 15 per leaf.

Right now, the biggest issue with the cotton crop is the grasshoppers.

Grasshoppers have been observed infesting field margins of some cotton fields in numbers that should cause some concern. Several species have been identified including adults of the differential, redlegged and two-striped grasshopper and the nymphs of the wingless jumbo or lubber grasshopper. Most problem situations have been field margins adjacent to wheat, CRP, range land or weedy areas such as fence rows and ditches. Grasshoppers have also been a cotton problem in some terminated wheat fields.

Treatment for grasshopper infested-cotton fields or areas of fields is justified when one lubber hopper is found on average per 3 row feet or two per square yard of vegetation around the field margin. For other species, we use twenty or more per square yard in crop margins or 10 or more per 3 row feet in the field as treatment guidelines. This is for smaller species of hoppers. Controlling grasshoppers early, especially when they are small is most effective.

While many folks that are controlling grasshoppers at this time have opted for the relatively cheap and effective pyrethroids, there is a downside to their use. Pyrethroids can increase later aphid problems. Pyrethroids also effectively kill and prevent re-colonization of beneficial insects for a longer period than most other insecticides. And---there are resistance issues. Consider using a different class of insecticide. OP's like Bidrin work well. So does methyl parathion or Penncap-M. These are toxic materials and must be carefully used in accordance to the label.

Turn-Row Meetings
1 hour CEU available
All meetings begin at 8:30 a.m.

Educational programs conducted by the Texas Agricultural Extension Service serve people of all ages regardless of socioeconomic level, race, color, sex, religion, handicap or national origin. The information given herein is for educational purposes only. References to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Cooperative Extension Service is implied. We will seek to provice reasonable accomodations for all persons with disabilites for all extension programs. We request that you contact Mr. Stephen Biles (915/236-9011) as soon as possible to advise us of the auxiliary aid or service that your require.

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Questions to Ask Before Pest Management Decisions Are Made

1. What pests are present, in what numbers and stages of development?
2. What conditions exist that may increase or decrease pest problems?
3. What natural enemies of the pests, such as parasites, predators, and diseases, are present that may play an important role in control?
4. What amount and type of damage is being caused or may soon be caused by pests?
5. What is the stage of development, condition, and value of the crop?
6. What is the potential for economical injury? How much damage is tolerable? Has the action threshold been reached?
7. What pest management options are available, and how do the advantages and disadvantages of each apply to the situation?
8. If alternatives are not available, is a pesticide treatment justified for the situation? If so, what is the material of choice?
10. If a pesticide is not justified, what approaches, if any, should be taken?

Field scouting and action thresholds can be used to provide much of the information needed to answer these questions. Thorough field scouting provided by an unbiased source who understands the crop and cropping system remains a major tenant of IPM.

Economic Injury Level (EIL)- the lowest level of a pest that will cause economic damage, ie. the level of pests where the dollar loss caused by the pest exceed the cost of control

Economic threshold (ET) is the level of pest infestation when control should be applied to keep an increasing pest population from causing economical losses. The ET is also called the action threshold because it is the pest level where action should be taken so that economic losses are avoided.

The economic threshold is a key IPM decision-making tool. Thresholds are based on considerable amounts of research and/or field experience. If the economic threshold is approached, but not reached, do not apply a pesticide at that time. Instead, re-scout the field within a few days to determine the status of the infestation. Pest populations can decline naturally due to mortality from natural enemies and unfavorable weather conditions. Also, many pests, such as caterpillars, change from an active feeding (larva) to a non-feeding stage (pupa) during their development. Such changes will often produce a natural decline in infestations as pupation occurs.

Mitchell Co.
City National Bank - Colorado City
First National Bank - Colorado City
Colorado Feed and Seed
Mitchell County Economic Development Board
Producers COOP Gin - Colorado City

Scurry Co.
Scurry County Board of Economic Development
Scurry County Cotton Producers Board

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