GENERAL SITUATION

Dry! Showers this week resulted in rainfall amounts up to an inch in part of the area. Insect activity remains fairly light.

THRIPS

Thrips numbers ranged from light to moderate in area fields. The only cotton that may still warrant thrips control are the weather damaged fields that do not need any more delay.

SCOUT SAFETY

Please contact your scouts or me if you are spraying the field they are scouting with an insecticide. We do not want anyone to be exposed unnecessarily to pesticides.

FLEAHOPPERS

Fleahoppers ranged from 0-8 per 100 terminals and the % square sets ranged from 88%-100%. Most fields that are squaring have good retention at this time. We are seeing a few of the first squares on the first fruiting branch aborting, probably caused by earlier thrips damage. We need to continue to watch for fleahopper activity especially in the later or weather damaged cotton that needs no more delays.

BASIC IPM CONCEPTS AND DEFINITIONS

Continuing series on basic IPM concepts and definitions.

Important Terms and Concepts in 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.

Why Aren't There ETs Available for Every Pest?
ETs are notoriously difficult to determine. At first

glance, an ET would appear to be a straightforward, cost-benefit relationship involving control costs and market values. However, if you consider the influence of multiple pests on a crop , injury per individual pest, crop response to injury at various stages of development, varying climactic conditions, nutritional stresses, varietal differences, the purpose for which the crop is grown and fluctuating market values, then you can see how ETs might be slow in development and constantly changing.

Who Needs ETs?
We all do! ETs are the most effective method of determining if control is justified. Also, if pesticides are to be used, ETs help determine timing of pesticide applications. ETs are available that work quite well in maximizing the effectiveness and minimizing the number of spray applications for many pests. Some are still under development and many more need to be
developed. ETs represent a giant step forward in timing pesticide applications when compared to calendar or preventive spray schedules.

Does IPM Use Biotechnology?
Yes, biotechnology is providing a number of new tools for IPM.. Some of these are:
* diagnostic technologies including immuno- and DNA-based bioassays for rapid and reliable identification and monitoring of pests, natural enemies and pesticide residues.
* tissue culture is used to "clean up" planting stock of viruses and for rapid multiplication
* development of microbial pesticides and baculoviruses as control options
* transgenic crops with resistance to insects, viruses and herbicides
* genetic markers to enhance and speed up identification of different biotypes of pests
and genotypes of plants with resistant traits

WEATHER DATA
Weather data for the past two weeks is included in the table that follows:

HEAT UNITS averaged 22 per day the past week. Heat units since 5-1 and 5-15 and 6-1 are compared with last year and a five year average in the table below.

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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.

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