GENERAL SITUATION

Scattered showers fell across the Southern Blacklands last weekend, bringing between a trace and 1.5 inches of rain and it looks like more is on the way this morning. Most areas received less than 0.3 inches. There are still fields that are to wet to get in with equipment.

Corn and grain sorghum are making good progress. Some of the maturest sorghum is in full bloom and small grain harvest is wrapping up. The oldest cotton is making good growth, but some of the later planted cotton is struggling due to thrips, injury from hail and high winds and and other problems.

CORN AND SORGHUM SOIL INSECT PESTS

Keep monitoring for adult mexican corn rootworm beetles in fields of corn that will potentially be planted to corn in . 02. Right now is the time when you can begin making notes for decisions on what type of early season management will be required for next season based on populations of the beetles currently in fields.

As sorghum begins to bloom, producers should begin close monitoring for sorghum midge. A few reports of sorghum midge have recently been received, many with levels low enough that they are not being detected. However, due to the fact that sorghum midge can complete a life cycle in 14-16 days, and that each female lays an average of 50 eggs, any sorghum blooming the week of May 29 or later has the potential to being exposed to the next generation of midge which could be relatively high. Therefore, keep you eyes and ears open to sorghum midge.

Sorghum midge are gnat-like insects and are orangish-red in color. As a rule of thumb, it does not take but about an average of one midge per head to cause significant damage. Inspect the blooming portion of the sorghum head where the bright yellow anthers extending out of the spikelets are located. Close-range inspection for midge is the most efficient detection technique, but clear containers (i.e., glass jar or plastic bag) can be placed over the head. Then by shaking the panicle, midges can be counted as they fall into the bag or container.

The need for insecticide is based on the number of adult midges during the flowering period. Use the economic injury levels for susceptible or resistant sorghum hybrids as presented in the following table. The density of adults per panicle that would justify chemical control can be determined by first estimating the per acre value of the crop, which is based on the condition of the current crop, and historical experience. Second, determine the per acre cost of control, which includes both the cost of the insecticide and cost of application. Read down columns for cost of control. The density of adult midges at that point in the table would cause damage sufficient to warrant the cost of control. If adults are still present 3 to 5 days later, immediately apply a second treatment. Several insecticide applications at 3-day intervals may be justified if the yield potential is high and midges are abundant.

COTTON

The majority of the cotton is at the matchhead square stage. There is still some cotton that is being replanted and some that will be blooming within a week.

Thrip numbers are relatively high in most fields of young cotton. There are some fields that have suffered considerable injury from thrips. Although much of the cotton in the area is past the stage where thrips can cause damage, there are still a good amount of late planted cotton that is being attached by heavy numbers of thrips.

Aphid levels are increasing in many fields, especially fields that have recently been treated for fleahoppers and overwintered boll weevils which have reduced the level of beneficial insects in these fields. As a result, a lot of growers are electing to put out a light "shot" of Provado in with their overwintered weevil treatment to help keep aphid levels from exploding.

Fleahopper levels remain high for the third week in a row. Currently, fleahopper counts range from 4 to 88 per 100 plants with the majority of fields ranging from 18 to 32 per 100 plants. Percent square set ranges from over 90% to around 50%. High levels of adults are being found migrating into fields following initial insecticide applications. Unfortunately, I do not see any reason to think that the fleas are going to let up anytime soon.

During the first three weeks of squaring, 10 fleahoppers per 100 terminals may cause economic damage. Be sure to carefully monitor fields for adult and nymph fleahoppers.

Some recommended insecticides to manage fleahoppers include Bidrin at 1 gal/40ac, Dimethoate 4E at 1 gal, 1/16 Othene (90S) at 4 oz/ac, Provado at 3.75 oz/ac, and Vydate CLV at 8oz/ac.

Boll Weevil trap catches remain low this week. Because the numbers remain low, we are reducing the number of treatments we make for overwintered weevils. In locations where we normally make two treatments, this year we are only making one application and where we normally make three we are generally scheduling two treatments. However, keep in mind that there are areas where late cotton was last fall. There will probably be higher levels of weevils infesting the cotton early this season. That will need to be managed accordingly.

About 70% of the traps that we monitored this week did not catch a weevil and the highest counts came along FM 1331 between San Gabriel and Hare where not to much cotton is being grown.

Some suggested insecticides labeled for overwintered boll weevil include Guthion 2L @ 1pt/ac, Phasar 3E at 1pt/ac, Vydate CLV at 8.5 oz/ac, and Penncap-M 2F @ 1pt/ac. Bidrin is also labeled at 4.0 to 8.0 ounces per acre for mid to late season control. Cost for the 4.0 ounce rate is approximately $2.75 per acre. For products such as Guthion that do not control fleahoppers, it may be necessary to tank mix Bidrin, dimethoate, or Provado to achieve fleahopper suppression.

Bollworm/budworm levels remain low this week. I am not expecting numbers to increase to much over the next two weeks.

GRASSHOPPERS

I encourage growers to continue treating for grasshoppers around the margins of fields, especially fields that join pasture/rangeland where grasshoppers are generally heavy. The majority of the grasshoppers are at the 3rd to 4th instar stage and are still relatively easy to kill with reduced rates of insecticides. Refer to the previous Pest Management Newsletter, No 4, for a list of some of the recommended materials to control grasshoppers.

Beginning the week of June 4, I will be meeting at the location and time listed below. In addition to myself, there will be representatives from the Southern Blackland Boll Weevil Eradication Foundation that will also be at Friday sites to help keep individuals updated on what they have going on and dispel rumors that are floating around.