ANNOUNCEMENTS
Pecan Crop Insurance Meeting: The USDA- Risk Management Agnecy, in conjunction with the North Carolina A&T University, will be holding listening session in Texas and New Mexico to surface comments on pecan crop insurance from pecan growers, bankers, crop insurance agents, extension agents and researchers. Two sessions will be held Wednesday, February 27, 2002 at the El Paso County Texas Cooperative Extension office. The 9:30 a.m. session is for pecan growers and researchers, while the 1:00 p.m. session will be for bankers and crop insurance agents. For more information please contact Texas Cooperative Extension at (915) 859-7725.

We are still using our "old" subscription list, we have only received about half of the list in renewals. If you haven't contacted us and still want the IPM Newsletter you need to do so before March 30, 2002, or else you won't be receiving the IPM newsletter. Our phone number at the Extension Office is 859-7725, ask for Renee Bishop.

Alfalfa:
We don't typically think about pest control in alfalfa, especially this time of year, but if you walk out into the field and look around you will most likely see some aphids. Aphid infestations in alfalfa are common every year and are spotty throughout the valley this spring. Some fields scouted had significant populations and some damage. Fields that have old growth on them have more aphids than those that were harvested late last fall.

When looking for aphids, pull the "trash" out from around the crown of the plant and look at the stems and crown. Aphids will congregate on the stems, leaves and ground. Make sure to observe any feeding on new growth, and determine if aphid infestations are causing stunting or damage to the crown. Common aphids found are: pea aphids, spotted alfalfa aphid and cow pea aphids. Pea aphids are bright green and were the most abundant aphid species seen in the El Paso Valley earlier this week. Spotted alfalfa aphids are easy to distinguish because of their spotted appearance; they are greyish-yellow with four to six rows of raised dark spots on the back, this was the least common species of aphid that was observed. (See table on back for treatment thresholds of pea aphids and spotted alfalfa aphids.) Cow pea aphids are black and are usually found congregating on the stems of alfalfa. This aphid was typically a pest of legumes (not alfalfa) and became noticed as a pest of alfalfa in California in 1999. Therefore, cow pea aphids are a relatively new pest to alfalfa. Last year this aphid caused severe economic damage to alfalfa producers in New Mexico; one grower estimated that he lost 20-30% of his stand to cow pea aphid infestations in early March 2001. Cow pea aphids prefer the cool time of year (late winter/early spring) which is why their populations can build up and cause lasting damage before it is even noticed. There are no established thresholds for cow pea aphid; common sense must prevail in making management decisions.

Often times we rely on natural enemies to control aphids, but this time of year there are few natural enemies in the fields. In fact, low populations of ladybugs were observed in fields around the valley this week. It may be hard to determine if aphid populations are hurting your alfalfa now, but as temperatures warm and alfalfa breaks dormancy and no growth is occurring because aphid infestations are so high, you may consider treatment options.

Things to consider when deciding on whether or not to treat for aphids are: Will this infestation hurt the stand? Does the root system have enough reserve to still have a productive first cutting? How long will it be until a good number of beneficial insects will be out to help control the pests?

Suggested Insecticides for aphid control include**
• chlorpyrifos (Lorsban 4lb) @ ½ pt. per acre
• dimethoate (Dimethoate 400) @ ½- 1 pt. per acre
  • Dimethoate 2.6 @ 3/4- 1 ½ pt. per acre
• malathion (Cythion 5lb.) @ 1 ½ - 2 pt. per acre
  • Cythion 8 lb. @ 1 1/4- 1 ½ pt. per acre
• methyl parathion (Methyl Parathion 4lb) @ 1 pt. per acre
  • Methyl Parathion 7.5 lb @ 1/4 - ½ pt. per acre
  • Penncap-M @ 2-3 pt. per acre

**Taken From: Integrated Pest Management Guide for Texas Forage Crops- Texas Cooperative Extension Service

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