Texas Cooperative Extension

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June 30 , 2006

Anyone wanting this newsletter by email please send me a note at the above address and I'll put you the list. If anyone has had an address change from a rural route box number to a 911 address please let me know so I can make the change. I have had to drop several producers because of returned letters with incorrect/old addresses.

Overall I would say the Texas crop is just average or a little bit less than average. I think we are past the “June drop” period where trees have shed nutlets. Rainfall across the sate has been variable the past couple of weeks so it is hard to make a general comment. However, I think rain is still the most critical factor needed to make and fill out this a crop.

Aphids : Blackmargined aphids are on the decline in many orchards. When possible I try to avoid treating yellow aphids or only treat specific varieties such as Cheyenne . Insecticides such as Provado, Centric and Fulfill are specific for sucking insects and can provide control of aphids and conserve the natural enemies.

Black pecan aphids : I've received a few reports of black aphids over the past week. Watch for black pecan aphid populations to increase in the shaded interior portion of the tree.

Adults and immatures can be found on both the upper and lower surfaces of a leaflet. Feeding by both adults and immatures causes the angular yellow and brown blotches on the leaflet. Adults and immatures feed between the secondary leaf veins and resulting damage will be angular or rectangular in shape. When making a management decision for black aphids, don't make a decision based only on damage. Black aphid populations fluctuate during the spring and early summer so check for the presence of adults and immatures. Feeding prior to mid July will result in leaf blotches but I have never observed defoliation during this time. I would restrict treatments until after mid July.

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Black aphid nymphs and damage .

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Colony of walnut caterpillars

Aphid parasite : There is a minute wasp, Aphelinus perpallidus (Gahan )that parasitizes pecan aphids and when parasitized, the aphid mummies turn shinny black and adhere to the leaflet. These aphid mummies should not be mistaken for black pecan aphids. If the adult parasite has emerged from the aphid the exit hole on the mummy can be easily seen with the aid of a hand lens.

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Parasitized yellow aphids

Pecan nut casebearer : The big question I'm hearing is “Where did the second generation go?” From all reports I have received and orchards I have monitored there was very little if any damage from the second generation. Trap catches were fairly high but very few viable eggs were found in orchards I monitored in Lee, Burleson and Washington counties. I attribute the light infestation to predation from beneficials.

Pecan nut casebearer prediction survey : Included with this newsletter is a short questionnaire/survey on the pecan nut casebearer prediction map that was made available this past spring. We would like to receive your input, if this map was beneficial to you or not, your thoughts on low to improve the map and would you like to see us continue to provide this map. Your input would be greatly appreciated. Surveys can be returned to me at the address listed above.

Walnut caterpillar : I have not received any reports on walnut caterpillar infestations - so far.
Watch for colonies of caterpillars on the terminals and terminals that have been stripped of foliage with only the leaf mid vein remaining.

State Meetings
July 9 -12
Texas Pecan Growers Conference and Trade Show Embassy Suites
Frisco , TX
Contact: TPGA @ 979-846-3285

Once again I will have a booth at the TPGA conference and hope that you will stop by to visit sometime during the meeting.

For more information, contact:
Bill Ree
Extension Program Specialist
Texas A&M University-Riverside Campus
Bryan, TX 77806-2150
Phone: 979-845-6800
Email: w-ree@tamu.edu

The information given herein is for educational
purposes only.  References to commercial products
or trade names are made with the
understanding that no endorsement by
Texas Cooperative Extension is implied.

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