Pecan Nut Case Bearer Spray Time

Pecan Nut Case Bearer Spray Time Carlsbad, NM, — It is that time of the year again to be thinking about spraying for Pecan Nut Case bearer (PNC). Populations appear to be lighter this year based on shoot damage from over-wintering larvae and the number in shucks from the end of last year. Using a Heat unit model developed by Texas A & M Cooperative Extension Service, the Eddy County Cooperative Extension Service predicts the Pecan Nut Case bearer would be little later this year. Based on this model crop protection chemical should be applied May 27 to June 10th. However, based on reported moth counts in pheromone traps we think you should be spraying starting May 21 to June 5 th. Computer predictions are best used to decide when to set out pheromone traps, look for eggs and to plan insecticide application but should not be used as the only source of information to make application decisions. This year proves that. Orchard scouting for eggs should begin two weeks before the predicted spray date as unusual weather conditions near the spray date, can either accelerate or delay egg-laying activity. Most Case bearer eggs are found at the tip of the nut let, either on the top or hidden just under the tiny leaves at the tip of the nut let. A good hand lens is necessary to determine their development, (hatched, white, or pink). Also, look for bud feeding just below the nut cluster to detect the presence of newly hatched larvae. You should examine 10 nut clusters per tree. A cluster is considered infested if it has a Case bearer egg or nut entry. If two or more clusters are infested, insecticide applications may be necessary. Application should be two days after the eggs hatch. When no infested clusters are found you should check again two days later. Keep checking until June 20, which then if an infestation is not found insecticide application should not be required, for the first generation. Scouting for the seconded generation should start July 4th as currently predicted by the heat unit model. Insecticide selection for backyard trees should be done with caution because of the great potential for spray drift onto nearby garden, pets, and living areas. Only products containing Carbaryl, and Malathion, are labeled and packaged for homeowner for control of pecan nut Case bearer in urban areas. Refer to label instructions for mixing and application rates and precautions. It is in violation of federal law to apply any chemical in any manner except what is on the label. For Commercial Orchards many insecticides are labeled for controlling pecan nut case bearer on pecan. Base your insecticide choice on applicator safety, grazing restrictions if livestock are present, and potential impact of the insecticide on beneficial insects and other pests. Insecticides labeled for pecans to control pecan nut case bearer include Interpid, Chlorpyrifos (Lordsban), Confirm 2F, Pyrethroid or Spintor insecticide. Intrepid is an insecticide, which is labeled for Pecans. This product has a very good residual and is very effective and much safer then Oregano Phosphates and is the current product of choice. It does not harm predatory insects. This product is very safe for use around people. Thorough spray coverage, accurate timing to treat hatching larvae, using recommended insecticide rates, and proper sprayer calibration are critical for achieving good control of the pecan nut case bearer. The use of parathyroid (e.g., Asana®, Ammo®, Warrior®) or carbaryl (e.g., Sevin®) insecticides has sometimes been followed by outbreaks of aphids or spider mites in pecans. For this reason, using these insecticides for the pecan nut case bearer is discouraged, especially if the orchard has a history of aphid or mite problems. If you use parathyroid insecticides, apply them no more than once per season. Insecticide labels can change from year to year so it is the user’s responsibility to follow current label directions for worker safety, grazing restrictions and application rates for target pests. Pecan nut Case bearer is one of the most important nut infesting insect pests of pecans. It is found in most the pecan growing areas from the east coast to Eddy County New Mexico. The Case bearer larva tunnels into nut lets shortly after pollination, often destroying all of the nut lets in the cluster. The most effective and reliable method of control is a well-timed insecticide application(s) made in the spring to kill hatching larvae before they tunnel into the nut lets. However, insecticides should only be applied if an infestations and nut load justify treatment. 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