I have identified the Sugarcane Aphid in Wheeler County. Pay close attention to grain sorghum and forage sorghum fields. Aphid numbers can explode over night, They can cause yield loss and harvest difficulties due to extreme amounts of honey dew. Attached is an article explaining more about the aphid. For pictures and more information go to http://txscan.blogspot.com/2015/02/recognizing-sugarcane-aphid.html . Treatment levels are when aphid reach 50 to 100 per leaf. The insecticide to use is TRANSFORM at 1 oz / acre.

The Sugarcane Aphid: A New Pest of Grain and Forage Sorghum

The sugarcane aphid (SCA) has recently become one of the most important insect pests of grain sorghum and forage sorghums in Texas and the southern US. It has recently been found in Frederick, Oklahoma, and the South Plains of Texas and could possibly make its way to Wheeler County later this year. The sugarcane aphid originally fed only on sugarcane in the US. In 2013, this insect was found for the first time feeding on sorghum in the US. This sorghum-feeding biotype of the sugarcane aphid resulted from either a genetic change in the existing US population or a new introduction into the US. In 2013, the sugarcane aphid, first found near Beaumont, TX, infested sorghum in the Rio Grande Valley and regions of north Texas, Oklahoma, Louisiana and Mississippi. Sugarcane aphids survived the 2013-2014 winter in south Texas and during the spring and summer of 2014, dispersed throughout much of Texas and 12 southern states. In 2015, the sugarcane aphid is expected to again be a concern throughout Texas. This pest can be controlled, but growers must frequently assess infestations to properly time an insecticide, if needed, to prevent crop loss and harvest difficulties due to honeydew accumulation. Sugarcane aphids are pale yellow, gray or tan. The cornicles or “tailpipes”, feet and antennae are black. The SCA feeds on the underside of sorghum leaves. Initial colonies consist of only a few aphids but can increase such that aphid colonies cover much of the lower leaf surface. Once the sorghum head emerges, SCA can also feed in the grain head. Sugarcane aphids produce large amounts of honeydew which collect on leaves, leaving them sticky and shiny. The greenbug is another common aphid that feeds on the underside of sorghum leaves. It has a dark green stripe down its back, unlike the sugarcane aphid. The corn leaf aphid is also found in sorghum but it is a dark green color, feeds in the whorl of the sorghum plant and is rarely a pest. Finally, the sugarcane aphid should not be confused with the yellow sugarcane aphid, which is bright yellow with rows of dark spots and short cornicles. A guide to recognizing sugarcane aphid is available at: http://txscan.blogspot.com/2015/02/recognizing-sugarcane-aphid.html .  All SCA are females and give birth to live young. Immature aphids mature to adults in about five days and live for about 4 weeks. Aphid numbers can increase very rapidly during the summer. At Corpus Christi, an infestation of 50 SCA per leaf increased to 500 per leaf in 2 weeks. For this reason, once SCA are found in a field, it should be monitored twice a week to determine if infestations exceed the treatment threshold at which an insecticide application should be considered to prevent crop loss. Sugarcane aphids are known to feed on grain and forage sorghum (Sudan grass, sorghum/Sudan hybrids) and Johnsongrass. All of these hosts are in the genus Sorghum. Laboratory tests show that SCA does not feed on wheat, oats, or on seedling foxtail millet or proso millet. There is no evidence to date that SCA reproduces on any other crop in Texas. Sugarcane aphids feed by sucking plant sap. Feeding causes leaves to turn yellow, purple and finally brown as leaf tissue dies. Infestations on pre-boot sorghum can result in significant grain loss, but infestations present during grain development can also reduce yields. Large infestations can stunt growth and result in uneven head emergence from the boot. The sticky leaves and stalks clog combines at harvest and reduce separation of the grain from the plants. Combines may require service time to wash off the honeydew and remove stalks and grain heads. Infestations in forage sorghums also kill leaves, slow growth and reduce forage yields. Honeydew contaminating leaves and stems can also gum up cutter bars and machinery at harvest. Honeydew is composed primarily of plant sugars and water and eventually dries to a harmless residue.Sorghum fields should be scouted for SCA one-two times per week. Look for colonies on the underside of leaves and for honeydew which can indicate a SCA colony on the leaf above. Once SCA colonies are found on lower leaves, begin scouting the field twice a week as aphid numbers can rapidly increase. Treatment thresholds for SCA infesting forage sorghums and Johnsongrass meadows have not been determined. Until those thresholds are available, the thresholds used for grain sorghum can provide a guide to making treatment decisions. Like grain sorghum fields, forage sorghum fields should be monitored as described above at least weekly for SCA and an insecticide treatment should be considered if aphid numbers exceed the treatment threshold of 50-125 aphids/leaf. Control of SCA with insecticides requires good coverage of the entire canopy, including lower leaves, which is difficult to achieve in forage sorghum due to the dense canopy and especially if the crop is tall. For this reason, early harvest or grazing may be the best option if good insecticide coverage cannot be achieved. The insecticide Transform WG (Dow AgroSciences) is labeled under a Section 18 Emergency Exemption in Texas for control of sugarcane in sorghum in 2015. Sivanto 200SL (Bayer CropScience) nsecticide has been issued a Section 2(ee) label for use on sorghum to control sugarcane aphid in 2015. Both insecticides can be applied to grain and all types of forage sorghums (all in the genus Sorghum).

For more information, contact the Wheeler County Extension Office at 806-826-5243 or log on to Texas Sugarcane Aphid News: http://txscan.blogspot.com