Thursday, July 16, 2015

Sugarcane Aphid in Central and North Texas. July 16.

Sugarcane Aphid in Central and North Texas. July 16.  

     Sugarcane aphid infestations began to exceed treatment threshold the last week of June and early July in central (Blacklands) and north Texas.  However, many fields are currently below threshold.  Several AgriLife Extension Agents in District 8 (Blacklands) are scouting sorghum fields weekly as part of a sugarcane aphid monitoring program.  To-date, about 35% of these 13 grain sorghum fields across 7 counties have been treated for SCA.  These represent the most promising fields as the sorghum crop has suffered from heavy rains in May that stunted growth, delayed or prevented planting and fertilizer applications.  In some fields in the southern Blacklands, SCA rapidly increased to treatment thresholds following treatment for midge and stinkbugs.  Infestations have extended as far north as Grayson County, on the TX/OK border, and fields there were treated for SCA the first week of July.  Syrphid fly predators and parasitized SCA were common in June, but lady beetles only recently appeared.  In early July, hot dry weather set in and winged aphids, along with a row of new nymphs behind them, were common in fields in north Texas.   Forage sorghum producers with increasing SCA infestations are harvesting early or applying an insecticide while others planted pearl millet to avoid SCA altogether.