Northern Blacklands Report, May 29, 2015.
Frequent and heavy rains during the past weeks have made many sorghum fields inaccessible to field scouting. However, sugarcane aphids were found in very low numbers in the sorghum fields that could be scouted this past week in Hill and McLennan Counties. Infestations average less than 1 SCA per leaf. When found, only 1-3 scattered nymphs are present and very few colonies have been observed. Also, very few beneficial insects are present. The scattered nymphs and lack of colonies suggest the frequent rains this spring, often accompanied by strong winds, have knocked aphids from the plants. This effect and cool temperatures have probably kept SCA numbers low to-date. Sorghum is pre-boot, about 2-3 ft tall. Sugarcane aphids were found on 16% and 25% of the Johnsongrass tillers examined at two locations in McLennan County, but again SCA were typically present as scattered nymphs. Winged aphids are rare, representing less than 1% of all SCA observed. Submitted by Allen Knutson and Marty Jungman.