–by Dr. Jeff Whitworth and Dr. Holly Schwarting
Sugarcane aphids are still present in sorghum fields examined over the last week but, like soybean aphids, seem not to have increased in densities or coverage. However, continued monitoring is prudent.
To see the current sugarcane aphid distribution map please visit MyFields: https://www.myfields.info/pests/sugarcane-aphid
For management decisions please refer to the 2017 Sorghum Insect Management Guide: https://www.bookstore.ksre.ksu.edu/pubs/MF742.pdf
—by the KSRE Field Crop Extension Entomology Team
This week, Kansas received a section 18 approval for the use of Transform (sulfoxaflor) against sugarcane aphid for 2016, which will give sorghum growers two effective materials to manage aphid infestations. Note, there are differences in price between these two products, which should be factored into any treatment decisions, especially when multiple applications may be necessary.
Recent reports have sorghum receiving insecticide treatments for relatively light populations of sugarcane in south Texas, but the aphid is beginning to slowly move north, so the potential exists for much earlier infestation of Kansas sorghum this year. There are also confirmed reports that the aphid overwintered on Johnsongrass rhizomes just north of Lubbock, TX. This is about about 80 miles further north than in 2015. Reports from Texas indicate some of the cultivars rated as resistant seem to be holding up well, probably with the assistance of good natural enemy populations.
The Sorghum Checkoff has a list of ‘tolerant’ (= resistant) hybrids, but it does not indicate any regional adaptations for the hybrids. We have not yet ranked Kansas-adapted hybrids for resistance to sugarcane aphid, but efforts are underway to evaluate hybrids this summer. We strongly recommend that growers and extension agents contact their local entomology specialists for advice, as management recommendations will vary regionally.
Scout early, scout often, and know before you spray!
A new report from Robert Bowling (TAMU) revealed that sugarcane aphids (SCA) are building in southern Texas volunteer sorghum and may soon start to move into Central Texas. What this means for Kansas and Oklahoma sorghum is still unknown at this point, but it is worth noting the aphid got a much slower start last year. In preparing for possible SCA aphid infestations, there are a few important things farmers should consider prior to planting sorghum this season:
- Plant as early as possible to give plants a head start on the aphids, which tend to arrive later in the growing season.
- Currently, the insecticide Sivanto (Bayer) is the only chemical labeled for Kansas sorghum for managing sugarcane aphid infestations. Last season in 2015, Kansas had a Section 18 approval for the insecticide Transform (Dow), and although a 2016 Section 18 has been requested, this has yet to be approved for Oklahoma or Kansas.
- Efforts are underway to screen hybrids for resistance to SCA, but few are being sold as resistant so far. However, data collected so far suggests that a number of varieties rated as resistant to greenbugs also express resistance to SCA – but not all of them.
- Farmers can expect SCA to arrive in Kansas as early as July, depending on weather conditions and wind direction. Be sure to monitor the spread of the aphids northward migration via updates from this blog, county agent updates, and twitter.
Read Dr. Bowlings full article here: https://drive.google.com/file/d/0B4lb0hWyS3iMaGV5dVVIcUd1YUE/view?usp=sharing
-Sarah Zukoff and JP Michaud
—Dr. J.P. Michaud
Dr. J. P. Michaud in a TV interview with Stacy Campbell about the SCA. To view information on sugarcane aphids go to: https://youtu.be/H2CZlq5tKlc