Monday, July 13, 2020

Sugarcane Aphid in Lubbock and Hale Counties (Probably Crosby and Floyd, Too)

I found sugarcane aphid colonies on post-flowering sorghum today at the Experiment Station in Lubbock. An independent crop consultant reported to Blayne Reed this afternoon that he had just found some in Hale County, about 6 miles northwest of Abernathy. So here we go.

In the last few years we have tracked the aphid's arrival on the southern High Plains, and traditionally it comes first through Floyd and Crosby counties, then to Lubbock, Hale etc. So it is most likely that Crosby and Floyd counties have it as well.

There is some good news: The aphid is a couple of weeks late in arriving, and many fields will be able to outrun it. And in what is really good news, we are not getting large flights from the south and southeast, so the invading population is relatively small, which gives the beneficial insects the upper hand for now.

I have been asked about the 106 - 108 degree days, and whether these will phase the aphid. I don't know. Drought stressed sorghum loses the ability to transpire in the hot part of the day, which means it does not have much evaporative cooling going on at the leaf surface. On days like we had today, I can easily see it being 120 degrees near the soil surface in full sunlight, and this is hot enough to affect some types of insects. Irrigated sorghum is less apt to shut down on these hot days, so it will continue to have some evaporative cooling at the leaf surface. I don't think aphids on these plants will be affected much.