agriculture

Sometimes a regional decision with national implications can have dire unexpected consequences half a nation away. The Ninth Circuit Court of Appeals in California handed out a ruling in early September that EPA should withdraw the Federal registration for sulfoxaflor insecticide. The logic for the decision was that sulfoxaflor was a neonicotinoid insecticide (according to press coverage) and EPA should not have registered it without more honeybee safety studies. Indeed, EPA did ask the Registrant, Dow AgroSciences, for additional bee safety data but registered the insecticide for national use without those additional studies. (Neonicotinoids are getting some of the blame for the decline in honeybee numbers, but the science on the issue shows it is a very complicated problem and insecticides might only play a minor part. The companies that manufacture and sell neonicotioids are making enormous (and expensive) strides in limiting bee exposure when valid science says there is a real risk...

As we start to wind down the season there has been a late surge of fall armyworm moths captured in the Lubbock traps. This puts late sorghum at risk of headworms. It also puts very late planted corn at risk of fall armyworm infestations in the ear.

Dr. Ed Bynum has addressed some unsubstantiated rumors flying around the High Plains; 1) that sugarcane aphid has become resistant to insecticides in Mexico and 2) that it is now able to develop on corn and is damaging corn in Mexico. I tried to address this last topic in my post last week, but Dr. Bynum has provided more detail on both issues in his newsletter post today . The bottom line is that there is no evidence of insecticide resistance and no evidence that the aphid can damage corn.

Many people on the High Plains are finding what looks like sugarcane aphids on corn and to a lesser extent cotton, and the question we are receiving is whether the aphid will get on these crops and, if so, will it become a problem. The answer to the first part is a definite YES; they will get on all of our plant species. In the past few weeks we have had billions of winged adults flying from sorghum fields and all of them need to land somewhere. They are basically like flakes of ash from a giant volcanic eruption and will settle out over the landscape. The answer to the second part of the question is that neither corn or cotton is a good host for the aphid. Small aphid colonies are being found on these crops but they are not expanding rapidly and will not get anywhere near pest status, at least if our aphids behave like sugarcane aphids do in Mexico and south Texas. Sandy Endicott from DuPont Pioneer monitors the sugarcane aphid situation in Mexico and the southern U.S. and provided so...

Headworms and Late Corn Fall Armyworm Corn earworm and fall armyworm adult trap captures are up significantly in the last week and this means headed sorghum should be scouted for headworms. It also means that late planted non-Bt corn should be scouted for fall armyworm. Corn earworm is not an economic problem in corn, but fall armyworm can do a lot of damage to ears if it infests them prior to hard dough stage. Prevathon and Belt are good choices for control of fall armyworm in corn and they will not flare spider mites (which are also being found readily in corn and sorghum). As headworm insecticides they will not flare sugarcane aphids in sorghum.  New Invasive Aphid Pest Sipha maydis, which we are choosing to call the hedgehog aphid after Colorado State University's lead, was found in Lipscomb and Hockley counties on sorghum on the same day last week. Given the distance between discoveries it is likely that the aphid is widely distributed on the High Plains and we ...

Experience with the sugarcane aphid in the last few weeks has prompted us to lower our treatment thresholds. The new thresholds can be found on our Sugarcane Aphid News website . The article concludes with suggestions for tank additives for sugarcane aphid control. 

Dr. Ed Bynum, Extension Entomologist in Amarillo, has published a good summary of the spider mite situation in sorghum this year. I have seen some fairly heavy infestations in fields but don't have time to write. And Dr. Bynum's article is better than I could do anyway. Spider Mites in Sorghum, Texas Panhandle Pest News, August 11, 2015.