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When farmers want to know how well an insecticide works they turn to their Land Grant University for unbiased information.
This little four-row planter is outfitted with some pretty high tech stuff. All of which must be calibrated before it goes to the field where it will be used to plant a western corn rootworm trial. A trial that will assess how well twelve different current in-furrow liquid and granular insecticides work. Well, at least some of them are current products, others are experimentals says University of Illinois Extension Entomologist Nick Seiter, "We like to evaluate all the different options that are out there. There is always potential that we could lose control tactics that we are using currently."
Researchers at Illinois want to make sure to evaluate everything available just in case something becomes ineffective. It is important to evaluate the efficacy of today's products and those in the pipeline. Illinois has long done research to test how well different control methods work on the western corn rootworm. Naturally, these include the Bt corn hybrids, too.
As for the insect, it is really nimble and quite capable of adapting to all sorts of ways farmers use to control it, says Seiter, "It is an insect that is very good at developing resistance to multiple different control tactics. Out of all the insects we deal with it is the one growers find of most interest in terms of efficacy; in terms of what products, what hybrids, what control tactics are going to give them the best control."
On that account, Nick Seiter from ILLINOIS, and his counterparts at Land Grants across the nation are working hard to stay up with the ever-changing western corn rootworm and the products used to control it.
The President has been tweeting about agriculture. He says the potential deal with China will result in "massive" export increases for farm commodities. Most have taken this to mean, at a minimum, that the flow of soybeans will be increased. University of Illinois agricultural economist Todd Hubbs has been pondering the implications and the deal.
Todd Hubbs specializes is row crop commodity marketing at the University of Illinois. You may read his thoughts on marketing soybeans in today's (this week's) post to the farmdocDaily website.
Friday, May 18, 2018, the United States House of Representatives voted on and failed to pass legislation to create the 2018 version of the Farm Bill. Fourteen members of the Republican Party's Freedom Caucus, 16 moderate Republicans, and the Democrats cast no votes. It sets up a complex path forward for the bill.
Farmers should be on the lookout for black cutworm in their corn fields.
The earliest projected cutting dates were late last week in Montgomery County. University of Illinois Extension Entomologist Nick Seiter says fields, especially at risk to having plants cut by the black cutworm, include those with later planted corn and those sown into grassy weeds or a late terminated cover crop. Seiter explains, “What you are going to want to do is to scout your field. Look for plants lying on the ground that appears to have been cut with scissors. This is different looking than damage from a bird digging up the plant looking for the seed. These corn plants will be cut off. When you start finding that, scrape around in the residue looking for the larvae. The black cutworm larva is dark colored, with a greasy appearance. It is not slimy, but it looks like it has been coated with Crisco. If you find the worms and about three percent of the plants have been cut throughout the field it is the time to initiate a treatment.”
Seiter says there are several pyrethroid insecticides that can be successfully used as a rescue treatment. He offers these black cutworm management pain on the University of Illinois the Bulletin website.
Infestations are more likely in later planted corn, as delayed planting means larger cutworm larvae are present at earlier stages of corn development.
Black cutworm moths prefer to lay their eggs on grasses, not bare ground. Therefore, fields with grassy weeds present at or shortly before planting are more likely to experience damaging populations. Similarly, monitor fields closely if a grass cover crop (e.g., cereal rye) is terminated while corn is susceptible to cutworm damage (emergence to ~V5).
The economic threshold for black cutworm is 3% of plants cut with black cutworms still present in the field. Look for plants that look like they have been cut roughly with scissors close to the base; plants with intact roots were most likely dug up by birds and do not represent cutworm damage. Remember, larvae do their feeding at night and hide in residue or just below the soil surface during the day, so you will have to do a little bit of digging near the base of the plant to find them.
Several Bt corn trait packages offer suppression of black cutworm, but these might be less effective under heavy infestations or against later stage larvae. Most pyrethroid insecticides labeled for use in corn will do an excellent job of controlling larvae as a rescue treatment; just remember that they only pay off when an economic threshold has been reached.
Kelly Estes at the Illinois Natural History Survey coordinates an insect trapping network throughout the state and those results, including the black cutworm cutting dates, are posted online at The Bulletin website - that’s bulletin.ipm.illinois.edu and on Twitter using the handles @ILPestBulletin or @ILPestSurvey.