Biological Control of Alfalfa Weevil – 2

Published Feb 15, 1996

Our project was getting local farmers involved in integrated pest management of alfalfa weevils. Entomologist Kris Giles worked with me to conduct the demonstration and collect data. I raised alfalfa weevil larvae in test tubes and noted deaths from fungal disease and two different parasites. I left a single swath of alfalfa unharvested on the west side of one field to see if this benefited the larval disease and parasites. Stem counts and sweeps showed very low numbers of alfalfa weevils all spring, and roughly half of them were dying (Figure 11).

In conversations with my neighbors, I realized there was universal acceptance of IPM techniques. There was some interest in the alfalfa strip I left unharvested; however, no one else volunteered to leave a strip. Many more people read the article in Iowa Farmer Today, and I was asked about it as I traveled to meetings statewide. The only down side was the article failed to mention PFI by name!

We had a successful field day on June 24, attended by 24 people. It was a very hot day, even under the 100-year old oaks, and we went through four gallons of milk donated by the co-op. Three families attended because of an add I took in the county paper. I was gratified by the number of Extension people in attendance. Tour stops included two solar design barns, one with sand stalls, where we looked at my handout showing economics of different feeding regimens. We stopped in the pasture for a look at paddocks for the intensive rotational grazing of 110 milk cows. We also discussed some CRP ground that was broken out early to graze 46 dry cows and heifers. And Kris Giles and I described our IPM research on alfalfa weevil.