ABW Report
Our lab spent much of the week looking for annual bluegrass weevil (ABW) adults, and trying to get a handle on where the majority of the adult population is located. Vacuum sampling between overwintering sites and short turf areas revealed that the VAST majority of weevils in central PA (> 95% at most sites) are still in the roughs. We found several sites where some weevils had made it all the way to the fairways, but most, if not all, were south-facing turf stands where it is likely to heat up faster than other areas on the course.
The results of the sampling are what I would expect based on what we are seeing for plant development in the area. Forsythia full bloom has arrived (or is very near) in most areas I have visited in Pennsylvania. Much of the Forsythia in central PA is not quite at 100% full bloom, but could get there with a couple of warm days. This has anecdotally being correlated with the start of the migration. This is only the tip of the iceberg! I have heard that several people have already initiated their adulticide applications. This is incredibly early (in my opinion). All of our true adulticides have a very short residual (at best 10-14 days at best). With colder temperatures expected over the next few days, we can expect that applications made this week are likely to have minimal effect on ABW populations, and therefore will require a re-application at a later date.
If you are concerned about the few weevils that made it to the short turf: don’t be. Dissections of weevil collected this week showed that their reproductive systems remain undeveloped. Remain patient and keep scouting.
Earthworm castings are appearing in full force within the last couple of weeks. Though Earthworms are beneficial to soils, their fecal matter (casts) make for some unsightly turf and can cause issue with machinery. We often observe castings being issues in the spring and fall, when there is ample moisture. The cool and wet weather that is forecasted for next week will not help in lessening the severity of damage.
On a recent visit to a central PA course, casts in excessive of 8 per square foot were observed on fairways and tee boxes. The turf in these areas was thin, as casts left on the surface smother the grass below. We have some earthworm trials in the works this spring at this site, and are excited to see the effects that some biorational products have on reducing extreme castings.
