Archive for September, 2012

Making sense of the turf damage

I have had many, many emails and phone calls about dead turf in the last two weeks.  In most cases the symptoms are as follows:

  • dead turf areas ranging in size from fist size areas to many metres in diameter
  • dead turf that pulls out easily when you tug on it
  • some areas where the damage has left bare soil
  • no insects present in the turf (currently)
  • damage showed up sometime in the last month

My best guess on what has caused this damage is that it was bluegrass billbug that was feeding last month.  (more…)

Read Full Post »

Just a note to explain the silence over the last three weeks for this blog.  I was away on holiday in England.  I have two things to say about turf in England – it is always green (they get rain all of the time) and it looks great (most of the turf has a sign saying “Please keep of the lawn”).

So, back to turf in Ontario – I got back to find my favourite turf insect in flight.  I am not sure when the adult crane fly flights began, but there were some flying by Tues. Sept. 4th in the Guelph area.  In spite of the very dry summer, the larvae and pupae seem to have survived based on the number of adults that I have observed.  Adult flights typically last for roughly four weeks in most areas with peak adult flights two weeks after the first adults are observed.  Female crane flies lay their eggs in moist turf areas. 

Adult female crane fly laying eggs on a green

Adult female crane fly laying eggs on a green

Eggs hatch within 10-14 days and young larvae start feeding on the turf leaf blades at the top of the thatch.  They are extremely small when they hatch and they will feed through the fall and overwinter as larvae.  The big feeding frenzy and growth spurt happens in the spring and that is the time that the damage to turf occurs.

If large numbers of adults are observed on greens, tees or on sod farms and if there is a history of leatherjacket infestation and damage, a preventative insecticide applications can be made any time now.  For homeowners, adult numbers should be monitored and if large numbers of adults crane flies are observed and there is a history of leatherjacket damage a nematode application can be made.  Our research indicates that an application of a 50/50 mixture of Steinernema feltiae and Heterorhabditis bacteriaphora applied in mid-late October to control the newly hatched leatherjackets can roughly 50-70% control based on one year’s data. 

 More information on the biology of the European crane fly can be found at http://www.nysipm.cornell.edu/factsheets/turfgrass/ecf.pdf

Read Full Post »