New insecticide registered for use on chinch bugs

In my last post about hairy chinch bugs, I mentioned that the only product that could be used against them for homeowners was Steinernema carpocapse . This was a mistake. Thanks to an email from an industry colleague, I was made aware of a new registration. The new insecticide that was registered in late spring of 2013 is an EC formulation of Met52 from Novozymes that has hairy chinch bug on the label. The label claims suppression which is <60% control. They also recommend a repeat application roughly 4 weeks after the first application. If you are going to try this new insecticide the timing for applying it against chinch bugs would be now and a repeat application in 4 weeks if monitoring proves it is necessary. We (my colleagues and I) do not have a lot of experience with this formulation of this active ingredient against hairy chinch bug, but it could prove to be a viable alternative to the nematode treatments.

One thing we have noticed this year is that the chinch bug damage is highly visible because the lawns are not dormant. This makes detecting and diagnosing chinch damage a much easier task than a year like last year. If anyone has used the product so far this season and has any comment, please feel free to post them here on this blog.

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Cutworm outbreak

Damage caused by birds pecking for cutworms

cutworm feeding damage

This week during her weekly scouting at GTI Erica Gunn found a large number of black cutworms on all of the closely mown turf areas. The damage ranged from pecking holes to holes with feeding damage around the edges. One really nice thing about cutworms is they are easy to monitor for with a soap flush and they are probably one of the easiest turf insects to control on a golf course with insecticide. Remember that they are nocturnal feeders and the best time to apply the insecticide is in the evening. For most insecticide applications for cutworm, do not irrigate for at least 24 hours after the insecticide application.

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Rust showing up on home lawns, sports fields and golf course roughs

During our visits to sports fields earlier this week we noticed a lot of off colour turf.  From a distance it looks like brown patches.  Up close the patches appear to be more yellowish in colour.  If you examine your shoes after you walk through the turf you will see that they are covered with yellow/brown spores.  If you examine the individual leaf blades it is very clear that the problem is rust.  One of the reasons that the turf looks like it has brown patches is that the rust prefers to attack perennial ryegrass which often grows in bunches.  Rust grows in temperatures ranging from 20-30 degrees.  It will infect when we have a period of low light intensity, moisture on leaf surfaces and moderate temperatures (22 degrees C).  Once it has infected the turf plant it will develop rapidly when conditions turf sunny, dry and hot.  It will be more of a problem on turf that is growing slowly (ie. unirrigated turf), home lawns, golf course roughs that haven’t been fertilized recently.  If possible, irrigation and ferilization will greatly help the turf outgrow this disease.  Keep the mowing height high and mow frequently.  This disease is considered a nuisance only and does not cause damage to the turf.

A clump of perennial ryegrass infected with rust

Close up of rust pustules on turf leaves

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Be on the lookout for wilting turf

Localized dry spot

This change in weather is going to bring with it lower relative humidity and bright sunshine.  This will result in high evapotranspiration rates.  After all of the intense heat and wet soils, many of the turf roots have died.  This will mean that the impending high ET’s could result in wilted turf or localized dry spots.  Keep a close eye on your irrigation and make sure that you don’t let the turf dry out.  Another factor that could lead to turf wilt is the continuing feeding of the black turfgrass ataenius grubs.  Most of them are now in the second instar and feeding heavily.  It is usually when they molt from the 2nd instar to the 3rd instar that we see the turf damage occurring.  This will probably occur sometime in the next week or two.  Be on the lookout or turf that is wilting even though it is well watered.  If this occurs, there is a good chance that it is the BTA grubs that are responsible.  Frequent light watering could help your turf survive with moderate numbers of BTA grubs.  If the numbers are too high, there will no doubt be some turf loss due to their feeding.

BTA grubs feeding below turf

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Cool front stalls summer diseases

The major thunderstom that blew through southwestern Ontario and Quebec has brought cool weather behind it and has stalled the further development of many of the warm weather turf diseases.  This is excellent news becauses these diseases have taken a toll on many golf courses.  I have never in my 23 year career seem so much brown patch and the amount of damage and thinning within each patch is also something that I have not witnessed before.  Again, thanks to the cooler temperatures, especially the night-time lows, this disease will virtually grind to a halt and the turf should be able to recover fairly quickly now.  The chances of new outbreaks Pythium blight or foliar anthracnose developing now is almost nil.  Basal rot anthracnose symptoms may continue on poorly drained golf greens.  Managing irrigation and supplying adequate nitrogen are key for managing this disease.  Dollar spot pressure will probably increase with the cooler nights and warm days that spawn heavy dew formation.  

Brown patch symptoms improving

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Chinch haven’t been stopped by wet weather

Dr. Michael Browbridge (Vineland Research and Innovation Centre), his gang and my summer student and I started the “Ultimate hairy chinch bug trial” last week.  It is a bit surprising that with all the wet weather the chinch bugs are thriving.  We are starting to see some early damage on the sites that we are using for our resesarch.  The nice thing about a year like this is that the damage is readily evident because the lawns are not dormant this year.  The scary part is that most of the hairy chinch bug nymphs that we are finding are still ranging from the 1st to 3rd instar.  There are five nymphal instars, so they still have a lot of growing, but more importantly, a lot of feeding to do.  Based on these observations, we expect to see the peak of the hairy chinch bug damage in about 2 weeks time.  The only product that is available for use agains hairy chinch bugs in Ontario is the nematode species Steinernema carpocapse.   More information on the identification, biology, monitoring techniques and cultural controls of hairy chinch bug can be found at http://www.omafra.gov.on.ca/english/crops/facts/08-019.htm.  If you going to be using this product, please follow the following best management practices to insure the best possible success. 

• Make sure you purchase the right nematode species (Steinernema carpocapse)
• Keep nematodes cool after purchase and until use
• Use within 4 weeks of purchase
• Water the lawn until moist but not wet before applying the nematodes
• Avoid applying when the sun is out (best time to apply is in the morning, evening or on an overcast day)
• Make sure the nematode mixture is well stirred before applying
• Water in nematodes immediately after application

Dr. Brownbridge conducting a chinch bug trial

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Disease pressure on the rise again

The short blast of  low humidity and cooler temperatures are on the way out and the temperatures and humidity are forecast to climb steadily over the next 3-5 days.  I was expecting that the brown patch symptoms would subside a bit, but they seem to be getting worse.  There was a confirmed report of Pythium blight during the last stretch of heat, humidty and thundershowers.  The other disease problem that has been reported is Pythium root disfunction.  This a problem on compacted, poorly drained soils and it is worse on shaded greens. It develops when soils are excessively wet. 

Another problem that has occured with all of this hot, wet weather is the growth of algae on thinned turf areas.  One of the best remedies for this is small amounts of ammonium sulphate (0.05 kg/ha of N)applied every two weeks until the algae is gone and the turf fills in.   There is an interesting slide show on research conducted by Dr. John Kaminsky on algae control at http://www.slideshare.net/johnkaminski/algae-management-for-golf-course-putting-greens-7336396

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Turf insect update

During our routine monitoring of golf course  now we are finding a few 4th and 5th instar larvae, but mostly we ar finding annual bluegrass weevil pupae and callow adults.  These are the next generation of adults and they are light brown in colour because their wing covers (elytra) are newly formed.  This is a good indication that the bulk of the damage from ABW is over. 

The black turfgrass ataenius grubs that we are finding so far are all first instar.  This is good news because the preventative insecticides should still give relatively good control of this early larval stage.  Once they start reaching the 2nd and 3rd instar these preventative insecticide treatments are much, much less effective.  Monitoring low cut turf areas is highly recommended to find this destructive grub species before the damage starts to occur.

European chafer adults flights have peaked and are now decreasing every day.  In most years the adult flights are virtually over by mid-July.  Because of the late start this year they could continue on for another week or two, but the numbers will be decreasing with every passing day.  We are just starting to see the early adult flights of Japanese beetles here in the Guelph area.   For sod farms and golf courses, now is the time to treat preventatively against these two destructive grub species.

On home lawns the early hairy chinch bug nymphs are present and feeding.  It is still way too late to see damage.  We are beginning a hairy chinch bug insecticide trial next week so we should have more information on the numbers and size of chinch bugs then.

Japanese beetle adult on a closely mown turf

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It’s a triple header: brown patch, annual bluegrass weevil and black turfgrass ataenius

As predicted, brown patch developed overnight on July 6th and was positively diagnosed at the Guelph Turfgrass Institute this morning.  Conditions favouring this disease are forecast for the next couple of days.  If a preventative fungicide application has not been made, it might be a good idea to make one.

It is early days still and the symptoms are only showing yellowing turf in the centre of the patch with no real turf thinning or loss yet, however if weather conditions favouring this disease persist and a fungicide treatment isn’t made, there could be some turf loss.

Brown patch symptoms on research green at Guelph Turfgrass Institute

The second problem that was observed today was large numbers of late instar (4th and 5th) annual    bluegrass weevil larvae.  There was some damage associated with these insects and the damage will continue to get worse over the next two weeks based on the annual bluegrass adult migration pattern this spring.  At this stage it is too late to treat with insecticide to control this insect pest.

Three late instar annual bluegrass weevil larvae

The third strike is the presence of early instar black turfgrass ataenius grubs.  They are still very small and have not caused damage yet, but we found them in very high densities.  The photo below has five larvae in a 10 x 10 cm square of turf.  As these grubs continue to feed and grow damage will become evident.  The one thing in our favour is that the wet conditions will help minimize the damage.  Damage is more evident if conditions are dry.

Early instar BTA grubs found in high density on a golf green

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Weather setting up for turf diseases

Summer patch symptoms on a golf green

Pythium mycelium growing on live grass blades

Brown patch symptoms showing the smoke ring and thinning turf.

With all of the recent rain and the forecast for a few hot, steamy days and nights there is a possibility of Pythium blight on golf course turf developing over the weekend. The conditions that are required for this disease to develop are high relative humidity (90% or greater) for 12-14 hours, daytime high’s above 30 degrees C and night-time lows 20 degrees C. Low lying areas with poor drainage are particularly susceptible. A preventative fungicide application on these disease prone areas are the recommended for control of this disease. The symptoms of this disease are fluffy white mycelium growing on healthy live turf blades unlike dollar spot mycelium which is usually seen on the already dead turf blades.

Brown patch is another disease that is also at risk of developing this weekend. It is much less damaging than Pythium blight. Thinning turf usually only results afer many consecutive days of disease development. Brown patch symptoms might occur, but if the conditions become less favourable for the disease the turf will quickly recover. This disease is easily diagnosed by the purple smoke ring that surrounds the patch in the early morning before mowing. If humidity is really high there might be grey aerial mycelium associated with the smoke ring. Again, preventative fungicidide applications are recommended for control of this disease.

Lastly, the wet conditions and warm soils will also probably bring on more summer patch symptoms. Some summer patch has been reported already last week. Poorly drained, compacted sites are the most susceptible. Unfortunately, once the symptoms of this root disease occur, the application of curative fungicide applications are not very effective.

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