Every year we heavily invest in the preventive treatment of the golf course for white grubs. The chemicals used to help control the population of white grubs are expensive and much consideration is given to their amount of use and placement. We cannot afford to treat for grubs wall-to-wall across the entire golf course. Our strategy is to protect our putting greens first, then tees, followed by the fairways.
Understanding the entire life cycle of the Japanese Beetle is a very important part of this (The most important actually.) Timing is everything, the most effective control is having the control ingredient in place right at egg hatch.
A. Sometime towards the end of June the first Adult beetles will crawl out of the ground and become active, feeding on the leaves of nearby plants. The picture below was taken on July 1, 2015 in the Kenmure Garden. It was the first Japanese Beetle sighting of the year.
B. The Adults quickly return to lay there eggs. The preventive chemical needs to be in place at this point in the life cycle if control is to be achieved.
C. During the months of September and October the grub larvae are very close to the surface feeding on the roots of the grass plants. This is when wildlife like crows and skunks forage for this great food source. This is when we see the damage we are seeing now.
The effectiveness of the Chemical will vary from year to year. OUTDOORS is not a controlled environment. The amount of the Thatch that has built up over the last 30 years is becoming substantial. Thatch layer and very dry conditions are what mostly contributed to an aggresive grub season, although the damage you have seen this fall is by no means even close to damage as seen in a Historic perspective here at the club. 80% of the damage is occuring in the Rough cut, which is the best place for this to happen from a maintenance perspective.
White grubs not controlled by the initial chemical application can show up during dry late summer as the grubs devour the root systems of the grass. The grass will show stress and we can find them and do a secondary treatment. If the end of summer is mild and wet it becomes more difficult to spot them. Frequent rainfall can keep the grass from showing any signs of stress even when the root system is virtually non-existent.
The damage caused is very unsightly, and can be very disruptive to the game of golf depending on the location of the problem. Obvioiusly damage like this in the middle of a golf green would be totally unexceptable.
No one likes to see this kind of damage on the golf course, I guess the only thing positive about this is if the crows, skunks, and turkeys were not eating the grubs the grass would still not have any roots and would probably die. The wildlife is actually doing us a favor by removing the grub larvae preventing them from reaching adult stage and laying more eggs.
If we can determine a large grub population is underneath a certain area on the golf course we can and frequently do go into these area and treat with another insecticide application to try to stop more damage from occurring.
Severely damaged areas will have all the debris removed and be reseeded as quickly as our maintenance schedule will allow. If you happen to hit into an area such as the one pictured above please take a free drop for Ground Under Repair.
Thank You,
Josh Laughridge
