n the lawn care business, you and your technicians have enough to worry about when it come to pests. And during certain weather conditions, bugs can prosper even more on your client’s turf.
Across the country, the weather in 2013 created a field day for insects, and that damage could carry through the spring.
“In my opinion, in 2013 we had at least a couple of different circumstances that lead to some of the insecticides that we’ve been using regularly over turf not being as effective as we’d expect them to be,” Dr. Patricia Vittum, a professor of turf entomology at the University of Massachusetts, told attendees at last month’s New England Regional Turfgrass Show and Convention in Providence.
The weather last year made lawn care difficult for contractors across the country.
Because of the wet spring, insect activity was delayed more than usual, because the ground is cold.
“Some females delayed egg laying because they could tell the eggs wouldn’t survive in the soil conditions,” Vittum says.
Insect outbreaks in new soil also were reported because flooding from the wet weather caused some insects to move to higher soil.
Another negative imapct of the wet spring weather was that it effected movement and efficacy of insecticides.
“With all the rain we had in June, if you made an early application in June, that product was moved and didn’t have the result you wanted,” Vittum says. “There were more reports of failures than usual for neonicotinoids applied in May or June and the rain may have diluted or moved that product.”
When the weather shifted into the summer months and temperatures rose, it also had a negative effect. “I think we had 38 days over 90, and eight or nine days over 100,” Vittum says.
Those high numbers put the turf under tremendous stress.
“We had very mild fall weather, which meant the grubs were feeding into October this year. We had a very late frost this year, so we had a longer period in the fall that the grub were feeding. I received more reports of chinchbug and billbug damage in 2013 than normal.”
Vittum says it’s not just the weather having a direct affect, but also people’s responses to the weather that plays a role.
“I will add that some insecticide failures reported to us can be traced to improper watering strategies,” she says. “It’s important to stress to the homeowner to follow whatever water applications you’re doing.”
When it comes to treating for grubs, it’s important to water as soon as possible, regardless of what chemical you’re using. If you’re using clothianidan to target surface insects, delay watering for about a day to give that product a chance to be absorbed into the foliage, she said.
If you’re using a pyrethroid, there’s more flexibility. Be sure to recognize the different water requirements for different insecticides.
What to watch for.
Because of all these changes in weather, Vittum highlighted a few species of insects that had unusual appearances in 2013.
With lots of rain in the spring, crane flies were more widespread as this kind of weather favors cranefly survival. “Many turf managers still do not know to watch for crane flies,” Vittum said.
“It doesn’t matter whether it’s golf or home lawns or cemeteries, a lot of managers don’t know to look for them.”
Invasive crane flies, also known as leatherjackets) tend to first colonize coastal areas. There are two species of crane flies: European and marsh, and although they are similar, the marsh species has two generations per year and can be active as larvae any month of the year, meaning they are feeding any month of the year.
The two best ways to look for the crane fly is in the pupa and adult stages. In late August to early September, as well as mid-April to mid-May, the pupa burrow into the ground and their tail ends stick up, looking like small twigs. If you lay down eye-level to the grass, you’ll be able to spot them easily. In the adult stage, crane flies look like very large mosquitos, she said.
Chinchbugs cause problems in the summer. They thrive in cool season turf, and do well in high temperatures, so 2013 was a good year for them. The damage they cause looks just like summer dormancy, so many lawn care professionals didn’t realize it was insect damage until it was more widespread.
If you’re managing turf in New England, you’re familiar with annual white grubs. A problem with these grubs is that not only do they cause damage to the turf, but skunks, raccoons and birds also cause damage as they dig for the grubs, something Vittum calls “unscheduled rototilling.”
“Skunks and raccoons can be terrific at grub control, but we’ve never been able to teach our skunks to put the grass back,” she says.
There are four species of annual white grub spread throughout New England: Asiatic garden beetle, oriental beetle, Japanese beetle and the European chafer. The beetles fly in the summertime, and then lay eggs. The eggs hatch seven days later and then the larvae feed until the soil starts to cool down.
The preventative window for white grubs is to apply a neonicotinoid when the beetles are laying eggs, Vittum said.
The eggs themselves aren’t vulnerable, but if you apply the product during this period, it becomes active right when the eggs are hatching. For chlorantraniliprole, apply from mid-April to mid-June because it takes 60 to 90 days to get fully immersed into the soil.
If you miss the window, you can do the curative approach and target the second instars in mid-August to the first week of September. This can be done with trichlorfon, available in most box stores.
Despite all these time frames for treating pests, weather will most likely play a roll. If the weather is unusual on a larger scale, it may cause the timing of egg laying, hatching, feeding to be off.
“(Some) imidacloprid failures in 2013 I personally think were because of the heavy rains in June and early July,” Vittum says. “The rain diluted or moved the product, and I think that was part of the problem we ran into.”
Although it’s early in 2014, and just a few weeks into spring, lawn care professionals should be cautious when inspecting and treating for pest damage, especially with the winter season the entire country experienced.