A West Coast Pest Settles in New York

Rod Ferrentino, who has spent 30 years as a horticulture specialist, extension entomologist and now golf course consultant in New York, has seen a lot of invasive pests come and go. But the new pest on the block – the European crane fly – has him concerned.

An adult European crane fly resembles a large mosquito. (Photo courtesy: Tom Cook, Oregon State University)

The invasive pest is popping up on dozens of courses, and has quite an appetite. In addition, its once- or twice-a-season life cycles (depending on the species) extend and complicate the typical pest -control season. For superintendents, this means more man-hours, more chemical inputs and the money to pay for both.

“Crane flies have spread throughout Rochester and Buffalo, and out to Long Island,” says Ferrentino, who travels around the state helping superintendents control pests and diseases like the annual bluegrass weevil and brown ring patch. “I’ve seen them chew large ballmark-like holes in greens and take out as much as two acres of rough.”

Ferrentino thinks the crane fly epidemic is only going to get worse, and could spread farther. “If you’re in New York and you haven’t seen them yet, you will,” he says.

European crane fly, Tipula paludosa, is one of two exotic species of crane fly, the other being the marsh crane fly, Tipula oleracea. Both first appeared in northwestern New York in 2004, most likely introduced via nursery stock from the West Coast or Canada. Until recently, crane flies were mostly confined to the northwestern United States. They are often called leatherjackets because of their tough larval shell, which, once discarded, looks like a small twig.

Crane fly damage on greens can look like ball marks or cutworm damage. (Photo courtesy: Rod Ferrentino)

According to Daniel Peck, Ph.D., an assistant professor of entomology at Cornell University, who has studied the pests since 2004, the potential for damage is immense. Left untreated and under the right conditions, crane fly larvae cause scalping damage, root injury and thinning on greens, fairways and roughs. The most damage is evident in early spring and in late fall (depending on the species), when the rapidly growing fourth-instar feeds on roots and root hairs, and attracts animals looking for food. In addition, during adult emergence windows, swarms of adults (which resemble large mosquitoes) can be a nuisance to golfers.

While most superintendents may see crane flies on just a few holes, there is potential for course-wide infestation when conditions are right. Scott Dodson, certified superintendent of Park Country Club in Williamsville, N.Y., manages a course that’s a particulary hospitable to crane flies—set in a flood plain in the cool, moist climate of northwestern New York. “We saw incredible numbers: hundreds of thousands in some low-lying roughs,” says Dodson. “By spring of 2007, we ended up having to spray 70 percent to 75 percent of the course. Left untreated it would have been disaster.”

Like most pests, the first step is: know what to look for. Matt Delly, superintendent of Monroe Golf Club in Rochester, N.Y., says scouting is key.

“We train our full-time staff and student interns to identify turfgrass pests and the signs and symptoms associated with them,” he says. “With crane flies, it’s better to have 12 sets of eyes rather than one.” Daily crane fly scouting is now part of his regular maintenance routine.

Delly suggests looking for anything resembling ball marks or common cutworm damage on greens in the spring and fall. According to Ferrentino, superintendents might also see:

• grasses that don’t recover or green up in the spring;
• vertebrate or bird activity (especially crows);
• a weak, thin turf stand that doesn’t water up (similar to white grub stress);
• larval activity on the turf surface (usually at night/early morning); and
• swarms of adults in the spring, late summer or fall (depending on species).

A fourth instar crane fly larvae on a green near Buffalo, N.Y. (Photo courtesy: Rod Ferrentino)

The second step is: know where to look. “Crane flies need moisture for egg laying, so we always scout low-lying areas with poor drainage or sandy soil profiles,” Delly explains. Peck suggests checking for larvae not only at the root/soil interface, but also at the soil surface where they can be found in the thatch layer.

But Ferrentino warns that the recent crane fly explosion means they will migrate beyond normal habitats. “They will go after any type of soil; you really need to scout your whole course,” he says.

Another way to check for the pest is to check the mower baskets every morning. Adult crane flies are primarily nocturnal, but will still be active during early morning hours. According to Dodson, his mower baskets would come back “filled” with adults.

The third step is: know when to treat. “You want to go after the youngest instar you can but make sure the majority of the eggs have hatched,” Ferrentino says. To determine application timing, he suggests cup cutting, digging through the thatch, or early morning (pre-mow) scouting of larvae on greens. Flushing also will work but only if the larvae are late instar, he adds.

According to Ferrentino, severe crane fly infestations require insecticide treatments, though mode of action and timing should be customized to each course. Dodson chose to spray Sevin insecticide at labeled rates in the spring and fall in areas where thresholds were high. Both Delly and Eric Birkmeier, the certified superintendent of Penfield Country Club in Rochester, spot treated with Allectus G insecticide, which has both curative and preventive modes of action. “I put it down the last weeks of April and in July, and it knocked them down pretty well,” Birkmeier says.

All three superintendents prevented serious damage through proactive treatments, rigorous scouting and staff training. But despite these successes and increasing awareness among superintendents, Ferrentino continues to spend much of his time helping superintendents with European crane fly outbreaks. “We have yet to see how far it will go,” he says. “Until we know more, it’s best to be aggressive.”