Japanese beetles quickly skeletonize foliage.
Photo courtesy of William Fountain, University of Kentucky, Bugwood.org

One of the most common insect pests faced in the nursery and landscape, Japanese beetles are also one of the most problematic to control for many reasons.

“Japanese beetles are very difficult to manage because they just keep coming,” says Dr. Daniel Potter, professor of entomology at the University of Kentucky. “They can fly long distances and are attracted to plants that other beetles have already fed on. You can control them one day, but there are going to be more flying in an hour later.”

Active in most areas of the country from late May through August, Japanese beetles are not picky when it comes to food sources and are known to feed on more than 300 types of plants, trees and shrubs. The beetles will also feed on flowers and fruits.

“If you look at the standard chemistries we’re currently using as sprays for control of Japanese beetles, none provide residual control for more than about 14 days,” says Dr. Carl Redmond, research scientist at the University of Kentucky. “You’re talking about having to reapply materials over their entire flight period, which lasts about two months.”

Among foliage-feeding insects, Potter finds Japanese beetles to be the most important, requiring residual protection because of their insatiable feeding and lengthy flight period.

Acelepryn® insecticide from Syngenta provides as much as four weeks of residual protection from Japanese beetles as a foliar spray.

“We’ve done several Japanese beetle trials looking at dosages and different ages of residue in the field. Acelepryn has performed as well or better than any standard out there on the market,” says Redmond. “It is superior in residue length. We’ve gotten control of up to four weeks for Japanese beetles from a single application, which is a major advantage.”

Targeted control

Acelepryn is also labeled for control of caterpillars, including eastern tent caterpillars, fall webworm and bagworms, and sawfly larvae. It offers a unique mode of action to help mitigate resistance concerns.

Neonicotinoids and pyrethroids have long been used to combat insect pests on trees and shrubs, but concerns about their potential hazard to bees have resulted in label restrictions on those types of products.

“The active ingredient of Acelepryn is chlorantraniliprole in IRAC group 28,” says Nancy Rechcigl, technical services manager for ornamentals at Syngenta. “It is a unique class of chemistry that offers an alternative for those looking for newer chemistries to add to their programs.”

Acelepryn has no signal word on the label and is registered as reduced-risk by the U.S. EPA under its Reduced Risk Program. Its active ingredient is target-selective, providing control of leaf-chewing insect pests without affecting beneficial insects such as bees and biological control agents.

“Acelepryn is unique in that foliar sprays will provide extended protection from a broad range of leaf-chewing pests with very low hazard to bees,” says Potter. “In our experiments, we have evaluated Acelepryn in real-use outdoor scenarios and have seen no impact on bees. The product is also quite compatible with biological control.”

In addition to its favorable environmental profile, Acelepryn offers a four-hour REI and requires minimal personal protective equipment. Its long residual activity also leads to fewer applications, saving time and resources for applicators.

Left: Stewartia sprayed with Acelepryn; Right: Untreated Stewartia with Japanese beetle damage. 2015 – Gill, U of MD

Product flexibility

Acelepryn can be used in commercial and residential landscapes. It can be applied to ornamental plants, trees, shrubs, bulbs and Christmas trees.

The product can be sprayed directly on leaves to control chewing insect pests, or as a bark application to ward off pests like clearwing borers.

When applied as a foliar spray, the leaves of plants are protected from Japanese beetles and lepidopteran pests. Acelepryn does not show strong contact activity, but once the treated leaves are ingested by pests, mortality will occur.

“Acelepryn should be applied before infestations reach damaging levels, especially on larger plants,” says Rechcigl. “Curative applications are often not successful with pests like Japanese beetles because they can very quickly cause damage and spread.”

A unique innovation

Acelepryn provides a unique tool for combatting Japanese beetles, caterpillars, and sawfly larvae on trees and shrubs. It has a novel active ingredient that provides excellent pest control while also demonstrating very low hazard to both humans and beneficial insects.

“The combination of strong efficacy, long residual as a foliar spray and very low hazard to non-target organisms is a unique combination,” says Potter. “Acelepryn controls a lot of important chewing pests, gives you the flexibility of not having to apply it over and over again, and provides a very favorable environmental and hazard safety profile.”

Federal registration of Acelepryn for use in nurseries and greenhouses is expected in summer 2018.

Learn more by visiting www.GreenCastOnline.com/Acelepryn

1A reduced-risk pesticide use is defined as one which may reasonably be expected to accomplish one or more of the following: (1) reduces pesticide risks to human health; (2) reduces pesticide risks to non-target organisms; (3) reduces the potential for contamination of valued, environmental resources, or (4) broadens adoption of IPM or makes it more effective. Acelepryn qualifies under one or more of the above criteria. All photos are either the property of Syngenta or are used with permission. © 2018 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/ or may have state-specific use requirements. Please check with your local extension service to ensure registration and proper use. Acelepryn®, GreenCast® and the Syngenta logo are trademarks of a Syngenta Group Company. All other trademarks are the property of their respective owners.