Remember beetle-damaged leaves emit air-borne chemicals that attract more beetles. Adult Japanese beetles become active in Minnesota in late June/early July. As infestations increase on farms, growers should be vigilant about control in order to prevent extensive leaf damage. Regents of the University of Minnesota. Since larvae feed primarily on the roots of grass, Japanese beetle is most prevalent in urban environments. The Japanese beetle, Popillia japonicaNewman, is a widespread and destructive pest of turf, landscape, and ornamental plants in the United States. Japanese beetle numbers continue to increase in the weekly trap counts conducted by University of Minnesota researchers in Forest Lake, Hastings, Chanhassen, and Rosemount. The traps attract beetles using synthetic female sex pheromone and a blend of chemicals with a strong floral odor. Neem oil is effective for several days but repeat applications are necessary. Although Japanese beetles feed on many different kinds of plants, there are some that they seldom damage. Yellowing or browning grass in August is an early symptom of white grub damage. Adult beetles can be found congregating on these plants and defoliating them in a manner described as “skeletonizing” because they leave the leaf veins intact but eat all of the tissue from between them. Please report Japanese beetles found outside the seven county Twin Cities metropolitan and southeast areas of Minnesota to Arrest the Pest. Since its discovery, the beetle spr… Grubs feed on the roots of grass and adults feed on the foliage of more than 300 plant species. Grub-damaged turf pulls up easily from the soil, like a loose carpet. 711 TTY, © Copyright 2020 Minnesota Department of Agriculture, Farm, Property, Real Estate Listing (MN FarmLink), Agriculture Chemical Response & Reimbursement Account, Agricultural Best Management Practices (AgBMP) Loan, Agricultural Growth, Research & Innovation (AGRI) Program, Sustainable Agriculture Demonstration (AGRI), More Business Development, Loans, Grants Topics, Minnesota Ag Water Quality Certification Program, Certified Testing Laboratories (soil & manure), Fertilizer Tonnage Reporting & Inspection Fees, Pesticide Dealer Licensing & Sales Reporting, Read about advice on managing Japanese beetle from the University of Minnesota, U of M Extension - Japanese Beetle Information, Minnesota Japanese Beetle Distribution Map. Grubs chew grass roots and reduce the ability of grass to take up enough water and nutrients to remain healthy. While they can be effective, results have been inconsistent. The larvae, commonly known as white grubs, primarily feed on roots of grasses often destroying turf in lawns, parks… Japanese beetle infestations in Minnesota are mostly found in the Twin Cities metropolitan area and southeast region of the state. Maybe I’m imagining it, but are Japanese beetle numbers down this year? In one year the Minnesota Department of Agriculture (MDA) trapped more than one million beetles. The best time to remove Japanese beetles is in the evening or in the morning when beetles on the plants are still cool and sluggish. Grubs. The University of Minnesota is an equal opportunity educator and employer. If you think you have an infestation of Japanese beetles, and you're located in a county that Japanese beetle has not been reported or is not known to be abundant (see map above), please visit our Arrest the Pest page to report your findings to the MDA. More Information. Plants usually not damaged by Japanese beetles include boxwood, clematis, chrysanthemum, conifers (e.g. Adults feed on more than 300 plant species, whereas the grubs feed mainly on the roots of grasses. In spring, grubs move toward the soil surface, pupate, and emerge as adults in mid to lat… ST. PAUL, Minn. (WCCO) — Call it summer’s version of beauty and the beetle – make that Japanese beetles! Preventive treatment may be warranted if a lawn has a recent history of grub infestation, or if the adult beetle flight is particularly high in a given summer. Pyrethroids, including bifenthrin, cyfluthrin, lambda cyhalothrin, and permethrin, last about two to three weeks. arborvitae, spruce, fir, pine), daylily, geranium, ginkgo, Japanese tree lilac, forsythia, common lilac, magnolia, red and silver maple, oak, white poplar, redbud, rhododendron and yew. The Japanese beetle is a serious pest of foreign nature to turf and ornamental plants. This may relate to the fact that Japanese beetles are exotic insects, native to Asia. Japanese beetles are only active for six to eight weeks, so leaf feeding typically ends around early August. After mating, females tunnel underground in the soil one to three inches to lay eggs. Grubs feed on the roots of turfgrass and adults feed on the foliage of more than 300 plant species. Signs of Japanese Beetle Damage. Two natural enemies of Japanese beetles have been released in Minnesota. If turf damage has been sporadic the last few years, it may be worth waiting to see if they are a problem. 2020 Rose chafers can also be mistaken for Japanese beetle but lack the white patches of hair along the abdomen entirely. Japanese beetles can be very abundant in some years and less in others. Beetles of Minnesota Showcase listing of Beetles found in the state of Minnesota. The Japanese beetle is a highly destructive plant pest that can be very difficult and expensive to control. The eggs hatch in about two weeks and the grubs feed mainly on the roots of lawn grasses. Check your plants daily and remove any beetles that you find to minimize feeding damage. Japanese beetles are a serious pest of flowers, trees and shrubs, fruits and vegetables, field crops and turf. The MDA maintains an updated distribution map of Japanese beetles. A systemic insecticide is absorbed by the plant and moved through its tissues and is applied as a soil drench or injection, a trunk spray or a trunk injection. There are many ways to deal with them. These large beetles with shiny green- and copper-colored bodies, chew small holes in the leaves leaving a lace-like appearance ( see image 1). Clothianidin, in particular, is systemic; i.e., it can be taken up by the roots and move into the nectar and pollen of flowering lawn weeds. University of Minnesota Professor Vera Krischik, one of the state's leading authorities on Japanese beetles, says climate change is partly to blame. Profile: Photo: Video : American carrion beetle (Necrophila americana)American rose chafer (Macrodactylus subspinosus). Photo by Whitney Cranshaw, Colorado State University, Japanese beetles were first found in United States in 1916, after being accidentally introduced into New Jersey. In Minnesota, Japanese beetle has been found in many counties but is only known to be abundant in some. Japanese beetle can be a significant landscape pest and difficult to tolerate, particularly when they first become abundant in an area. Damaged leaves attract more beetles so minimizing beetles on plants should mean fewer beetles will be attracted to them. Tree & Shrub Fertilizer. This usually results in more damage to nearby gardens and landscape plants than would have happened if no traps were present. Virgin females produce a sex pheromone for mating that is highly attractive to males. Acephate is toxic to bees so applications should not be made near bee attractive plants until after bloom. The Minnesota DNR is asking the public to watch out for the European chafer beetle (left), which is shown here in comparison with the better-known Japanese beetle. Japanese beetles are not the end of the world. Neem oil helps deter Japanese beetles but is less effective when large numbers are present. Curative means treating white grubs when they are feeding and damage is noticed. While the insect has been in Minnesota for about 50 years, its population density has been relatively low statewide, with significant numbers building in just the past 3-5 years. Here are some other options from the University of Minnesota Extension and the Minnesota DNR., including this homeowners Japanese beetle handbook! Trees: apple, crab apple, linden, birch, and other fruit trees; Other plants: shrub roses, vegetables, and annual flowers; Organic Japanese Beetle Control Benefits. Japanese beetles were originally from Asia and were first detected in the U.S. in the early 1900's and now occur throughout much of the eastern United States. 625 Robert Street North Japanese beetles feed on the leaves, flowers or fruit of more than 300 species of plants. NEW: Conditions related to movement of plant products that could carry Japanese beetle between states are set by the Japanese Beetle Harmonization Plan which has recently been updated, read about the updated plan. The Japanese beetle (Popillia japonica) is a species of scarab beetle.The adult measures 15 mm (0.6 in) in length and 10 mm (0.4 in) in width, has iridescent copper-colored elytra and a green thorax and head. They are applied to the soil and only one application is needed per year. Although both natural enemies became established here, neither is very abundant and they have little impact on Japanese beetle populations. Damaged leaves turn brown and may fall off. More details regarding JB certification can be found on the National Plant Board Website as listed under "external links." If possible take a picture or collect a specimen to document the identity of the insects. Photo by William Fountain, University of Kentucky, Japanese beetle adults attack the foliage, flowers, or fruits of more than 300 different ornamental and agricultural plants. They chew grass roots, causing the turf to brown and die. Preferred plants include rose, grape, linden, apple, crabapple, cherry, plum and related trees, birch, elm, raspberry, currant, basil, Virginia creeper, hollyhock, marigold, corn silks and soybean. At first, only a few beetles were found. Trunk injections should be done by a certified tree care professional. Japanese beetles are an invasive species. Beetles emerging from non-treated grass areas can fly a considerable distance to preferred adult food plants. The half-inch-long, adult beetles are metallic green with bronze wing covers. argus tortoise beetle (Chelymorpha cassidea) In Minnesota, Japanese beetles (Popillia japonica) are primarily found in the Minneapolis-St. Paul Metropolitan area, and in some areas in southeast Minnesota.Japanese beetles have an exceptionally large host range, feeding on the leaves of over 300 species of plants, including apples, grapes, blueberries, raspberries, roses and plums. Japanese Beetles. Only treat white grubs to protect lawns from damage. Always follow the pesticide label directions attached to the pesticide container you are using. They can fly up to several miles to feed. Ants. Trees and Shrubs. ant-like longhorn beetle (Cyrtophorus verrucosus). Several effective, longer lasting insecticides are available for treating Japanese beetles. They have coppery-brown wing covers with five tufts of white hairs along the sides of their bodies. Destructive pest of turf, landscape plants, and crops; adults feed on the foliage and fruits of several hundred species of trees, shrubs, vines, and crops, while larvae feed on the roots of grasses and other plants (APHIS 2015) Japanese beetle grubs look like other white grubs and can only be positively distinguished by examining the pattern of spines and hairs on the underside of the tip of the abdomen. They assume the typical C-shaped position in the soil as other grubs. Professional pesticide applicators can also apply acephate (Lepitech) systemically as a soil drench. Authors: Jeff Hahn, Extension entomologist, Julie Weisenhorn, Extension horticulturist, and Shane Bugeja, Extension educator. As the soil starts to cool in the fall, the nearly mature, full-sized (third instar) grubs dig deeper in the soil, where they spend the winter. All rights reserved. Avoid areas being used by ground-nesting bees. The best timing is during the month or so before the adult beetles first emerge and start laying eggs (mid-June to mid-July in Minnesota). Japanese beetle is a destructive pest in North America where it has no natural enemies. Watch closely for symptoms of turf damage. Homeowner products for preventive grub control usually have the words "season-long" grub control on the packaging. If grubs are not found, examine still living turf at the edges of damaged areas for their presence. Physically removing beetles can be a practical and effective management practice for smaller landscapes or a few plants, especially when only small numbers of Japanese beetles are present. Controlling Japanese beetle grubs is unlikely to reduce the number of adults on landscape plants. Means of spread: Japanese beetles can disperse by flying. They were developed by researchers to monitor for the presence of Japanese beetles so that management strategies could be implemented. Rose chafers. In the United States, Japanese beetle was first found in 1916 at a nursery near Riverton, New Jersey and is speculated to have arrived via imported rhizomes of Japanese iris, Iris ensata Thunb. Fruits, vegetables and herbs can tolerate limited leaf feeding, but severe damage may affect plant growth and reduce yield. Products containing imidacloprid or clothianidin are also effective if applied preventively, but they can pose a hazard to bees foraging on flowering weeds or nesting in treated lawns. While Minnesota gardeners were in a bit of a frenzy about Japanese beetles when the insect was new to the state in the 1990s, beetle populations are cyclical. Feeding on grass roots, Japanese beetle grubs damage lawns, golf courses, and pastures. Once there, click on the double arrows at the top left to view the map legend. Beetle-damaged leaves emit feeding-induced odors that attract other beetles (like sharks to blood). Although these bacteria occur naturally in the soil and may infect a small percentage of the grub population, applying commercial milky spore products has not been shown to provide any benefit in modern university research trials. Regulatory classification (agency): There are no regulations for movement of Japanese beetle within Minnesota. To access the information, click on the map below. The Japanese beetle is a serious pest of turf and ornamental plants. In some cases, it is possible to protect plants with fine netting to prevent beetle damage. “This year it’s an epidemic, they’ve gone over to corn and soybeans now. Adult beetles start to emerge from the ground in late June or early July. This list includes only beetles that have been recorded in Minnesota, but not all of the beetles found in Minnesota. Until that time, this insect was restricted to Japan where it is not a major pest. By 2001, they occurred in much higher numbers. Healthy turf grass can typically tolerate up to 10 grubs per square foot. Some years are bad, others not so … Japanese beetle grubs are pests of turfgrass. However, anytime that it can be done is still useful. See How to hire a tree care professional. To minimize the hazard of curative grub insecticides to pollinators, mow any flowering weeds just before or right after the pesticide application. This can be useful to avoid pesticide drift, especially when treating large trees. What Trees & Shrubs Can Leaf-Eating Beetles Damage? Parasitic nematodes, such as Heterorhabditis bacteriophora, are available. And they may attract more insects to your yard. The … Native to Japan and first discovered in the U.S. in 1916, the Japanese beetle is now found in almost every state east of the Mississippi River, as well as Minnesota, South Dakota and Montana. Grubs feed on the roots of turf grass and adults feed on the foliage of more than 300 plant species. Products containing Btg (grubGONE!®, grubHALT!®) have provided inconsistent (i.e., variable) levels of grub control in recent university trials. Photos by Jeff Hahn, University of Minnesota Extension. While they are not prevalent all over Minnesota, Japanese beetles are “abundant” in the seven county metro area, as well as in Blue Earth, Freeborn, Steele, Omstead and Winona counties. Start management when they first appear. Carbaryl or acephate will provide one to two weeks’ protection. How to manage Japanese beetles without harming the environment (PDF) - from the Minnesota Landscape Arboretum; U of M Extension article - Dealing with Japanese beetles; U of M Extension Yard and Garden News - June 2018 This product is long lasting and is a low risk to bees. Review of Pesticide Options for Japanese Beetles. Popular methods include a trapping survey, soil sampling, and treatment of plants prior to shipment. 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