Japanese Beetle Alert
Extension Entomologist Japanese beetle (Popillia japonica) has begun emerging this summertime too our earliest reports are coming from Ottawa County.
Entomology too Plant Pathology, Oklahoma State University Vol. 17, No. 17 http://entoplp.okstate.edu/pddl/pdidl June 20, 2018
Scout Now for Japanese Beetles inward Ornamental, Fruit, too Row Crops Eric J. Rebek, Extension Entomologist Tom A. Royer,
Although this exotic, invasive pest has been steadily expanding its arrive at westward, it is primarily a employment inward the eastern one-half of Oklahoma. Japanese beetle is becoming ane of our most meaning insect pests because it congregates inward large numbers to feed on the foliage, fruits, too Distribution: Japanese beetle is native to Asia too the showtime U.S. written report is from Riverton, New Bailiwick of Jersey inward 1916. The beetle was probable introduced every bit white grubs hitchhiking inside the origin zone of irises shipped from Japan.
The beetle is mutual inward all states due east of the Mississippi River, except Florida, too is steadily encroaching westward. The distribution of Japanese beetle inward Oklahoma is currently express to some 10 counties, but the beetle is widespread throughout several northeastern counties including Adair, Cherokee, Delaware, Tulsa, too Wagoner Counties.
Isolated populations receive got been found inward Creek, Kay, Oklahoma, too Payne Counties, too the pest probable occurs inward small-scale pockets elsewhere inward the state. Life Cycle: Japanese beetles receive got one‐year life cycles. Overwintering larvae migrate upward inward March too Apr too resume feeding on flora roots until May, when they displace deeper inward the soil, degree an earthen cell, too pupate.
Adults emerge slowly June through July too are active during the day, commonly found feeding too mating inward large numbers on susceptible plants. Females repeatedly larn into the soil too tin lay 40‐60 eggs during their lifetime. Eggs hatch 1 to ii weeks subsequently too showtime instars get feeding on flora roots.
The showtime instars molt inward 17 to 25 days, spell minute instars accept xviii to 45 days to railroad train too molt again. Most grubs attain 3rd instar yesteryear slowly September, too yesteryear Oct they dig deeper into the soil to overwinter. Hosts: Adults feed on to a greater extent than than 300 dissimilar flora species too are considered major pests of ornamental, fruit, too vegetable plants. Japanese beetles besides assault several row crops, including soybean too corn. Adults tend to prefer feeding on roses (Rosa spp.), flowering crabapple (Malus spp.), birch (Betula spp.), elm (Ulmus spp.), too zinnia (Zinnia spp.).
Japanese beetle is besides an of import economical pest of grapes too other economically of import crops.
Damage: Adults feed during the day, preferring hot atmospheric condition too plants located inward total sun. In fruit too vegetable crops, defoliation oftentimes results inward reduced yield. Healthy host plants tin endure fifty-fifty consummate defoliation yesteryear the beetle, but immature or weak host plants may non live able to withstand heavy attacks. Adults besides feed straight on fruits too flowers of ornamental, fruit, too vegetable plants.
Feeding harm to these tissues is characterized yesteryear large holes, too fruits too flowers are oftentimes consumed alone nether intense pest pressure. When feeding on foliage of soybean too other plants, they prefer consuming the softer leafage tissue too avoid whatever leafage veins. This creates a leafage “skeleton” that is referred to every bit skeletonization. The visible harm they motility tin live rattling disturbing to someone unfamiliar alongside their feeding. In soybeans, they typically feed on the upper leaves of the canopy too are to a greater extent than numerous along the champaign margin. This tin resultant inward overestimating the amount of actual defoliation that is nowadays inward the crop.
When scouting for defoliation, collect leaves from the upper, middle, too lower portions of the canopy too scout the interior of the champaign to larn an accurate justice of actual pct defoliation. To justice defoliation inward soybean, randomly collect vi leaflets (2 from the lower, ii from the middle, too ii from the run yesteryear of the canopy) from v locations too justice pct defoliation yesteryear averaging the defoliation flat from thirty leaflets using the visual nautical chart below. (see http://entoplp.okstate.edu/pddl/2018/PA17-17.pdf)
Japanese beetle volition feed on the leaves, but the mostserious injury occurs when they feed on corn ear silks every bit the plants are pollinating, causing a reduced number of kernels. To justice ear damage, banking concern fit v randomly chosen plants from v locations inside the field. Be certain to banking concern fit plants inside the field, because this pest tends to prefer feeding along champaign margins. Count adult beetles, too justice the length of silk remaining on those ears. Estimate the maturity of the corn yesteryear counting immature tassels too shaking emerged tassels to encounter if pollen is yet beingness shed. Consider an insecticide application if at that topographic point is an average of iii or to a greater extent than beetles per ear, silks receive got been clipped to less than ½ inch, AND at that topographic point is less than 50% consummate pollination. For command suggestions, refer to CR-7167: Management of Insect too Mite Pests inward Soybean, or CR-7192: Management of Insect too Mite Pests inward Corn. Both fact sheets tin live obtained from your local Cooperative Extension Office or through Oklahoma Extension Fact Sheets at http://factsheets.okstate.edu/.Cultural command for landscape plants: Handpicking adult beetles tin live effective when they showtime colonize landscape plants. Beetles are less active inward the forenoon too level when it is cooler too tin live killed yesteryear dropping them inward a solution of soapy water.
Japanese beetle traps, which comprise an aggregation pheromone too a floral lure to attract both males too females, receive got been commercially available for several years. However, these traps ordinarily attract to a greater extent than beetles than they capture, leaving landscape plants vulnerable. In addition, adult Japanese beetles tin wing ane mile or more, thus beetles that are caught inward traps are readily replaced inward the landscape yesteryear colonizing individuals. Thus, the purpose of Japanese beetle traps is by too large non recommended. The only province of affairs where traps may live useful is if traps are used across a large expanse similar an entire neighborhood. If traps are used, they should live checked too emptied regularly, making certain to kill whatever alive beetles yesteryear dunking them inward soapy water. Biological control: Biological command of Japanese beetle is an active expanse of research, too several species of natural enemies receive got been released against this pest inward other states. However, institution has been express for parasitic flies too wasps released for Japanese beetle control. Efforts are right away beingness directed toward biological command of these beetles alongside disease‐causing microbes, too several insecticide formulations comprise these microbial agents. Chemical command for homeowners:
There are many insecticides labeled for Japanese beetle control, too several are available to homeowners. Look for insecticide products containing acephate (Orthene), carbaryl (Sevin), bifenthrin, cyfluthrin, deltamethrin, lambda‐cyhalothrin, or permethrin. When adult activeness is heavy, insecticide sprays may live needed every v to 10 days. Applications of imidacloprid (e.g., Bayer Advanced Tree & Shrub Concentrate) should live made at to the lowest degree twenty days prior to Japanese beetle adult activity. However, banking concern fit the label carefully for pollinator protection requirements for purpose of products containing imidacloprid too other neonicotinoids. In general, soil applications of insecticides to target larvae volition non cut adult Japanese beetle populations because adults are rigid fliers too colonize landscapes from surrounding areas. For insecticide recommendations for nurseries, homeowners, too fruit crops, refer to E-832: OSU Extension Agents’ Handbook of Insect, Plant Disease, too Weed Control.