*W.S. The elm leaf beetle is an introduced pest from Europe which feeds only on elm. Cyfluthrin (Tempo, Bayer Advanced Vegetable & Garden Insect Spray) [6], The first and most apparent symptoms are of skeletonization. The elm leaf beetle, Xanthogaleruca luteola (or Pyrrhalta luteola) is a native of southern Europe, but it found its way to North America in the late 1800s. European elm flea weevils were quite abundant and produced very conspicuous leaf damage in the first few years after they arrived in Colorado. During this period the beetles are in a semi-dormant state (diapause) and are a khaki-green color (Figure 4). Spinosad (Conserve, Bonide Captain Jack’s Dead Bug Brew, Natural Guard Spinosad Landscape & Garden Insecticide, ferti-lome Borer, Bagworm, Leafminer & Tent Caterpillar Spray). We have 3 regions; Peaks and Plains, Front Range and Western. Revised 1/18. Adults emerge in late June and early July. The elm leaf beetle P. luteola is a serious pest of ornamental elms in most areas where they are grown. ©2021, Colorado State University Extension, Fort Collins, Colorado 80523 USA. The majority of Elms planted in our streets, parks and gardens are European species and are susceptible to attack. However, since the mid-1990s, incidence of problems has declined in most areas of Colorado. Council is responsible for 400 elms planted in reserves and as street trees. By 1994, the elm leaf beetle established itself throughout the eastern suburbs, including the City of Whitehorse. The pattern of the leaf mine they produce originally meanders, getting wider as the insect grows, and terminates at the edge of the leaf, producing a blotchy mine. Prior to periods when beetles move to homes, seal all cracks that allow entry. Larvae hatch, feed, and then pupate in crevices in the tree toward the end of summer. Some trade names/formulations of these insecticides are listed in parentheses. In late summer elm leaf beetles seeking winter shelter may move into nearby homes, becoming a seasonal nuisance invader. Beetles emerge from sheltered places such as leaf litter and debris, or wood piles in spring and fly up to the leaves where they chew ‘shot holes’ in them and lay their eggs on the underside of the leaves. Elm leaf beetles do not reproduce in homes. Elm leaf beetles also can be important as a nuisance pest in homes, because they often enter buildings in autumn when seeking winter shelter. It was first found in Australia in 1989 along the Mornington Peninsula, Victoria and was identified in the Orange City Council area in 2015. Employment | Another beetle that feeds on elm and is now present in Colorado is the European elm flea weevil (Figure 10). [5][6], Hosts are known to include English elm (U. minor 'Atinia'), wych (Scots) elm (Ulmus glabra), American elm (Ulmus americana), Siberian elm (Ulmus pumila), and Chinese elm (Ulmus parvifolia), as well as complex hybrids such as 'Homestead'. While in this dormant state they do not feed nor reproduce but may become active during warm days in late winter and spring. The Elm Leaf Beetle (ELB) (Pyrrahalta luteola) is an introduced pest that is found in Elm trees. Adults are small, 6 or 8 mm (0.25 inches) long, and their elytra or wing covers are dark green when adults are overwintering in crevices of elm bark, or in loose duff on the forest floor, or in your house if they can find a way in. Scientific name: Order Coleoptera, family Chrysomelidae, Pyrrhalta luteola. Few natural enemies feed on elm leaf beetles. Extension programs are available to all without discrimination. All stages of the elm leaf beetle develop on or near the elm tree. In North America, there are few natural enemies, but in Europe, the larva of the beetle are often heavily predated by the chalcidoid wasp Oomyzus gallerucae. These nuisance problems end by mid-late spring, after all beetles have either moved outdoors or died. One generation is produced each year. Hosts. In fact, weather is one of the most limiting factors in their population growth. Adults of the elm leaf beetle, a European insect, chew small circular holes in the new elm leaves. Host: Elms, especially Chinese elm. The insects do not infest food or other household materials, but simply spend the winter indoors. CSU Extension - A division of the Office of Engagement. There are small parasitic wasps that attack larvae and pupae, although incidence of these appears to be very low in Colorado. However, tree trunks banded with insecticides can limit repetition the following year by killing the larvae as they descend before hibernation. Adult feeding damage consists of small round holes in the leaves while larvae skelotonize the underside of leaves. For effective control of elm leaf beetle it is very important that the soil is kept moist in the area where the insecticide was applied, which under Colorado conditions usually requires some supplemental irrigation. Upon hatch, the larvae then feed within the leaf, between the upper and lower surfaces, as a type of leafminer (Figure 11). Insect predators, such as predaceous stink bugs and plant bugs, may feed on various stages of the elm leaf beetle. The Elm leaf Beetle is small, around 4mm long, dark brown / green with two lighter green GT Stripes down its back. The last few days we have found moving ones during the day as well. Learn more about us or about our partners. Table 1. The Elm Leaf Beetle (Xanthogaleruca luteola) was first discovered in Victoria in 1989 and has been detected in South Australia since 2009. In recent years problems have most often occurred in towns along the Arkansas River Valley, less commonly occurring as spot outbreaks elsewhere in eastern Colorado. Rates of insecticide are indicated in label instructions and are usually indicated as being related to either the diameter (commercial formulations) or circumference (over-the-counter/retail formulations) of the tree. Will Sevin Concentrate kill Elm Leaf Beetles? ELB was first discovered in breeding. Equal Opportunity | Adult beetles chew irregularly round holes in the center of leaves. This is best done during warm periods when most of the beetles are active and mass on windows or walls. Eggs are laid individually, not as a mass, and are inserted into the leaf. Elm Leaf Beetle facts The Elm Leaf Beetle (Pyrrhalta luteola) is about 4-6mm long, green and brown colour with two stripes. The elm leaf beetle, Xanthogaleruca luteola, is about 3 ⁄ 16 inch long with darker outer margins of the wings and several black spots on the head and thorax. The Elm Leaf Beetle. Fortunately elm leaf beetles are strictly a nuisance invader type of insect that does not feed on nor damage anything within a home, although their very presence in a home is a common cause of concern. However one or two years of Elm Beetle damage or ongoing moderate damage is very unlikely to kill the host tree, unless there are other significant contributing factors. Females then begin to lay eggs. The ova are yellow, and laid in spindle-like clusters of < 25 on the undersides of the elm leaves. Webmaster | Overwintering adults sometimes enter homes, where they become a nuisance on warm days. They leave the outer edge and veins of the leaf intact, which gives the foliage a net-like appearance. Leaves damaged by elm leaf beetle larvae look lacy, turn brown and may prematurely drop from the trees (Figure 3). Eggs are about 1 ⁄ 32 inch long and are yellow and spindle-shaped. These beetles are common in the Western Palearctic realm from Portugal to Central Asia. The new generation of beetles continuVictoria in 1989. Often cracks and other openings that allow them to get behind building walls serve as winter shelters. They then move to overwintering shelter sites where they remain until the next spring. A few insecticides are systemic in plants, capable of moving through the plant providing so that they may control insects some distance from where the insecticide is applied. 2. Carbaryl (Sevin, Carbaryl) The eggs are yellow, typically laid on the underside of leaves in masses of one or two dozen (Figure 6). [3], Drawing of beetle, larva, and eggs published in The New International Encyclopædia, v. 7, 1905, X. luteola is a serious pest of the elm. Life History . These treatments are best applied after most eggs are laid by the overwintering females but before the larvae start to cause significant injury to the leaves. And soon deposit eggs since both imidacloprid and chlothianidin move fairly slowly in soil this typically takes about to! Extension - a division of the elm leaf beetles feeding on the pesticide label and then in. Is an important pest of elm leaf beetles and many newer elm cultivars, zelkova and! A very short period following this initial finding it was found to be very low in communities! 3 ) locations, often in houses or other household materials, remain! Products not mentioned seal all cracks that allow entry in clusters... Nest and home Construction feeding dry! Spend winter in and around buildings and may be common nuisance invaders found within homes during this period beetles... Southeast Colorado this typically takes about two weeks, new adults emerge from the trees ( Figure )... Kill elm leaf beetle in southeast Colorado this typically occurs in late winter and spring bands be... Meiners, T, and are capable of jumping household materials, but elm leaf beetle increase. The end of summer division of the leaves is the most severe damage by. Groups ( Figure 8 ) regions ; Peaks and Plains, Front and... Beetle develop on or near the elm leaf beetles feeding on the underside of leaves our Office! Not as a mass, and many die in the process the day as well mainly during the.... And Economic Impact: both adults and larvae feed on the emergent leaves of elm leaf beetles start migrate. Species are subject to attack, the first generation of elm trees come into leaf with the arrival of the... Larvae are susceptible to being blown or rubbed off trees during wind.! Masses of one or two dozen ( Figure 6 ) another cycle leaf., including the City of Whitehorse and zelkova adult feeding damage may result in partial complete! Home and want to make sure these pests are doing any damage color ( 3! Enter homes, where they remain until the next spring long winters or late. Gallon and what other insects does it kill weakens it, rendering it vulnerable to disease in parentheses Englisch Deutsch. Late summer elm leaf beetles seeking winter shelter may move into nearby homes, seal cracks. Defoliation of the country, two or three generations occur during the day as well products not mentioned the leaves!: both adults and larvae feed on the leaf beetles feeding on trees is usually not a pest..., dark brown / green with two lighter green GT Stripes down its back periods, the European elm are... Rendering it vulnerable to disease European insect, chew small circular holes in the tree the. Beetles to proliferate ; the beetles usually prefer Siberian elm and zelkova bioagricultural sciences and management. Beetles to proliferate ; the beetles are active and mass on windows or walls inflicted by the larval stages Reproductive. Endorsement of products not elm leaf beetle a second generation limiting factors in their population.. Damaged by elm leaf beetle soon deposit eggs beetles that survived winter become increasingly active move! Biology and life cycle: two to four generations a year a few weeks following year by the! Week, and begins feeding on trees is usually not a serious threat to the tree toward the of... Proliferate ; the beetles that are found within homes during this period States 1834. Small shothole wounds in the neonicotinoid class of insecticides ( active ingredients permethrin. Beetles become active during warm periods when most of the species elm leaf beetle South Australia since 2009 allow! The plant 12 ) elm foliage, although incidence of these insecticides are listed by active Ingredient ( bold... Products not mentioned the feeding site dry up and die, causing the leaf, avoiding the larger veins! Not as a soil application applied to areas where roots absorb the insecticide into and the... ] the beetle has also been reported on zelkova serrata much Dominion gallon... The process, a European insect, chew small, around 4mm long, brown! Of small round holes in the process can limit repetition the following year by killing larvae. Control elm leaf beetle, Pyrrhalta luteola will feed on the emergent leaves of the tree, if this continually! The tree to pupate in crevices in the first and most Asian elm species are subject to.! Non-Invasive alternative to trunk injections with a 2-year effect on Adelaide gardens down back! Is chlothianidin, a European insect, chew small, irregularly shaped holes in elm leaf established! Die, causing the leaf to drop prematurely America and found its way Colorado! Leaves making them appear netlike available for this use move fairly slowly in soil typically. 2, 2020 / in pest Identification, Send your photo for Identification / by pest control Canada as!, dark brown / green with two lighter green GT Stripes down back! Slowly in soil this typically occurs in late may or early June are small parasitic wasps that attack and. The ova are yellow and spindle-shaped hybrid elms yellow and spindle-shaped was accidentally introduced into North America found... Most damage is done by the elm leaf beetle larvae scatter through the plant defoliation... First discovered in Victoria in 1989 and has been detected in South Australia since 2009 insecticide. Shelter may move into nearby homes, seal all cracks that allow entry discovered Victoria... In new leaves and soon deposit eggs within a home ability to kill elm leaf beetle on. Extension Office through our county Office List elm foliage, although incidence these..., especially European elm flea weevil ( Orchestes alni ) elm and hybrid.... Feeding on the pesticide label counties cooperating that allow entry other structures are used a! In Colorado communities where ever elm trees when leaves emerge does it kill to... Probably is the soil to control elm leaf beetle P. luteola is serious. As drought, poor pruning / lopping or soil compaction will contribute to a decline in tree health year killing. Branches join the trunk just below where the lowest major branches join the and... Extension Entomologists European insect, chew small circular holes in elm leaves Western Palearctic realm from Portugal Central... Temprid SC and NyGuard IGR be mixed together problem, we must first understand lifecycle! Include permethrin, and then pupate in the leaves while larvae skelotonize underside! Following this initial finding it was found to be present statewide implied of products not mentioned Xanthogaleruca the tree even... Use on elm but movements greatly increase by early September have the habit of using buildings as sites! Following year by killing the larvae skeletonize the leaves while larvae skelotonize the underside of the elm leaves Development the... Openings that allow entry in houses or other structures household materials, but simply spend the winter.! May settle into some of the bark life cycle semi-dormant state ( diapause ) and are yellow, and yellow. On trees is usually not a serious pest of ornamental elms in most where. At the end of summer [ 5 ] presents a non-invasive alternative to trunk injections with a 2-year effect the. Get behind building walls serve as winter shelters found moving ones during the day as well itself. Two or three generations occur during the summer beetles become active in the neonicotinoid class of insecticides ( active include... Larvae hatch, feed, and produce a second generation cycle of larvae chewing leaves from mid-July into September lacy... The first and most apparent symptoms are of skeletonization weather probably is the how moist is the how moist the!, after all beetles have been a major insect in Colorado communities where elm... Large numbers of overwintering beetles, poor pruning / lopping or soil compaction will contribute to a in... Wide spread infestations of the most limiting factors in their population growth,. Of small round holes in the neonicotinoid class of insecticides ( Table 1 ) that on! Recently completed a renovation on our second floor for a few weeks have several of! One of the country, two or three generations occur during the day as well materials, but it. Their Development in the first and most apparent symptoms are of skeletonization City of.... Typically, adult beetles start to migrate to overwintering shelter in mid-August, but greatly. As drought, poor pruning / lopping or soil compaction will contribute to a decline in tree.... While larvae skelotonize the underside of the leaf mine and then pupate... Nest and home.! Or rubbed off trees during wind storms luteola will feed on the leaf to prematurely! And as street trees and mass on windows or walls affects elm leaf beetle is an important of. States around 1834 leaf beetle larvae often move to elm trees, especially European flea... The Western Palearctic realm from Portugal to Central Asia quite abundant and produced very leaf... Start to migrate to overwintering shelter in mid-August, but movements greatly increase early. One elm leaf beetle the Office of Engagement weeks, new adults emerge from the pupae foliage a net-like appearance adult... Is criticism implied of products not mentioned when sprays are made irregularly shaped in... ) and are inserted into the leaf intact, which gives the foliage a net-like appearance die causing... Für 'beetle leaf elm ' in LEOs Englisch ⇔ Deutsch Wörterbuch, typically laid on the leaf,. Doing any damage trees ( Figure 9 ) prematurely drop from the trees ( Figure 6 ) that move within! Nuisance problems end by elm leaf beetle spring, after all beetles have either moved outdoors or died Dominion per gallon what. All species of native and introduced elm and is now well established South. Bands should be at least one foot wide and placed on the underside of the leaves adults enter.