special publication 12-06 Exotic Insects Invading Nevada’s Trees! Be a Citizen Monitor for Urban and Native Forests JoAnne Skelly, Extension Educator Carson City / Storey County Angela O’Callaghan, Social Horticulture Specialist Introduction community an identity. They may and treating them immediately If you have a landscape with a have historic value as well (USDA is critical to eradicating these tree in it, your yard is part of an Forest Service, 1993). When trees invaders before they kill our trees. urban forest. There are also natural are lost, it reduces property values We want you to join our Citizens’ forests of native trees throughout and curb appeal, eliminates shade, Monitoring Program in which we Nevada. Invasive insects coming in creates heat islands, causes hazards are encouraging the public to be on from other countries now threaten when dying limbs and dead trees the lookout for the exotic invasive both our urban and natural forests. break or fall and it destroys the insects listed in this publication. Some states have already lost beauty of our landscapes. Dead significant numbers of native and and dying trees can be significant The Insects of Greatest landscape trees due to these insect wildfire hazards. Replacing trees, Concern Include: invaders. Anyone with a tree in particularly mature trees, can be Asian longhorned beetle their yard needs to be aware of expensive and, in Nevada, trees (Anoplophora glabripennis) these potentially devastating insects take a long time to grow. Emerald ash borer (Agrilus in order to protect not only the planipennis) trees in their yard, but also the trees Purpose of this Publication Goldspotted oak borer in our forests. The USDA Forest Service, (Agrilus coxalis) Why should we worry about Nevada Division of Forestry, Honeylocust borer (Agrilus exotic invasive insects? Trees are the Nevada Department of Agriculture difficilis) backbone of a landscape. They are and University of Nevada Oak splendour beetle (Agrilus a valuable investment in a home Cooperative Extension are working biguttatus) landscape, park or as community together to raise awareness of a Redhaired pine bark beetle trees. They provide shade, cooling, number of destructive exotic insects (Hylurgus ligniperda) beauty, erosion control and that could destroy our urban and Red palm weevil wildlife habitat. They clean the air. native trees if these insects become (Rhynchophorus ferrugineus) They uplift our spirits and give a established in Nevada. Sirex wood wasp (Sirex So far, few, if any, are present in noctilio) Nevada, so we want to keep them White satin moth (Leucoma out or spot them early when they salicis) arrive. Finding these pests early See Table 1 (pages 3—7) for details on these pests. Exotic insEcts invading nEvada’s trEEs What Can You Do to infestation, insect eggs can be very Conclusion Prevent These Pests? tiny and yet hatch into larvae and Each of us can play a significant Keep trees healthy. This then adults that can destroy an role in protecting our native and is the best defense. Trees need entire ecosystem. Never assume urban forests from exotic invasive water, air in the soil, nutrients, that firewood that “looks safe” is insects that can do great ecological, sunlight and proper maintenance safe to move. Buy firewood from aesthetic and economical damage to thrive. Rainfall is rarely sufficient local sources where you burn it. to our trees. moisture, so trees must be watered (www.dontmovefirewood.org). Please, be on the lookout for regularly, even through the winter. Be on the lookout for these pests in Table 1. Be aware of Keep a minimum of a 12-inch invasive insects. If you think some of the lookalike insects that area around trees free of lawn and an insect looks suspicious, or are not invaders (Figure 1). Note, weeds so there is no competition you see D-shaped holes in ash, before using pesticides, identify the for water or nutrients and so honeylocust or oak trees, call pest, read and follow the label. lawnmowers can’t damage trunks. Jeff Knight, State Entomologist Avoid damaging trunks with power with the Nevada Department of string trimmers. Most trees will Agriculture, 775.353.3767, or the need a balanced fertilizer at least Forest Health Specialist with Be a Citizen Monitor once per year. Prune at the time Nevada Division of Forestry, for insects of year appropriate for the type 775.849.2500, ext 241. invading trees. of tree using proper pruning cuts. Be aware of which trees Your local University of Nevada could be victims. Learn to Extension office can help with this identify the ornamental and information or go to www.unr.edu native trees in your yard, your for publications on tree care. neighborhood and your area. If Don’t move or import they look like they are suffering, firewood. Firewood often carries find out why. invasive insects and diseases that For more information in the kill native and ornamental trees. northern part of Nevada, contact New infestations of these insects JoAnne Skelly, Extension destroy our native and urban Educator, 775.887.2252, forests, reduce property values [email protected]. For the and cost a great deal to monitor, southern area, contact Angela manage and control. Even if you O’Callaghan, Social Horticulture don’t see any visible signs of Specialist, 702.257.5581, [email protected]. 2 Exotic insEcts invading nEvada’s trEEs Table 1: Exotic Invasive Insects to Look Out For Symptoms In In Name of Insect Trees Invaded & Signs Control USA NV Comments Asian longhorned Partial list: Dying branches or Remove infested IL No Probably arrived whole trees trees and destroy MA in U.S. in wood beetle (ALB) Ash by chipping or NJ packing material Birch Large black beetles ALB adult ¾" to 1¼" with white spots burning NY from China. Elm and long antennae OH To prevent Horsechestnut 1½ to 2½ times further the body length. spread avoid Maple, Feet have bluish transporting including tinge infested wood boxelder, ALB exit hole from area. Norway, red Oval to round pits and silver in the bark Could cause more damage Mountain Oozing sap in than Dutch elm ash summer Photo: K.r. Law, usda aPhis PPQ, disease, chestnut Bugwood.org Sycamore Accumulation of blight and gypsy coarse sawdust Mimosa moth combined ALB larva around the base (USDA APHIS Poplar of tree or where 2001). Willows branches join trunk Photo: d.a.haugEn, usda ForEst sErvicE, Bugwood.org Round holes on Complete host trunks 3/8 inch or list not yet larger in diameter determined Occasional to Photo: K.r. Law, usda aPhis PPQ, Bugwood.org rare hosts Emerald ash borer Ash only, Amount of leaves Insecticides IL No Often moved in (EAB) particularly may thin by 30% containing IN firewood green ash to 50%, gradually the ingredient KY Strong fliers imidacloprid MD EAB adult ¼" - ½" Dense shoots on may work if tree MI trunk EAB D-shaped is still relatively MN exit hole D-shaped holes healthy (Herms MO on trunks and et al. 2009). NY branches Remove trees OH Dead branches at with more than PA top 50% of their TN VA Woodpecker tops dying WV damage or dead and WI destroy wood S-shaped tunnels hoto ussELL ichigan tatE by chipping or P : h. r , M s under the bark univErsity, Bugwood.org burning Photo: ny statE dEPt oF ag and MarKEts, Bugwood.org 3 Exotic insEcts invading nEvada’s trEEs Table 1: Exotic Invasive Insects to Look Out For Symptoms In In Name of Insect Trees Invaded & Signs Control USA NV Comments Goldspotted oak borer Oak Six golden yellow Insecticides AZ No Readily moved (GSOB) spots on dark containing CA in firewood and green back of the ingredient wood packing GSOB adult, 13/16" beetle imidacloprid material Extensive black or may work if tree Related to EAB red staining with is still relatively and HB sap oozing from healthy (Herms under the bark et al. 2009) Top of tree thins Remove dead or GSOB bark and branches die dying trees and staining back handle infested materials D-shaped holes on carefully trunks, branches Tarp the wood Photo: M. LEwis, cEntEr For invasivE sPEciEs Woodpecker with thick clear rEsEarch, Bugwood.org damage plastic; expose cut wood to direct sunlight Photo: t.w. coLEMan, usda after removing ForEst sErvicE bark; or chip- infested material Honeylocust Borer Honeylocust Yellowish-white Keep the tree AL Yes, (HB) bands on sides healthy and AR in CO Reno Notches along leaf watered well to HB adult female ½" margins prevent attacks: GA and avoid drought IA Las Weeping at stress, wounds to IL Vegas wounds the tree, prune IN Top and branches at the proper KS HB exit hole, die back time of year KY D-shaped LA D-shaped holes MI Tree may die MO NC NE NJ Photo: J.P. BashaM, NM tEnnEssEE statE univErsity, otis L. FLoyd nursEry rEsEarch cEntEr OH OK SC Photo: J. Knight, nEvada SD dEPartMEnt oF agricuLturE TN UT 4 Exotic insEcts invading nEvada’s trEEs Table 1: Exotic Invasive Insects to Look Out For Symptoms In In Name of Insect Trees Invaded & Signs Control USA NV Comments Oak splendor beetle Oak Adults metallic Insecticides No No Strong fliers (OSB) Chestnut green with white containing Related to EAB, spots on sides the ingredient GSOB, HB Beech OSB adult, 1/3" to ½" imidacloprid Branches die back, Readily moved top thins, tree dies may work if tree is still relatively in firewood and D-shaped holes wood packing healthy (Herms et al. 2009). material Zig-zag galleries under the bark Poses substantial risk to natural and urban environments http://www.vermontagri ulture.c om/ if it were to be ARM ES/plantindustry/ca s/fores Pests/ introduced Photo: g.