3/12/2021
Urban trees: Pests, Diseases, and Solutions
Elizabeth McCarty Warnell School of Forestry and Natural Resources
Insect Pests
• Invasive insects •Caterpillars Lepidoptera •True bugs Hemiptera •Beetles Coleoptera
Mark Dreiling,, Bugwood.org
1 3/12/2021
Asian Longhorned Beetle
• Anoplophora glabripennis • Adult - ¾ to 1.5 inches long • Larvae girdles tree stems and branches • Introduced in wood packing materials
Asian Longhorned Beetle
• Prefers maple species (Acer spp.), horsechestnut, willows, elms, birches and poplars • Infestations in Illinois, Ohio, Massachusetts, New York, New Jersey, and South Carolina Information - Clemson Extension - https://www.clemson.edu/public/regulatory/plant-industry/plant- pest-regulations/state-plant-pest-information/pest-alerts/alb.html - Bugwood - https://www.invasive.org/browse/subinfo.cfm?sub=2178 - Warnell School of Forestry and Natural Resources https://www.warnell.uga.edu/sites/default/files/publications/Asian% 20Longhorned%20Beetle_Infographic.pdf
2 3/12/2021
Spotted Lanternfly
• Lycorma delicatula – a planthopper • Hosts: tree-of-heaven, apples, plums, cherries, peaches, nectarines, apricots, almonds, pine, oak, walnut, poplar, and grapes. • Damage: sucking sap from stems and leaves; feeding can cause the plant to ooze or weep; possible honeydew
Spotted Lanternfly
• Where To Look: • Gathered in large numbers on host plants • Easiest to spot at dusk or at night - migrating up and down the trunk of the plant. • Daytime - clustered near the base of the plant • Egg masses - on smooth surfaces on the trunks of host plants and on other smooth surfaces
3 3/12/2021
Laurel Wilt Disease
• Xyleborus glabratus - vector • Raffaelea lauricola – pathogen • Both species are native to Asia • First detected in Georgia 2002 • Vascular wilt disease – clogs vascular tissue • Affects – redbay, sassafras, silkbay, camphor tree, avocado, northern spicebush, pondberry, and pondspice
Contact GFC if you suspect laurel wilt in your area.
4 3/12/2021
Photos: Cameron Walters, Westervelt Company
RAB attacks trees Wood staining
www.rrisc.org Bud Mayfield, USFS Ron Billings, Texas Forest Service
RAB galleries and fungi Foliage turns purple to brown
Bud Mayfield, USFS
Lyle J. Buss, University of Florida
5 3/12/2021
2020 Cherokee and Cobb Counties
ARCGIS laurel wilt dashboard https://gfcgis.maps.arcgis.com/apps/opsdashboard/index.ht ml#/d43391c8fdb741b597e6ccf1236d2a02
Laurel Wilt Management
• Sanitation • “Don’t move firewood” • Insecticides?? • Fungicides propiconazole preventative
JB Toorish, Arborjet Contractor’s Edge PA
6 3/12/2021
Emerald Ash Borer
• First found in Michigan in 2002 • Introduced from Asia in wood packing material • Metallic green beetles • About 1/2-inch long • Attacks ash trees (Fraxinus spp.) • **Quarantined in numerous states
Emerald Ash Borer
• Killed > 25 million trees
• Nation-wide loss of $20-60 billion if all ash trees die
• Pathways: infested ash trees, limbs, firewood, logs, and untreated lumber
7 3/12/2021
Ash Symptoms
Leah Bauer, USDA Forest Service Northern Research Station, Bugwood.org Kenneth R. Law, USDA APHIS PPQ, Bugwood.org Daniel Herms, The Ohio State University, Bugwood.org
Chemical Control
•Foliage sprays •Systemic •Carbaryl (Sevin) •Basal drench •Permethrin •Trunk injections •Trunk sprays •Systemic •Imidacloprid •Dinotefuran •Emamectin benzoate
8 3/12/2021
Fall Webworm
• Hyphantria cunea • Glistening webs in treetops • Can defoliate entire trees • Hundreds of hosts: pecan, hickory, walnut, sweet gum, river birch
Fall Webworm
• White moth with dark wingspots, 1.4 – 1.7 in wingspan • Up to 5 generations each year • Two color forms: red-headed and black-headed
Black-headed Red-headed More northern More southern
Gerald J. Lenhard, Louisiana State University Agricultural Center, Bugwood.org
9 3/12/2021
Black-headed
James B. Hanson, USDA Forest Service, Bugwood.org Red-headed
Fall Webworm
• Females begin laying eggs in spring • Caterpillars develop in web • Mature caterpillars leave the nest to feed • Return to nest before daybreak • Populations naturally controlled by parasites and predators • Birds, spiders, wasps, small mammals
10 3/12/2021
Fall Webworm
• Often not noticed until considerable damage occurs • Best to control webworm when caterpillars are younger • Disrupting the web to allow natural enemies access is effective in smaller trees
Fall Webworm
• Webbing makes control more difficult • Systemic insecticide is possible if known beforehand • Or…just let kids play with the nest and enjoy learning about nature
11 3/12/2021
Eastern Tent
• Malacosoma americanum • Nests in the crotches of trees • Attacks many Prunus species • One generation each year • Mostly aesthetic problem • Chemical controls are usually not justified • Contact insecticides at the right time if necessary
Lacy L. Hyche, Auburn University,, Bugwood.org
Eastern Tent
• Can defoliate entire trees in outbreak • Caterpillars leave tree to pupate • Wandering caterpillars can be a nuisance • Occurs earlier in season than fall webworm – most damage in May
12 3/12/2021
Eastern Tent
• Larvae get up to 2.5 in and have black heads • Striping along back, blue and black spots on the side • Larvae spin cocoons, pupate, and emerge as adults
Mark Dreiling,, Bugwood.org • Females deposit egg masses around twigs • Eggs hatch the next spring
Lacy L. Hyche, Auburn University,, Bugwood.org
Black/blue dots
White Stripe
Pennsylvania Department of Conservation and Natural Resources - Forestry , Bugwood.org
13 3/12/2021
Overwinter as egg masses Nests on shrub
Alan T. Eaton Marie-Eve Jacques
Forest Tent Caterpillar
•Malacosoma disstria •Deciduous hosts •Do not make a noticeable nest •Silken mats on trunks and large branches •Molt and rest from feeding in the webbing •May cluster on the trunk
Herbert A. 'Joe' Pase III, Texas A&M Forest Service, Bugwood.org
14 3/12/2021
Forest Tent Caterpillar
• Overwinter as eggs, attack in spring • Larvae have blue lines on side and • Shoeprint yellowish markings • Adults are brown with two darker parallel lines
Forest Tent Caterpillar
• One generation per year • Larvae overwinter within egg masses • Hatching peaks earlier in spring • Older instars can wander, becoming a nuisance • Natural enemies important for population control • Control is not warranted or easily implemented
,Ontario Parks.com
15 3/12/2021
• Can occur at outbreak levels • May outbreak every 6 – 16 years • Cyclical population cycles • Outbreaks may occur for 2-4 years • La and AL – annual outbreaks • Trees are rarely killed on water tupelo
Forest Tent Caterpillar Eastern Tent Caterpillar Fall Webworm
William M. Ciesla, Forest Health Management International, Bugwood.org Larry R. Barber, USDA Forest Service, Bugwood.org James B. Hanson, USDA Forest Service, Bugwood.org
16 3/12/2021
Forest Tent Caterpillar Eastern Tent Caterpillar Fall Webworm
William M. Ciesla, Forest Health Management International, Bugwood.org Larry R. Barber, USDA Forest Service, James B. Hanson, USDA Forest Service, Bugwood.org Bugwood.org
6 sets of red spots
5 sets of blue spots
European Gypsy Moth
Jon Yuschock, Bugwood.org
Oakworms Defoliating Insects
• Three most common species • Orange-striped oakworm, Anisota senatoria • Pink-striped oakworm, Anisota virginiensis • Spiny oakworm, Anisota stigma • Voracious feeders and can quickly strip foliage • Defoliation usually occurs late-summer to fall • Does not usually harm the tree – minor economic impact
Orange-striped oakworm Pink-striped oakworm Spiny oakworm
Lacy L. Hyche, Auburn University, Bugwood.org James Solomon, USDA Forest Service, Bugwood.org Lacy L. Hyche, Auburn University, Bugwood.org
17 3/12/2021
Bagworms
• Moth caterpillars • Mostly an issue for conifers • Make the bag after hatching • Carry the bag around as they feed • Males emerge from bags after pupating • Mate with females who are still in their bags • Females lay eggs and die • Eggs hatch the next spring • Pick off bags or spray early in the season
Bagworms
18 3/12/2021
Leafminers
• Moths, beetles, flies, or sawflies • Attack may different tree species. • Blotch or serpentine leaf mines • Feed between the top and bottom leaf surfaces • Generally have little effect on plant health • Control • Natural controls usually sufficient • Contact insecticides during egg laying • Systemic insecticides for some leaf miners
https://publiclab.org/, cfastie
Gallmakers
• Each species makes a characteristic gall on specific plant parts • Not economically important in forest stands • Can be in issue in ornamentals and Christmas trees
Maja Jurc, University of Ljubljana, Bugwood.org
Ronald F. Billings, Texas A&M Forest Service, Bugwood.org
19 3/12/2021
Gallmakers
• Insects and mites can inject substances that causes abnormal plant growth (galls) • Found on leaves, buds, stems, or roots • Culprits are often – gall wasps (Cynipidae), gall midges (Ceccidomyiidae, and eriophyid mites (Eriophyidae)
Scales
• Suck plant fluids
• Many different species Scott Yollis, Bugwood.org • Not always a problem • No simple control answers
Raymond Gill, California Department of Food and Agriculture, Bugwood.org
Lorraine Graney, Bartlett Tree Experts, Bugwood.org
20 3/12/2021
Soft Scales
• Family Coccidae • Approx. 1/4 inch long • Smooth, cottony, or waxy surface • Excrete sticky honeydew • Associated with blackish sooty mold • Usually 1 generation/year
Andrew J. Boone, SC Forestry Commission, Bugwood.org
Armored Scales
• Family Diaspididaea • Approx. 1/8 inch diameter • Plate-like cover over body • “Body” is underneath • Do not produce honeydew • The “armor” can make them hard to kill • Usually many generation/year
Raymond Gill, California Department of Food and Agriculture, Bugwood.org
21 3/12/2021
Control Options
Should you control the scale? • Systemic insecticides – neonics, acephate • Horticultural oil • Insecticidal soap • Contact insecticides - carbaryl (Sevin), dimethoate, bifenthrin, esfenvalerate • Insect growth regulators - pyriproxifen • Best method depends on the scale insect
Coccus sp. Lecanium Scales
• Soft scale • Shade trees and woody ornamentals
Andrew J. Boone, SC Forestry Commission, Bugwood.org • Oaks, Maples, Birch Coccus sp. • Imidacloprid, dinotefuran • Contact insecticides: crawlers
James Solomon, USDA Forest Service, Bugwood.org
22 3/12/2021
Japanese Wax Scales
• Ceroplastes spp. Florida Scott Yollis, Bugwood.org • Soft scale • Japanese, Florida, Indian • Hollies, boxwood, spirea, barberry, citrus, jasmine… • Start checking in May Indian US National collection of scale Insects, Bugwood.org • Control – oil, contact, systemic
J.A. Davidson, Univ. Md, College Pk, Bugwood.org
Sycamore Lacebug
• Corythucha ciliata (Hemiptera: Tingidae) • Nymphs and adults feed on leaves • May cause chlorotic spots on upper leaf surface • Cast nymphal skins and frass may be visible on underside of leaves • Several generations per year • Nymphs are dark colored • Adults have broad, transparent, lacelike wing-covers • Natural enemies usually effective control populations • Chemical control for high value trees
23 3/12/2021
Sycamore Lacebug
Ambrosia Beetles
• Usually very small • Can cause damage in hardwoods • Decomposers of dead/nearly dead pine trees • Use the tree to grow their fungal gardens • Larvae eat the fungi
24 3/12/2021
Ambrosia Beetles
• Many species • Some are native • Many non-natives – redbay ambrosia beetle, black twig borer • Mostly attack stressed trees • Forests • Nurseries • Urban areas
WalterReeves.com
Black Twig Borer
Dead twigs in an otherwise healthy canopy
25 3/12/2021
Black Twig Borer
Small hole in the twig
Gallery with beetle
Elm Leaf Beetles and Larger Elm Leaf Beetles
Greater Elm Leaf Beetle
Charles Todd, Jasper County Extension, UGA M. Huston, BugGuide.net
26 3/12/2021
Elm Leaf Beetles Pyrrhalta luteola • 6-7 mm • Native to Europe • Has a longitudinal stripe on elytra • Can have 2 (3?) generations per year • Skeletonizer • Can defoliate elms, usually does not cause tree death
http://entoweb.okstate.edu/
Larger Elm Leaf Beetles Monocesta coryli • 10 – 16 mm • Native to United States • 1 generation per year • Defoliates elm trees • Skeletonizer Gerald J. Lenhard, Louisiana State Univ, Bugwood.org • Systemic insecticide early in the year • Do not do whole canopy sprays
M. Huston, BugGuide.net
27 3/12/2021
Black turpentine beetles Dendroctonus tenebrans • Feed on injured/stressed trees • Lower 1-2 meters of the trunk • Scattered/patchy pine mortality • Accumulated attacks over numerous years
Erich G. Vallery, USDA Forest Service, Bugwood.org
Engraver Beetles Ips avulsus, grandicolis, calligraphus
• Isolated occurrence (usually) • Colonize stressed trees, branches, slash • Secondary
28 3/12/2021
Engraver Beetles Ips avulsus, grandicolis, calligraphus • Colonize stressed trees, braches, slash • Secondary • Usually isolated occurrence
Pennsylvania Department of Conservation and Natural Resources
Ambrosia beetles Xyleborus spp., Xylosandrus sp., Platypus sp. • Small (approx. 2mm) • Usually attack only dead/dying trees • Part of the decomposition process • Fungus-feeding beetles • Dig tunnels in trees to grow fungi • Fungi is their main food source • Beetle brings their fungi to the tree • Cannot survive on plant tissues alone • Managed with permethrin or bifenthrin if problematic on live trees
Wayne Brewer, Auburn University, Bugwood.org
29 3/12/2021
Roundheaded Wood Borers • Longhorned beetles (Cerambycidae) • Pine sawyers Monochamus spp. • 1-3 yr life cycle • Can tunnel into heartwood and sapwood • Attack weakened/dying trees
Eugene E. Nelson, Bugwood.org Eugene E. Nelson, Bugwood.org
Questions?
Elizabeth McCarty [email protected]
30