FOREST INSECT & DISEASE ISSUES IN ORNAMENTAL TREES GENERAL COMMENTS The distinction between “wild/native” and “ornamental” is fuzzy TRA Native forest plant values tend to be low, PEST MANAGEMENT WORKSHOP GRAND JUNCTION, CO which dictates fewer options & tactics FEBRUARY 2012 Likewise, higher-value ornamentals with
issues may warrant action more often
Many ornamental causal agents are typical of the surrounding forest (i.e., mobile) Dave Leatherman [email protected] Climate change influence on all of this is real and requires constant observation
DOMINATE ISSUES IN THE NATIVE INSECTS AND FIRE FORESTS OF COLORADO
Wild or out-of-prescription fire fires can create “habitat” for insects in the form of bark beetles dead or stressed trees Insect-caused mortality regional defoliators like budworm may lead to temporarily deer and elk increased ignition potential and fuel-loading borers Prescribed fire can be used to dispose of dwarf mistletoe susceptible or insect- infested woody debris decay
FIRE MITIGATION REDUCTION OF
Slash creation could SLASH INSECTS invite pest issues Ips beetle such as ips, twig PROMOTE DRYING (CHIPPING OR LOPPING-AND- beetles, and even SCATTERING IS BETTER THAN PILING) rodents IF PILES ARE PRODUCED, PLAN TO BURN PRIOR TO EMERGENCE OF BARK BEETLES Monitor stems TRY NOT TO PRODUCE SLASH DURING FLIGHT PERIODS Change timing of (Dendroctonus especially) actions if build-up BEST TIME TO CUT IS USUALLY LATE FALL-EARLY WINTER of pests noted REMOVAL FROM SITE IS ANOTHER OPTION
1 MOVEMENT OF BARK BEETLES FIREWOOD MOVEMENT IN FIREWOOD RULES OF THUMB
*BARK BEETLE EXTERNAL EVIDENCE + NO EXIT HOLES = DANGER
*EXTERNAL EVIDENCE + EXIT HOLES = OK
*EXTERNAL EVIDENCE = PITCH TUBES, BORING DUST, WOODPECKERING, AND/OR CROWN FADING (AND, OF COURSE, LIVE LIFE STAGES UNDER THE BARK)
MOUNTAIN PINE BEETLE
Covered in detail in “Forest Pest Control” session (tomorrow, presenter: Roy Mask)
Main “Green Industry” activity is preventive spraying
Other activities might include:
Identifying infested trees
Removing infested trees
Thinning of live forests
Planting of replacement trees ENTRY EXIT
OTHER BARK BEETLES RED TURPENTINE BEETLE (Dendroctonus valens) Attacks only the Secondary pine species (Ips spp., twig lower 3 feet of beetles, Red Turpentine Beetle) trunk Large red adults Douglas-fir species (Douglas-fir Beetle, Big pitch tubes Douglas-fir Pole Beetle, Scolytus spp.) Often occurs Spruce Beetle following fire Aspen Bark Beetles injury, grade change, root Fruit Tree Bark Beetles damage
2 IDENTIFICATION OF IPS EXTERNAL IPS INFESTATION CLUES
Rarely does ips produce pitch tubes
Most common sign is boring dust in little piles within Various species range from 1/16 to ¼ inch long (i.e., some as big as MPB) bark crevices CO has at least 14 spp., most in pine, some in spruce Woodpecker Adults all have spiny back ends (as opposed to rounded back activity may ends of Dendroctonus spp.) indicate where the problem trees are
IPS GALLERIES TWIG BEETLES
VERY SMALL, Multiple females MANY SPECIES involved, thus each USUALLY IN BRANCH ENDS
gallery is branched or INDICATE WATER STRESS forked (result is a “Y” CAN BE IN TRUNKS OF or “X” pattern) TRANSPLANTS AFTERMATH OF OTHER Galleries made by BARK BEETLE EPIDEMICS adults usually clear CAN INCLUDE A BRIEF of frass OUTBREAK OF THESE
PINE TWIG BEETLES TWIG BEETLES
MOST IN THE GENUS Pityogenes sp. PITYOPHTHORUS USUALLY DO NOT REQUIRE TREATMENT* CAN BE AN INDICATOR OF DRY CONDITIONS
*Transplants are the
exception Pityophthorus sp.
3 DOUGLAS-FIR BEETLE BARK BEETLES OF DOUGLAS-FIR (Dendroctonus pseudotsugae)
Although related to Douglas-fir Beetle MPB, not nearly as Restricted to large-diameter trees aggressive
Attacked trees often set-up by fire or drought Rogaine user? Douglas-fir Pole Beetle Likes large-diameter
Likes 6-10” diameter trees (i.e., “poles”) blowdown, fire- charred trees, Engraver Beetles in the genus Scolytus drought, and trees Like “Ips” in pines, often secondary, may stressed by budworm occur in all sizes of trees, often with the Photo by Contech defoliation above Flies in early summer
SPRUCE BEETLE SPRUCE BARK BEETLES (Dendroctonus rufipennis)
Spruce Beetle (requires large-diameter trees, outbreaks usualy start with a wind event blowing down areas of trees, can be a major influence on the landscape)
Spruce Ips (at least 3 species: one in Likes standing, big, spruce near a stream blue spruce in urban areas can be Likes fresh windthrown spruce somewhat troublesome, others in forest Epidemics start in blowdown and move into standing trees situations are usually not serious) Major outbreaks in CO in the late 1940s (Trapper‟s Lake) and late 1990s (nw of Steamboat Springs) Other minor species (twig beetles, etc.) Presently active on Grand Mesa, elsewhere in w CO
THE “BLOWDOWN” BARK SPRUCE BEETLE BEETLE SIGNS AND SYMPTOMS
FINISHED HERE
STANDING “FADER”
STARTED HERE
PITCH TUBES GALLERIES Area near Clark, Routt County CO. 1997 NEEDLE DROP
4 MORE SPRUCE BEETLE TRUE FIR BARK BEETLES BIOLOGY Balsam Bark Beetle - in genus Sometimes produces runny pitch tubes, (Dryocoetes, pronounced “dry-o-see’-teez” sometimes coagulated acts in concert with root disease fungi and ones. can result in large-scale mortality of high- elevation stands under moisture stress Crown discoloration of infested trees is Fir Engraver (Scolytus ventralis) can difficult to detect cause widespread top-kill and whole tree mortality 3-toed woodpecker is primary avian predator Other minor species
BALSAM BARK BEETLE (Dryocoetes confusus) BALSAM BARK BEETLE EGG GALLERY
Distinctive “stellate” pattern Note central nuptial chamber Female egg galleries (6 plus a partial 7th) radiate males (top), females (bottom) from the mating area by Jeff Witcosky of USFS Staining fungus Ophiostoma dryocoetidis Affecting subalpine fir (Abies lasiocarpa) statewide in involved in beetles‟ Usually acts in consort with root disease fungi such as Armillaria and success Fomes (together, called “SUBALPINE FIR DECLINE”) Prime suspect as being a consequence of climate change
FIR ENGRAVER CEDAR BARK BEETLES (Scolytus ventralis)
Ecologically similar to Ips in pine and Found only in spruce junipers and Usually only found Eastern Red Cedar in stressed white fir in our area
Often attacks Require upper trunk first considerable stress Egg galleries are (usually lack of horizontal adequate water) Has been a an Galleries distinctive issue n of Durango We have 4 spp.
5 URBAN BARK BEETLES OF DECIDUOUS HOSTS ELM BARK BEETLES
ELM Smaller Eur. Elm Bark Beetle (Scolytus multistriatus) Banded Elm Bark Beetle (Scolytus shevyrewi) ASH Ash Bark Beetles (few species in genus Hylesinus) HACKBERRY Hackberry Bark Beetle (Scolytus muticus) FRUIT TREES Shot-hole Borer (Scolytus rugulosus) Smaller European Elm BB Banded Elm BB ASPEN From Europe 100+ years Recently from Asia Two minor, unaggressive species Being replaced by BEBB? Now the default elm bb BLACK WALNUT Has been the major vector of Apparently a poor DED vector Walnut Twig Beetle (Pityophthorus juglandis) DED in NA
ELM BARK BEETLE GALLERIES
ASH BARK BEETLE SIGNS AND SYMPTOMS
SMALLER EUROPEAN BANDED
ASH BARK BEETLE SHOTHOLE BORER (Scolytus rugulosus)
Essentially our only bark beetle in fruit trees (cherry, plum, peach, etc.) Usually stress is the problem, not these bark beetles Paying attention to water/borer issues is best prevention WITH BARK WITHOUT BARK
6 ASPEN BARK BEETLES (2 spp.) WALNUT TWIG BEETLE
Vector of Thousand Canker Disease fungus (Geosmithia morbosum) New to CO How did they get here? Nothing known to date to stop them Native to Mexico and Southwest U.S.
BARK BEETLE INFO AVAILABLE FROM CSU/CSFS WESTERN SPRUCE BUDWORM CSU Cooperative Extension Fact Sheets MOST IMPORTANT 5.563 “Firewood & House Log Insects” FOREST DEFOLIATOR 5.558 “Ips Beetles” IN CO 5.528 “Mountain Pine Beetle” DOUGLAS-FIR IS 2.948 “Pinyon Pine Diseases & Insects” FAVORED HOST Garden Insects of North America (book) CAN KILL TREES CSU Bioag Sci. and Pest Mgmt. Dept. website WITH 3+ YEARS OF
Outreach and Extension HVY. FEEDING Thousand Cankers Disease/Walnut Twig Beetle PRESENTLY ACTIVE IN SAN JUAN AND LA “Whitney for President” GARITA MOUNTAINS
WSBW EGG MASSES HOW DO BUDWORMS COPE OUT THERE IN FEBRUARY?
Very tiny larvae live in shelters called OLD “hibernaculae” up in FRESH the tree crowns
USED TO PREDICT POPULATIONS LAID IN EARLY SUMMER ON NEEDLES GREEN ONES ARE FRESH GRAY ONES ARE OLD AND HATCHED EACH MASS CONTAINS DOZENS OF EGGS
7 WSBW LARVA WSBW DEFOLIATION
STARTS AT TOP OF EARLY TREE SUMMER STARTS AT BRANCH MINES OLD ENDS NEEDLES OCCURS IN EARLY THEN IN SUMMER BUDS CAN RESULT IN TOP- THEN IN KILL OR MORTALITY NEW NEEDLES
WSBW TREATMENT TIMING WSBW AERIAL SPRAYING
WILL BE RARE IN SPRAYING IS NOT ALWAYS NEEDED THE FUTURE BUT WHEN IT IS, BEST DONE TIMING IS WITH Bacillus CRITICAL thuringiensis BEST TIME IS PRODUCTS (low WHEN BUDBREAK impact on non- IS OCCURRING target species) FOR THE MOST- VALUABLE HOST MOST ECONOMICAL WAY TO TREAT BIG AREA
TIGER MOTH PINE SAWFLIES
Chew mostly “old” needles Longterm defoliation gives trees “tufted” appearance (needles at ends of branches OK, interior needles Forms a white tent at the very top gone) of various conifers Female has sawlike egg-laying organ, Larvae active in winter, stay in tent deposits eggs inside Larval hairs irritate skin needles May kill tree tops, at most Tend to like smallish Has been an issue in p-j near trees, often open- Ridgway grown
8 EUROPEAN FLEA WEEVIL EUROPEAN ELM FLEA WEEVIL
Leaf miner and ADULT chewer of elms, VIEWS mostly Siberian (actual size about 1/8”) European species
Has exploded on the scene in CO over the last 5 years (replacing Elm Leaf Beetle?)
Adults are small weevils that “hop”
LARVAL MINING AROUND LEAF EDGE ADULT FEEDING INJURY
EUROPEAN ELM MANAGEMENT OF FLEA WEEVIL ELM FLEA WEEVIL
Probably not necessary, if tree mortality is the LARVAL only concern and there are not additional MINING stresses like extreme drought, leafminer or ELB
In cases where esthetics matter and/or there ADULT are other serious stresses: FEEDING Systemic application or foliar spray in early summer Perhaps an additional foliar spray in mid-summer Promote bird populations and proper watering
SAWFLY LEAFMINER OF ELM STAGES OF SAWFLY MINING (early at left, later at right) Fairly new Mostly aesthetic in impact Larval mining mostly May Would require systemic or eggs and foliar treatment early in early the growing season mines Adults present in the weeks immediately after budbreak mature larva Following larval mining, within larvae drop to ground and mine pupate in soil in early summer (beginning ~ June1)
9 ELM LEAFMINER (Kaliofenusa ulmi) WOOD BORERS
Used to be mostly minor miner (Am. Elm)
Now a much more Mostly beneficial major minor Mostly secondary
„Mazing Usually best considered symptoms of the problem, not the actual problem Much more common now in Siberian elm Insects with this habit include beetles (longhorned and metallic wood borers), moths than it used to be (carpenterworms), and wasps Probably mostly an (wood wasps/horntails) aesthetic issue
PONDEROUS BORER POPLAR BORER (Saperda calcarata)
Type of longhorned wood borer (beetle) Dripping orange or purple stain on bark of living tree is best symptom Boring dust often Biggest beetle in CO produced in spring- Unusual to see early summer at hole Usually found at the base on the north side of large Fixing stress fixes the pines dead about 2-5 years borer Make a hole the size of your thumb
“ANASAZI” ANTS CARPENTER ANT (aka CARPENTER ANT)
Carpenter ants are usually big and black, but some species are intermediate in Ants do not “eat” wood but size and may have reddish rather excavate it for coloration nesting They normally live in wood and forage elsewhere Wood chosen by ant Carpenter Ants colonies is usually moist Thin waist and semi-decayed Usually black or red in all stages Elbowed antennae Boring dust produced Flying stages with unequal wings (unlike termites)
10 DWARF MISTLETOE (Arceuthobium vaginatum) MISTLETOE “BROOMS”
Parasitic plant
Has explosively-discharged seeds (short-distance spread)
Long-distance spread via birds and mammals
Can lead to dense branching called “witches‟-brooms” (favored nesting location of certain birds, incl. Spotted Owl)
SHOOTING SEEDS! EGADS! MISTLETOE MANAGEMENT
Mistletoe seeds are Most of the time, just live with it explosively discharged in late Ethephon (“Florel”) sprays are very difficult summer via water and expensive (not normally recommended) pressure If infections are light, or isolated to one area May disperse by this of your property: method up to 48 feet! (birds and Clearcut small infected areas mammals can carry If infections are very light in a given tree, prune them further) out affected branches Speed of seeds is Isolate infected portion of the property by up to 55mph cutting a buffer 1-2x tree heights
DECAY GALL RUSTS
At left is a common decayer of ponderosa pine, Red Belt Occur on both Fungus (Fomitopsis pinicola) forest and ornamental Fruiting body (as shown) is junipers/pines called a “conk”. This is what produces the spores. Usually have a deciduous Decay can be either outer alternate host wood or heartwood or both & Sporulate in lead to tree falling within 3- to-several years of time of moist periods death Damage minor
Wound = decay = hazard
11 SPRUCE BROOM RUST* PLEASING FUNGUS BEETLE Seen these? Forms large, Larvae feed on round brooms the spore- Broom are producing yellow during undersurface of sporulation decay conks When you see May kill these, it means branches and long-dead trees top of tree are nearby Alternate host Beneficial, part kinnickkinnick of the recycling process * SIMILAR DISEASE ON FIRS (alternate host chickweed & other plants)
WHITE PINE WEEVIL WESTERN CONIFER SEEDBUG (Pissodes strobi)
Infests spruce terminals (“pig‟s tail” curl)
Leads to dieback and forked topped-trees THIS AND RELATED Treatment is best in late spring when SPECIES FEED ON adults are laying eggs in spruce tops SEEDS AND BERRIES OF MANY WOODY PLANTS
HOUSE INVADER
MOSTLY A NUISANCE Chip cocoons (diagnostic) for WPW
PINE SCALE INSECTS HONEYDEW-PRODUCING APHIDS
SEVERAL APHID SPECIES Pine Needle Scale can INVOLVED also occur on spruce Most effective ELMS, OAKS, treatments target the PINES AND “crawler” stage SPRUCE, PINE NEEDLE SCALE (above) ALONG WITH To be anticipated with BLACK PINELEAF SCALE (below) BOXELDER, insecticide treatments LINDEN, AND for other things WILLOWS (especially chronic INVOLVED AS applications) HOSTS (OTHERS?)
12 COOLEY SPRUCE GALL ADELGID COOLEY GALLS AS A FUND-RAISER ITEM Major source of phone inquiries from the public
Insect is a “woolly aphid”
Life cycle involves both spruce and Douglas-fir
Not a problem, really PORCUPINE “EGGS” $1 EACH
ARTICHOKE GALL MADE BY ERINEUM MITES ON MOUNTAIN MAPLE THE JUNIPER TIP MIDGE (Oligotrophus betheli) ON UTAH JUNIPER
Microscopic mites formation of a “felt” (erineum) made up of zillions of tiny balloons (galls) in which the mites live Looks like confectionary sugar, with each sugar grain being one gall In this species, the erineum is bright red Not harmful to the tree
ASPEN ISSUES ASPEN ISSUES TENT CAT
TORTRIX
LEAFMINER
LEAF BLIGHT IDIOTS DECAY CANKER
13 PUTNAM‟S CICADA ROOT WEEVILS Otiorhychus spp.
Adults are black, broad-nosed weevils Adults feeding results in notched leaves Larval feeding is in the soil to roots and is the real damage This is what makes that clicking sound in the mountains in Several CO species early summer Treat with soil drench Nymphs feed on woody plant roots Oviposition occasionally causes minor twig breakage
MAGNESIUM CHLORIDE LICHENS
Used as both winter de-icer and summer dust control agent Studies by both CSU (Betsy Goodrich) and UNC found issues with trees Kent Simmons U of Winnipeg near roads Plants made of both fungi and algae Movement away from immediate Foliose and fruticose types shown above roadside does not Some fix nitrogen, some are eaten by animals appear to be serious Being recognized as ecosystem health indicators Note resin bands = salt Do NOT harm trees, contrary to popular opinion
FOREST INSECT & DISEASE REFERENCE BOOKS
Western Forest Insects by Furniss and Carolin
Insects and Diseases of Woody Plants of the Central Rockies (REVISION COMING 2013?) (CSU Ext. Bulletin 506A) 970/491-6198 ($50)
Others (Cornell books, Kansas, Garden Insects, etc.)
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