1 FOREST INSECT & DISEASE ISSUES IN ORNAMENTAL TREES TRA PEST MANAGEMENT WORKSHOP GRAND JUNCTION, CO FEBRUARY 2012 Dave Leatherman [email protected]GENERAL COMMENTS The distinction between “wild/native” and “ornamental” is fuzzy Native forest plant values tend to be low, which dictates fewer options & tactics Likewise, higher-value ornamentals with issues may warrant action more often Many ornamental causal agents are typical of the surrounding forest (i.e., mobile) Climate change influence on all of this is real and requires constant observation DOMINATE ISSUES IN THE NATIVE FORESTS OF COLORADO fire bark beetles regional defoliators like budworm deer and elk borers dwarf mistletoe decay INSECTS AND FIRE Wild or out-of-prescription fires can create “habitat” for insects in the form of dead or stressed trees Insect-caused mortality may lead to temporarily increased ignition potential and fuel-loading Prescribed fire can be used to dispose of susceptible or insect- infested woody debris FIRE MITIGATION Slash creation could invite pest issues such as ips, twig beetles, and even rodents Monitor stems Change timing of actions if build-up of pests noted REDUCTION OF SLASH INSECTS PROMOTE DRYING (CHIPPING OR LOPPING-AND- SCATTERING IS BETTER THAN PILING) IF PILES ARE PRODUCED, PLAN TO BURN PRIOR TO EMERGENCE OF BARK BEETLES TRY NOT TO PRODUCE SLASH DURING FLIGHT PERIODS (Dendroctonus especially) BEST TIME TO CUT IS USUALLY LATE FALL-EARLY WINTER REMOVAL FROM SITE IS ANOTHER OPTION Ips beetle
14
Embed
FOREST INSECT & DISEASE ISSUES GENERAL COMMENTS IN … · FOREST INSECT & DISEASE ISSUES IN ORNAMENTAL TREES TRA PEST MANAGEMENT WORKSHOP GRAND JUNCTION, CO FEBRUARY 2012 Likewise,
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1
FOREST INSECT & DISEASE ISSUES IN ORNAMENTAL TREES
The distinction between “wild/native” and “ornamental” is fuzzy
Native forest plant values tend to be low, which dictates fewer options & tactics
Likewise, higher-value ornamentals with issues may warrant action more often
Many ornamental causal agents are typical of the surrounding forest (i.e., mobile)
Climate change influence on all of this is real and requires constant observation
DOMINATE ISSUES IN THE NATIVE FORESTS OF COLORADO
fire
bark beetles
regional defoliators like budworm
deer and elk
borers
dwarf mistletoe
decay
INSECTS AND FIRE
Wild or out-of-prescription fires can create “habitat” for insects in the form of dead or stressed trees
Insect-caused mortality may lead to temporarily increased ignition potential and fuel-loading
Prescribed fire can be used to dispose of susceptible or insect-infested woody debris
FIRE MITIGATION
Slash creation could invite pest issues such as ips, twig beetles, and even rodents
Monitor stems
Change timing of actions if build-up of pests noted
REDUCTION OF SLASH INSECTS
PROMOTE DRYING (CHIPPING OR LOPPING-AND-SCATTERING IS BETTER THAN PILING)
IF PILES ARE PRODUCED, PLAN TO BURN PRIOR TO EMERGENCE OF BARK BEETLES
TRY NOT TO PRODUCE SLASH DURING FLIGHT PERIODS (Dendroctonus especially)
BEST TIME TO CUT IS USUALLY LATE FALL-EARLY WINTER
REMOVAL FROM SITE IS ANOTHER OPTION
Ips beetle
2
MOVEMENT OF BARK BEETLES IN FIREWOOD
FIREWOOD MOVEMENT
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)
ENTRY EXIT
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
OTHER BARK BEETLES
Secondary pine species (Ips spp., twig
beetles, Red Turpentine Beetle)
Douglas-fir species (Douglas-fir Beetle,
Douglas-fir Pole Beetle, Scolytus spp.)
Spruce Beetle
Aspen Bark Beetles
Fruit Tree Bark Beetles
RED TURPENTINE BEETLE (Dendroctonus valens)
Attacks only the lower 3 feet of trunk
Large red adults
Big pitch tubes
Often occurs following fire injury, grade change, root
damage
3
IDENTIFICATION OF IPS
Various species range from 1/16 to ¼ inch long (i.e., some as big as MPB)
CO has at least 14 spp., most in pine, some in spruce
Adults all have spiny back ends (as opposed to rounded back ends of Dendroctonus spp.)
EXTERNAL IPS INFESTATION CLUES
Rarely does ips produce pitch tubes
Most common sign is boring dust in little piles within bark crevices
Woodpecker activity may indicate where the problem trees are
IPS GALLERIES
Multiple females involved, thus each gallery is branched or forked (result is a “Y” or “X” pattern)
Galleries made by adults usually clear of frass
TWIG BEETLES
VERY SMALL, MANY SPECIES
USUALLY IN BRANCH ENDS
INDICATE WATER STRESS
CAN BE IN TRUNKS OF TRANSPLANTS
AFTERMATH OF OTHER BARK BEETLE EPIDEMICS CAN INCLUDE A BRIEF OUTBREAK OF THESE
PINE TWIG BEETLES
MOST IN THE GENUS PITYOPHTHORUS
USUALLY DO NOT REQUIRE TREATMENT*
CAN BE AN INDICATOR OF DRY CONDITIONS
*Transplants are the exception
TWIG BEETLES
Pityophthorus sp.
Pityogenes sp.
4
BARK BEETLES OF DOUGLAS-FIR
Douglas-fir Beetle
Restricted to large-diameter trees
Attacked trees often set-up by fire or drought
Douglas-fir Pole Beetle
Likes 6-10” diameter trees (i.e., “poles”)
Engraver Beetles in the genus Scolytus
Like “Ips” in pines, often secondary, may occur in all sizes of trees, often with the
above
DOUGLAS-FIR BEETLE (Dendroctonus pseudotsugae)
Although related to MPB, not nearly as aggressive
Rogaine user?
Likes large-diameter
blowdown, fire-charred trees, drought, and trees stressed by budworm defoliation
Flies in early summer
Photo by Contech
SPRUCE BARK BEETLES
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 blue spruce in urban areas can be somewhat troublesome, others in forest situations are usually not serious)
Other minor species (twig beetles, etc.)
SPRUCE BEETLE (Dendroctonus rufipennis)
Likes standing, big, spruce near a stream
Likes fresh windthrown spruce
Epidemics start in blowdown and move into standing trees
Major outbreaks in CO in the late 1940s (Trapper‟s Lake) and late 1990s (nw of Steamboat Springs)
Presently active on Grand Mesa, elsewhere in w CO
THE “BLOWDOWN” BARK BEETLE
Area near Clark, Routt County CO. 1997
STARTED HERE
FINISHED HERE
SPRUCE BEETLE SIGNS AND SYMPTOMS
STANDING “FADER”
NEEDLE DROP
GALLERIES PITCH TUBES
5
MORE SPRUCE BEETLE BIOLOGY
Sometimes produces runny pitch tubes, sometimes coagulated ones.
Crown discoloration of infested trees is difficult to detect
3-toed woodpecker is primary avian predator
TRUE FIR BARK BEETLES
Balsam Bark Beetle - in genus (Dryocoetes, pronounced “dry-o-see’-teez” acts in concert with root disease fungi and can result in large-scale mortality of high-elevation stands under moisture stress
Fir Engraver (Scolytus ventralis) can cause widespread top-kill and whole tree mortality
Other minor species
BALSAM BARK BEETLE (Dryocoetes confusus)
Affecting subalpine fir (Abies lasiocarpa) statewide
Usually acts in consort with root disease fungi such as Armillaria and Fomes (together, called “SUBALPINE FIR DECLINE”)
Prime suspect as being a consequence of climate change
males (top), females (bottom)
by Jeff Witcosky of USFS
BALSAM BARK BEETLE EGG GALLERY
Distinctive “stellate” pattern
Note central nuptial chamber
Female egg galleries (6 plus a partial 7th) radiate from the mating area
Staining fungus Ophiostoma dryocoetidis in involved in beetles‟ success
FIR ENGRAVER (Scolytus ventralis)
Ecologically similar to Ips in pine and spruce
Usually only found in stressed white fir
Often attacks upper trunk first
Egg galleries are horizontal
Has been a an issue n of Durango
CEDAR BARK BEETLES
Found only in junipers and Eastern Red Cedar in our area
Require considerable stress (usually lack of adequate water)
Galleries distinctive
We have 4 spp.
6
URBAN BARK BEETLES OF DECIDUOUS HOSTS
ELM Smaller Eur. Elm Bark Beetle (Scolytus multistriatus) Banded Elm Bark Beetle (Scolytus shevyrewi)
ASH Ash Bark Beetles (few species in genus Hylesinus)