Insects Pest of SECO S. Sky Stephens Forest Entomologist Colorado State Forest Service www.csfs.colostate.edu
Outline Introduction xxx Pest Ecology and Management Elms Ashe Walnuts Thousand Cankers Disease Emerging Pest Issues
Insects Everywhere Millions of insect species in the world 10,000,000,000,000,000,000 individuals 91,000 species in U.S.A. Coleoptera Beetles Diptera Flies Hymentoptera Ants, Bees, Wasps Lepidoptera Moths, Butterflies 35,000 species in Colorado
Threats to our valuable trees Why are our trees important? Enhance our communities Improve property values Provide shade Protect fields, buildings, roadways and livestock from winds
Forest Pests and People Public s interaction with forest pests Demand for results Regional Local Personal Do something Do something soon Something NOW!
Balancing Act Demand for action Pest severity Property management Constraints of cost Application techniques Application constraints Product testing Product success history
Elms Defoliators Elm leaf beetle European elm flea weevil Defoliation Poor aesthetics Stressors, but not killers
Management Defoliating beetle management usually isn t warranted as trees recover. Chemical sprays available if consecutive years of defoliation are detrimental to tree. Maintain tree health through watering, pruning and good maintenance.
Elms Suckers European elm scale Branch and twig dieback Stunted discolored foliage Presence of sooty mold Slow tree killer!
Management Soil treatments, horticultural oils and contact insecticides can be useful. Time application of contact insecticides and oils with crawler stages in late June. Systemic treatments can be effective on adults. Natural enemies.
Elms Bark Beetles and DED Dutch elm disease Effects American elms Dose not effect Siberian elms Siberian elms provide habitat for vectors Lesser European elm bark beetle Vector of DED Banded elm bark beetle Aggressive tree killer Possible DED vector
Treatment No treatment for DED Removal of dead, diseased elms material Preventative bark beetle chemical sprays
Ash Ash/lilac borer Adult resembles clear wing moth Tunnel beneath bark in large branches and trunk May expel frass Induce canker-like swellings Repeat damage can cause extensive breakage and mortality, especially in windrows
Management Maintaining tree vigor Watering Avoiding tree injury Young trees are especially susceptible Chemical preventatives during adult flights April-June can reduce/prevent attack
Walnut Twig Beetle Pityophthorus juglandis Twig beetles normally attack small, weakened twigs BUT in CO and other states found attacking large diameter boles In CO has caused significant mortality in black walnuts Range of Juglans major
TCD Update Presently found in 16 counties in CO Been identified in 9 western states and 3 eastern states 9 currently unimpacted states have enacted quarantines No known preventative treatments Treatments under investigation
Distribution of 1000 Cankers
September 2008 June 2008 June 2009
Comparison of Epidemics of Dutch Elm Disease (historical) and TCD in Boulder
Emerging Pest Issues
Exotic Pests Update Asian long horned beetle Maples, horse chestnuts, poplars, willows, elms, mulberries, black locusts. Several Colorado look-a-likes White spotted pine sawyer Cottonwood borer No treatments warranted at this time
Defoliator of over 100 species of trees and shrubs Annually defoliates ~1 million acres Quarantines exist in 18 states Notorious hitchhiker on outdoor material from wood pallets to automobiles Gypsy Moth
Occurrence of Gypsy Moth purple - established yellow - moths detected green - moths not detected brown - eradication efforts white - not trapped.
Exotic Pests Update Gypsy moth Observed regularly in Colorado since 1980 s Several moths trapped in 2009 and 2010 Not detected in 2011 Several commonly misidentified natives No treatments warranted at this time
Emerald Ash Borer Causes mortality in all ash species 20 million ash trees killed across 15 states Cost of treatment, removal and replacement in communities alone will exceed $10.7 billion Notorious hitchhiker in firewood and untreated ash material
Exotic Pests Update Emerald ash borer Sales media suggested preventative treatment in 2011 Not been detected in Colorado Nearest positives are in Missouri, Iowa and Minnesota No treatments warranted at this time
CAPS Program
Colorado State Forest Service Website Links to information on insect and disease pests of Colorado Forests. CSFS Insect and Disease Quarterly Reports
Questions? Sky.Stephens@colostate.edu 970-491-7282 www.csfs.colostate.edu