Insect Updates ISA-RMC Pesticide Conference. Whitney Cranshaw Colorado State University

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1 Insect Updates 2014 ISA-RMC Pesticide Conference Whitney Cranshaw Colorado State University

2 Photograph by Steven Valley Managing Emerald Ash Borer in Colorado

3 that develops in ash trees (Fraxinus species) Emerald ash borer (EAB) is a green-colored beetle.

4 and is Native to Asia

5 Emerald ash borer was accidentally introduced into and has since spread through North America

6 Known distribution November 2014 Known distribution June 2010 Emerald ash borer has spread rapidly across North America

7 Emerald ash borer is a wood boring beetle in the family B Emerald ash borer Agrilus plannipennis Photograph by Debbie Miller Order Coleoptera (beetles) Family Buprestidae (metallic wood borers, flatheaded borers) Photograph by David Cappaert

8 Emerald ash borer does not equal Lilac/Ash Borer! Lilac/ash borer, a clearwing borer moth Emerald ash borer, a metallic wood borer/ flatheaded borer

9 Lilac/Ash Borer Podosesia syringae Order: Lepidoptera (Moths and butterflies) Family: Sesiidae (Clearwing borers)

10 Emerald ash borer larvae create meandering tunnels in the cambium that produce girdling wounds. Note: Attacks can occur throughout the crown and on the trunk of the tree. Photograph by Eric Day

11 Lilac/ash borer larvae create irregular gouging wounds that extend often into the heartwood. Photograph by David Cappaert Attacks are concentrated at the lower trunk of the tree

12 EAB adults chew through the bark, producing D-shaped exit holes

13 Extruded pupal skin Lilac/ash borer emerges from irregularly round holes. The pupal skin is pulled out when the adult emerges. through irregularly

14 EAB likely will emerge sometime in mid-late May. Photograph by David Cappaert Most eggs will be laid in June, into July Photograph by Dan Herms

15 Giant emerald ash borer found flying in our Department office last summer

16 After emergence emerald ash borer adults feed on ash foliage for a period of weeks and eggs mature.

17 Adult stages of the lilac ash borer do not feed on any parts of the ash tree. Male flying to a pheromone trap Adults of the lilac/ash borer are present in mid-late spring. Most eggs are generally laid in May through early June.

18 Eggs of both species are laid on the bark of the host tree EAB egg Clearwing borer eggs

19 Damage potential to its host 2, maybe 3 Lilac/ash borer has far lower ability to seriously damage its host

20 Damage potential to its host 10 EAB now defines an aggressive tree killing insect in North America.

21 Emerald ash borer is devastating to all species of ash that are native to North America

22 Emerald Ash Borer is an Introduced Species Native to Asia

23 No EAB Resistance Why is EAB so destructive to ash trees in North America? NA ash species lack ability to ability to resist EAB No EAB Resistance

24 EAB Will Kill All Unprotected Ash These trees can t be saved. They are already dead. 24

25 EAB Invasion Wave and Protection Needs Percentage of Maximum 100% 80% 60% 40% 20% 0% Management Phase Aggressive Maintenance Affected Ash EAB Time (Years) Cusp Crest Post Crest * Assumes doubling of affected ash and EAB yearly during growth

26 Colorado EAB Tree #1 (September 2013) Located near the intersection of 30 th and Valmont, Boulder Suspected area of original introduction is a couple miles to the south

27 Present distribution of EAB in North America

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32 Example for discussion: Let s assume that the area of Boulder within the circle is the limit of current infestation

33 Main Points About Emerald Ash Borer in Colorado Known infestation presently confined to areas within Boulder City limits In time will spread throughout South Platte drainage Other areas of the state are at no greater risk than before detection Treatments are available that will protect individual trees Each treatment option involves decisions balancing costs, environmental hazards, effectiveness and ease of application

34 The current infestation is an infestation of the South Platte River drainage, not the State of Colorado Unlike states to the east, Colorado is highly compartmentalized due to its geography

35 Emerald Ash Borer has become established within in the South Platte River Drainage of Colorado not the entire state of Colorado!

36 Within the next five years, emerald ash borer will move out of Boulder into the surrounding counties

37 Over time the South Platte River Drainage will be colonized by emerald ash borer??

38 Most of Colorado is no more nor less at risk of infestation by Emerald Ash Borer EAB will be a problem due to Boulder infestation No change in Risk

39 How far away is emerald ash borer from your community?

40 How far away is emerald ash borer from your community? One truckload

41 Insecticide treatments Host plant resistance Control Options for Management of Emerald Ash Borer Biological controls

42 What about using Asian species of ash??? Manchurian ash Fraxinus mandshurica

43 No EAB Resistance Why is EAB so destructive to ash trees in North America? NA ash species lack ability to ability to resist EAB No EAB Resistance

44 Asian species of ash are highly susceptible to lilac/ash borer

45 Parasitic wasps that attack EAB larvae Biological Control Agents for Emerald Ash Borer Parasitic wasps that attack EAB larvae

46 What can we expect from biocontrols of EAB Slight suppression, at best. Percentage of Maximum 100% 80% 60% 40% 20% 0% Time (Years) Cusp Management Phase Aggressive Crest Maintenance Post Crest Affected Ash EAB * Assumes doubling of affected ash and EAB yearly during growth

47 Insecticide treatments Host plant resistance Not applicable Control Options for Management of Emerald Ash Borer Biological controls Potential value, minor during outbreak, perhaps greater after EAB wave

48 Important note regarding EAB control Present controls can allow trees to recover if EABinduced crown thinning has not exceeded 30-50%

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50 Smitley, Davis and Rebek Progression of ash canopy thinning in Southeast Michigan. J. Econ. Entomol. 101:

51 Emerald Ash Borer Control Options Soil applications with systemic insecticides imidacloprid, dinotefuran Non-invasive trunk sprays of systemic insecticides dinotefuran Trunk injections of systemic insecticides Emamectin benzoate (TREE-Age, Arbormectin), azadirachtin (TreeAzin), imidacloprid

52 Adults as they feed on foliage Target Life Stages for EAB Treatments Young larvae that tunnel in the phloem and cambium

53 Emerald Ash Borer Insecticides Imidacloprid (Merit, Xytect, Criterion, etc.) Soil drench, possible trunk injection Dinotefuran (Safari, Zylam, Transtect) Basal trunk spray, possible soil drench Emamectin benzoate (TREE-Age, Arbormectin) Trunk injection only Azadirachtin (TreeAzin) Trunk injection only

54 Soil Treatment Options for EAB Imidacloprid Merit, Xytect, Criterion, Zenith, Bandit 75WSP and 2F formulations Several retail formulations now available Typically 1.47% liquid formulations Dinotefuran Safari, Zylam, Transtect

55 Soil application option imidacloprid applied as drench or injection

56 Over-the- Counter Imidacloprid Formulations

57 Primary method of imidacloprid application soil applications for root uptake

58 Optimal Application Soil drench within inches of the Trunk Yes No?

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63 Injections can be very useful to bypass mulch or fabric barriers Injections also prevent the presence of surface residue of the applied insecticide

64 Soil applications of systemic insecticides should not be made if there are flowering plants at the application site

65 Modifying DBH-based rates by tree size

66 What rate of use for imidacloprid soil treatments? 1X rate = 1.4 grams active ingredient/inch trunk diameter Rates of use allowed in label directions 75 WP formulation - 1X/application 2F and 75WSP formulations - 1X up to 15 inches diameter; 2X in larger trees Retail nursery formulations 1/2X Limited to single application/year

67 Soil drench with dinotefuran (Safari, Zylam, Transtect)

68 Basal trunk spray with dinotefuran (Safari, Zylam)

69 Relative Water Solubility of Neonicotinoids: Water Solubility (Active Ingredient) Clothianidin Imidacloprid Acetamiprid Thiamethoxam Dinotefuran 0 Information sources Clothianidin (Celero), Acetamiprid (Tristar), Dinotefuran (Safari) EPA Pesticide Fact Sheet Imidacloprid (Marathon), hiamethoxam (Flagship) MSDS for Products Slide information courtesy J. Chamberlin

70 Dinotefuran 26 Thiamethoxam K oc Values of Neonicotinoids: Acetamiprid Imidacloprid Clothianidin Source Data: EPA Pesticide Fact Sheets

71 Basal Trunk Sprays of Dinotefuran Enters tree through thin areas of bark Can be expected to reach peak levels in foliage in about 2-3 weeks Adjuvant? May help some to increase deposition into trunk fissures, slow drying

72 Trunk Injections

73 Imidacloprid can be trunk injected for EAB Control

74 Trunk injection with emamectin benzoate (TREE-age, Arbormectin)

75 Trunk injection with azadiractin (TreeAzin) Some efficacy and tree wounding issues are unresolved at present

76 All Systemics Need Water Soil drench Trunk sprays Trunk injection Water carries the pesticide

77 Conditions Optimizing Uptake and Distribution of Systemic Insecticides Soil is moist (but not saturated!) Soil temperatures are above 45 0 F Ambient air temperatures are between F In other words, conditions are most favorable to transpiration.

78 Some Researchable Questions about EAB and its Management How effective are available chemical controls? How well do ash trees in Colorado close wounds made by trunk injections? Are residues of EAB insecticides a risk to non-target species?

79 EAB Control Trial Spruce Street Site TREE-Age, every other year TreeAzin, every other year TreeAzin, every year Azasol, every year Untreated Check

80 EAB Control Trial CU Campus Site TREE-Age, every other year Greyhound, every year TreeAzin, every year

81 Evaluations of efficacy will be done by annually assessing crown condition

82 Smitley, Davis and Rebek Progression of ash canopy thinning in Southeast Michigan. J. Econ. Entomol. 101:

83 Trunk Injections Produce Wounds Tissue discoloration from drilling Old AceCap Injection in Cottonwood

84 Concerns - Trunk Wounding and Injections Wounding will have to occur annually every other year Relatively slow growth of regional ash may result in slow wound closure

85 Good News: There is reported good incidence of wound closure from injections in the MidWest wound closure rates are strongly dependent on tree health as expressed by ring growth. Problem? Ash trees in the western states grow much slower than in the Midwest and have much lower rates of ring growth

86 Some Researchable Questions about EAB and its Management How effective are available chemical controls? How well do ash trees in Colorado close wounds made by trunk injections? Are residues of EAB insecticides a risk to non-target species?

87 Study Sites for Wound Closure Boulder Cemetary Site (trees slated for removal, idissection) CSU Campus (trees slated for removal, dissection) External measurements at other study sites (Spruce Street, CU Campus)

88 Some Researchable Questions about EAB and its Management How effective are available chemical controls? How well do ash trees in Colorado close wounds made by trunk injections? Are residues of EAB insecticides a risk to non-target species?

89 Neonicotinoids and Pollinators Should we be concerned about their use on woody plants?

90 Soil Applied Systemic Insecticides and Honey Bees Targets for Concern Plant is visited heavily by honey bees Plant is common in a location so many honey bees are visiting it Plant is treated often with soil applied systemic insecticides for some pest insect

91 Top honey bee-visited plants include: most Sedums, most thistles, catmint, Gaillardia, most Agastache, Blue mist spirea, Russian sage, fruit trees, linden, golden raintree..

92 Do honey bee-visited plants include: Ash???

93 Pollen Study

94 Pollen Study Overall Goal: Determine what types of pollen are and are not being used by honey bees in urban/residential areas of Colorado. Used to identify useful pollen sources to incorporate into landscape plantings Used to identify plants where use of pesticides may increase hazard to pollinators

95 Last April, seven beekeepers placed a pollen trap on their hives. Locations were Boulder (2), Longmont (1), Fort Collins (3) and Loveland (1) A sample of the collected pollen was taken one day a week through the spring and summer.

96 The pollen trap knocks off the pollen loads of honey bees as they return to the hives

97 Rasha Al-Akeel The samples are now being separated by type, identified, and weighed to determine the percentage of pollen types collected each week.

98 Early results from April, May Samples Among wind pollinated trees, Acer (maples, boxelder) are very important early season sources of pollen

99 Yes Early results from April, May Samples Among wind pollinated trees, so far, no pollen from Fraxinus (ash) has been detected in samples. No

100 Decreasing risk Highest Risk in 2015 Decreasing risk

101 EAB Risk Zone Maps Located at the eabcolorado.gov site maintained by the Colorado Department of Agriculture Provides regionally adapted guidelines for EAB recommended practices in upcoming year based on present known distribution

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104 EAB Risk Zones Zone 1 Area within 5 miles of all presently known locations of EAB in Colorado

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106 Highest Risk Zone for 2015 Definition: Areas are presently known to be infested by emerald ash borer or that have good likelihood of having some emerald ash borer within the near vicinity in Area presently affected (November 2015): The nine, milesquare quadrants within the City of Boulder where EAB has been detected and areas up to 5 miles from these areas.

107 Highest Risk Zone for 2015 Definition: Areas are presently known to be infested by emerald ash borer or that have good likelihood of having some emerald ash borer within the near vicinity in Area presently affected (November 2014): The nine, mile square quadrants within the City of Boulder where EAB has been detected and areas up to 5 miles from these areas.

108 EAB Risk Zones Zone 1 Area within 5 miles of all presently known locations of EAB in Colorado Zone 2 Area that is presently under quarantine due to EAB detections (i.e., Boulder County) Zone 3 Area that will eventually be affected by presently known infestation (South Platte drainage) Zone 4 Area outside South Platte Drainage and unlikely to be infested through natural spread

109 EAB Risk Zone 2 The Quarantine Zone that encompasses the entire county* within which EAB has been detected * Plus some areas of Jefferson, Weld and Larimer Counties that include landfills used by Boulder County

110 EAB Risk Zones Zone 1 Area within 5 miles of all presently known locations of EAB in Colorado Zone 2 Area that is presently under quarantine due to EAB detections (i.e., Boulder County) Zone 3 Area that will eventually be affected by presently known infestation (South Platte drainage) Zone 4 Area outside South Platte Drainage and unlikely to be infested through natural spread

111 EAB Risk Zone 3 The South Platte Drainage

112 EAB Risk Zones Zone 1 Area within 5 miles of all presently known locations of EAB in Colorado Zone 2 Area that is presently under quarantine due to EAB detections (i.e., Boulder County) Zone 3 Area that will eventually be affected by presently known infestation (South Platte drainage) Zone 4 Area outside South Platte Drainage and unlikely to be infested through natural spread

113 How far away is emerald ash borer from your community? One truckload

114 EAB Risk Zones Zone 1 Area within 5 miles of all presently known locations of EAB in Colorado Zone 2 Area that is presently under quarantine due to EAB detections (i.e., Boulder County) Zone 3 Area that will eventually be affected by presently known infestation (South Platte drainage) Zone 4 Area outside South Platte Drainage and unlikely to be infested through natural spread

115 Detecting Emerald Ash Borer

116 The presence of the insect is a positive detection Detecting Emerald Ash Borer in Colorado

117 Local Flatheaded borers of similar appearance to the EAB Cypriacus intricata Buprestis confluenta Agrilus cyanescens Agrilus lacustris

118 Also on RamCT homepage Web Links

119 Colorado hosts many metallic colored beetles that may be mistaken for emerald ash borer

120 Other wood boring insects can be found in ash trees

121 Lilac/ash borer

122 New Fact Sheet Available: Lilac/Ash Borer: A Common Wood Borer of Colorado s Street Trees

123 Flatheaded appletree borer A generalist flatheaded borer/metallic wood borer that is associated with many hardwood that are in decline

124 Ash bark beetles An important contributor to limb dieback in Colorado ash

125 Ash bark beetles usually are found in limbs but can occur in the trunk

126 Redheaded ash borer Two roundheaded borers/ longhorned beetles occasionally occur in ash trees in advanced decline Banded ash borer

127 Meandering tracks under the bark of ash always indicate some flatheaded borer. They will almost always indicate emerald ash borer. Detecting emerald ash borer in Colorado ash

128 Flatheaded appletree borer A generalist flatheaded borer/metallic wood borer that is associated with many hardwood that are in decline

129 Flatheaded appletree borer larvae produce dry, powdery sawdust excrement

130 Look for D-shaped exit holes in ash trees Detecting Emerald Ash Borer in Colorado

131 Flatheaded appletree borer larvae and pupae occur under the bark

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135 Flatheaded appletree borer also produces a D-shaped exit hole when it emerges from an ash tree

136 Easily viewed D- shaped exit holes are not going to be found in the trunk during the first couple of years of infestation! Early EAB activity will be higher in the crown of the tree and requires inspecting upper branches.

137 Bark cracking can be a good clue that EAB may be present in a tree

138 Peeling the bark away from a cracked area may reveal earlier larval tunneling

139 A good place to look is the underside of limbs, particularly in the area near the trunk Bark cracking can be a good clue that EAB may be present in a tree

140 Symptom that will develop as EAB injuries accumulate Progressive dieback of the crown

141 ADIOS condition of Colorado Ash complicates EAB detection

142 Residual effects of drought Residual effects of freezing injuries Cumulative effects from secondary insects??????

143 Possible EAB Symptom - Epicormic branching

144 Possible symptom of EAB injury irregular yellowing of the foliage

145 Declining ash trees with dead leaves hanging on the tree High likelihood of EAB

146 What to Do in 2015? Boulder residents in High Risk areas need to make EAB treatment decisions now Everyone in Colorado should renew vigilance in detection of EAB infestations Communities within the South Platte drainage need to make long-term plans for EAB management now Revisit the Colorado situation this time next year (and every year)

147 Entertaining visitors from the East this year? Tell them you will provide all the firewood they need.

148 Sources of Information for Emerald Ash Borer in CO Colorado Department of Agriculture Colorado State Forest Service and CSU Extension Offices Insect Information Web Site

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152 Control Options Document produced last week

153 European Elm Scale Is resistance to neonicotinoids the status quo of the future in Colorado?

154 European elm scale nymphs on leaves in summer

155 Honeydew is excreted. Where it lands and persists, sooty molds grow.

156 Prior to about 1995 European elm scale was controlled by spraying elm trees with insecticides in spring to kill overwintering stages on the twigs.

157 European elm scale was one of the first shade tree insects against which the new insecticide imidacloprid was tested (ca 1993). The results were fantastic. Soil injection of elm was embraced rapidly by the Colorado tree care community

158 European Elm Scale in Colorado A poster child example of how to develop insect resistance in a shade tree pest

159 Primary Neonicotinoid Insecticides Used in the United States Imidacloprid (Admire, Provado, Merit, Marathon, Gaucho, etc.) Clothianidin (Clutch, Celero, Arena, Poncho) Thiamethoxam (Actara, Cruiser, Flagship, Meridian) Dinotefuran (Venom, Safari) Acetamiprid (Assail, Tristar) Thiacloprid (Calypso)

160 European Elm Scale Options in a Post-Neonicotinoid Period Soil/Trunk Injections? Acephate (ACE-jet, Leptotect, etc.) Foliar Applications Horticultural Oils Insect growth regulators Pyriproxifen (Distance) Buprofezin (Talus) Broad spectrum crawler treatments Pyrethroids

161 Elm Scale trial at the CSU Oval

162 Treatments in 2014 Elm Scale Trial Distance spray May 25 Distance + Oil spray May 25 Talus spray May 25 Talus plus oil spray May 25 Zenith (imidacloprid) soil drench June Azasol trunk injection June ACE-jet trunk injection June Untreated Check

163 Elm Scale Trial - Early Results Imidacloprid provided no control or negative control High levels of imidacloprid remained in leaves in trees treated a year earlier Azasol (azadirachtin), trunk injected, did not provide control

164 Elm Scale Trial - Early Results Talus, Distance, sprayed May 25, provided about 75% control Addition of oil did not seem to increase efficacy ACE-jet (acephate), trunk injected, provided about 80% control

165 Where are we for options to control European elm scale?

166 European Elm Flea Weevil are natural enemies finally catching up?

167 European Elm Flea Weevil are natural enemies finally catching up? Yes!

168 Adults and their parasitoids emerge in early summer

169 Tentative identification of primary parasitoid: Eupelmus vesicularis (Hymenoptera: Pteromalidae)

170 Finally It is done! Latest revision of Bulletin 506A Cost: $40 Available through the CSU University Resource Center (and outside at the table)

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172 Endangered Species Plant Pathologists with an interest in tree health care Ned Tisserat Bill Jacobi

173 Developments with Tree Health at CSU Presently interviewing last candidates to replace Bill Jacobi (trees) and Ned Tisserat (crops) CSFS has hired Dan West as an entomologist to begin work January 1 Department of Forestry/Dean of Natural Resources are considering the idea of developing a Center for Tree Health Please tell them it is a good idea!