Systemic Insecticide Technology for Tree Care Dan Herms Department of Entomology The Ohio State University Ohio Agricultural Research and Development Center Wooster herms.2@osu.edu
Landscapes are diverse ecosystems
Advantages of systemics: Effective control of diversity of pests. Timing: fall or spring. Diverse application methods. Can be used where spraying is undesirable. Very low use rates: low environmental risk. Very low vertebrate toxicity. Reduced impact on natural enemies.
Advantages of systemics: Effective control of diversity of pests. Timing: fall or spring. Diverse application methods. Can be used where spraying is undesirable. Very low use rates: low environmental risk. Very low vertebrate toxicity. Reduced impact on natural enemies. But they have to be applied preventively.
Questions: Selectivity: which pests are controlled? Patterns of uptake, translocation, and accumulation in the plant? Length of residual activity? Timing: fall vs. spring vs. summer? Application rate vs. tree size? Placement?
Systemic Insecticides: Soil Systemic vs. Foliar Translaminar
Soil Systemic Activity
Systemic Activity?
True Systemic Activity?
Translaminar Activity
Systemic Insecticides Soil Drench / Injection: Acelepryn Acephate (Lepitect) Clothianidan (Arena) Dinotefuran (Safari, Transect) Imidacloprid (e.g. Merit, Xytect, Bayer Advanced Tree & Shrub Insect Control) Systemic Trunk Injections: Acephate (Acecap) Emamectin benzoate (TREE-äge) Imidacloprid (IMA-jet, Imicide, Pointer) Systemic Trunk Sprays Dinotefuron (Safari)
Soil Treatments: Drench / Injections
Trunk Injections
Systemic Basal Trunk Sprays
Selectivity: Imidacloprid is effective against: Sucking insects: plant bugs, lace bugs, adelgids, aphids, soft scales, psyllids (but not armored scales) Defoliators: sawflies, leaf beetles, Japanese beetle, (but not caterpillars) Leafminers: sawflies, dipterans Borers: flatheaded and roundheaded borers (but not clearwing borers)
Selectivity: Acelepryn Controlled: Gypsy moth Rhododendron lace bug Birch leafminer Magnolia scale (fall not spring) Clearwing borers Did not control: Mimosa webworm Bagworm Holly leafminer Emerald ash borer
Systemics for Control of Wood Borers
Bronze birch borer
Emerald Ash Borer
Host Impact: Larvae feed under bark; disrupt transport of water, nutrients, carbohydrates. All major ash species are susceptible (white, green, black, blue, pumpkin). Healthy trees killed within 2-3 years of first symptoms. Trees of all size are susceptible: 1/2 inch saplings to the largest mature trees.
A Toledo street before and after EAB June 2006 August 2009
Systemic Insecticide options for EAB: Systemic Soil Injections / Drenches: Imidacloprid (e.g. Merit, Xytect, Bayer Advanced Tree & Shrub Insect Control) Dinotefuran (Safari, Transect) Systemic Trunk Injections: Imidacloprid (IMA-jet, Imicide) Emamectin benzoate (TREE-äge) Systemic Trunk Sprays Dinotefuron (Safari, Transect)
EAB larvae per m2 Deb McCullough, MSU Trees treated in 2007 & 2008 120 100 a 80 ab 60 40 20 abc bc c abc bc 0 Ctrl Dino Dino-PB Em Ben Imid Imid-PB Maug-imi
EAB larvae per m2 Deb McCullough, MSU Emamectin benzoate (Tree-age): 2 years control with a single injection. Trees treated in 2007 120 100 80 a a a a a a 60 40 b 20 0 Ctrl Dino Dino-PB Em Ben Imid Imid-PB Maug-imi
Objective: multi-year evaluation of systemic insecticides for control of EAB on street trees Imidacloprid soil drenches Imidacloprid and Emamectin Benzoate trunk injections
Trial 1: Imidacloprid Soil Drenches 1. Merit 2F, 1.4 g ai / inch DBH, spring 2. Merit 2F, 1.4 g ai / inch DBH, fall 3. Xytect 75WP, 1.4 g ai / inch DBH, fall 4. Xytect 75WP, 2.8 g ai / inch DBH, spring 5. Xytect 75WP, 2.8 g ai / inch DBH, fall
Treatment evaluation: Canopy decline rating using photographic scale (Smitley et al. 2008. J. Econ. Entomol. 101:1643-1650) Exit hole density in canopy branches.
2008 2009
Four years of imidacloprid soil drenches (D. Smitley, MSU)
Trial 2: Systemic trunk injections, product comparison Emamectin benzoate (Tree-äge) Rate: 0.4 g ai / inch DBH 1. 2006 2. 2006 & 2008 Imidacloprid (Ima-jet), Rate: 0.4 g ai / inch DBH 1. 2006 & 2007 2. 2006 & 2008
Systemic Trunk Injections for Control of EAB Treatment % Canopy Decline 2006 2007 2008 2009 Untreated 0 6 51 a 90 a Tree-äge, 2006 0 0 0 b 13 c Tree-äge, 2006 & 2008 0 0 3 b 6 c Ima-jet, 2006 & 2007 0 0 0 b 33 b Ima-jet, 2006 & 2008 0 0 9 b 20 bc
Systemic Trunk Injections for Control of EAB Treatment Exit holes / m 2 2008 2009 Untreated 15.3 a 34.7 a Tree-äge, 2006 0.1 b 1.9 c Tree-äge, 2006 & 2008 0.1 b 0.6 c Ima-jet, 2006 & 2007 0.1 b 3.8 c Ima-jet, 2006 & 2008 4.4 b 11.9 b
Trial 3: Systemic trunk injections, rate comparison Emamectin benzoate (Tree-äge) 0.1 g ai / inch DBH 0.2 g ai / inch DBH 0.4 g ai / inch DBH 0.8 g ai / inch DBH Imidacloprid (Ima-jet) 0.4 g ai / inch DBH Treat in 2006 and see how long they work.
Effect of Emamectin Benzoate Applied in 2006 for Control of EAB Treatment % Canopy Decline 2006 2007 2008 2009 Untreated 0 8 53 a 96 a Emamectin benzoate 0.1 g ai / inch DBH 0 0 3 b 13 bc 0.2 g ai / inch DBH 0 0 3 b 38 b 0.4 g ai / inch DBH 0 0 10 b 38 b 0.8 g ai / inch DBH 0 0 0 b 5 c Ima-jet, 0.4 g ai / inch DBH 0 0 8 b 53 ab
Effect of Emamectin Benzoate Applied in 2006 for Control of EAB Treatment Exit Holes / m 2 2008 2009 Untreated 19.2 a 24.6 a Emamectin benzoate 0.1 g ai / inch DBH 0.2 b 2.9 c 0.2 g ai / inch DBH 0.5 b 10.1 ab 0.4 g ai / inch DBH 1.4 b 3.3 c 0.8 g ai / inch DBH 0.0 b 0.5 c
Trunk Injections vs. Soil Treatments Soil treatments: Non-invasive. More uniform distribution in the tree. Can be applied under diverse environmental conditions. Can be applied during dormant season. Slower uptake. No way to know how much uptake. Don t require specialized equipment. Trunk injections: Less environmental exposure. Faster uptake and distribution in tree. May be more effective on larger trees. Rate of uptake is weather dependent. Invasive: wounding and compartmentalization.
Optimal Timing of Treatments Soil treatments: in spring allowing time for uptake before adults begin feeding and eggs begin to hatch. Fall treatments can also be effective. Trunk injections: in spring just after the canopy has fully developed
EAB adult emergence begins when black locust blooms. Black locust, Robinia pseudoacacia
www.oardc.ohio-state.edu/gdd Google: OSU degree-day website
Banded Ash Clearwing Borer
Banded Ash Clearwing Borer
Emamectin Benzoate Controls Banded Ash Clearwing Borer
Soil Drenches: 8 DBH Street Trees Treatment % Decline Untreated control 41 Merit 2F 5 Bayer Advanced TSIC 12 Imidacloprid + Clothianidin 14 Acelepryn, fall 37 Acelepryn, spring 52
Chief Conclusions: 1. Insecticides can control EAB on large caliper trees even under intense pest pressure. 2. Imidacloprid soil drenches are most effective on large trees when applied at the 2X (2.8 g ai / inch DBH) rate. Xytect is the only product currently labeled at this rate. 3. Soil drenches must be applied annually. 4. A single application of Emamectin Benzoate can provide three, and possibly four, years of control. 5. Emamectin benzoate also controls banded ash clearwing borer.
Bark Beetles
% Control 100 80 Imid a c lo p rid So il Dre n c h e s fo r Co n tro l o f Pi n e Ba rk Be e tl e s Ev a l u a te d J u l y 2 0 0 4 60 40 20 0 June 2003 Nov 2003 April 2004 Nov 2003 Merit 75 WP Bayer Advanced Tree and Shrub
Insecticides to not control blue stain fungi
White Pine Weevil
Soft Scales: phloem sap
Magnolia Scale
Calico Scale
% Survival Imid a c lo p rid fo r Co n tro l o f Ca l i c o Sc a l e 100 a 80 60 b 40 20 c 0 Cont rol Bayer Advanced Tree and Shrub I micide Application: 14 June Evaluation: 10 September
Calico scale nymphs on untreated control (left) and Imicide treated (below) honeylocust trees
Armored scales: Oystershell scale Pine needle scale Euonymus scale
Euonymus scale feeding sites: Intracellular (palisade, spongy mesophyll) C.S. Sadof and J.J Neal. 1993. Ann. Entomol. Soc. Am. 86:614-620 (Figs. 1-3).
Pine needle scale
% Control Al l e c tu s fo r Co n tro l o f M o l te d Pi n e Ne e d l e Sc a l e 100 80 60 40 20 0 Alect us 1% Oil Alect us + 1% oil
Boxwood Psyllid
% Control Imid a c lo p rid So il Dre n c h e s fo r Bo x wo o d Ps y l l i d 100 80 60 40 20 0 May 2001 Merit 75 WP Dec 2001 Dec 2001 Bayer Advanced Tree and Shrub Evaluated May 2002
Lace Bugs
Acephate (Lepitect) as a systemic soil treatment for spider mites
Defoliators Imidacloprid controls sawflies but not caterpillars. Bt controls caterpillars but not sawflies.
European pine sawfly
% survival European pine sawfly survival in bioassays one year post treatment (May 2001) 100 80 1 No v 1 9 9 9 1 Ap r 2 0 0 0 60 40 20 0 Cont r ol Mer it 75WP Flagship 25WG
Birch leafminer
No control of birch leafminer one year post treatment (May 2001)
Gypsy moth
Acephate (Lepitect) soil drenches controlled gypsy moth on small caliper but not large caliper trees
Japanese Beetle
Acephate (Lepitect) soil drench provided excellent control of Japanese Beetle
Soil applications for control of black vine weevil larvae
Timing: fall vs. spring? Uptake by dormant deciduous trees
Honeylocust plant bug
Insects / sample Imidac loprid soil injec tionsfor plant bug on large c aliper( honey l oc us t 24") trees 25 20 a 15 10 5 0 b Untreated 24 October Evaluated on 6 May
Length of residual activity?
Birch leafminer
No control of birch leafminer one year post treatment (May 2001)
European pine sawfly
% survival European pine sawfly survival in bioassays one year post treatment (May 2001) 100 80 1 No v 1 9 9 9 1 Ap r 2 0 0 0 60 40 20 0 Cont r ol Mer it 75WP Flagship 25WG
Length of residual activity? Residual toxicity? or Lack of recolonization?
Placement? Fine root density is highest adjacent to the trunk.
How much water to apply? Balancing the trade-off. Not enough water: poor distribution Too much water: dilutes the soil solution, which may reduce uptake rate and concentration in the plant
www.ashalert.osu.edu herms.2@osu.edu