Hunger Games: Enemies, Arenas and Fighting to the Death!!

Whitney Yeary, Amy Fulcher and Bill Klingeman University of Tennessee

Winning the Hunger Games

Arena!

Image credit: http://www.landscape-design-advisor.com/design-styles/english-country/cottage-garden

Introduction

• Insect pests cause economically significant damage to nursery crops

• In NC, the green industry reported annual losses of $91,000,000 due to insects and diseases

NCDA. 2005. North Carolina green industry economic impact survey. Photo credit Bambara and Baker - via Bugwood

Introduction

• Insecticides can be useful in managing pest problems.

• Insecticides can: – Harm natural enemies– Exacerbate secondary

pest populations

Cloyd, R. 2009. Pesticide use in ornamental plants: what are the benefits? Pest Management Science. 65:345-350

x

Data & Image Credit: Frank, S. and C. Sadof. J. Econ. Entomol. 104(6): 1960‹1968 (2011); DOI: http://dx.doi.org/10.1603/EC11124

• 50% more natural enemies and 50% fewer spider mites with spray wand than airblast sprayer

Introduction

• Imidacloprid caused outbreaks of an obscure spider mite on elm trees in NYC

Szczepaniec, A., S. F. Creary, K. L. Laskowski, J. P. Nyrop, and M. J. Raupp. 2011. Neonicotinoid insecticide imidacloprid causes outbreaks of spider mites on elm trees in urban landscapes. PLoS ONE 6(5): e20018. doi:10.1371/journal.pone.0020018.

Introduction

• Lab expts, predators of T. schoenei were poisoned through ingestion of prey exposed to imidacloprid

Szczepaniec, A., S. F. Creary, K. L. Laskowski, J. P. Nyrop, and M. J. Raupp. 2011. Neonicotinoid insecticide imidacloprid causes outbreaks of spider mites on elm trees in urban landscapes. PLoS ONE 6(5): e20018. doi:10.1371/journal.pone.0020018.

Introduction

• Imidacloprid’s tendency to elevate reproduction of T. schoenei also contributed to their elevated densities on treated elms

Szczepaniec, A., S. F. Creary, K. L. Laskowski, J. P. Nyrop, and M. J. Raupp. 2011. Neonicotinoid insecticide imidacloprid causes outbreaks of spider mites on elm trees in urban landscapes. PLoS ONE 6(5): e20018. doi:10.1371/journal.pone.0020018.

Introduction

• 3 cover sprays/year for 4+ years had greater scale species diversity and more likely to be scale infested than shorter treatment

Raupp et al.: Effects of Cover Sprays and Residual Pesticides. Journal of Arboriculture 27(4): July 2001

Introduction

Introduction

• Insecticides can negatively affect natural enemies

• Growers tell us scale pests are a relevant problem in the nursery trade– More than previously??

Adkins, C., G. Armel, M. Chappell, J.C. Chong, S. Frank, A. Fulcher, F. Hale, K. Ivors, W. Klingeman III, A. LeBude, J. Neal, A. Senesac, S. White, A. Windham. 2010. Pest Management Strategic Plan for Container and Field-Produced Nursery Crops in GA, KY, NC, SC, TN. A. Fulcher, ed. Southern Region IPM Center.

Objectives

• Investigate the effects of systemic & contact insecticides on natural enemies to direct contact with insecticide residue – a worst-case exposure scenario

• Determine if systemic insecticides offer a more sustainable insecticide choice

Materials and Methods

• Marathon II, Safari, Sevin, Talstar, water• Sprayed on tuliptree• Conducted two experiments:– Lab– Field

Lab Materials and Methods• 3 leaves from each tree• 10 insects /arena, CHO supply– Minute Pirate Bug, Lady beetle, and Lacewing

• 8 replicate arena/trt• Assessed survival

every 24 h for 4 d• Removed dead daily

Lab Materials and Methods

Field Materials and Methods

• Attached three arenas to each tree (one species per arena) – Lady beetle, Minute

Pirate Bug, Aphidius

Field Materials and Methods

• Installed pitfall trap at base of each tree

• Every 48 h– Assessed survival– Replaced 10 new

insects

Lacewing, Minute Pirate Bug, Lady Beetle

Lady beetle

Minute Pirate Bug

Lacewing

Experiment ScheduleSunday Monday Tuesday Wednesd

ayThursday Friday Saturday

28Spray, cages

29 30

1 2 3 4 5 7

8 9 10 11 12 13 14

15 16 17 18 19 20 21

22 23 24 25 26 27 28

Survival %

29

Survival %

1 2

Survival %

Survival %

6

Results Lab

Lacewing Survival 48 h after Applications

Insecticide 2011 2012 Marathon II 45 b 64 a Safari 48 b 74 a Talstar 88 a 54 a Sevin 25 b 15 b Control 100 a 83 a p-value <0.0001

Lady Beetle Survival 48 h after Applications

Minute Pirate Bug Survival 48 h after Applications

Insecticide 2011 2012 Marathon II 9 c 26 b Safari 3 c 25 b Talstar 0 c 0 c Sevin 38 b 20 bc Control 71 a 71 a p-value <0.0001

Lacewing Survival 96 h after Applications

Insecticide 2011 2012 Marathon II 25 bc 43 ab Safari 35 bc 61 a Talstar 64 ab 24 bc Sevin 21 c 6 c Control 83 a 59 a p-value <0.0001

Lady Beetle Survival 96 h after Applications

Insecticide 2011 2012 Marathon II 21 b 44 abc Safari 62 a 65 a Talstar 26 b 40 bc Sevin 1 b 31 c Control 80 a 61 ab p-value <0.0001

Minute Pirate Bug Survival 96 h after Applications

Conclusions

• Limited study• Worst case scenario• Insecticide effect on beneficial insect varies with

insect species, pesticide, and times after application

• Sevin and Talstar appear to be most toxic• Minute Pirate Bug most affected• Safari appears to have the least negative effect

Implications on Pest Mgt

• Augmentative Biological Control• Where to release• Plant density influence natural enemy survival

19 1135

75

Implications on Pest Mgt

Hydrangea Spray Penetration

• Dense canopy– Droplet density was reduced from 56 deposits/cm2

on the exterior position to 2 deposits/cm2 on the middle and interior positions• 96% loss

Hydrangea Spray Penetration

• Sparse canopy– Received 463% more coverage in the middle of

the canopy than the dense plants • Regardless of density, the interior received

less than 1% coverage!

Beneficial Insect Survival

• Only the interior and middle positions of dense plants protected greater than 50% of the lady beetles

• Only the interior position of dense plants protected greater than 50% of lacewings over the course of the experiment

• If not lethal to natural enemies perhaps not lethal to pest insects!

Intelligent Spray Systems

• Automatic controllers– Computer program– Signal generation and

amplification unit– Pulse width modulated

solenoid valves– AlgorithmUltrasonic sensor

Laser sensor

Hydraulic Boom Sprayer

Test Drive

• Compared to the constant application rate of 50 gpa– the intelligent sprayer reduced the application rate

by • 70% in April• 66% in May • 52% in June

Powdery Mildew Control

• Powdery mildew rating– Not different conventional versus intelligent

sprayers.– Not different based on interior or outer row

Thank you!

• Funded by • Center for Applied Nursery Research• Tennessee Institute of Agriculture• Phil Flanagan, S. Evan Wilson, Casey Sullivan,

Ann Reed, Xiaocun Sun