Combining Different Control Tactics to Reduce Hydrilla Biomass

Transcription

1 Combining Different Control Tactics to Reduce Hydrilla Biomass 2014 Aquatic Weed Control Shortcourse, Coral Springs, FL, 5-8 May 2014 James Cuda, Jennifer Gillett-Kaufman, William Overholt, Karen Stratman, Raymond Hix, Eutychus Kariuki, Judy Shearer, Emma Weeks, Joan Bradshaw, Ken Gioeli, Verena-Ulrike Lietze, Elroy Timmer University of Florida, Florida A&M University, COE-ERDC, Citrus & St. Lucie Co. Extension, Aquatic Vegetation Control USDA NIFA RAMP Grant

2 Outline Background on hydrilla Options for hydrilla management Overview of Hydrilla IPM RAMP Introducing the new IPM model Current status of research Summary and resources USDA NIFA RAMP Grant

3 Outline Background on hydrilla USDA NIFA RAMP Grant

4 Hydrilla, Hydrilla verticillata Submersed, rooted aquatic plant, propagates tubers, turions, fragments Monoecious or dioecious forms Stems long and slender with some branching Leaves small (max. 4/5 inch long, 1/6 inch wide), lanceolate, in whorls of 3-8 Midrib distinct and can bear small spines

5 Worldwide Distribution of Hydrilla

6 Hydrilla Distribution (U.S.A.) Introduced in the 1950s Occurs in Florida, along southern and eastern coasts, and in California Continues to spread (top map = records 2002, bottom map = records 2011)

7 Hydrilla Genetic Studies China A 1 China B, India 1 Florida, Texas, California, 1 Louisiana, 22 China D 6 China E Africa, India, Panama, Pakistan 3 11 China C 19 China F 11 Korea, NE U.S.A 11 Australia, New Zealand 19 Indonesia 12 Taiwan China J China G 2 China I Poland 10 China H cpdna haplotypes Japan Williams et al., unpubl.

8 Why is hydrilla such a problem? Non-native plant, introduced without its natural enemies, outcompetes native vegetation Forms dense vegetation mats Resistance development to certain herbicides Withlacoochee River, FL, 1997 Lake Tohopekaliga, FL, 2008

9 Hydrilla s Impact on Wildlife Algae-Harboring Hydrilla Causing Bald Eagle Deaths in the Southeast

10 Who Cares? We Do! State and County Agencies Federal Government Anglers Residents Duck Hunters Lakefront Homeowners Boaters & Airboaters Aquatic Plant Managers Local Businesses Elected Officials USDA NIFA RAMP Grant

11 Outline Background on hydrilla Options for hydrilla management USDA NIFA RAMP Grant

12 What are the Options for Hydrilla Management? Physical control (drawdowns, barriers) Chemical control (herbicides) Mechanical removal (harvesting) Biological control (herbivores, pathogens) USDA NIFA RAMP Grant

13 Chemical Control - Advantages Applicable for both small and large areas Relatively fast action Useful for initial removal of large amounts of biomass Selectivity possible through proper choice and rate Newer products have good toxicology profiles Compatible with other control methods USDA NIFA RAMP Grant

14 Researched since the 1970s Importation BioControl Foreign exploration in Asia, Africa, and Australia Four insect species approved for release only one established persistent populations with some impact Sterile grass carp successful in closed systems Hydrellia pakistanae Hydrellia balciunasi Bagous hydrillae Bagous affinis Asian grass carp Insect images copyright USDA-ARS

15 Augmentative BioControl One insect species (native range unknown) : First record in the U.S. (Louisiana) : First record in Florida (SW, specific location unknown) : Detected in Crystal River, Florida A fungal pathogen discovered in 1970s; isolated from several U.S. hydrilla populations in 1990s Cricotopus lebetis Mycoleptodiscus terrestris

16 Hydrilla Miner Tip- mining midge - Larvae feed on living plant tissue - Rare occurrence Prevents topping out Naturalized in Florida - No swarms - Low dispersal distance - Easily mass reared Female Larva

17 Hydrilla Miner Life Cycle Egg mass Larva Pupa Female Male Cuda et al. (1999, 2002)

18 Larva and Associated Tip Damage Credit: D. Denson, RCID

19 Block 1: Control Block 1: Midge Cuda et al. (2011)

20 Lake Rowell, Bradford Co., FL September 2010

21 Outline Background on hydrilla Options for hydrilla management Overview of Hydrilla IPM RAMP USDA NIFA RAMP Grant

22 Hydrilla IPM RAMP Hydrilla Integrated Pest Management (IPM) Risk Avoidance and Mitigation Project (RAMP) USDA-funded Collaboration between research and extension experts Innovative methods for managing hydrilla in Florida freshwater bodies USDA NIFA RAMP Grant

23 Hydrilla IPM RAMP Objectives Evaluate compatibility of new hydrilla control technologies Insect, pathogen, herbicide Demonstrate a novel integrated strategy for controlling hydrilla USDA NIFA RAMP Grant

24 Hydrilla IPM RAMP Collaborators USDA NIFA RAMP Grant

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26 Educational Materials & More Campaigns with local newspapers & television stations Signs for boat ramps are being developed

27 Potential benefits Why IPM? Increased efficacy Decreased herbicide use rates & contact times Long term control Reduced reliance on herbicides alone Resistance management USDA NIFA RAMP Grant

28 Integrating BioControls & Herbicides Messersmith and Adkins Weed Technol. 9:

29 Outline Background on hydrilla Options for hydrilla management Overview of Hydrilla IPM RAMP Introducing the new IPM model USDA NIFA RAMP Grant

30 Players in the New Hydrilla IPM Model Target weed: Hydrilla verticillata (hydrilla) Herbivorous insect: Cricotopus lebetis (hydrilla tip miner) Plant-pathogenic fungus: Mycoleptodiscus terrestris (Mt) New chemical herbicide: imazamox (inhibits acetolactate synthase, ALS)

31 Expected Interactions Imazamox branching New shoot tips breeding sites for hydrilla tip miner Larvae develop within plant tissue (mining) Damage kills growing tips & increases susceptibility to infection by Mt

32 Integrating BioControl Agents with Herbicides Must confirm that herbicide does NOT negatively impact biocontrol agents Directly- Causes mortality Indirectly- Herbicide reduces plant density (= food source) below critical level Consider applying herbicides to maximize impact of biocontrol agents (tip miner & Mt) Location Timing

33 Outline Background on hydrilla Options for hydrilla management Overview of Hydrilla IPM RAMP Introducing the new IPM model Current status of research USDA NIFA RAMP Grant

34 Compatibility Studies Replicated Tank Tests Conducted in Lewisville, TX & Vicksburg, MS Miner/Mt- Jan to Feb 2013 Miner/Imazamox- Apr to Jun 2013 USDA NIFA RAMP Grant

35 Compatibility Tests Mt and Tip Miner USDA NIFA RAMP Grant

36 Courtesy of L. Nelson & J. Shearer, US ACE ERDC

37 Untreated Controls Low & High Treatments Imazamox (Herbicide) Mt (Pathogen) Tip Miner (Insect) Tank Test Methods

38 Tank Test Results

39 Compatibility Tests Tip Miner and Imazamox USDA NIFA RAMP Grant

40 Midge Adults Tank Tests- Compatibility Midge Larvae Midge Larvae + Imazamox

41 Number of hydrilla shoot tips Tip Miner and Imazamox (30 DAT) a a a b Control Tip miner Imazamox Tip miner + Imazamox Treatment

42 Compatibility Tests Mechanical Control and Tip Miner USDA NIFA RAMP Grant

43 USDA NIFA RAMP Grant Tank Tests- Compatibility

44 USDA NIFA RAMP Grant Tank Tests- Compatibility

45 USDA NIFA RAMP Grant Tank Tests- Compatibility

46 USDA NIFA RAMP Grant Tank Tests- Compatibility

47 USDA NIFA RAMP Grant Tank Tests- Compatibility

48 USDA NIFA RAMP Grant Tank Tests- Compatibility

49 USDA NIFA RAMP Grant Tank Tests- Compatibility

50 USDA NIFA RAMP Grant Tank Tests- Compatibility

51 Outline Background on hydrilla Options for hydrilla management Overview of Hydrilla IPM RAMP Introducing the new IPM model Current status of research Summary and resources USDA NIFA RAMP Grant

52 Summary Research - Laboratory compatibility studies completed Mt and tip miner (2013) Tip miner and imazamox (2013) - Mesocosm tests Tip miner and mechanical control (2014) Extension and Outreach - Field demonstration sites (2014) USDA NIFA RAMP Grant

53 Management Goals Integrate Different Control Tactics = IPM Eliminate Adverse Effects of Surface Mats Reduce Reliance on Herbicides Create More Favorable Habitat

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55 Hydrilla IPM RAMP Expected Impacts Demonstrate compatibility of different low-risk control tactics IPM=> safe, sustainable & cost-effective control of both susceptible and fluridone-resistant hydrilla Develop Hydrilla IPM Guide for Florida & other states with hydrilla problems USDA NIFA RAMP Grant

56 Resources Hydrilla IPM Risk Avoidance and Mitigation Project, Osceola County Hydrilla and Hygrophila Demonstration Project (link available) UF/IFAS Center for Aquatic and Invasive Plants (link available) Featured Creatures of the UF/IFAS Entomology and Nematology Department (link available) Cooperative Extension System (extension) USDA NIFA RAMP Grant

57 Food for Thought * Are we as a weed science discipline choosing to ignore true integrated solutions to the herbicide resistance problem? More research on herbicide alternatives is required. Combinations of a diversity of tactics in [ IPM ] systems augment herbicide-based weed control... and lengthen the useful life of valuable herbicide tools. *Harker et al Our view. Editorial, Weed Sci. 60: 143.

58 USDA NIFA RAMP Grant Thanx!