Quarterly Progress Report: Fourth Quarter FY 2008
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Grant ID: X7-96433105-1 (Hydrilla/ Hygrophila Demonstration Projects - Osceola County, FL)
Project description and Goals:
This project is a combination of studies that will result in improved water quality and natural habitat in Osceola County lakes. Hydrilla and Hygrophila are exotic invasive weeds that are dominating the lakes aquatic ecosystem, shading out natural vegetation, reducing oxygen level, increasing the amount of sediments, and impacting flood control in lakes and canals. The project objectives are to evaluate the effectiveness of Experimental Use Permit herbicides, biological controls and application methods of herbicides in the treatment and control of Hydrilla and Hygrophila using small-scale fieldwork, large-scale field demonstrations and public outreach on the progress and findings.
Participants: Hilda Hatzell, EPA Project Officer, Region 4
Eleanor Foerste, Project Manager, Osceola County
Reporting period: Fourth Quarter, EPA Fiscal Year 2008 July 1 - September 30, 2008
Project activities during reporting period:
What work was accomplished for this reporting quarter?
Element 1
Continued monitoring:
- Stewart Rd pond with FL EUP number FL08-EUP-01 at a rate of 50ppb.
- Granada Blvd pond was treated with FL EUP number FL08-EUP-02 at a rate of 400ppb.
- Oak Tree Pond was treated with FL EUP number FL08-EUP-02 at a rate of 400ppb.
Begin monitoring:
- BVL pond treatments with Clearcast (imazamox) and Galleon (penoxulam).
Element 2
- Continued collecting long-term field efficacy data from large-scale hydrilla treatments conducted in the Fall of 2007 and the Spring of 2008 on Lakes Tohopekaliga and Lake Cypress.
- Established 48 sample grids (2 x 2 m) on Lake Tohopekaliga to determine the impact of herbicide treatments on the distribution of the native submersed plant vallisneria and the invasive plant hydrilla.
- Sampled sediments to determine hydrilla tuber populations in 24 sites throughout Lake Tohopekaliga.
- Screened combinations of endothall and diquat on hygrophila in mesocosm studies at University of Florida Center for Aquatic and Invasive Plants (UF CAIP) to determine the most effective ratio for control of this plant.
- Initiated mesocosm studies at the UF CAIP to evaluate the comparative impact of endothall on two ecotypes of vallisneria.
Element 3 Task 1
- Conduct mesocosm studies to evaluate:
- change in hydrilla net photosynthesis in early stages of Mycoleptodiscus terrestris (Mt ) infection
- temperature-dependent changes in Mt microsclerotia germination, spore production and fungal growth related to biocontrol performance
Element 3 Task 2
- Foreign exploration for natural enemies on Hygrophila spp. (a defoliating caterpillar and rust fungal pathogen)
- Study effect of simulated herbivory on growth and biomass of hygrophila
Element 3 Task 3
- Exploration for insect herbivores of hydrilla continuing in Burundi and Uganda
- Efforts to colonize Polypedilum wittei and/or Polypedilum dewulfi underway in Burundi
- Exclusion study initiated in Uganda to test the hypothesis that herbivorous fish control hydrilla
Element 4
- Completed Quarterly and Budget Reports for Third Quarter 2007/08.
- Conducted July 1, 2008 Hydrilla Field Day with 84 participants.
- Planned, and conducted teacher training, CSI-Osceola regarding invasive aquatic and upland plant identification and management with Center for Aquatic and Invasive Plants (CAIP) staff July 28-31, 2008. Fourteen (14) teachers attended.
- Advertised and recruited to fill Extension Agent Aquatics position vacancy which will be filled 10/27/2008 with Stacia Hetrick as new faculty in Osceola County.
- All element coordinators have presented posters, exhibits and/or professional papers this reporting period.
- Significant Findings this Quarter?
- Mt dry materials are stable for as long as 18 months under refrigerated storage.
- Two natural enemies of hygrophila were discovered in Assam, India- a defoliating caterpillar and a rust fungus.
- Fish herbivory was confirmed in four (4) cichlid species.
- Is the project work on schedule?
- This quarter?
Yes, with some delays in Element 3 Task 1, and Element 4 Task 4. Element 3 Task 1 is behind schedule in terms of decision to scale-up and test Mt bioherbicide at larger field scales. However, a significant new production process for Mt continues to be investigated, and a commercial scale-up of production is now targeted for winter 2008. Element 4 Task 4 was delayed due to the extended extension faculty vacancy but will be completed in FY 2009.
- For the project? Yes
- Does the new schedule require a time extension? A time extension is not necessary at this time.
- Is there a change in the Grantee’s Authorized Representative or any of the key contacts?
Element 1 and 2: Jeremy Slade will be assisting Dr. Michael Netherland and work in Element 1 and 2.
Jeremy Slade, Senior Biological Scientist
Center for Aquatic and Invasive Plants
7922 NW 71st Street
Gainesville, FL 32653
352-392-9981
352-392-3462 fax
Email jgslade@ufl.edu
Element 4: Stacia Hetrick will replace Dr. Tina Bond as Element 4 coordinator and will be employed by UF/IFAS Osceola County Extension effective 10/27/2008.
Stacia Hetrick, Faculty-Aquatics
UF/IFAS Osceola County Extension
1921 Kissimmee Valley Lane
Kissimmee, FL 34744
321-697-3000
321-697-3010 fax
Email shet@osceola.org
- Project spending for reporting period:
$31,223.07 was expended this quarter, with total project costs at 9/30/2008 $1,126,633.54. Project balance is $ 2,881,000 - 1,126,633.54= $1,754,366.46.
Reporting period: Fourth Quarter, EPA Fiscal Year 2008
July 1-September 30, 2008
Person Reporting: Sarah T. Berger, Senior Biologist
Dr. William T. Haller, University of Florida
Element 1: Development and Testing of New Aquatic Herbicide
Project activities during reporting period:
What work was accomplished for this reporting quarter?
The following activities were undertaken from July 1 – September 30, 2008 in Osceola County, Florida:
1. The storm-water pond located at the corner of Stewart Rd and Pleasant Hill Rd was treated during the last reporting period on April 30, 2008 with FL EUP number FL08-EUP-01 at a rate of 50ppb. Plant heights were measured on a bi-weekly basis and this continued through the current quarter. The trend is shown below.
2. The storm-water pond located at the corner of Granada Blvd and Pleasant Hill Rd was treated on June 9, 2008 with FL EUP number FL08-EUP-02 at a rate of 400ppb. Plant heights were measured on a bi-weekly basis and this continued through the current quarter. The data is shown below.
3. The storm-water pond located across from Pleasant Hill Estates on the east side of Pleasant Hill Rd (referred to as “Oak Tree Pond”) was treated on June 9, 2008 with FL EUP number FL08-EUP-02 at a rate of 400ppb. Plant heights were measured on a bi-weekly basis and this continued through the current quarter. The data is shown below.
4. Rainfall Data for the quarter is listed in the following table by week.
5. Four ponds (#1,2,3, & 40) in the Buena Ventura (BVL) subdivision were treated by Applied Aquatics under contract with and the direction of Osceola County. Various rates and combinations of two new labeled products for aquatic use (Clearcast – imazamox and Galleon- penoxsulam) were applied and hydrilla plant heights were monitored during the fourth quarter of this reporting year.
The Hydrilla plant height mean is listed for each pond in the following table.
6. An educational poster highlighting current research activities on Lake Tohopekaliga and local ponds on Pleasant Hill Road was presented at the July1 , 2008 Hydrilla Field Day.
- What Milestones have been met for your Element?
Two aquatic herbicides, Galleon (penoxsulam) by SePRO and Clearcast (imazamox) by BASF have been fully labeled during the grant program.
- Were there any significant problems encountered?
There were no significant problems encountered this quarter.
- Is the project work on schedule?
- This quarter? Yes
- For the project? Yes
- Are there any significant findings this quarter? NA
- What is the future direction of the work? Continue EUP research in ponds in Osceola County.
- Is there a change in the key contacts for this element? No
Reporting period: Fourth Quarter, EPA Fiscal Year 2008
July 1 – September 30, 2008
Person Reporting: Michael D. Netherland
Element 2: Evaluation of Currently Registered Herbicides for Control of Hydrilla
Project activities during reporting period:
- What work was accomplished for this reporting quarter?
Management activities for large-scale hydrilla control are typically curtailed during the summer months. Therefore, most activities during the current reporting period were conducted to evaluate data collected in the field during the previous quarters, to prepare for upcoming treatments in the first quarter of 2009, or to continue efficacy and selectivity evaluations of treatments conducted during earlier reporting quarters.
- Continued collecting long-term field efficacy data from large-scale hydrilla treatments conducted in the Fall of 2007 and the Spring of 2008 on Lakes Tohopekaliga and Lake Cypress. Data was collected along several transects within each treatment plot using a recording fathometer. Data collected from these transects is currently being analyzed.
- Prepared a poster summarizing activities conducted under Element II of this grant and discussed this information with participants in a field day at Lake Tohopekaliga, July 1, 2008. Also served as a technical guide on field tours that allowed people to go out on Lake Tohopekaliga and see some of the treatment areas. I also presented information generated from this project at the Texas Aquatic Plant Management Society and the Northeast Weed Science Society Short Course in September 2008.
- Participated in several meetings and conference calls with US Fish and Wildlife Service, Florida Fish and Wildlife Commission, and South Florida Water Management District personnel related to preparing draft guidelines for Hydrilla Control and Aquatic Plant Control Best Management Practices for protection of habitat and foraging grounds for the federally endangered snail kite.
- Prepared a presentation for the upcoming Florida Aquatic Plant Management Society meetings (Oct 13-16) using data collected from this project. The talk will focus on control of hydrilla using different treatment strategies with endothall.
- What work was accomplished for this reporting quarter?
- Established 48 sample grids (2 x 2 m) on Lake Tohopekaliga to determine the impact of herbicide treatments on the distribution of the native submersed plant vallisneria and the invasive plant hydrilla. Grids were established with 3 different plant densities, 90% hydrilla and 10% vallisneria, 50% hydrilla and 50% vallisneria, and 10% hydrilla and 90% vallisneria. Initial plant coverage and biomass data was collected. These sample grids will be monitored over the next year and data will be used to provide improved recommendations for use of endothall when both hydrilla and vallisneria are present.
- Sampled sediments to determine hydrilla tuber populations in 24 sites throughout Lake Tohopekaliga. Of these sites, 14 represent longer stations that have been sampled during the past 3 years, and 10 represent new sample sites located mainly on the south end of the lake. Sampling was initiated prior to the onset of new tuber formation, and the relative increase/decrease of tuber populations will be monitored in both managed and unmanaged sites of the lake.
- Screened combinations of endothall and diquat on hygrophila to determine the most effective ratio for control of this plant. These screens were conducted on mature and well-established plants in a mesocosm facility at the University of Florida Center for Aquatic and Invasive Plants. We exposed these plants for 12 and 24 hours to diquat alone, endothall alone, and 4 combinations of these products. While all of the treatments provided strong initial injury symptoms (defoliation of upper leaves) and some level of biomass reduction at 6 weeks post-treatment, none prevented rapid recovery of the plants. Given these results, we are reluctant to provide field recommendations in areas where rapid water exchange is likely to occur. Unfortunately, in Osceola County, the vast majority of areas containing hygrophila are higher flow areas such as creeks. We have struggled to find an appropriate field site for evaluating hygrophila control in Osceola County. Our strategy has been to tie in with operational control efforts, and to date there has been limited emphasis on controlling hygrophila.
- Initiated mesocosm studies at the University of Florida Center for Aquatic and Invasive Plants to evaluate the comparative impact of endothall on two ecotypes of vallisneria. Vallisneria has made a strong comeback in many areas of the Kissimmee Chain of Lakes. This increase in native plant abundance is seen as a positive for overall lake health, and therefore, we need to insure that the choice and timing of hydrilla management activities have limited impact on this plant. There have been some anecdotal observations that hydrilla control efforts may impact the two ecotypes in a different manner. Studies were initiated in August (warm water) and will be repeated in late October (cool water).
- What Milestones have been met for your Element?
- An article entitled “Response of Hydrilla to Various Field Concentration and Exposure Time Scenarios with the Herbicide Endothall” is in preparation and will be sent out for internal review early in the next quarter.
- Experimental field evaluations of diquat and endothall combinations for hydrilla control have been completed. Based on the information collected to date, we are coming up with a set of guidelines for recommending this treatment combination at an operational scale in Osceola County water bodies. We may continue to monitor some of these operational treatments depending on scale or timing.
- We have evaluated numerous large block and shallow water treatments of hydrilla with endothall. We have evaluated different timing, use rates, and water depths. While we plan to continue monitoring of these treatments, we have been meeting these evaluation milestones for each quarter.
- Were there any significant problems encountered?
There were no significant problems encountered this quarter.
- Is the project work on schedule?
- This quarter?
An operational endothall drip application planned for Lake Tohopekaliga was pushed from this quarter to the 1st quarter of 2009.
- For the project?
The work is generally on schedule with some projects slightly ahead and some projects slightly behind schedule. Moreover some issues, such as selectivity versus vallisneria, have taken a greater priority as this project has moved forward.
- If the project is not on schedule, what is proposed for a revised schedule? NA
- Does the new schedule require a time extension? NA
- Are there any significant findings this quarter? NA
- What is the future direction of the work?
Large-scale littoral zone and open-water endothall treatments are planned for the upcoming 2 quarters. We will put more emphasis on monitoring residues and water quality changes as well as efficacy and selectivity (vallisneria) following these treatments. In addition, experimental treatments that include combinations of the recently registered product penoxsulam with endothall will be evaluated to determine the potential advantages of mixing an ALS herbicide with endothall for hydrilla control. Issues with the federally endangered snail kites will likely require more time in planning and getting key stakeholder agreement for conducting large-scale management of hydrilla in Osceola County. The time spent on this issue is relevant to both currently registered (Element II) and new herbicides (Element I). The current discussions are related to treatment timing and location in relation to snail kite nesting and foraging areas.
- Is there a change in the key contacts for this element?
Jeremy Slade, Senior Biological Scientist
Center for Aquatic and Invasive Plants
7922 NW 71st Street
Gainesville, FL 32653
352-392-9981
352-392-3462 fax
Email jgslade@ufl.edu
The UF Center for Aquatic and Invasive Plants recently hired Mr. Jeremy Slade to assist with evaluating statewide hydrilla control activities. Jeremy has a Master of Science Degree from Mississippi State University and has worked as a contract research scientist evaluating herbicides for aquatic plant control for the US Army Engineer Research and Development Center the past 3 years. As part of his statewide responsibilities, Mr. Slade will assist in conducting hydrilla control evaluations in Osceola County and he should be added to the key personnel list. It is likely the bulk of his work will be conducted under Elements I and II.
Reporting period: Fourth Quarter, EPA Fiscal Year 2008
July 1 – September 30, 2008
Person Reporting: Mark A. Heilman
Element 3 Task 1 Demonstration of Hydrilla Control in Osceola County, Florida using Mycoleptodiscus terrestris (Mt), a new contact bioherbicide, for Aquatic Plant management
Project activities during reporting period:
What work was accomplished for this reporting quarter?
1. Laboratory Evaluations of Mt Formulations and Methods
Laboratory studies focused on two questions in the last quarter:
- Does change in hydrilla net photosynthesis in early stages of Mt infection correlate well with control achieved in mesocosm screening studies?
- Do temperature-dependent changes in Mt microsclerotia germination, spore production and fungal growth have impact on biocontrol performance?
For the first question, 15 different Mt materials were evaluated in an aquarium mesocosm study. Due to space limitations, this study was conducted with an unreplicated design. The study showed mixed results but demonstrated rate-dependent reductions in hydrilla biomass for most materials (Figure 1). The results of this study were compared to analysis of hydrilla net photosynthesis (see 2. Collaborative Research with NCSU). For question 2 on temperature dependence, a laboratory aquarium study is underway looking at water temperature effects on Mt virulence at three different water temperatures (20, 26, 32C). Water temperature in aquariums is being maintained with a custom heating/cooling ‘bath’ system (Figure 2). A preliminary study was initiated to determine Mt performance under static conditions required by the design of the temperature control system. Most aquarium studies are provided slight aeration for improved hydrilla growth. Four different materials were studied with the primary goal of selecting the best performer under static conditions for the temperature study. The study had the secondary goal of quantifying the storage stability of the various Mt materials tested, which had been stored between 14 – 18 months since production in 2007.
Figure 3. Controlled temperature system for Mt aquarium studies.
The results of the initial study to select product for temperature study indicated that all 4 stored materials showed similar virulence on hydrilla (Figure 3), but static test conditions did appear to reduce activity versus aerated trials. Material “C” was selected for the definitive temperature study, and results of that study will be reported next quarter.
2. Collaborative Research with NC State
In combination with screening of new materials, collaborative work with NC State has started further investigation of the relationship between early changes in photosynthetic capacity and correlations to percent control in aquarium test conditions. A bench-scale study was set up by SePRO and NCSU staff using small 0.5 L containers with hydrilla apical tips grown out in a Percival growth chamber (Figure 4). The tips were treated with various rates of dry and liquid Mt culture generally equivalent in activity based on previous tests to those utilized for concurrent aquarium study (Figure 1). Treated hydrilla tips were then evaluated at 3 days post treatment for net photosynthetic capacity by placing treated tips in BOD bottles, incubating for one hour, and measuring dissolved oxygen changes with DO meter. Fresh weight of incubated tissue was measured to calculate oxygen change relative to quantity of incubated hydrilla tissue. Due to design constraints across many Mt materials and rates, this study was conducted with an unreplicated design. Most treatments produced anticipated reductions in dissolved oxygen production by Mt-treated hydrilla tissue versus untreated controls, but rate dependent responses were not always consistent (Figure 5). When compared directly to aquarium study, there was no correlation between net photosynthesis in lab study and hydrilla biomass measured in aquarium study (Figure 6). Further work is necessary to better define this relationship for more efficient Mt material evaluations.
Figure 5. Setup of laboratory study examining Mt effects on net photosynthesis.
Figure 6. Net photosynthesis of apical hydrilla tips treated with various rates/formulations of Mt in laboratory growth chamber study.
Figure 7. Plot of changes in oxygen production/consumption by apical hydrilla tips treated with Mt in lab screening study versus harvested fresh weight of hydrilla treated with Mt at similar rates of activity in concurrent aquarium study. No relationship between these variables was detected (Spearman Rank Order Correlation test; p=0.184).
3. Pilot-scale commercial production
There remains no definitive date for scale-up of Mt production due to continued questions on commercial cost feasibility for current Mt process. At this point, in large part through field evaluations conducted as part of the current grant, the performance of the original liquid fermentation process for Mt bioherbicide has been deemed insufficient and not cost effective. Barring any unanticipated developments, we will be transitioning away from this process during the next few months. An entirely new Mt production process is under investigation, and will be considered for scale-up as merited by performance characteristics defined starting during the upcoming quarter. Two commercial sources have been contacted again by USDA as potential sources for scale-up production of this process and discussions have started to determine a potential path forward. At this point, full-scale up using the alternate process is projected for the late winter or early spring. Smaller test batches will be evaluated through replicated laboratory studies in the coming quarter.
4. Outdoor testing of best formulations
No outdoor testing of Mt materials was performed during this reporting quarter.
5. Small-scale field demonstrations in Osceola County
No Mt field demos were conducted during this reporting quarter. As described in recent project updates, this hiatus was scheduled due to concern that high water temperatures and other mid-late summer environmental factors in small, topped-out test ponds were not conducive for effective biocontrol demonstration.
6. Hydrilla Field Day
SePRO participated in the July 1, 2008 Hydrilla Field Day, providing an interactive display relating to Mt and current research under this element.
- What Milestones have been met for your Element?
Laboratory-scale testing of Mt materials continues, and NCSU staff are actively collaborating on this component of the project. These evaluations should further refine temperature requirements for effective bioherbicide use. Field demonstrations of Mt in Osceola County were put on hold for this reporting quarter due to unfavorable environmental conditions in test ponds.
- Were there any significant problems encountered?
As has been described above, the original production process for bioherbicide has been determined by field trials to provide insufficient efficacy relative to cost of production to pursue production scale-up for expanded scope of field evaluation. An alternate production method is being investigated, and preliminary results from these investigations should be reported in the coming quarter.
- Is the project work on schedule?
- This quarter?
For this quarter, we shifted emphasis to internal lab studies on physiological questions, and evaluation of alternate production approach is pending..
- For the project?
The project remains behind schedule in terms of decision to scale-up and test Mt bioherbicide at larger field scales. However, a significant new production process for Mt continues to be investigated, and a commercial scale-up of production is now targeted for winter 2008.
- If the project is not on schedule, what is proposed for a revised schedule?
Field demonstrations of Mt bioherbicide using an alternate Mt production approach should be able to be conducted during the second quarter of this funding cycle. Laboratory evaluation of new test batches will be initiated during the upcoming first quarter.
- Does the new schedule require a time extension?
At this time, no formal request for time extension will be made. However, progress towards full operational-scale Mt demonstration has been slowed by insufficient performance of the bioherbicide under smaller-scale test conditions. We will keep the County informed of progress on new production methods and what that means for FY09 field demonstrations.
- Are there any significant findings this quarter?
Mt dry materials are stable for as long as 18 months under refrigerated storage.
- What is the future direction of the work?
Mt evaluation at laboratory scales is planned for the coming quarter but final schedule for further field development will be dependent upon overall developmental progress. We will continue to search for additional pond study sites to expand quantity available for future field demonstration.
- Is there a change in the key contacts for this element? No.
Reporting period: Fourth Quarter, EPA Fiscal Year 2008
July 1 – September 30, 2008
Person Reporting: James P. Cuda
Element 3, Task 2: Foreign Exploration for Natural Enemies of Hygrophila
Project activities during reporting period:
- Foreign exploration for natural enemies on Hygrophila spp. (a defoliating caterpillar and rust fungal pathogen)
- Study effect of simulated herbivory on growth and biomass of hygrophila
- Exhibit at July 1, 2008 Hydrilla field day
- What work was accomplished for this reporting quarter?
Activity 1 Milestone: Foreign exploration for natural enemies on Hygrophila spp.
Field surveys for natural enemies of hygrophila are in progress in the state of Assam situated in northeastern India. The surveys, which were initiated on 13 September, have produced several natural enemies of hygrophila. An unkown caterpillar (Fig. 1) was discovered near a small village (Maj Baghmaro) causing severe defoliation of the plants in a roadside ditch in the Tezpur region of Assam. Samples of the insect were collected; some of the larvae were preserved and some were held to obtain adults for species identification and/or description.
A rust fungus (Fig. 1) infecting the leaves of hygrophila was found at another site (Betbari). The rust looks promising as a biological control agent because this group of fungi is often highly host specific.
Activity 2 Milestone: Domestic survey to identify insects associated with hygrophila
No activity to report in this quarter
Activity 3 Milestone: Genetic analysis of Hygrophila polysperma using microsatellite primers
Samples of hygrophila plants are being collected from the Assam, India survey site for DNA analysis.Activity 4 Milestone: Effect of simulated herbivory on growth and biomass of hygrophila
The invasive characteristics exhibited by hygrophila are consistent with that of the ‘enemy escape hypothesis’ thus making classical biological control an appealing option. The objective of a ‘simulated herbivory’experiment conducted during this reporting period was to determine the effects of an insect defoliator on hygrophila growth and biomass development. A mesocosm experiment was conducted using a Randomized Complete Block Design with 7 treatments. The treatments, which consisted of manual defoliations of plants, comprised 3 defoliation levels (0%, 50% & 100%) with 3 frequencies (defoliation once, twice or at weekly intervals). In total, 20 plastic pots (7 cm x 7cm x 6 cm), with a mixture of sand and soil (3:2) containing hygrophila sprigs, were randomly assigned to each treatment. Leaves were cut widthwise from the middle and from their bases with a sterile scissors to achieve 50% and 100% defoliation, respectively. To simulate field conditions, this replicated experiment was conducted in 3 concrete vaults (approx. 900 L capacity) at Biven’s Arm Research Center, University of Florida. Hygrophila plants were kept completely submerged and the water in the tanks was changed 3 times a week. The entire experiment lasted 8 weeks. Plant growth characteristics, e.g., plant height and number of sprigs per pot were recorded at weekly intervals. Initial (using a separate set of control plants) and final dry weight of the plants also was recorded. Results were analyzed by the PROC GLM procedure, SAS® statistical package (SAS institute) to compare the effects of treatments on final growth characteristics at 5% level of significance. Our preliminary findings showed there were significant differences in the growth of hygrophila among treatments (Fig. 2). We expect that this experiment will elucidate the level of herbivory required to significantly reduce the growth of this invasive weed, and aid us in prioritizing insect biological control agents for this invasive aquatic weed.
Figure 8. Two natural enemies shown attacking hygrophila in the state of Assam, India, September 2008. Defoliating caterpillar (left) and leaves of hygrophila infected with a rust fungus.
Figure 9. Effect of manual defoliations on growth of hygrophila. Plant height (top) and biomass were significantly reduced when plants were defoliated twice and weekly at both defoliation levels.
- Were there any significant problems encountered? No
- Is the project work on schedule? Yes
- Are there any significant findings this quarter?
The discovery of at least two natural enemies of hygrophila in Assam, India- a defoliating caterpillar and a rust fungus.
- What is the future direction of the work?
Obtain positive identifications of the caterpillar and rust fungus. Conduct preliminary screening tests, especially field surveys of non-target plants, to determine if these two natural enemies are likely to be host specific.
- Is there a change in the key contacts for this element? No
- Exhibit at July 1, 2008 Hydrilla Field Day
- Exploration for insect herbivores of hydrilla continuing in Burundi and Uganda
- Efforts to colonize Polypedilum wittei and/or Polypedilum dewulfi underway in Burundi
- Exclusion study initiated in Uganda to test the hypothesis that herbivorous fish control hydrilla
- What work was accomplished for this reporting quarter?
- What Milestones have been met for your Element?
- Were there any significant problems encountered? NO
- Is the project work on schedule?
- This quarter? YES
- For the project? YES
- Are there any significant findings this quarter?
- What is the future direction of the work?
- What work was accomplished for this reporting quarter?
- Completed Quarterly and Budget Reports for Third Quarter 2007/08.
- Conducted July 1, 2008 Hydrilla Field Day with 84 attendees.
- Planned and conducted teacher training, CSI-Osceola regarding invasive plant identification and management with Center for Aquatic and Invasive Plants (CAIP) staff July 28-31, 2008. Fourteen (14) teachers attended.
- Advertised and recruited to fill Extension Agent Aquatics position vacancy which will be filled 10/27/2008 with Stacia Hetrick as new faculty in Osceola County.
- What problems, if any, were encountered?
- If a problem was encountered, what action was taken to correct it?
- Is the project work on schedule?
- This quarter? Yes, except for the kiosk display portion.
- For the project? Yes.
- If the project is not on schedule, what is proposed for a revised schedule?
- Does the new schedule require a time extension? No.
- Is there a change in the key contacts for this element? Yes.
- The CAIP participated in the Demonstration Project on Hydrilla and Hygrophila in the Upper Kissimmee Chain of Lakes on July 1st at the Kissimmee Lakefront Park Pavilion. A display booth was staffed for the duration of the event and educational materials were distributed to attendees.
- Each Element Coordinator was responsible for an educational poster/exhibit about their part of the project. (See Task 7 for titles.) In addition, 5 other displays were included on invasive aquatic plant identification, pesticides, nutrient runoff reduction and snail kite issues. Exhibits were prepared by Florida Department of Environmental Protection Bureau of Invasive Plant Management (FDEP-BIPM), Osceola County Stormwater, Osceola County Parks and Lake Management, US Fish and Wildlife Service, and UF Cooperative Fish and Wildlife Research Unit. There was much support from South Florida Water Management District as well as the Florida Fish and Wildlife Conservation Commission, with FWC providing use of their airboat and captain Bruce Jaggers. Dr. Mike Netherland and Ed Harris of FDEP served as guides for the lake tours. Eighty four (84) elected officials, media, agency personnel and stakeholders were present and got to view exhibits, ask questions and tour research plots and hydrilla infestations on Lake Tohopekaliga.
- Monday, July 28th, 2008 Aquatic Plant Field Trip -
- Tuesday, July 29th, 2008 Do We Need to Manage Invasive Plants?
- Wednesday, July 30th, 2008 Develop Curricula
- Thursday, July 31st, 2008 Develop Curricula
Reporting period: Fourth Quarter, EPA Fiscal Year 2008
July 1 – September 30, 2008
Person Reporting: Bill Overholt
Element 3 Task 3: Collaborative effort to search for natural enemies of hydrilla in East Africa (Project Ongoing)
Project activities during reporting period:
Exploration for insect herbivores of hydrilla in Burundi and Uganda: We continue to collect hydrilla from water bodies in Uganda and Burundi and rear out the insects in/on the plants. In Lake Tanganyika in Burundi, we have now reared 9,340 adult chironomid midges from hydrilla, representing 21 species. Of these, ~ 75% are Dicrotendipes fusconotatus, a species which is considered to be a scraper feeding on algae and other organic matter in the water. The two Polypedilum species that were earlier reported to mine hydrilla tips, P. wittei and P. dewulfi, accounted for only 0.2 and 2.2% of the collection. In addition to the mass rearing of insect from hydrilla, 449 hydrilla tips have been inspected under a microscope, from which 837 larvae were found. A sub-sample of 462 of these larvae were identified, of which ~75% were D. fusconotatus, 9% Cricotopus sp. and 8% P. dewulfi. The P. dewulfi found were not clearly mining in the tips, as had been previously reported. Thus, the putatively herbivorous Polypedilum spp., are not common, and to date we do not have evidence that they are herbivorous. It would seem unlikely that the Polypedilum spp. are responsible for maintaining hydrilla at low densities in Africa. In Uganda, the results are similar, although the two Polypedilum spp. appear to be even less common than in Lake Tanganyika. We have also dissected ~ 600 hydrilla tips in Uganda and have not found clear evidence of herbivory.
Colonization of Polypedilum wittei and/or Polypedilum dewulfi in Burundi: Efforts are underway to establish laboratory colonies of P. wittei and/or P. dewulfi in Burundi. Neither species is ever highly abundant in our samples, but previous work indicated that both species mined the terminal buds of hydrilla. One site near Bujumbura had a fairly high density of P. dewulfi in November, 2007. In October/November 2008, we will make a large collection of hydrilla at the site, rear out the insects, separate out the two Polypedilum spp. and release the adults in a large cage which has an aquarium with clean hydrilla. The large cages have been constructed (Figure 1) and clean hydrilla has been established in the aquarium (Figure 2).
Figure 10. Rearing cage for Polypedilum in Bujumbura, Burundi.
Figure 11. Aquarium with clean hydrilla inside rearing cage.
Figure 12. Gut contents of Tilapia zilli with leaf of Hydrilla.
Figure 13. Fish exclusion cage in Lake Bisina, Uganda
Collaboration established
Hydrilla found in 5 water bodies in Uganda and Burundi
A large number of insects have been reared and identified
No evidence of insect herbivory has been found
Genetic analyses indicate that hydrilla in Africa is probably introduced
The finding that fish predate on hydrilla is significant in that it may answer the question about why hydrilla is not a problem weed in Central/East African lakes. We anticipate obtaining further evidence of this through the exclusion study.
We will continue to try and colonize P. wittei and P. dewulfi so that we can conclusively determine their trophic relationships with hydrilla. The two previous studies conducted on hydrilla natural enemies in Central/East Africa indicated that Polypedilum spp. mined in hydrilla tips. These studies were conducted by highly reputable scientists, and therefore we have not ruled out the possibility that this may indeed be true. Additionally, we plan to complete the fish study in hopes of providing a clear answer as to why hydrilla is not a problem in the African water bodies we are sampling.
Is there a change in the key contacts for this element? NO
Reporting period: 4th Quarter, EPA Fiscal Year 2008
July 1 – Sept. 30, 2008
Person Reporting: Karen Brown
Amy Richard
Eleanor Foerste
Element 4: Demonstration and Outreach
Project activities during reporting period:
A delay in the completion of the kiosk component of the project has occurred while awaiting hiring of replacement extension faculty member. This will be a primary task for the new faculty member for FY09.
A template has been created for four individual kiosk panels about invasive plants. It is waiting completion pending review by the new (replacement) extension faculty member.
CAIP staff would like to extend the target for completion of the kiosk panels to the end of the 1st quarter for 2009 (February 28, 2009).
Stacia Hetrick will replace Dr. Tina Bond as Element 4 coordinator and will be working from Osceola County Extension.
Stacia Hetrick, Faculty-Aquatics
UF/IFAS Osceola County Extension
1921 Kissimmee Valley Lane
Kissimmee, FL 34744
321-697-3000
321-697-3010 fax
Email shet@osceola.org
Element Objective: To develop and utilize public forums such as field days, visual displays, kiosks, websites and written materials for public education and outreach. Develop curricula for science teachers in secondary schools in Osceola County.
Task 1, Year 2 -- Fourth Quarter
Demonstration field days and media events to keep stakeholders informed on the progress of hydrilla and hygrophila management work.
Task 2, Year 2 -- Fourth Quarter
An interactive website will keep citizens/agencies informed of the various stages of research and allow citizens to communicate directly with researchers and county officials with questions and/or concerns.
According to Google Analytics, the website had 395 visits and 527 page-views during the fourth quarter of Year 2. The following new web pages were created:
Four photo gallery pages from the CSI-Osceola Teacher Training:
The Osceola County Hydrilla and Hygrophila Demonstration Project web site has been compared to the Section 508 Web Accessibility Regulations and is in full compliance. Three edits were made to bring the site up to the standard.
Task 3, Year 2 -- Fourth Quarter
Database development.
Twenty-seven retrospective citations were added from the APIRS collection providing additional information on hydrilla and hygrophila control to citizens of Osceola County.
Copies of publications are available from the CAIP Information office and online at http://plants.ifasufl.edu.
Task 4, Year 2 -- Fourth Quarter
Develop portable Aquatic Plant Management Displays/ Kiosks that can be used for local events such as the County Fair, Earth Day, Great Outdoors Days, scientific conferences and at various public areas such as boat ramps, parks, libraries and county offices.
Further development of the public information displays is on hold (behind schedule), pending the hiring of a replacement extension faculty for the project.
Once the new faculty member is in place, we will move forward quickly and complete the kiosk displays. Slight alterations of text and images will be needed for final production, based on edits/suggestions from this new individual.
Task 5, Year 2 - Fourth Quarter
Development of interactive science curricula for Osceola County teachers: 4 PPT lessons, 2 web-based activities, hands-on lab/field activities & modules tailored for Osceola County for UE, MS, HS. (June 08)
Osceola County’s first Invasive Aquatic Plant Teacher Training workshop was held July 28-31, 2008 (Title: CSI Osceola -- Creative Science Investigations at the Waterfront). The workshop was facilitated/organized by Eleanor Foerste with the UF/IFAS Osceola County Extension Service and Amy Richard with the UF/IFAS CAIP. Rob Horsburgh (CAIP) assisted. Two Osceola County teachers also attended and served as volunteer assistants (i.e., Wendy Norton and Amy Johnson-Henson). These individuals have been collaborating with CAIP staff to develop and test lessons in the classroom.
The purpose of the workshop was to provide teachers with expanded content knowledge and laboratory/field experience in the area of aquatic (and also upland) plant biology and ecology. Participants learned new investigative and instructional methods for exploring and teaching about Florida's diverse native, non-native and invasive plant communities. Participants also assisted in testing curricula and activities. Professional development points (CEUs) were provided upon completion of the 4 days of instruction and activities. The broader goal was to inspire these educators to take the information back to their students and teach with renewed enthusiasm and creativity.
July 28 (Monday) An Introduction to Aquatic Plants -- featured an aquatic plant exploration field trip, via airboat, on East Lake Toho in Kissimmee. UF/IFAS faculty Ken Langeland and FWC biologist Ed Harris were the guest speakers/field guides. Participants were taken to locations where they could see infestations of non-native invasive plants, as well as native plant communities. The afternoon session included a number of lectures and presentations about the problems caused by non-native invasive plants in Florida. One of the newly developed activities (i.e., the Hydrilla Game) was also tested during the afternoon, followed by a “brainstorming” review session, during which teachers provided their observations and ideas for improving the activity. Overall response to the activity was extremely positive; several teachers listed it as a highlight of the day’s activities.
July 29 (Tuesday) Why Do We Need to Manage Invasive Plants? -- This session included more aquatic plant exploration activities, but this time from the shoreline at St. Cloud’s Waterfront Park (AM session) and also at the Peghorn Nature Park (for the afternoon session). Plant identification along the lake shoreline was the morning activity, in an effort to help teachers learn how to utilize easily accessible aquatic plant samples for their own student activities.
The afternoon session included a brief hike within the park to see and identify a number of invasive upland plants. Biologist, Sarah Berger, presented an overview of her work on hydrilla on local ponds and Lake Tohopekaliga. Teachers then reviewed the recently developed audio/video presentation, Why Manage Invasive Plants?, and provided feedback on potential activities that can be developed for this lesson. The session ended with teachers trying out a Plant ID activity, featuring a number of aquatic plant species.
July 30 (Wednesday) Curricula Development -- Teachers previewed A Fish Tale, a recently completed audio/visual presentation and discussed materials to accompany the lesson. Next, teachers viewed a sampling of Public Service Announcements about invasive plants before being challenged to create their own video PSA on the same topic. Once completed, the videos were quickly downloaded and edited by video/new media expert Phil Chiocchio, with the assistance of the teachers. The final product was then viewed by all, followed by a discussion on the potential for conducting this same activity with students as a learning assessment tool and to help generate further interest in the topic within their community (aka “viral marketing”). The remaining afternoon session was spent testing out lessons and activities about invasive plants and animal species (i.e., adaptations from FWC’s Project WILD program). Lori Haynes, with the Florida Fish and Wildlife Conservation Commission facilitated this portion.
July 31 Curricula Development – This final session included the following activities: Invasive Species impacts to Ecosystems (teachers toured and practiced invasive species identification); Plant Diversity Study, with quadrant analysis to integrate math and science skills; additional Project WILD training (i.e., an aquatic ecosystem lesson/activity that combined plant and animal invasive species). The session was facilitated by Eleanor Foerste (UF/IFAS) and Lori Haynes (FWC).
RESULTS: Teachers who attended the workshop were given pre- and post-tests, as well as an evaluation form to complete at the end of the 4-day workshop. The average PRE-TEST score was 11 out of a possible 24 points. The average POST-TEST score was 21.6 out of 24 points -- a gain score of more than 10 points. Evaluations were positive overall. In every instance, the majority of participants felt the information learned throughout the workshop was “very useful.” As well, they provided positive ideas for improving next year’s workshop. An evaluation summary spreadsheet has been compiled and will be used for planning next year’s workshop.
Task 6, Year 2 - Fourth Quarter
Development of additional demonstration and outreach strategies.
Additional strategies to demonstrate and educate stakeholders about hydrilla and hygrophila management are being considered:
Teachers at the recent CSI-Osceola Invasive Plant Workshop were quite enthusiastic about the possibility of working with their students to create their own Public Service Announcements or “info-mercials” about invasive plants/species, using new media (digital, computerized, or networked information and communication technologies). This outreach strategy will need to wait for the new extension faculty member to help facilitate with the local school board and teachers.
Task 7, Year 2 - Fourth Quarter
One paper and one poster per year to share research progress and management technology, to be published on EDIS and presented at meetings.
All element coordinators have presented posters, exhibits or professional papers this reporting period.
Presentations:
Netherland, Michael D. 2008. Linking Mode of Action to Use Pattern and Strengths and Weaknesses of Registered Aquatic Herbicides. Texas Aquatic Plant Management Society, Bandera, TX.
Netherland, Michael D. The Aquatic Plant Control Decision Making Process and Management Examples With Hydrilla. 2008 Northeast Weed Science Society Short Course, Manheim, PA.
Posters:
Netherland, Michael D. 2008. . Evaluation of Currently Registered Herbicides for Control of Hydrilla.
Berger, Sarah and Haller, William. 2008. Research on Hydrilla Management on Local Ponds and Lake Tohopekaliga in Osceola County.
Mukherjee, A., Cuda, J.P., Overholt, W.A. and Ellison, C. 2008. Biological Control of Hygrphila polysperma: Searching for Natural Enemies in India- First Trip Report.
Overholt, William. 2008. Hydrilla biocontrol exploration in Africa.
Heilman, Mark. 2008. Mycoleptodiscus terrestris Mt. fungus potential for biocontrol of hydrilla in Osceola County.
Brown, Karen and Hathaway, Elizabeth. 2008. Center for Aquatic and Invasive Plants- resources in aquatic plant identification and management.
