DEVELOPMENT OF EAVES TUBES AS A NEW PEST MANAGEMENT TACTIC FOR IPM OF MUSHROOM FLIES

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: OTHER GRANTS
• Reporting Frequency: Annual
• Accession No.: 1014152
• Grant No.: 2017-70006-27263
• Cumulative Award Amt.: $199,532.00
• Proposal No.: 2017-04722
• Project Start Date: Sep 1, 2017
• Project End Date: Aug 31, 2019
• Grant Year: 2017
• Program Code: [ARDP]- Applied Research and Development Program

Recipient Organization
PENNSYLVANIA STATE UNIVERSITY
408 Old Main
UNIVERSITY PARK,PA 16802-1505

Performing Department
Entomology

Non Technical Summary
Pennsylvania produces over 63% of the total US mushroom crop and is currently facing significant issues with the mushroom phorid fly (Megaselia halterata). No chemical adulticides are currently approved for use in mushroom production, and growers have no method for bringing this pest under control. We will investigate the potential for implementation of novel 'eaves tubes' technology, initially developed for mosquito control, using insecticide impregnated eaves tubes, which contain insecticide treated electrostatic gauze, fitted to buildings to channel odor cues from inside a house. M. halterata behave very similarly to mosquitoes around mushroom houses. Growers already implement extensive exclusion strategies to try to reduce the influx of M. halterata from the external environment. We will screen suitable commercial pesticide formulations for efficacy against mushroom flies in combination with electrostatic gauze. In order to determine the best placement of eaves tubes technology we aim to identify the key points of entry and exit for M. halterata, and their movement patterns within houses throughout the crop cycle. Successful implementation of eaves tubes technology will result in an effective, affordable and environmentally sound IPM strategy and reduction in economic, environmental, and societal losses from mushroom pests.

Animal Health Component

75%

Research Effort Categories

Basic

10%

Applied

75%

Developmental

15%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
216	1470	1060	50%
211	1470	1070	50%

Knowledge Area
211 - Insects, Mites, and Other Arthropods Affecting Plants; 216 - Integrated Pest Management Systems;

Subject Of Investigation
1470 - Mushrooms and other edible fungi;

Field Of Science
1060 - Biology (whole systems); 1070 - Ecology;

Keywords

agaricus bisporus

eaves tubes

electrostatic gauze

megaselia halterata

mushroom phorid

Goals / Objectives
The overall goal of this project is to determine if the concept of installing insecticide impregnated mesh in commercial mushroom houses can be implemented for control of mushroom phorid flies.Objective 1. Design effective eaves tube technology for control of phorid fly (Megaselia halerata) adults.1a Identify most effective powdered pesticide for further implementation.1b. Determine most effective mesh carrier for powdered insecticides.1c. Select powdered insecticides with long-term stability/efficacy under field conditionsObjective 2. Determine air flow characteristics and identify optimal placement of impregnated mesh for effective deployment of mesh inserts in mushroom production rooms.2a. Determine airflow characteristics in all commonly utilised mushroom house designs.2b. Identify most suitable locations for deployment of mesh ports according to mushroom house design.Objective 3 Determine immigration and emigration patterns of phorid flies between growing rooms and mushroom houses.3a. Obtain mark release recapture data using sticky trap monitoring.4. Maintain excellent communication and dialogue with growers to ensure compatibility of proposed eaves tubes deployment with management practices.5. Obtain appropriate regulatory guidance on EPA and Pennsylvania Department of Agriculture regulatory oversight of eaves tubes technology.6. Train Postdoctoral scientist in pest management and IPM for the mushroom industry.

Project Methods
To better understand phorid fly movement into and around mushroom growing houses we have begun recording air currents within mushroom growing rooms via an ultrasonic anemometer (Gill Instruments, Hampshire, UK). Preliminary recordings in several mushroom houses around Kennet Square, PA, suggest that the inside of mushroom growing rooms maintain a positive pressure. Airflow into the sampled growing room was around 4.2 cubic meters/second, and the exhaust from that same room was 3.1 cubic meters/second (unpublished data). Using this ultrasonic anemometer we will continue to record the intake, exhaust, and airflow within growing rooms at 14 different mushroom farms. This information will inform our understanding of how mushroom phorid flies enter and move within mushroom growing houses.We will also pay special attention to placing traps outside the mushroom houses at points where house air is exhausted. Traps will be monitored to determine fly emigration during different phases of mushroom cultivation.Mark, release and re-capture (MRR) techniques will be used to study the movement of marked individuals between growing rooms (at different stages in the cropping cycle) within a single mushroom house. Preliminary data suggests that mushroom flies enter growing rooms at two stages of the cropping process. When populations inside the rooms are dense, flies migrate to adjacent rooms and infest new crops (Figure 1). Flies inside mushroom houses will be collected with an electric aspirator, the receptacle of which will contain a fine (3-5 microns) non-toxic fluorescent dust (i.e. Brilliant General Purpose Fluorescent Pigments, San Francisco, CA) (Kluiters et al., 2015). Flies collected in the receptacle become marked with the dust particles, which adhere to their exoskeleton. These flies will be released inside the growing rooms. MMR will be conducted at different cropping stages using different colored powders for each room and crop stage. Dispersal will be studied by placing white sticky traps on fly monitors inside the growing rooms and in breeze ways, as well as vents and fans will be placed for mushroom phorid fly recapture. Different colored powders will distinguish identify flies from different rooms and crop stages.We hypothesize that in certain crop stages, phorid fly's exit the growing rooms to mate after which females re-enter new rooms to lay eggs. Identifying this step of phorid fly dispersal is crucial to our main objective of enhancing fly exclusion. Fly recapture outside mushroom houses will be achieved via yellow sticky traps, (which we have found to be effective for capturing phorid flies outside mushroom farms). Traps will be placed in radial transects around the farms at different crop stages. Again, different colored powders will be used to enable the identification of the crop stage(s) when fly emigration is highest.Cracks, poorly sealed doors, and windows offer vulnerable areas of entry and exit for phorid flies on mushroom farms. In order to better understand the role these structural vulnerabilities play in the pest ecology of phorid flies in white button mushrooms we will identify these weak points. By placing these cards on the inside and the outside of these structural vulnerabilities we can determine if captured flies were entering or exiting a growing room. These cards will be examined daily throughout and entire cropping cycle for the presence of adult phorid flies. These data will help us determine if and when within the cropping cycle, these vulnerable areas contribute to phorid fly pressure in a mushroom farm.We propose to screen up to 10 powdered formulations of insecticides with current registration in the US for pest control in other industries and permitted for use in PA. The most effective insecticide formulation will be selected on the basis of mortality after 5 min exposure in standard WHO tube bioassays. In brief, powder formulated insecticides will be applied in excess to electrostatic gauze (Van Heek Textiles BV), excess powder is removed by tapping the gauze, the remaining powder is strongly bound to the gauze by electrostatic forces and is not easily dislodged. The actual dose of dose of insecticide remaining on the gauze will be calculated by the difference in weight of gauze before and after insecticide application and expressed as mg AI/cm2. Treated gauze will be placed in a standard WHO insecticide test kit with groups of 10 adult flies released into the chamber (5 replicate chambers). Flies will be removed after 5 min and evaluated for knockdown and mortality immediately following removal from the test cylinder, and 1 and 24 hr following exposure, to account for potential recovery after knock down (pyrethrid insecticides). For each treatment, the mortality of flies exposed to insecticide will be corrected for the mortality of counterparts exposed to control netting using Abbott's formula. Significant differences in mortality will be determined by chi-squared test. Bioassays on each pesticide formulation will be replicated in time (x3), to ensure reliable results.The three most effective pesticide formulations will be selected for stability testing. To determine the duration of efficacy of the treated gauze over time, five replicate gauzes for each pesticide formulation will be treated and stored for re-evaluation at regular intervals up to 6 months. Every month, 10 phorid flies will be exposed for 5 min to the treated gauze (replicated and conducted as per the screening bioassay above) and evaluated for mortality. Mortality results for each pesticide formulation will be plotted over time to monitor for decline in efficacy of the treated gauze. These data will be used to inform the selection of the most promising pesticide formulation for the field evaluations.

Progress 09/01/17 to 08/31/19

Outputs
Target Audience: During this reporting period, we have worked with mushroom growers in the Chester Country region, and the American Mushroom Instistute (AMI) to provide information on our pesticide screening progress. We have participated in IPM group meetings held monthly by the AMI. Additionally we have particpated in township meetings with members of the local residential community to provide information on our activities, which aim to reduce the numbers (poulation) of flies emerging from mushrrom houses and entering residential properties. Many of the mushroom farm workers and residential community are hispanic. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Two postdoctoral research students have participated on this project. Both have had the opportunity to work directly with the mushroom industry and have presented their research at the Mushroom short course. They have gained experience in mushroom farming, collaboration and communication with the industry, and made significant progress in the implementation of research results. How have the results been disseminated to communities of interest?We have presented and discussed project objectives and progress at the 2018 and 2019 Mushroom short Course, which is the key annual conference attended by mushroom growers in the US. Further, we have presented and participated in CEU training events for mushroom farm workers and IPM committee meetings organized by the American Mushroom Institute. Overall, the industry is well informed of our research progress and enthusiastic to implement the products and techniques that we have identified for phorid fly control on mushroom farms. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objectives 1a,b and c. We screened 17 commercial, powdered insecticide products for efficacy against Megaselia halerata. All insecticidal powders were evaluated on the day of application to electrostatic mesh (PollenTec™) and again 30 days after the application (Objective 1c). M. halterata were exposed to the mesh for 5 min, then removed to a clean environment and observed for mortality. Of the 17 powdered insecticides evaluated, 7 products resulted in 100% mortality after 5 min exposure to both freshly applied powder and 30 days after the powder application (Tempo Ultra, OHP Decathlon, Demon WP, Drione dust, Merit WP, EcoPCO WP-X, and EcoVia WD). Of these most effective powdered insecticides, the first 6 listed are registered by the EPA for other applications, but did not have a label for mushrooms, and the 7th, EcoVia WD is a FIFRA 25 (b) product. In the interest of expediting the implementation of this technology in mushroom houses, we decided to focus on FIFRA 25 (b) products, as these had potential for implementation without regulatory delay. We were unable to find any other powdered products with FIFRA 25 (b) exemptions. However, we screened 3 additional liquid FIFRA 25 (b) products (EcoVia 3-in-1, Naturecide Pest Management X2, and Essentria IC3). These liquid insecticides were applied according to label to blue insulation material (Objective 1b). This material is commonly used in mushroom houses to fill holes and voids. Adult phorid flies were exposed for 5 min to treated blue insulation material, removed to a clean environment and observed for mortality. All 3 products resulted in 100% mortality. Objectives 1a through c were achieved. We identified four highly effective insecticide products with long-term residual efficacy (>30 days) which were effective of on two carrier materials with potential for immediate implementation on mushroom farms. On-farm airflow and ventilation characteristics were analyzed on a range of mushroom house designs. In all cases, the exit vents and widows were identified as the key areas for implementation of electrostatic mesh. Additionally, blue insulation material, which is found throughout the mushroom house structures was identified as a key target area for application of liquid insecticides. We conducted observational studies to determine the movement of flies both between growing rooms, and in and out of the farm buildings. It became apparent that flies move readily from room to room via the attic space above the growing rooms. Adult flies crawl up walls to the ceiling, where they gain access to the roof areas via cracks and voids of any size. Once in the attic space, they can gain access to the adjacent growing rooms. We consider this behavior to be one of the key drivers of phorid fly population growth through the season, as flies have free access to each crop at its most attractive stage of development. 3a UV attraction with sticky traps is used to monitor fly populations inside our study farms. However, mark release recapture activities proved extremely difficult. We use direct observation to gain a better understanding of fly movements both inside and outside houses in combination with extensive trapping activities. 4 We have presented and discussed project objectives and progress at the 2018 and 2019 Mushroom short Course, which is the key annual conference attended by mushroom growers in the US. Further, we have presented and participated in CEU training events for mushroom farm workers and IPM committee meetings organized by the American Mushroom Institute. Overall, the industry is well informed of our research progress and enthusiastic to implement the products and techniques that we have identified for phorid fly control on mushroom farms. 5 We have three effective FIFRA 25 (b) exempt pesticide products that are effective in the lab, and available for immediate implementation on farms dues to their regulatory status. A long-term field trial was set up on one collaborating farm to evaluate the implementation of two products (Eco-Via WD and Eco-Via 3-in-1) in key immigration and emigration areas within the mushroom house. We are monotring fly population numbers using UK light attraction and sticky cards to evaluate the difference in fly numbers throughout multiple cropping cycles and growing rooms. This trial will continue for 12 months to ensure sufficient data to demonstrate the overall efficacy of the interventions on fly populations throughout the season. We presented preliminary data on this trial to the industry at the 2019 Mushroom short course. Final results will be presented at the 2020 Mushroom short course, in addition to publication in a peer reviewed journal and publication of extension materials to assist the industry with implementation of the most effective strategies for use of these products 6 Two postdoctoral research students have participated on this project. Both have had the opportunity to work directly with the mushroom industry and have presented their research at the Mushroom short course. They have gained experience in mushroom farming, collaboration and communication with the industry, and made significant progress in the implementation of research results.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Ikkei Shikano and Mike Wolfin. 60th Annual Mushroom Short Course, Pennsylvania State University. Oct. 9, 2018. Presentation title: ⿿Methods of phorid fly control⿝
• Type: Other Status: Published Year Published: 2018 Citation: Ikkei Shikano and Mike Wolfin. 3rd Annual Penn State Mushroom Industry Strategic Planning Meeting, Kennett Square, PA. Nov. 29, 2018. Presentation title: ⿿Fly control⿝
• Type: Other Status: Published Year Published: 2019 Citation: Ikkei Shikano. Mushroom Growers⿿ Pesticide Credit Meeting, Kennett Square, PA. March 27, 2019. Presentation title: ⿿Mushroom fly biology and management⿝.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Title: Methods of phorid fly control (Presented in English and Spanish) Authors: Mike Wolfin, Caryn Michel, Baker-Jenkins Mushroom Pest Research Team Mushroom Short Course, Kennett Square, PA, 19348 October 2019
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Title: Methods of phorid fly control Authors: Mike Wolfin, Caryn Michel, Baker-Jenkins Mushroom Pest Research Team Entomological Society of America Annual Meeting, St. Louis, MO November 2019
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Title: Potential of OMRI approved products for mushroom phorid fly Authors: Caryn Michel, Michael Wolfin, Nina Jenkins, Tom Baker Mushroom Short Course, October 2019

Progress 09/01/17 to 08/31/18

Outputs
Target Audience:During this reporting period, we have worked with mushroom growers in the Chester Country region,and the American Mushroom Instistute (AMI) to provide information on our pesticide screening progress. We have participated inIPM group meetings held monthly by the AMI. Additionally we have particpated in township meetings with members of the local residential community to provide information on our activities, which aim to reduce the numbers (poulation) of flies emerging from mushrrom houses and entering residential properties. Many of the mushroom farm workers and residential community are hispanic. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The post doc will give a research paper at the annualmushroom shrot course to be held at Penn State in September 2018. How have the results been disseminated to communities of interest?We provide regular research updates to the American Mushroom Institute at their monthly IPM meetings. We have also attended the quarterly Township meetings in Chester county to appraise members of the public affected by phorid flies of our research progress. What do you plan to do during the next reporting period to accomplish the goals?We will conduct more laboratory evaluations of the three most promising pesticide products with the aim of developing robust and effective use startegies. These use strategies will form part of the regulatory dossier that will be required for label extension of these products for use in mushroom houses.

Impacts
What was accomplished under these goals? 1a We have identified 3 effective pesticides with great potential for implementation with the eave tube technology. 1b Electrostatic mesh is a very effective carrier for powdered insecticide products, but we have also evaluated the use of water-based spray application as an additional control method for one of these pesticide products. 1c All three powdered pesticide products result in100% mortality of adult phorid flies after just 1 minute exposure and remain effective for 30 days. Long-term activity will continue to be evaluated at 60 and 90 days after application of the insecticide to the mesh. 2a Airflow/ventilation characteristics have been analyzedfor a range of mushroom house designs, and changes in air flow according to crop stage have been determined. 2b The exit vents and widows have been identified as the most promising areas for implementation of the electrostatic mesh technology. 3a Sticky trapping of flies is ongoing inside our study farms. Mark release recapture activities are proving extremely difficult, but we are gaining a better understanding of fly movements both inside and outside houses from extensive trapping activities. 4 We are working closely with the management of one farm on eave tube deployment and are conducting our first field trials this season. 5We have three effective pesticide candidates for implementation. We are currently concentrating in on a FIFRA 25b product as this can be deployed without regulatory clearance. We will work on regulatory activities for the remaining two pesticides during the next reporting period. 6 Postdoc is progressing very well and is conducting on-farm field trials this season to inform best IPM practice. ?

Publications