Performing Department
Entomology
Non Technical Summary
Problem Statement(s): In 2004, the bed bug resurgence became a major topic of discussion within the Virginia Pest Management industry. However, the Virginia pest control industry had very little knowledge as to which bed bug control products were actually effective, and simply continued their decades-old practice of applying pyrethroid spray insecticides. Moore and Miller documented bed bug resistance to pyrethroids in 2006, and confirmed that bed bug resistance to spray formulation insecticides was a major hinderance to control efforts (Moore and Miller 2009). Over the following decade (2006-2016), many studies documented bed bug resistance to multiple spray formulation insecticides. The most recently documented type of bed bug resistance has been that of reduced cuticular penetration. Unfortunately, this type of physiological resistance has been the most detrimental to the efficacy of all spray formulation insecticides. If the insecticide is sprayed directly on their bodies, we can kill a significant number of the bed bugs. However, if the bed bugs only pick up insecticide residues, the residues do not penetrate the insect cuticle. Therefore, there is no residual insecticide working for bed bug control. In response to the difficultly of eliminating bed bugs using spray insecticides, many entrepreneurs have been working to develop novel methods for controlling resistant infestations. Our challenge in 2020 is to identify bed bug control strategies (chemical and non-chemical) that can successfully be used to eliminate bed bugs. The focus of our laboratory is to evaluate the efficacy and efficiency of some of the most novel and comprehensive bed bug treatment methods available.Relevance to advancing Virginia/Region and the U.S.:Although bed bugs no longer dominate the media, their populations are becoming well established, particularly in locations where the infested residents do not have the capacity (mental, physical, or financial) to eliminate these populations. As a result, each year our laboratory delivers numerous training presentations to different organizations across Virginia. These Virginia organizations have included: the pest control industry, apartment management associations, assisted living facilities, school districts; social service organizations, dialysis centers; women's shelters, hospital emergency facilities, city and county health departments, the hotel industry, the Virginia Tech Veterinary School, Virginia Tech housing facilities managers, and poultry rearing facilities. Because the economic impact of these bed bugs infestations is so great when we consider remediation costs (up to $500K-$1million/year for apartment facilities; and $5,000-$10,000/year for women's shelters, emergency rooms, and hotels; Miller personal communication), it is very important that researchers continue to look for innovative ways to eliminate these pests that are clearly not controlled by pesticide applications alone.Approach: Over the next five years, our laboratory will focus on evaluating novel treatment methods for the control of resistant bed bugs. Specifically, we intend to determine the efficacy and efficiency of these novel methods for use in the pest management industry. The three novel technologies that we will be evaluating in this project are: 1) the use of sulfuryl fluoride (Vikane®; Douglas Products; Liberty, MO) fumigation for the elimination of bed bugs in vehicles and chambers filled with infested household belongings; 2) the efficacy of multiple whole-home heat treatment systems for eliminating bed bugs in apartment units; 3) the efficacy and cost of Aprehend® (fungal spore product) applications to control bed bug infestations in apartment units.1). Our laboratory was recently made aware of bed bugs infesting automobiles. Automobiles (taxis, Uber and Lyft vehicles) are a source of re-infestation after an apartment, home, or any other location has been treated for bed bugs. There is no widely used bed bug elimination method for automobiles or for personal belongings. Within the last five years, sulfuryl fluoride has been labelled for bed bug control at a dosage rate of 1.9X. This dosage rate has been documented to kill bed bugs in our recent field assays. Moving forward, we will document the efficacy of sulfuryl fluoride (using statistical analysis) when applied for bed bug control in both vehicles and enclosed trailers packed with furniture and personal belongings to 85% capacity. Our goal of this study, is to provide fumigation information to pest management companies who want to expand their service offerings.2). While heat treatments are often recommended for treating resistant bed bug populations, our field observations have repeatedly confirmed that many of the (less expensive) heat systems being used do not have the power necessary for treating multi-story apartments or commercial facilities. Thus, it is important to understand the heating capabilities of each system before hiring a company to simply put heaters in an apartment and then remove them several hours later. At this time there has been no research comparing the capacities of the whole-home heat systems for bed bug remediation. We will evaluate individual bed bug heating systems as they are applied by trained personnel. We will place remote temperature monitoring devices (12 or more) throughout the structure to observe the temperatures during the treatment. We will also place sentinel bed bugs in known hard-to-heat locations to assess mortality after treatment. The length of the heat treatment, the set-up time, temperature readings, and bed bug mortality will all be used to develop a publication comparing the attributes and efficacy of different heating systems. This information will be distributed as a Virginia Cooperative Extension publication.3) Aprehend® is a new fungal spore product that we intend to evaluate in infested apartment units to quantify the number of applications necessary for bed bug elimination. Aprehend's unique mode of action should be very effective for killing pyrethroid resistant bed bugs. Our intention is to locate 10 infested apartment units that are similar in size and structure. All bed bugs and their harborage locations will be recorded. Five of the apartment units will then be treated with Aprehend® at 4-week intervals for a total of 8 weeks. The other five units will be treated with a conventional standard using the product Crossfire (clothianidin 4%, piperonyl butoxide 10%, and methoflutrin 0.1%). The number of live bed bugs, and existing bed bug harborages will be counted every two weeks. Bed bug elimination will be declared when no bed bugs have been found, and the resident has not suffered bites.Anticipated Outcomes and Impacts:Property owners, private companies, and state organizations often make poor bed bug remediation decisions out of fear or ignorance. These costly control measures have often failed to deliver bed bug elimination. Within the state of Virginia, there have also been many cases of homes or facilities being treated for bed bugs multiple times, but the bed bugs have persisted. In most of these cases the treatment has failed, yet, failures have typically been blamed on the residents or employees bringing new bed bugs into the facility. Thus, the presentation of our findings at a variety of local, state, national, and international bed bug training programs, will allow stakeholders to make informed decisions. We also intend to publish these efficacy evaluations in scientific journals as well as in Virginia Cooperative Extension Fact Sheets. The overall goal of this series of applied projects is to deliver research-based training programs to stakeholders, informing them how these bed bug control methods are intended to work, the costs and benefits associated with using these methods, potential hindrances to their efficacy, and how these hinderances can be avoided.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Goals / Objectives
Overall goal for the next 5 years: To complete the evaluation of novel pest management methods for eliminating insecticide resistant bed bugs populations in low-income, multi-unit housing, and automobiles.Objective 1. Develop sulfuryl fluoride fumigation parameters (1.9X application rate) for control of bed bugs in motor vehicles and loaded cargo trailers.Perform chamber and vehicle fumigation studies under the supervision of a licensed fumigator in the state of Virginia.Produce a research-based fact sheet for registered technicians regarding how to use enclosed cargo trailers as containers to fumigate bed bug infested belongings.Produce an information fact sheet for registered technicians regarding how to use sulfuryl fluoride fumigation to eliminate bed bugs from motor vehicles.Make this information available to the pest management industry in Virginia as a Virginia Cooperative Extension Fact sheet; a web publication on the VDACS OPS website, a publication on the Virginia Tech Bed Bug and Urban Pest Center Facebook page; and as a scientific publication.Develop a presentation documenting how these sulfuryl fluoride fumigations are to be conducted using the 1.9X dosage factor under varying temperatures, windspeeds, and sealing conditions for delivery at national, regional, and local pest management conferences.Objective 2. To evaluate the efficacy of multiple whole-home heat systems for their ability to eliminate bed bug populations in apartment units.Evaluate the efficacy of each heating system in apartment units of different cubic footage, clutter levels, and bed bug population sizes.Produce an information table comparing the attributes, costs, advantages, and disadvantages of each heating system.Make this information table available to the public as a Virginia Cooperative Extension Fact sheet; a web publication on the VDACS OPS website, a publication on the Virginia Tech Bed Bug and Urban Pest Center Facebook page; and a scientific publication.Develop a presentation comparing the results of these evaluations for delivery at national, regional, and local pest (and apartment) management conferences.Objective 3. To compare the ability of the Aprehend® (Beuveria bassiana) fungal spore product with that of a conventional standard insecticide (clothianidin 4%; metofluthrin 0.1%; piperonyl butoxide 85.9%) to eliminate bed bugs and bed bug harborage locations in "minimal preparation" apartment units over an 8-week time period.Evaluate the costs and efficacy of each product in bed bug infested apartments of similar size and clutter levels that have been "minimally prepared" for spray application treatment.Use bed bug sniffing canines to determine bed bug elimination time.Produce a scientific publication comparing the efficacy of the Aprehend® and Crossfire products when applied in bed bug-infested apartment units over an 8-week period.Develop a presentation comparing the results of these field evaluations for delivery at national, regional, and local pest and apartment management conferences.
Project Methods
Objective 1. Develop sulfuryl fluoride fumigation parameters (1.9X application rate) for control of bed bugs in motor vehicles and loaded cargo trailers.Study Site: All sulfuryl fluoride fumigation trials were conducted at the Dodson Brothers home office in Lynchburg, VA, under the supervision of a Virginia licensed fumigator.Fumigation Chambers &Vehicles: All chambers (n = 5, plus one control) were enclosed trailers (1.5 m x 2.4 m x 1.5 m; 5.4 cubic meters) filled with furniture, bags of clothing, booksetc. to 85% capacity. Vehicles used in this study (n=5, plus one control) were Dodge Caravans.Bed bugs: Groups of 10 adult bed bugs, 10 nymphs, and 10 eggs, were placed on filter papers inserted into knee-high stockings. Stocking were placed in inaccessible locations within each fumigation replicate. Control bed bugs were also placed inside vehicle and chamber replicates but were not fumigated.Fumigation: An electric fan and two plastic hoses were placed inside each fumigation replicate. One of the hoses was attached to the canister of sulfuryl fluoride and the other was attached to a SF-ExplorIR monitoring device. The SF-ExplorIR is an electronic system that measures the quantity of fumigant in each chamber which determines when the correct number of ounce hours has been met. Once the replicates were sealed, the fumigant was introduced. Each replicate held the fumigant until the ounce hours had been met for a 1.9X dosage rate, and then they were aerated.Data Collection: Sentinel adult and nymph bed bugs were removed from all replicates after aeration to record mortality. Bed bug eggs were monitored for 23 days after the fumigation to determine mortality. Statistical Analysis: The Fisher's Exact Test (Hoffman 2015) will be used to evaluate a two by two contingency table that has the fumigation replicates versus the control replicates on one axis and "success" (100% mortality) versus "failure" (< 100% mortality) on the other axis. In this study the null hypothesis is that the control and the fumigated chambers are equally likely to result in 100% bed bug mortality. The alternative hypothesis is that the fumigated chambers are more likely to result in 100% mortality than the controls. For both the van and the cargo trailer comparisons values of P < 0.05 will be used to indicate significance.Objective 2. To evaluate the efficacy of multiple whole-home heat systems for their ability to eliminate bed bug populations in apartment units.Study sites:We will conduct a cockroach remediation study in three housing facilities (Hopewell, VA; Richmond, VA; and Baltimore MD). Because we are already working in these facilities, we intend to collaborate with multiple heat contractors to evaluate the use of different bed bug heat systems in infested US HUD apartments for this Hatch project.Heating Systems: In this study, we intend to evaluate three commonly used whole-home heating systems currently marketed for bed bug control. These systems will include the Temp-Air heating system (electric; Temp-Air Inc. Burnsville, MN), the Green Tech system (propane), and the Assault Heating system (heated glycol). Copies of product manuals will be acquired from each heating company so that all pre-treatment preparation, use directions, and equipment features can be compared.Evaluations Procedures: Researchers will observe the set-up and implementation of five heat treatments for each different system. We will record the set-up time and placement of any temperature sensors. We will record heater and fan placement. We will measure the cubic footage of the apartment and the cubic footage of items filling the apartment space to categorize clutter levels as "high", "medium" or "low". We will also record all technician activities before, during and after the heat treatment is completed.Data collection: Our representative will place remote temperature sensors (n=12; Temp-Air Inc. Thermal Wireless Logger System, Burnsville, MN) in hard to heat locations prior to the heat treatment set-up. Temperature readings will be recorded remotely throughout the heat treatment process.Bed bugs: Live sentinel bed bugs (eggs, nymphs, and adults) will be confined in nylon stockings and placed in multiple locations throughout the apartment unit prior to heater installation. Sentinel bed bugs will be collected after treatment and mortality will be recorded for adults, nymphs and eggs (14 days).Treatment Information Records: The information we intend to collect for each heating system will include, but is not limited to the following: resident preparation instructions; the cost of the system; type of system (electric, propane, glycol); the number of BTUs; the amount of equipment used (heaters and fans); amperage required; temperature measuring devices; insulating material; temperature sensor reading at half-hour intervals; time for temperature sensors to reach 50o C; and treatment duration.Statistical Analysis: Percent mortality for each bed bug life stage treated with different heating systems (n=3 systems; five replicates each) will be compared. Differences in mortality will be analyzed using ANOVA (n=5; P < 0.05). Tukey multiple comparison tests will be used to assess differences between heat treatment groups. The percent of the heat sensors for each system reaching 50o C (thermal death point) will be compared using ANOVA (n=5; P < 0.05 for system replications; and n=15; P < 0.05 for comparisons between systems.) Again, Tukey's multiple comparison test will be used to assess differences between heat treatment groups.Objective 3. To compare the efficacy and cost of Aprehend® with those of Crossfire to eliminate (comparing bed bug counts from Day 0 to counts on Day 57) bed bugs in "minimally prepared" apartments over an 8-week time period. Study sites: A minimum of five infested units will be selected for treatment with either the Aprehend® product or Crossfire. A pre-treatment inspection and assessment will be made of each unit to determine the number of bed bug harborages and the population size.Treatment Procedures: In each apartment, all infested locations will be treated with the assigned product according to the label directions. Apartments will be re-inspected for bed bugs at weeks 2, 4, 6, and 8. At each inspection interval, the number of harborages and live bed bugs will be counted. If live bed bugs are found, units that were treated with Crossfire will be re-treated at two-week intervals. Units treated with Aprehend® will be re-treated at weeks four, and eight. Apartment residents will be consulted prior to the inspection to determine if they are seeing or being bitten by bed bugs. At the end of the 8-week test period, a scent detection canine will inspect all units to determine if they are bed bug-free.Data Collection: Visual inspections will be conducted in each apartment unit at two-week intervals starting at Day 0. All bed bug harborages and individual bed bugs and eggs will be counted and photographed. Percent bed bug life-stage reduction will be quantified for both treatments. Treatment costs will be assessed by weighing the application device to determine the amount of product applied in each apartment. The amount of time taken to inspect/treat each apartment unit will also be recorded. Treatment time will be converted into $1.25/per minute (pest control operator break-even cost).Statistical Analysis: A Negative Binomial Mixed model with bed bug life stage and treatment type as predictor variables. Different link functions and correlation structures will be compared. The overall percent reduction will be compared using the Student's t-test, df=4, P < 0.05). The Student's t-Tests will be used to compare the costs for the apartment units that were treated with either Aprehend® or Crossfire®. Values of P < 0.05 will be used to indicate significance.