Recipient Organization
BENEFICIAL INSECTARY, INC.
9664 TANQUERAY CT
REDDING,CA 960036812
Performing Department
(N/A)
Non Technical Summary
House flies (Musca domestica) are global pests associated with animal agriculture. Insecticide resistance and growing demand for organic products is increasing the need for alternative methods of fly control. Parasitic wasps ("parasitoids") have been a success in biological fly control, and several commercial insectaries produce and sell them. However, these species only attack the fly after it has reached the pupal stage. Tachinaephagus zealandicus is a parasitoid that attacks the larvae and would be a helpful compliment to pupal parasitoids. Previous efforts to commercialize this species have been unsuccessful because of rearing challenges. They cannot be reared on house flies, which is used for producing the other parasitoids sold for fly control. Blow flies and Sarcophaga spp. can be used to produce T. zealandicus but they are expensive and require major modifications to production systems that are optimized for house flies. Recent research has shown that another fly, Hydrotaea aenesscens, can serve as a host for this parasitoid. Moreover, H. aenescens can be mass-reared using methods similar to those used for house flies. We propose to start new colonies of T. zealandicus from wild populations and develop production protocols using H. aenescens as a host. We will then scale production up to a commercial scale and determine the economics of producing this species as a product. We anticipate that the project will result in determining that T. zealandicus can be mass-reared on H. aenescens at a cost that is somewhat higher than pupal parasitoids but still at a price point to make this a competitive product in the fly control marketplace. Moreover, we anticipate that this will provide the groundwork for a Phase II proposal in which the efficacy of T. zealandicus for fly control will be established in on-farm trials.
Animal Health Component
(N/A)
Research Effort Categories
Basic
50%
Applied
(N/A)
Developmental
50%
Goals / Objectives
Background and Rationale Pest status of flies. House flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), (Diptera: Muscidae) belong to the group commonly known as "filth flies." These flies are two of the most common pests on livestock, poultry, and equine facilities. Stable flies are obligate blood feeders that inflict painful bites. They have been estimated to cost the US agricultural economy over $2 billion per year in production losses in the cattle sector alone. House flies are nuisance pests that are also involved in the movement of animal and human pathogens. The four most common bacterial pathogens associated with food-borne illness are Salmonella spp., Clostridium perfringens, Escherichia coli, and Campylobacter spp. (CDC 2017).Insecticide resistance drives the need for new fly control products. House flies are notorious for their ability to develop behavioral and metabolic mechanisms to avoid and detoxify chemical insecticides. Flies havedeveloped resistance to organophosphate, carbamate, and pyrethroid insecticides (Boxler and Campbell 1983, Butler et al. 2007, Kaufman et al. 2001, Kozaki et al. 2009, Memmi 2010, Plapp 1984, Scott and Georghiou 1986, Scott et al. 1989) as well as to growth regulators such as diflubenzuron and cyromazine (Bloomcamp et al. 1987, Shen and Plapp 1990). During the past 13 years, several promising new insecticides were introduced in bait form that, at least for a time, provided control of populations that were resistant to older chemistries. Spinosad and neonicotinoids, such as imidacloprid and nithiazine, were highly effective at the time of their introduction to the market. However, resistance to spinosad was documented almost immediately after market entry (Deacutis et al. 2006, Shono and Scott 2003). Early warning signs of resistance to imidacloprid appeared within 2 years of product rollout (Kaufman et al. 2006) and have now reached levels where product failure is commonplace (Kaufman et al. 2010a, Kaufman et al. 2010b, Memmi 2010). The only other "new" house fly product in a decade is Zyrox bait, containing cyantraniliprole. Because this is a slow-killing product to which flies will inevitably develop resistance (Li et al. 2015, Murillo et al. 2015), the country's animal agriculture producers face a fly control crisis with few options to choose from.Parasitic wasps for fly control. Commercially available pupal parasitoids (Hymenoptera: Pteromalidae) are the most common biological control agents used for filth fly management, and their use is increasing (United States Department of Agriculture [USDA] 2006; Machtinger et al. 2013). There is a well-established market for parasitoid sales, and Beneficial Insectary already has a major presence in that market. Tachinaephagus zealandicus fills an empty niche. All of the commercially produced parasitoids attack the fly after it has pupated. At present there is no biocontrol agent for use against larvae, leaving an empty niche to be filled for biological fly control. A biocontrol product that targets larvae would reduce insecticide use and increase the efficiency of pupal parasitoids. This species kills large numbers of house fly larvae and would be an attractive novel addition to the suite of fly control products for use as biological larvicide.An opportunity. Past attempts to develop produce T. zealandicus as a product have been unsuccessful. They do not reproduce well on the house fly hosts that are used to produce pupal parasitoids. Although they can be raised on blow flies and flesh flies, such hosts are costly to rear and require major changes to mass-rearing operations that have been optimized for house flies. Hydrotaea aenesscens can also serve as a host for this parasitoid. This fly is easily reared in large numbers using methods very similar to those used for house flies. We hypothesize that H. aenescens can be used as a mass-rearing host to economically produce T. zealandicus as a biological larvicide product. Relationship with Research or Research and Development.Our long-term goal is commercial development of an effective biological control agent product (T. zealandicus) that can be used as a biological larvicide for fly control in animal agriculture facilities. The Phase I project is a necessary first step to determine whether this species can be produced at all on hosts that are easily reared in large quantities (H. aenescens).Technical Objectives Objective 1. Establish new colonies of T. zealandicus, Hydrotaea aenescens, and Sarcophaga bullata. This part of the project will be conducted by Dr. Christopher J. Geden at the USDA, ARS laboratory in Gainesville, FL. Dr. Geden will be a consultant/contractor on the project.Objective 2. Determine the efficiency of production of T. zealandicus on Hydrotaea aenescens compared with Sarcophaga bullata. This part of the project will be conducted by Dr. Christopher J. Geden at the USDA, ARS laboratory in Gainesville, FL. Test will be performed in small scale to determine the proper host: parasitoid ratio to maximize parasitoid yield. Once determined, test will be performed to determine if the host: parasitoid ratio will maintain optimal yields in a large scale.Objective 3. Evaluate different larval diets to optimize production parameters of H. aenescens. This part of the project will be conducted by Dr. Christopher J. Geden at the USDA, ARS laboratory in Gainesville, FL.Because Hydrotaea aenescens is a facultative predator of other fly larvae it has long been believed that larval diets for this species must include supplemental protein compared with house fly diets. Test will be formed to determine the optimal diet for H. aenescens.Objective 4. Conduct pilot mass-rearing of T. zealandicus on Hydrotaea aenescens in a dedicated commercial facility. The goals of Objective 4 are to maximize the rearing space, develop rearing techniques to determine the most cost-effective methods for H. aenescens egg production and evaluate the effects of temperature manipulation on both H. aenescens and T. zealandicus.
Project Methods
Objective 1. Establish new colonies of T. zealandicus, Hydrotaea aenescens, and Sarcophaga bullata. This part of the project will be conducted by Dr. Christopher J. Geden at the USDA, ARS laboratory in Gainesville, FL. Dr. Geden will be a consultant/contractor on the project. S. bullata is a well-known production host for T. zealandicus that has also been used as a sentinel host to collect this species in the field (Geden and Skovgaard 2014).Larvae will be reared on beef liver and adults fed a semi-moist cake composed of 3:1 sugar and yeast hydrolysate. Parasitoids will be collected by placing pans of liver and mature S. bullata larvae in habitats in Florida and Georgia where T. zealandicus is known to occur (Geden and Skovgard 2014). Pans will be left in place for 24-48 hours then returned to the lab. Fly pupae will held for fly (8 days) and parasitoid (22 days) emergence. Parasitoids will be housed in 17.5- × 17.5- × 17.5-cm cages (Bugdorm; Megaview Co., Taichung, Taiwan) and provided with water and honey. S. bullata will be used for routine rearing during the early stages of the project.Adult H. aenescens will be collected from poultry farms, placed in cages and provided with water and a dry food made of 8:8:1 sugar: powdered nonfat milk: powdered egg yolk (by volume). Larvae will be reared on the diet described in Hogsette and Washington (1995), which is composed of water and a dry mixture of wheat bran, corn meal, alfalfa meal, and meat/bone meal.Objective 2. Determine the efficiency of production of T. zealandicus on Hydrotaea aenescens compared with Sarcophaga bullata.This part of the project will be conducted by Dr. Christopher J. Geden at the USDA, ARS laboratory in Gainesville, FL. Bioassays with the two hosts will be conducted by presenting groups of five female T. zealandicus with mature host larvae (wandering stage L3's) at host: parasitoid ratios of 30, 20, 10 and 5 larvae per parasitoid. Parasitoids will be removed after 24 hours and the hosts will be allowed to pupate in vermiculite. After emergence of any flies, uneclosed pupae will be placed in individual gelatin capsules and held for parasitoid emergence. Data will be collected for each host species and host: parasitoid ratio on the number of hosts killed, the number that produce parasitoids, and number of parasitoids produced from each parasitized host. The experiment will be conducted on three separate occasions (replications) using three sets of 5 parasitoids per replication for each host species and host: parasitoid ratio. Data will be analyzed by two-way ANOVA using host species and host: parasitoid ratio as main effects as well as the interaction. Analyses will be performed using SAS version 9.3.The parasitoid ratios which maximized parasitoid yield will be tested in larger arenas. For these tests, groups of 100 female T. zealandicus will be placed in large cages and presented with H. aenescens larvae either alone or in larval rearing medium. This will be done to determine whether the parasitoids are equally able to locate host larvae in rearing medium as they are when presented with larvae alone. Host larvae will be allowed to pupate, and pupae will be held for fly and parasitoid emergence. The experiment will be conducted on three separate occasions (replications) using three sets of 100 parasitoids per replication for each treatment (presence/absence of larval medium). Data will be analyzed by one-way ANOVA using the presence/absence of larval medium as the main effect.Objective 3. Evaluate different larval diets to optimize production parameters of H. aenescens. Because H. aenescens is a facultative predator of other fly larvae it has long been believed that larval diets for this species must include supplemental protein compared with house fly diets.A H. aenescens diet wasdeveloped almost 25 years ago at the USDA-ARS-CMAVE lab in Gainesville, Florida. In the intervening years, the base house fly diet used in the CMAVE lab has changed from wheat bran: alfalfa meal: corn meal to one composed of wheat bran and pelleted calf feed (Calf Manna) at a ratio of 13:1 (by volume, or 7.7% Calf Manna). Calf Manna is a pelleted animal feed with 25% protein. The meat/bone meal ingredient is now difficult to purchase because of concerns about prion diseases in the meat meal. For this objective we will first determine the suitability of the current CMAVE house fly diet for producing H. aenescens compared with other recipes in which the amount of calf manna varies from 7.7 (house fly diet) to 25%. Bioassays will be conducted by placing 200 g test diets in cups and adding 250 H. aenescens eggs per cup. The experiment will be replicated 3 times using 3 cups of media and eggs for each treatment per replication. Data will be collected on development time, number of pupae produced, and the weight of the pupae. Data will be analyzed by one-way ANOVA using the amount of Calf Manna in the diet.Calf Manna is widely available.. Pending results of these bioassays we may explore additional sources of supplemental protein such as Purina Dog Chow (21% protein.), fish meal (60-72% protein.), or blood meal (90-95% protein.).Once the most effective diet has been identified in small-container bioassays, experiments will be conducted to determine the carrying capacity of the diet by varying the number of fly eggs added to a fixed volume of media. For these tests we will first prepare larger pans containing 6.75 liters of dry ingredients plus sufficient water to bring the moisture content to 65% (about 3.8 liters). For house flies, the standard practice at the USDA lab is to add 20,000 eggs to this amount of medium. We anticipate that H. aenescens has a lower tolerance for crowding than house flies. Using the house fly loading rate as an upper benchmark, H. aenescens eggs will be added to trays of larval diet at rates of 5000, 10,000, 15,000 and 20,000 eggs per tray. The experiment will be replicated 3 times using 3 trays of diet and eggs for each egg-loading rate per replication. Data will be collected on the number of pupae produced and pupal weights from each tray and analyzed by one-way ANOVA. The data will also be to calculate the cost of ingredients for producing each fly.Objective 4. Conduct pilot mass-rearing of T. zealandicus on Hydrotaea aenescens in a dedicated commercial facility. Beneficial Insectary Inc. (BI) will construct a pilot mass-rearing facility in Cleveland, AL. BI has commercial production facilities in the Redding, CA area where house fly and pupal parasitoids are produced. Due to predatory behavior of H. aenescens towards house fly larva a separate facility is needed to prevent possible contamination.The goals of Objective 4 are to maximize the rearing space, develop rearing techniques to determine the most cost-effective methods for H. aenescens egg production and evaluate the effects of temperature manipulation on both H. aenescens and T. zealandicus.Tests will be performed to maximize the adult H. aenescens density in rearing cages. The physical space required for production is critical to cost-effective production.For these tests we will vary the stocking rates of adults in cages and determine whether mortality or egg production rates are impacted.Tests will also be performed to evaluate the production and viability of H. aenescens eggs based on the age of the adult. Egg counts and hatch rate will be recorded from cages of different ages to determine the most cost-efficient length of time the adults should be left in production.Finally, tests will be performed to determine the effect of temperature on the development of H. aenescens and T. zealandicus. Commercial production requires that both the host and parasitoid be temperature-manipulated with minimal loss of production efficiency. This includes the ability to stockpile parasitized hosts at low temperatures with minimal loss of viability