Black Soldier Fly Larvae as a Tool for Managing Animal Waste and Providing a Food Source for the Aquaculture Industry

Final Report for SW06-083

Project Type: Research and Education
Funds awarded in 2006: $117,682.00
Projected End Date: 12/31/2009
Region: Western
State: Idaho
Principal Investigator:
Sophie St-Hilaire
Idaho State University
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Project Information

Abstract:

Results of our 8 week rainbow trout feed trail suggests fish will grow on a black soldier fly- based diet and the taste of the fish is not affected. During the summer of 2008 we grew black soldier flies in an outside facility on a dairy farm near Twin Falls, Idaho. We were able to demonstrate approximately 40% dry matter reduction in the laboratory and in our pilot on-farm system. We were only partially successful at harvesting prepupae from our system. The poor harvests were attributed to 1) the cold night-time temperatures (~50 F or lower), when the larvae are most active, 2) lack of fish offal in the diet in some containers, and 3) the prepupae’s inability to efficiently migrate out of our large containers. Given our results from the farm study, raising black soldier flies in Idaho will most likely require a temperature controlled environment and modification to the rearing units. Once this is achieved there will be a number of potential uses for the prepupae by-product.

Project Objectives:
  1. 1) Determine, using a 20-week feed trial in rainbow trout: a) whether the feed conversion ratio (weight of feed fed / weight gain) of fish fed omega fatty acid enhanced prepupae and cow manure fed prepupae at 25% and 50% fishmeal replacement are equal to or better than the commercial control diet, and b) the optimal inclusion level for prepupae in rainbow trout diets (i.e. 25% or 50% fish meal replacement) to achieve a feed conversion ratio that is equal or better than the a commercial diet.

    2) Determine (and demonstrate on a small scale) at least one method of adapting proven techniques of raising larvae to cold-weather climates (e.g., Idaho) and to cow manure.

    3) Develop and provide a cost-benefit analysis to each of the industries participating in the project: One for using black soldier fly larvae for manure reduction on diaries in Idaho, and another for using black soldier fly prepupae as a partial replacement for fishmeal and fish oil in rainbow trout diets.

    4) After the successful completion of objectives 1, 2, and 3, identify rainbow trout producers, feed manufacture(s), a maggot producer, and dairy producers in Idaho to plan and design a commercial pilot-scale demonstration project. By the end of the project, the target is to have all industry partners in place for seeking and obtaining the necessary funds for such a pilot commercial project.

Introduction:

This was a collaborative project between Idaho State University, the University of Idaho, and Idaho’s dairy and aquaculture industries. It investigated a single approach to mitigating two large and growing concerns: 1) management of animal waste and, 2) exploitation of wild caught fish for fish-based diets used in aquaculture. The commercial trout industry in Idaho has traditionally used a fishmeal derived from wild caught fish in their diets. The continuing demand on wild fisheries is not sustainable1 and is increasingly expensive, resulting in significant production costs for aquaculture farmers. Meanwhile, Idaho’s rapidly expanding dairy industry needs to reduce the impacts of an unavoidable by-product of production: manure.
This project addressed these problems by studying the feasibility of adapting a biological technique proven in concept (in part with SARE funds LS93-056 and LS90-027) to Idaho. The proposed technique was to use black soldier fly larvae (a non-pest species of fly) to decompose manure and provide a food source for the aquaculture industry.
The implication of this project for the dairy industry in Idaho was a potential reduction in manure of up to 48% and a net reduction of nitrogen and phosphorus of 63% and 52%, respectively. Idaho is ranked 6th in the nation for milk production with an estimated 388,000 dairy cows in the state (Idaho State Department of Agriculture, 2003). Each dairy cow produces approximately 8.9 kg of dry matter waste per day (ASABE standard 384-2005). Although Idaho has a large land base to apply manure to, the majority of dairy cows are concentrated in a relatively small area. Manure must therefore be transported off farms to be applied. The cost of transporting manure can be as high as $30,000/1000 head. There are also other issues such as air quality and surface and ground water contamination. As Idaho’s dairy industry grows, these concerns are becoming more significant for farmers and the public. The black soldier fly will reduce the volume of manure requiring disposal and, therefore, the risk of air and water pollution.
The implication of this project for the rainbow trout industry in Idaho was to decrease dependence on capture fisheries for fish diets. The aquaculture industry is, worldwide, one of the largest consumers of wild-caught fish. The demands on this natural resource are continuously increasing. The Food and Agricultural Organization (FAO) estimated that, in 2003, 52% of all fishmeal and 86% of all fish oil harvested, were used in fish diets. The continuing demand on wild fisheries is not sustainable. Furthermore, the price of fishmeal and fish oil is $900/ton and $600/ton, respectively (aquaculture industry personal communication), and is increasing. The use of black soldier fly prepupae in fish diets will make the aquaculture industry more sustainable and less dependent on natural resources.

Cooperators

Click linked name(s) to expand
  • Mireille Chahine
  • Gary Fornshell
  • Ron Hardy
  • Wendy Sealey
  • Ron Sheffield
  • Craig Sheppard
  • Kelly Tindall
  • Jeff Tomberlin

Research

Materials and methods:

Objective 1) 20 week rainbow trout feed trial using prepupae

Task 1) Grow prepupae for feed.

Idaho State University researchers grew the omega-3-fatty acid enhanced prepupae required for the fish feed trial. Black soldier fly prepupae were reared on dairy manure and enriched by supplementing fish offal to the growth medium during the last month of culture.
Task 2 and 3) Conduct feed trial and sensory analysis of the fish

For the fish feeding trial, a practical-type trout diet was formulated to contain 45% protein, with roughly half of the protein derived from fish meal and the remaining from soybean meal, corn gluten meal and wheat meal (Appendix A). Four test diets were developed by substituting 25% and 50% of the fishmeal component of the control diet with normal (BSF) or enriched (EBSF) black soldier fly prepupae on an amino acid equivalents basis (Figure 1). Dietary fat content was adjusted to approximately 20% lipid using fish oil and poultry fat to provide required levels of essential fatty acids and maintain approximately equivalent fatty acid ratios between the treatments. Diets were fed to three replicate tanks of fish per treatment (15 fish/tank, mixed-sex House Creek strain) for 8 weeks . Trout were reared in 140 L tanks supplied with 6 L/min of constant temperature (14.8°C) flow-through spring water (Figure 2). Bulk tank weights were taken every three weeks until the end of the trial. At that time, three fish per tank were sampled for determination of hepatosomatic index, intraperitoneal fat ratio and muscle ratio. The muscle portion obtained was subsequently utilized for determination of proximate and fatty acid composition. Fish remaining after sampling were pooled by tank, euthanized and immediately transported on ice to a commercial fish processing facility. At the processing facility, fish were individually hand-filleted as gourmet fillets with ribs and pin bones removed. Following filleting, samples were pooled by tank and stored at -20C until shipment (approximately 1 week) to Washington State University for sensory evaluation.

Objective 2) Adapt proven methods of growing black soldier flies to dairies in Idaho

The experiment tested whether black soldier fly larvae could be grown under field conditions in Idaho. The study was conducted on a 3000-cow dairy located in Southeast Idaho. An unused manure separator facility was adapted for a shelter which provided shade and wind protection for the BSF rearing containers (Figure 3). Netting was used around the facility to reduce escapment of adult flies, colonization of BSF containers by house flies and provide shade and wind protection. A wooden floor with a 2 inch high border was constructed to contain larvae and prepupae if they migrated out of the collection containers or primary containers. Three different types of containers were tested:
• Circular, 8 feet diameter and 3 feet deep container (Figure 4)
• Recycle bin (Rectangular shape with gradual slope on one side) (Figure 4)
• Smaller 3 feet diameter circular container (purchased from ESRI International LLC) (Figure 5).

The experiment was conducted in three phases
Phase 1: Larvae were grown at Idaho State Laboratory for 2.5 months. The cooler than normal early summer temperatures necessitated that the larvae were maintained in the laboratory for a longer period of time than anticipated. To delay the development of the larvae during this time, the laboratory temperature was maintained at approximately 70°F. The farm study was started June 11, 2008. Approximately 1,763,100 larvae were distributed in the three previously mentioned containers as follows:
• Large circular container = 417 Kg of bedding and approximately 1,445,742 larvae
• Recycle bin = 78 Kg of bedding and approximately 264,465 larvae
• Small circular Container = 13 Kg of bedding and 52,893 larvae

On June 27, 2008 the larvae were fed fish offal to stimulate their growth.

Phase 2 began on July 18, 2008. Additional eggs were received from Georgia (Craig Sheppard), maintained for two weeks at the Idaho State University laboratory and subsequently divided into two containers: a large 8 ft circular and a smaller 3 ft circular container. Fourteen kg of manure with an estimated 407,000 larvae was placed in large circular container, and 3 kg of manure with an estimated 111,000 larvae were added to the smaller circular container. The change in the quantity of bedding was based on the observations from the first trial which suggested the larvae only feed in the top 5 cm of manure.

Phase 3. The study was repeated with a large 8 ft circular container. Approximately 350,000 eggs (treated in a similar manner as in trial 2) and approximately 10.6 kg of manure was seeded in the container. This third farm trial was initiated on August 6, 2008.

Additional small projects conducted on the black soldier fly:

1) Establishing a breeding colony
Two attempts were made to establish a breeding colony of black soldier flies in Idaho. A facility was built at ISU to house adult flies. This outbuilding had heat and a fan. The roof also had natural lighting to stimulate mating. A humidifier provided some humidity. A second attempt was made to breed flies in a greenhouse. A small enclosed plastic container (3ft X 4ft X 3ft) was constructed to contain the flies and permit aerial mating.

2) Shelf-life study

Black soldier fly eggs were obtained from an established colony at University of Georgia. These were grown at 250C on cow manure until they were approximately two weeks from the prepupae stage. At this time two hundred larvae were distributed to each of six 946 ml Tupperware containers. The weight of the 200 larvae in each container ranged between 16.37 and 22.26 g. All containers were fed a 50/50 mixture of fish offal and cow manure. After one week of feeding, 1.5 g of vitamin E was added to the three containers in group E. This was repeated for three more days. All prepupae were ready for harvest 5 days after the last vitamin E treatment. In total, approximately 250 g of feed was provided to the larvae. All 602 prepuae were harvested from the containers in group D and 604 prepupae were harvested from the containers in group E. The average weight of the prepupae in group D was 0.114 and in group E it was 0.113.

The prepupae were euthanized by placing them in the -20 C freezer for 2 hours. Subsequently they were maintained at room temperature (~25 C) for the remainder of the experiment until they were sampled for fatty acid analysis and fat oxidation. Samples (2-3g) from each container were submitted to the University of Idaho (UI) Department of Animal and Veterinary Science for analysis at approximately time 0, 1, 3, 7 and 12 months post-harvest for fatty acid analyses. The samples were frozen and stored at -80 C until processed.

Fatty acid analysis:
Samples were freeze-dried before lipids were extracted using chloroform: methanol (2:1) 11. Lipids were methylated using base catalyzed transesterification12 with a reaction time of 10 min. The fatty acid methyl esters (FAME) were analyzed on a gas chromatograph (Hewlett-Packard 6890 Series with auto injector) fitted with a flame ionization detector and a 100 m x 0.25 mm, with 0.2 m film capillary column coated with CP-Sil 88 (Chrompack; Middelburg, The Netherlands). Initially, the oven temperature was set at 70C (for 3 min) and then increased to 175C at a rate of 3C/min and held for 3 min. Oven temperature was subsequently increased to 185C at a rate of 1C/min and held for 20 min, increased to 215C at a rate of 3C/min, and then increased to 230C at a rate of 10C/min and held for 5 min. Response correction factors determined by the analysis of a butter oil standard with certified values (CRM 164; European Community Bureau of Reference, Brussels) were used to quantify fatty acids.

Statistical analysis:
Data were summarized. Differences in the total dry matter weight of the different fatty acids (% of the specific fatty acid X the total fat content) for prepupae on the two different diets were compared using an analysis of variance (or a Kruskal-Wallis test when parametric test assumptions were not met) at time 12 months. Comparison between time 0 and time 12 months was also compared for groups within the same diet treatment. A time series was conducted to determine whether there was a significant change over time in each treatment group.

3) Evaluation of remaining larval processed manure as a fertilizer :

We planted 38 tomato seeds (L.lycopersicum) in commercial soil within one tub, and we allowed the seeds to sprout into cotyledons with their first leaves. Once the plants had their first leaves, we planted each tomato plant into a single pot with 6 different types of soil treatments. Each pot contained 10% peat moss. Group A had 90% sterile soil; group B had 80% sterile soil and 10% larval processed manure (LPM); group C had 65% sterile soil, and 25% LPM; group D had 40% sterile soil and 50% LPM; group E had 90% commercial soil in each of the six pots; and group F had 65% commercial soil and 25% LPM. The plants were watered with 400 ml of mineral free water 3 times per week, for 2 weeks. For the next 4 weeks, the plants were watered with 800 ml of mineral free water 3 times per week. We measured the plants with a meter stick once every two weeks. Over the course of the fruit production period, we collected and weighed the tomatoes from the individual plants once they turned orange/red.

We conducted statistical analysis to compare the growth and fruit production trends between treatment groups A through D and E between F. We conducted repeated measures to determine if there was a difference in the growth trends between groups A through D and between E and F. Our individual comparisons between groups at different times were done using Bonferoni adjusted Tukey pairwise comparisons, which adjusted for our multiple tests.

Comparison of fruit production (number of fruit and total weight) for different treatments was done using general linear models (GLM). Tukey pairwise comparisons were used to determine differences between and within treatments. Residual diagnostics were done on all models to determine if the parameteric test assumptions were met. We completed all statistical analysis using excel, SAS, and SPSS (14.0).

For photos, figures and appendices please see the CD version of the final sent to the Western SARE office in Logan UT.

Research results and discussion:

Task 1) Grow prepupae for feed.

Researchers at Texas A& M University grew the (non-enhanced) prepupae required for the feed trial. These prepupae were grown on cow manure only. They were smaller on average (0.04 g less) than the enhanced prepupae.

Task 2 and 3) Conduct feed trial and sensory analysis of the fish

Growth of fish fed the EBSF diets was not significantly different from those fish fed the fishmeal-based control diet, while growth of fish fed the BSF diets was less than those fed the control diet (Table 1). Muscle ratio was not altered by diet but control fish had significantly higher inter-peritoneal fat than those fish fed the EBSF or BSF diets.
A group of 30 untrained panelists did not detect a significant difference in a blind comparison of fish fed the fishmeal control diet as compared to fish fed the EBSF or BSF diets (Table 2). These data suggest that EBSF can be used to replace up to 50% of fishmeal portion of a practical trout diet for 8 weeks without significantly affecting growth or sensory quality of rainbow trout fillets.

Objective 2) Adapt proven methods of growing black soldier flies to dairies in Idaho

Phase 1: On July 4, 2008, the first prepupae started migrating out of the containers. There was an intensive period of two weeks (July 10, 2008 to July 24, 2008) when the majority of the prepupae migrated out of the containers. After this period, the harvest of prepupae decreased dramatically.
Manure fed to the larvae was collected on the farm after the separation process. It was approximately 80% dry matter. The total quantity of manure added to the containers was 1,588 kg for the large circular container, 380 kg for the recycle bin, and 128kg for the small circular container. Larvae were fed this quantity of manure between June 11 2008 and July 28 2008. The feed was delivered every two or three days. The total amount of prepupae harvested per container was: 6.75kg for the large circular container, 3.65 kg for the recycle bin (the larvae were transferred into 4 smaller containers to permit the migration of prepupae), and 1.64 kg for the small circular container. A significant amount of prepupae were collected from the floor (1.2 kg). In total, approximately 13.3 kg were harvested from all three containers and the floor.
The average weight of a prepupae was 0.14 g. There were approximately 71 prepuapae in 10 g. Based on this estimate, we harvested approximately 93,990 prepupae. This value represents only 5.3% of the original population, 88% of these migrated out within a 2 week period. The large proportion of losses was distributed between immature and dead larvae within the containers. Very few larvae developed into flies (fewer than 100).
The shape of the recycle bin container did not permit the prepupae to migrate properly, therefore, on July 9, 2008 the Recycle bin was divided among four of the smaller 3 foot circular containers to prevent losing prepupae. These four containers were treated as a single unit for measuring manure and prepupae production.
We suspect that the mortality occurred because the manure was turned over. We initially believed this would improve consumption; however, it buried the larvae and we believe they were not able to re-surface. We also over-watered the containers, which rendered the bottom 1/3rd anaerobic.

Phase 2 :
The migration of the prepupae in this second trial started August 31, 2008. Approximately 6 weeks after migration, the larvae were transferred to the farm. The time period of initially being brought onto the farm and migration was similar to the first trial, despite the shorter laboratory growth period; however, the harvest was much smaller than in the initial trial. Additionally, no intensive period of migration was observed. Minimal migration continued until October 8 2008 when all activity stopped.
The total quantity of processed manure in phase 2 (July 18 2008 through October 27 2008) was: 1074 kg in the large circular tank and 125 kg in the small circular container. Larvae were fed this manure intermittently, based on activity level. The total weight of prepupae harvested was 122 g and 139 g in the large and small container, respectively. The average weight of the prepupae was 0.12 g (less than the first trial); 80 prepupae weighed approximately 10 g. It is estimated, based on this weight, that only 0.4% of the prepupae migrated out of the containers.
It was hypothesized that the low yield was due to two factors: 1) the night time temperature (50 F) during the second trial approached the lower limit for the black soldier fly and 2) the larvae were not fed fish offal during the second trial.

Phase 3:
Only a negligible number of prepuape (71g) migrated out of the container. Despite efforts to increase the night time temperature in the facility it remained below 50° F during the predicted migration period. Given the low day and night time temperatures, the field study was concluded on November 18, 2008. No fish offal was included in this trial either.
Farm data on manure consumption on a dry matter basis suggested a 40% reduction. Preliminary conclusions on raising black soldier flies from this farm study are:

•Under field conditions, prepupae are very susceptible to management issues like transfers, bedding turn over, flooding and temperature changes.
•Feeding the larvae with fish offal appeared to provide a great stimulus for growth and maturity.
•For larger container surfaces, more ramps and collector buckets are needed per unit. Under low temperatures. It is more difficult to maintain the temperature of the bedding especially when there is no drainage and the bedding is wet or flooded.
•Although the dark cloth container covers helped the larvae remain active during the daylight hours and protected them from possible outside predators, they were not hermetic and some losses occurred.
•The best behavior and development of prepupae occurred when the maximum environmental temperature reached more than 30° C.
•For better results, it would be important to design a facility that provides better protection against the environment, including a constant temperature. The larvae and prepupae are most active in the dark so it is important to have warm night-time temperatures, which limits the natural growth season for black soldier flies in Idaho. The solution to this issue is to use a faster growing species of fly and/or grow the larvae in a controlled environment. The latter will add considerable cost to rearing the larvae, but will improve the harvest.
• Even during the summer, the wide range in temperature fluctuation between day and night could present challenges for growing black soldier larvae outside.

Objective 3) cost benefit analysis. The latter was not completed because we did not develop an adequate system to grow prepupae on dairy farms (see issues that we encountered).

Objective 4) plan and design a commercial pilot scale project. A proposal was submitted to the Idaho Dairymen’s association in the fall of 2008 and declined. The dairy farmer on whose farm the flies were grown is interested in pursuing the project. As well, a house fly grower in Oregon is interested in submitting an SBIR with ISU and U of I as partners for developing an insect based fish feed. We are going to pursue a USDA SBIR proposal with this farmer (Skip Cockerum) in the fall of 2009.

Additional small projects conducted on the black soldier fly:

1) Establishing a breeding colony
All attempts at establishing a breeding colony were unsuccessful. We believe the problem with our systems were too few adult flies in our facility and too low of humidity. The newly hired entomologist at UI will improve on the basic design (we recently were given mosquito tents from our Chinese colleagues, which should improve our success).

2) Shelf-life study
We successfully grew black soldier fly prepupae with LC-PUFA by including fish offal in their cow manure diets. No mortality was observed during the duration of the study.
The BSF prepupae enriched with LC-PUFA do not undergo significant degradation of these fatty acids as was apparent by the constant percent of DHA, EPA, and ALA over the 12 months storage period (Figure 6). There was no difference in the percent of DHA, EPA, ADA between treatment groups after 12 months and there was no difference in the fatty acid profiles over time (STAT). We were unsuccessful at applying the oxidation test to the black soldier fly prepupae samples.

Overall summary of findings from shelf-life study:
There was little reduction in the LC-PUFA over time, even in the prepupae that were not fed vitamin E, a known antioxidant used for prevention of peroxidation (Figure 6). These findings suggest that the black soldier fly could easily be stored for several months at room temperature without becoming rancid, a characteristic that is beneficial to the feed industry if this product is to be considered as a feed ingredient for animal diets. The lack of oxidation in LC-PUFA enriched BSF prepupae, which are approximately 30% lipid was unexpected. The mechanism by which these lipids were preserved for up to 12 months is unknown and warrants further investigation.

3) Evaluation of remaining larval processed manure as a fertilizer
All plants were between 3.8 and 8.8 cm when they were initially transplanted into their respective treatment groups and all 6 plants in each treatment group survived the entire duration of the study (196 days). Final height measurements were between 58 and 135 cm (Figure 7).
The repeated measures analysis for plants in treatment groups A through D, indicated that sphericity was not met (P <0.001), so the data were transformed using Greenhouse-Geisser. Within-subject effects for the growth of treatment groups A through D differed slightly within time and time* treatment group (F2.77,16 = 931.4, P < 0.0001; F8.31,16 = 2.84, P = 0.009 respectively). While between-subject effects for the growth of treatment groups was significant (F3,20 = 4.85, P=0.011) . Tukey pairwise comparisons indicated significant differences in growth between A and D only (t = -4.89, P = 0.0504).
Our repeated measures on growth for treatment groups E and F indicated sphericity was met, and that within time there was significance (P = 0.405). Growth trends indicated that after 28 days all height measurements between treatment groups E (commercial soil) and F (25% LPM with commercial soil) were different, and on average plants in group F were taller. Within-subject Tukey pairwise comparisons indicated that time, time*treatment group were significant (F5,6 = 490.0, P<0.001; F5,6= 31.792, P<0.001). Tukey pairwise comparisons indicated significant differences in growth between E and F after time week 2. Tomato plants growing in only commercial soil and peat moss, produced no fruit (treatment group E). All other treatment groups produced an average between 0 and 6 tomatoes (Table 3). Average weight of fruit produced ranged from 0 g in group E to 39.62 g in group D (Table 3).
There was a significant difference in the weight and count of tomatoes produced plants in treatment groups A through D (F3,20 = 22.36, P<0.001). Group D was statistically higher for both count and average weight (Table 4).
A Kruskal-Wallis non-parametric test showed a statistical difference between treatment groups E and F (H1 = 9.47, P = 0.002). While Tukey pairwise comparisons between groups E and F indicated that there was a significant difference in the total weight of tomatoes produced (F1,10 = 18.085, P = 0.002; Table 4). On average plants in treatment group F produced 4.167 tomatoes compared to zero tomatoes in group E (Table 3).

Overall summary of findings for fertilizer study:
Larval processed manure mixed with commercial soil (treatment F) appeared to improve growth and production of tomatoes when compare to commercial soil alone (treatment E). When sterile soil was used instead of commercial soil we only observed improved fruit production, no effect on growth was noted (Figure 7 and Table 3).

For photos, figures and appendices please see the CD version of the final sent to the Western SARE office in Logan UT.

Research conclusions:

We have determined that black soldier fly prepupae can be used as a partial fishmeal replacement in rainbow trout diets without significantly decreasing the growth of the fish. The fish readily accept feed made with black soldier flies and the flesh quality is not affected by this feed ingredient. Further, if the black soldier fly are enhanced with long chain unsaturated fatty acids (i.e. omega-3 fatty acids) it is possible to reduce the fish oil component of the fish diets and not significantly affect the fatty acid content of the fish fillets and the feed conversion ratio.
This insect-derived source of protein and fat may be a viable alternative to fishmeal for aquaculture industries.

We also were able to reduce cow manure on a small scale using the black soldier fly larvae. However we were unsuccessful at scaling up our model to make this system efficient in Idaho. This lack of success was attributed to cold night-time temperatures and an inefficient container design for outmigrating prepupae. It may be possible to circumvent these issues by heating the facility where the flies are grown and with more research on container designs.

Participation Summary

Educational & Outreach Activities

Participation Summary

Education/outreach description:

We had several local, national and international newspapers cover this project in 2008 (see Appendix B for the article in Associated Press and UI’s press release covering this project).
Also, three Western US agricultural radio stations have featured our project. Two undergraduate student at ISU and one at UI, and two undergraduate students at Texas A & M University have been trained on how to raise black soldier fly larvae, conduct feed trials in rainbow trout, perform fat oxidation tests, and plant fertilizer studies.

Dissemination of results in 2009:

A demonstration project with live prepupae and larvae in a 3 ft circular container was presented at the following events:
•University of Idaho Twilight Tour-July 2008
•Gooding County State Fair-August 2008
•Thousand Spring Festival-September 2008
All three of these events are well attended by the farming community in Idaho.

The fish feed trial and sensory analysis was presented at the Aquaculture America Conference and the U.S. Trout Farmers annual meeting in February 2009. Aquaculture American 09 is the annual meeting of the U.S. chapter of the World Aquaculture Society. More than 2000 fish farmers, researchers and aquaculture industry personnel attend. Topics covered include the latest research on challenges to sustainable and profitable aquaculture.
The findings from this study were also presented at both a technical session and at the Trout producers session to detail how replacing 25% of the fishmeal component of trout diets can improve sustainability of trout production through reduced dependence on wild-harvested fishmeal while maintaining fillet product quality for human consumption.
A manuscript to the Journal of the World Aquaculture Society has been accepted detailing our trout feed trial and sensory analysis. This journal is widely distributed in a number of countries to both the scientific community and the aquaculture industries.
We have presented an overview of the project to the Idaho Aquaculture industry at their annual meeting on June 13, 2009. The project was also featured in Ag-Weekly in February 2009.

For photos, figures, and appendices please see the CD version of the final report sent to the Western SARE office in Logan, UT.

Project Outcomes

Project outcomes:

Due to our inability to develop an efficient system for growing large numbers of black soldier fly prepupae on dairy farms we were unable to conduct an economic analysis.

Farmer Adoption

The participating dairy farmer on this project has agreed to provide us with space to work on optimizing a containment area for growing black soldier fly larvae. There is an Oregon farmer that grows house flies commercially that is interested in moving to Idaho to establish a fly farm in Idaho.

Recommendations:

Areas needing additional study

Further research is required to adapt existing economically viable black soldier fly bioconversion systems to Idaho.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.