her hand reaches into the black bin of composting food scraps and pulls out a speck of rotting something, careful not to disturb the inch-long vagrant clinging to it. the handler, carolyn hoagland, flicks the food off her palm and lets the female soldier fly crawl across her hand while quickly and skillfully shepherding the fly toward a bit of torn cardboard. enticed, the female crawls onto the board and perches on its exposed internal grooves. her black abdomen curves downward as she gingerly placed her egg depositor at the entrance to a thin column of paper, and leaves behind a small clutch of nearly 1,000 young.<\/p>\n
this was late july of 2017: exhausted from farm work and eager for a break in the shade, my coworkers and i were more than happy to indulge our manager in watching this menacing-looking fly lay her eggs.<\/p>\n
the university farm in sewanee can afford these small breaks and experiments. subsidized by the university of the south, the farm was reestablished in 2012 as a research and hands-on learning opportunity for undergraduate students, like christopher hornsby, who has been intentionally breeding these \u2018black soldier flies\u2019 on the farm for over two years, harvesting their maggots.<\/p>\n
these flies\u2019 larvae are grown on a commercial scale across the united states for fish and chicken feed, but chris\u2019s project focuses on what the larvae can feed on: once hatched, these larvae fatten for two weeks before emerging as adults, eating twice their own weight every 20-24 hours. to chris, and to many small farmers, this can be an invaluable service. reducing whatever mass of food waste given to them by ninety percent, the flies would expedite the university\u2019s composting process by weeks, if not months, and allow the farm to accept 400-500 pounds of food waste from sewanee\u2019s dining facilities every day.<\/p>\n
an impressive metabolism hardly signifies the soldier fly as unique; most larvae can consume a large amount compared to their own mass. but many species\u2019 adult flies can damage the local environment or become a nuisance to humans if their populations get out of hand, so it took a few weeks of research for chris to find the right fit for sewanee\u2019s ecosystem.<\/p>\n
\u201cthey\u2019re very harmless,\u201d chris explained; \u201cwhen it becomes an adult fly it sheds the inner lining of its gut, expelling any hazardous microorganisms. and it loses its mouth. so it\u2019s got no mouth, meaning it\u2019s not a disease vector, it\u2019s not a crop pest, and they won\u2019t swarm in houses, usually, unless you\u2019ve got a mountain of food waste in there. and they die after two to three days.\u201d he paused momentarily, and added almost as an afterthought, \u201cthey\u2019re also native to the entire western hemisphere. \u201d<\/p>\n
but even this fly isn\u2019t perfect. according to a pair of uga entomologists\u2019 research from 1984, 99.6% of egg-laying takes place from 81.5\u00b0 to 99.5\u00b0, and the university of windsor released a study from 2010 suggesting that the larvae’s ideal developmental environment has about 70% relative humidity. although a tennessee july easily provides these conditions, only tropical climates can host them year-round. the seasonality of the larvae may not be a problem to small farmers hoping to establish their own backyard colony because most agricultural systems dwindle as winter encroaches, anyway. but at sewanee, the converse is true: winter is when all 2,000 students are huddled together in the same dining hall, and it\u2019s when the farm grows the most greens and accepts the most food waste. so chris\u2019s project comes down to controlling climate, which would allow the flies\u2019 reproduction and developmental cycle to continue through the farm\u2019s busiest season.<\/p>\n
chris and carolyn have worked on multiple prototypes for smaller weather-controlled breeding boxes, but in the summer of 2017 the university\u2019s domain management raised a pole barn for the farm to house tractors, large equipment, and gave them the space to accommodate a room full of soldier flies. so chris\u2019s project has shifted from research to construction, as he tries to plan and prepare an insulated and vermin-proof home for his maggots.<\/p>\n
\u201ci don\u2019t know how to vermin-proof a building, but i\u2019m learning. but it\u2019s just me, and i can\u2019t do that kind of construction on my own. if i had more time and more people and more skills\u2026 it would all be very helpful.\u201d<\/p>\n
since he graduates in 2019, chris\u2019s project might not be completed soon enough for him to see it. with preliminary research finished and finding success in smaller-scale larvae breeding, now he needs to build the larvae a home. as a full-time student he can only work eight hours a week on the farm, which limits a project that is now so contingent on major construction work.<\/p>\n
however close his graduation looms, he is confident that another student will bear the torch after him. once it\u2019s finished, he sees sewanee\u2019s waste management system as a model that can be used by other small farms across the country, like bill keener\u2019s sequatchie cove farm.<\/p>\n
keener, a dairy, poultry, and vegetable farmer outside of sewanee, is intrigued by chris\u2019s work. sold at first by the prospect of self-producing chicken feed, he\u2019s now hoping to do research about a small-scale implementation of a soldier fly colony in his farmland.<\/p>\n
\u201cmaybe i could find an easy and big enough source of food waste to feed them with. maybe i could talk to local public schools.\u201d<\/p>\n
keener typically feeds his hogs excess whey from his dairy operation, and if the public school falls through as a food source, he may be able to use the whey as a substrate for soldier fly growth. the soldier flies would create an organic alternative to grain chicken feed, which would lower the price of his organic eggs and increase his competitivity in the local organic market.<\/p>\n
\u201ci think it\u2019s a good project for me. for a homestead, it\u2019d just make sense.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"
undergraduate student chris hornsby (’19) studies black soldier fly larvae as a possible means of closed-loop waste processing and livestock feeding at sewanee’s university farm.<\/p>\n","protected":false},"author":9596,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[4919,4896,4900,5196,4914],"tags":[112,206,129,3537,3353,591,232],"storyfest_categories":[],"class_list":["post-12254","post","type-post","status-publish","format-standard","hentry","category-agriculture","category-food","category-green-living","category-past-storyfest","category-sustainability","tag-agriculture","tag-education","tag-food-waste","tag-food-waste-prevention","tag-livestock","tag-storyfest","tag-urban"],"acf":[],"yoast_head":"\n