Organic Value Recovery Solutions LLC
© Organic Value Recovery Solutions 2010
© Organic Value Recovery Solutions 2010
A Brief Discussion of Food Safety Issues Associated with
Production and Feeding of Black Soldier Fly Larvae to Food Animals
D. Craig Sheppard, Assoc. Prof., Department of Entomology,
Tifton Campus, University of Georgia
Feeding of animal manures to food producing animals and manureing of fish ponds to increase food fish production are
common practices generally accepted around the world. Still, the question of food safety often arises when discussing
the feeding of insect larvae raised in animal manures to food producing animals. This apprehension is natural, especially
in Western culture, where there is a strong aversion to eating insects. But insectivory and coprophagy are essential
components in the natural recycling of nutrients. Reintroducing these natural principals into agricultural food animal
production can increase efficiency and decrease environmental nutrient overloads, especially in areas of high production.
Sheppard et al. (1994) proposed a low-input system using the black soldier fly to achieve this objective and reviewed
research on similar systems. This soldier fly system greatly reduces plant nutrients (manure residue), produces high
quality feedstuff, chitin and possibly antibiotics. Fifty-eight tons or more of prepupae containing 44% dry matter could be
collected from a 100,000 hen laying facility in five months. Food safety issues need to be critically assessed as this or
similar systems are integrated into commercial food animal production. But available research and production information
indicates that food safety is not likely to be a problem.
Addition of animal manure to ponds is practiced in the Orient and Europe to increase food fish production. This practice
is common in Czecholovakia, Hungary, the Philippines and China, and probably many more countries not found in my
cursory review. Manure may be applied actively or more passively by raising ducks and/or swine over or at the pond so
that the pond receives a steady stream of nutrients.
In the U.S. refeeding of manure, especially broiler litter to beef cattle is a well established practice with no history of food
safety problems. A report by CAST (1995) reviewed research from a 30 year period of feeding poultry litter to livestock.
The only health problem they attributed to this practice was copper toxicity when sheep were fed broiler litter with high
There is a substantial body of literature on using various fly larvae (face fly, house fly, blow flies and the black soldier fly),
reared in animal manure as feed. Researchers in China, the USSR, the USA, Mexico and in Eastern Europe have fed
these to poultry, swine, shrimp, several species of fish, turtles and frogs with no reports of health problems.
There is reason to believe that dipterous larvae which habitually colonize manure possess natural antibiotics for
protection from bacteria. Attempts to ensile soldier fly prepupae using the same general procedures that were successful
in ensiling fish and animal processing wastes were unsuccessful. Antibiotics released from the chopped soldier fly larvae
may have stopped the activities of the Lactobacillus culture used to initiate the ensiling process. Addition of corn was
helpful, but even then, activity was low. Research in Chile is studying value recovery from swine manure, using house
flies. They are reportedly finding anti-microbial factors in the house fly larvae. These natural antibiotics may reduce the
chance of the feedstuff transmitting pathogens, and could conceivably improve animal health, while reducing pathogen
content in the digested manure that may be used to fertilize food crops.
There are many instances where manure and larvae raised in manure have been used to feed animals for human
consumption. There seem to be no general health problems resulting from any of practices. Bacteriological assessments
and other food safety issues need to be addressed on a case by case basis, but the prospects of safe use of these
valuable resources is promising.
CAST (1995) in a report on wastes of food production and processing notes that “A new emphasis should be placed on
converting these wastes into marketable products”. Reintroducing insects into the agricultural food chain will help
achieve this objective.
CAST (Council for Agriculture Science and Technology) Ames Iowa, USA. 1995. Waste management and
utilization in food production and processing. CAST Task Force Report No. 124. Oct. 1995. 125 pg.
Sheppard, D. C., G. L. Newton, S. A. Thompson, and S. Savage. 1994. A value added manure management
system using the black soldier fly. Bioresource Technol. 50: 275-279.