Fish love to eat flies, but can mass-produced fly larvae
replace fishmeals in fish feeds?
An Ohio company claims that it is ready to
answer that question using protein derived from soldier fly
larvae. '
Enviroflight was formed by Chief Executive Officer Glen
Courtright in 2009 and now has a production-and-research
operation that employs about 10 people in Yellow Springs,
where the company is planning to install a large larvae-based
feed production unit.
According to Courtright, the current operation has
overcome a number of obstacles during the development of
various larvae-based diets and the scaling-up of the facilities
and production.
"We have the ability to produce, as a finished formulated
feed (for various species), upwards to about 1,000 tonnes a
year (of fly-based feed) out of our present research facility,"
said Courtright, "and we're getting ready to go to large scale.
We think the future is optimistic."
Courtright said he's applied for several patents for the
larvae production and feed-manufacturing processes so he's
reluctant to give too much detail about the program and
technology.
The company's research is concentrated on the soldier fly
and the use of its larvae for fish-oil-light and fishmeal-free
feeds for tilapia, basa, catfish, freshwater prawns and red-claw
crayfish. Additionally, the company is starting to look into a
larvae-based feed for rainbow trout.
To date, Enviroflight has produced soldier fly larvae using
dried distillers' grains with soluble (DDGS) and brewers'
grains - a diet that soldier flies can live on exclusively.
By not using animal manure or food scraps as food
sources for the larvae, production results in zero odor,
pathogens and waste.
Dependent upon temperature and
environmental controls, the process proceeds at the
speed of the lifecycle of the soldier fly - about 33
days.
"Eggs are laid on day one, and on day three they
hatch; and at about one to two weeks they go into
the production area," Courtright explained.
He added that one of the advantages of very
high-density larvae production is that the insects
and larvae generate considerable amounts of heat.
T he facilities still have to be heated during winter in
Ohio, but the heat from the insects helps markedly.
Courtright said the larvae are harvested when
they're around.08-.09g, each measuring maybe
about a centimetre long.
"We can produce, in one faci lity, about 15-
20 tonnes of insect larvae a year, on a small area
of 1,000 square feet," said Courtright. Another
advantage of the Enviroflight system is that the
company uses not only the larvae but also the waste
the flies and larvae leave behind, known as frass.
He indicated that it's taken "three years of
research and a lot of money and heartache (over
repeated failures)" to refine the process and feels the
developed system can be used anywhere in the world
to grow fish for an ever-increasing global population.
"We're constantly running feed trials and
working on diet formulations for different fish,
because each different species requires a differentdiet,
and the amino and fatty acids to be just the right
balance," said Courtright. We've eliminated the fish oil in
tilapia and basa too."
"We don't have any fish meal at all in our diets. In most
cases we don't have fish oils. T he prawn diet is zero fish oil
"We really think that insect-based technologies are the
way to go (for the aquaculture industry), if we can do it clean
- and we're proving we can," he said.
- Quentin Dodd •
