Diet is one of the most widely studied topics in BSF literature. So many articles—so many different diets. The information can be overwhelming, but the bottom line is that diet impacts growth and development. You may be thinking, well, that’s a no-brainer.
We have seen countless times that if we feed BSF a low-quality diet, we can expect prolonged development, reduced larval weights, and reduced survivorship, etc. But, do you know why this occurs?
Metabolism is key—the feed we give BSF is either assimilated into new biomass or is utilized to generate energy. I recently found a new BSF publication that investigated how diet quality effects metabolic performance and the findings lend insight as to why poor diets result in reduced growth and development. I have included the citation below if you wish to look up the paper for specific details about the study.
To summarize the results, Laganaro et al. (2021) found that larvae fed a low-quality diet sustained their maximum growth rate for less time than those fed a high-quality diet. So, on the surface, when we feed low-quality diets, we see delayed development and small larvae, and one of the reasons is because the larvae are not meeting their maximum growth rate for the same amount of time as they would if they were fed a more nutritious diet. Why?
Because of the demand for maintenance purposes. Larvae fed a poor diet have higher energy requirements and higher CO2 respiration, so more of the feed is lost to energy production and respiration; therefore, less is available for new biomass. And collectively, this slows the growth rate and results in smaller larvae.
Although BSF are generalist feeders, the authors make an important statement worth noting, and that is that feed conversion into new biomass is substrate specific. In other words, as Jeff Tomberlin once told me, “Not all diets are hot dogs”—meaning the composition of diets differ and the ability of BSF to convert their feed will vary. I wondered after he said that when and where I would use that little nugget of knowledge, and I think I found the perfect place.
The take home message is if your larvae are developing slow and are small, and you are looking for ways to change this, a good starting place is to go back to the basics and evaluate your diet.
This makes me think: if only junk food would keep me young and skinny…
Laganaro, Marcello, Simon Bahrndorff, and Niels Thomas Eriksen. "Growth and metabolic performance of black soldier fly larvae grown on low and high-quality substrates." Waste Management 121 (2021): 198-205.
Chelsea Miranda, PhD
I am excited to contribute to this blog and talk about all things black soldier fly.
But first, a little about me...
It is fair to say that I am not your typical "bug loving" entomologist. In fact, as a child I was terrified of insects- and to be honest- I still am to some extent. So how does someone who fears insects go on to study and then work for a company that mass rears them?
This seems odd. I know.
The simple answer is that I have a greater love for domestic animals (and I am not afraid of the insects that plague them). There hasn't been a time in my life that I did not have a pet. I grew up raising gerbils, turtles, rabbits, ducks, pigs, and dogs- even an arctic wolf. So naturally, upon entering college, I knew I wanted to study animals.
Initially, my bachelor's degree focused on animal science, and my love and desire to help them ultimately led me to studying entomology. I completed my B.S. in Entomology at Texas A&M University in 2011 and was primarily interested in pest control. Subsequently, I carried that interest through my master's degree at Tarleton State University where I studied the green June beetle, an insect that feeds on manure and is a pest of vineyards. As a bonus/side note- my advisor thought I needed to leave with a valuable skill and so he taught me how to make wine, something I still do from time to time. Still, I wanted to study insects associated with animals, which led me to my PhD.
Enter the black soldier fly into my life.
I started studying the black soldier fly in 2014 as a member of Dr. Tomberlin's lab at Texas A&M. Originally, my doctoral research centered on the competitive interaction between black soldier flies and house flies in manure. However, during pursuit of my PhD, the idea of industrializing insects as food and feed blossomed and my research changed accordingly with the addition of studying the bioconversion of black soldier flies and house flies fed manure (swine, dairy, and poultry) at different rearing scales (hundreds of larvae fed grams of diet vs thousands of larvae fed kilograms of diet). I also investigated the manure after fly digestion at two different scales to determine how scale impacts the ability of the flies to reduce various constituents (nutrients, heavy metals, and fiber) in manure.
I graduated with my PhD in August 2019, and five months before completing my degree, I began working at EVO. Looking back, I never imagined I would study insects in this capacity, and yet, I am so grateful this is the was the cookie crumbled.
I find it interesting that my goal to help animals led me to this point. Initially, I narrowly focused on helping animals via pest control, but I have found a better way to fulfill this aspiration. Not only did I meet my goal by working for a company that produces black soldier flies as a healthy treat for chickens, but by working in this industry, I am also part of a greater effort- one that improves the environment through waste management and promotes sustainable production of protein and fat for a variety of animals and other valuable purposes. And this was more than I could have ever envisioned.
I am excited to provide fodder for this blog and look forward to discussing all of the new findings, beneficial attributes, factors that inhibit or enhance production, or any other topic that pertains to black soldier flies.
Chelsea Miranda, PhD
Individuals with over 25 years research experience with the black soldier fly. We are passionate about the science behind the black soldier fly and its ability to convert waste to protein.
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