The number of papers exploring the adult behavior/biology of the BSF is extremely limited globally. Predominantly, most work focuses on the the larval development and its uses for waste conversion to protein. This focus is understandable given most industry using this insect for such purposes have made this ability the cornerstone of their operation.

But, as any practitioner (e.g., backyard producer, researcher, or corporation) understands, if an adult BSF colony cannot be maintained and fertile eggs produced at a consistent rate, there will be unpredictability in the system with regards to how much waste can be managed and what to expect with larval output.

I always tell people that have interest this industry that the BSF the colony is the HEARTBEAT of their operation. If it ceases, their larval production also will meet its demise.  Because the colony is so important, I have encouraged researchers to explore the biology of adult BSF. My hopes and ambitions are we can remove the variability with regards to fertile egg production and then focus on optimizing production.  

With everything I have said, a paper was recently published on the adult behavior of the BSF:

Giunti, G., O. Campolo, F. Laudani, and V. Palmeri. 2018. Male courtship behaviour and potential for female mate choice in the black soldier fly Hermetia illucens L. (Diptera: Stratiomyidae).

I am not sure if you can access it- so I will provide a general synopsis: The authors indicate male same-sex mating attempts are made by BSF held in colony. They also indicate wing-beating is a key aspect of the adult behavior with males exhibiting this behavior when attempting to mate with a female. 

Some side notes (outside of the paper) on BSF adult mating behavior:

Always remember that BSF are forced to remain in perpetual lekking (mating) sites. So- why does it matter?

1) Adult males are constantly attempting to mate with females that are, a) not ready to mate, b) already mated and are developing eggs, or c) no longer available as they have laid their eggs.

2) Adult males that have already mated once are most likely still trying to mate with females even though they cannot perform.

3) Adults are not able to regulate their temperature given uniform conditions typically in cages (they only have access to what a producer feels is appropriate). What is best to induce optimal mating, egg fertilization, and oviposition?

4) Cage dimensions are highly variable- more studies are needed outdoors at natural lekking sites. I remember studying such behavior at a poultry farm in Alma, Georgia, USA in 1999. The space and density of flies was quite low when compared to what many producers use. How does forcing a high density impact fertile egg production?

These are just a few thoughts that come to mind with regards to BSF adult biology. But, what this means is currently colony methods are extremely non-biological and thus inefficient. 

If anyone is interested in doing adult behavior work- feel free to reach out to me. I truly believe this aspect of the BSF life cycle is sorely understudied but incredibly important for mass production (a paradox of sorts). Someone could really make a name for themselves by researching this aspect of the BSF.

As always, I like to make sure you all are aware of the productivity of hard-working students throughout the world. This thesis came across my email this past week, and I had a chance to review it this morning (fairly brief- about 30-40 pages of text).

The MS student did a nice job reviewing the nutritional, economic, legal, and marketing challenges associated with the insect-meal industry (for aquaculture in Europe). The obvious points are that insect-meal is still a bit expensive; however, with the industry growing astronomically, the price point (while remaining profitable) should continue. 

If you have time and interest- check out this thesis. Nicely done, Florent!

Introducing Insect-Based Salmon Feed: From a Nutritional, Economic, Legal, and Marketing Perspective. 

Great review article by colleagues and friends (Stefan Dinner and Christian Zurbrügg) assessing the global warming potential when using the BSF to recycle biowaste. 

Mertenat, A., S. Diener, and C. Zurbrügg. 2019. Black soldier fly biowaste treatment – assessment of global warming potential. Waste Management 84: 173-181.

The main take-home message:
1. CO2 emissions from BSF recycling waste is 47X lower than from composting alone.
2. Global warming potential by BSF is primarily attributed to residue post-composting and the electricity needed to run the system.
​3. While there is potential, and no one is denying it, the BSF has more benefits than simply allowing the waste to compost. Using the BSF to recycle waste and then replacing fishmeal with BSF can reduce global warming potential from this industry sector by 30%.  

What can I say? Money in the bank (translation- good news!).