Soldier Flies Join the War against Antibiotic Resistance

by Jess Beecroft, class of 2020.

Preventing plant diseases using fly larvae fat

Black Soldier Fly Head, Hermetia illucens. Image by Thomas Shahan via Creative Commons

Plant diseases present never-ending problems for food production. With loss of crops leading to food shortages and negative economic impacts that range from local to worldwide scales, it is no wonder that so much research is invested in preventing or treating them.

One of the main players in causing plant disease are bacterial phytopathogens (pathogen- causes harm, phyto- to plants) which historically have been fought with antibiotics. However, our excess use of antibiotics in literally every field has created a new problem altogether. The reign of antibiotic resistance has put pressure on scientists to find natural antimicrobial compounds. The urgency is ever-increasing as an array of solutions are required if the planet is going to live to eat another day.


Even ancient civilisations, although unaware, used compounds to treat bacterial infections but the discovery of the first ‘true’ antibiotic occurred in 1928. Penicillin revolutionised medicine and human mortality but the extreme overuse of antibiotics since then has finally caught up to us.

Antibiotics either kill or stop the growth of bacteria but they haven’t managed to stay around this long without developing ways to fight back. Some will be naturally resistant and these few that survive can multiply at an extremely fast rate. They can even pass on the instructions on how to be resistant to other bacteria!! The video below shows just how easy and quick it is for them to overcome antibiotics-

Every time we use an antibiotic we essentially generate bacteria resistant to that particular one. When someone is ill the next feasible option is to try another antibiotic so we started using multiple antibiotics to treat infections… then combine this with excessive preventative use on crops and livestock… and with people not finishing their treatment courses… and with mass misuse of antibiotics…and any guesses on what we created??


Great, so now we have bacteria (and other microorganisms but that’s a whole other topic) that are resistant to almost all antibiotics. Hopefully I have been clear enough for you to be able to appreciate the gravity of the situation, but to help put it into perspective here are some ‘fun’ quotes from the World Heath Organisation (WHO).

“Antibiotic resistance is one of the biggest threats to global health, food security, and development today”

“Without urgent action, we are heading for a post-antibiotic era, in which common infections and minor injuries can once again kill”

Infectious diseases used to be the leading global cause of death and if we can’t discover enough new treatments, they soon will be again.

Right, enough doom and gloom now it’s time for…


Biotechnologists from MIPT belief that “Antimicrobial compounds of natural origin stand up as frontiers in the attempts of the antibiotic overuse replacement”. This actually makes a lot of sense as plants and animals never created nor discovered antibiotics, but somehow they are still about which so they must have natural defences. Previous research pointed towards the black soldier fly, H. illucens, as having antimicrobial properties but before we dive into their findings, a quick side note to clear up some definitions— antimicrobials inhibits growth or kills microorganisms, antibiotics falls under this umbrella term and is specific to bacteria.

Once it was determined that the fly did have potential, the scientists go to work:

Step 1: Figure out that the best method of extracting solution from the flies to test on is  through pulping fly larvae (yuck)

Step 2: Determine that it is the fatty acids in the solution that are responsible for the antimicrobial properties

Step 3: Test the extract on phytopathogenic bacterial strains to see if it effectively kills or inhibits them

And it did!! The larvae pulp extract has “substantial antibacterial potential” therefore more research could be done to work out a way to use them for crop protection.


In agriculture antibiotics are used mainly as a preventative measure but the widespread use contributes heavily to antibiotic resistance. This potential application of fly larvae may not solve the problem but solutions like this will sure slow it down.

In a way, antibiotic resistance is just like climate change.. it happens naturally but humans are accelerating the process at not only an unsustainable, but a dangerous rate.