Diesel fuel ‘bugs’ are a range of bacteria and fungi generally known as hydrocarbon utilising micro-organisms.
They can metabolise or breakdown hydrocarbons – in essence ‘feed’ on the fuel.
Vehicles with poorly maintained fuel systems or tanks that are subject to water contamination (from water leaks, condensation, or contaminated fuel), or those that see infrequent use are most susceptible.
Fuel in storage can also become infested. These microbes mostly live at the interface between the fuel and water layers.
They can enter through tank vents or during fuel transportation and under the right conditions, some varieties can double their numbers every 20 minutes.
Read more: https://www.racq.com.au/articles/drive/2023/1/diesel-fuel-bugs-a-serious-pest