Fuelstat Test Kit Diesel MarketThere are a number of different types of microorganisms that can grow in certain types of fuel. The biggest problem is presented by a filamentous fungus called Hormoconis resinae, (H Res). Previously called Cladosporium resinae, and more commonly referred to as the diesel bug. H Res is a fungus that thrives in diesel fuel. It requires only a minimal amount of water content in the fuel to grow and will cause filter blockages, component failure and tank