Signals such as temperature, food supply, and levels of a dauer-inducing pheromone, a population density cue, influence this dauer decision.
L2d larvae can either continue normal development or enter dauer stage depending on whether the conditions that triggered their formation persist.
In fact, if the food supply and the population density become optimal for growth the dauer larvae can exit this stage and become L4s and then adults.
[6] Dauer larvae are extensively studied by biologists because of their ability to survive harsh environments and live for extended periods of time.
For example, C. elegans dauer larvae can survive up to four months, much longer than their average lifespan of about three weeks during normal reproductive development.
They can stand on their tails, waving their bodies in the air, and attach themselves to any passing animals, particularly insects, enabling them to travel to new food sources.
[2] C. elegans strains lacking polyunsaturated fatty acids (PUFAs) undergo increased dauer arrest when grown without cholesterol.
A study found endocannabinoids inhibit the dauer formation caused by PUFA deficiency or impaired cholesterol trafficking.
In parasitic species of nematodes, this alternative stage is called the “infective juvenile”, and facilitates transmission not between environments, but hosts.