When it comes to longevity and surviving extended amounts of time without food, the Argas brumpti species of African tick is hard to beat, newly published research shows.
Observed close-up in the lab over the course of 45 years by entomologist Julian Shepherd from Binghamton University in New York, some of these ticks have survived as long as 27 years – way above the average of 2-3 years for tick species in general.
What’s more, some of the arachnids were able to survive an astonishing eight years without any food, which is impressive even for a creature that’s evolved to get by without much to eat or drink.
And for a final trick, one of the female ticks laid eggs four years after the death of the last male tick in the group. This is most likely down to the female being able to store male sperm for a much longer period of time than normal.
“The longevity of these ticks is apparently a record for any species of tick,” writes Shepherd in a newly published paper outlining his results.
“The delay in reproduction likely represents long-term storage of viable sperm, also apparently a record for any species of tick.”
The original ticks were a gift to Shepherd in 1976, and he set them up for observation in his lab under stable conditions – 21 degrees Celsius or 69.8 degrees Fahrenheit, and 81 percent relative humidity. The offspring of that original group are still alive and reproducing today.
It was when the food source – rabbits, mice and blood from rats – ran out in 1984 that the research into starvation started, and it was halfway through the eight-year fast that the last original male tick died.
“I am always enthralled by the adaptations of organisms to their environment,” says Shepherd. “In this case, a dry environment with virtually no access to water for long periods of time and a lifestyle that must wait for very long intervals of no food between encounters with host animals.”
A. brumpti are relatively large for ticks, measuring up to 20 millimeters (0.79 inches) long. Traditionally, they often hang out in burrows, dust baths or termite mounds, looking for other animals (including humans) to snack on.
While they do bite humans, however, they’re not the cause of any known diseases. These creatures also have a soft and leathery skin without the hard plates found in more commonly known species of ticks.
Whether or not the offspring of the original ticks end up living as long is yet to be determined – the younger ticks are now headed to South Africa to help with DNA research.
“Research on how organisms master such challenges can inform understanding of how other organisms, including us, might manage similar challenges,” says Shepherd.
Shepherd’s paper has been published in the Journal of Medical Entomology.