Hairy, Fleshy, and Swarming: Why Hundreds of Tarantulas Will Soon Invade the Southern United States ?

Ces araignées velues, appartenant à l’espèce Aphonopelma hentzi, ou tarentules brunes du Texas (illustration). Unsplash – Lena Taranenko

Plusieurs centaines de tarentules migrent chaque année dans le sud des Etats-Unis vers la fin de l’été malgré leur déclin en raison du réchauffement climatique. Explications.

Every year in late summer, hundreds of tarantulas migrate across the southern United States, according to the journal ScienceAlert.

These hairy spiders, belonging to the species Aphonopelma hentzi, or Texas brown tarantulas, are about the size of a fist. They are therefore preparing to live an important period of their life.

Neither harmful nor dangerous

Although their appearance can be frightening, they are neither harmful nor dangerous to humans. These spiders, quite discreet, spend most of their time hidden in abandoned burrows and come out at night to feed on insects. But when temperatures start to drop, from late August to October, their behavior changes radically.

In fact, at the end of summer, males emerge from hiding, driven by the reproductive instinct. They travel up to a kilometer to find a mate. These males can mate with more than a hundred females in a season. Once the eggs are fertilized, the female watches over her egg sacs, which will give birth to thousands of small tarantulas in 45 to 60 days, just in time for Halloween.

However, the number of these spiders has been declining in recent years. According to ScienceAlert, this decline is likely due to climate change, unregulated harvesting and the degradation of their natural habitat. The situation is all the more worrying because male tarantulas only live for ten years and do not reach maturity until they are about eight years old, making each breeding season crucial.

La Junta, Colorado, celebrates “Tarantula Mardi Gras” every September to raise awareness about their conservation. Similarly, the village of Coarsegold, California, holds an annual festival dedicated to the local arachnids.

Don't Kill It

For those who come across a tarantula, it is advisable not to kill it. It is rather recommended to “take a bowl and a sheet of cardboard to create a small basket and place it outside”.