Spiders might not be everyone’s favorite creature, but they provide a vital service to us all, every year consuming as much prey as all the world’s whales do. But the eight-legged critters don’t just limit themselves to insects, they also snack on vertebrates, and now researchers have discovered that one group of spider found in Florida that was thought to be largely insectivorous actually feasts on lizards and frogs.
While it has long been known that many species of spider catch and devour a whole host of different types of vertebrates, from birds to fish, those that belonged to the group known as the jumping spiders were not thought to have a predilection for vertebrate flesh. That was until researchers found that one species living in East Africa had a particular penchant for supping on vertebrate blood.
They found that the species known as Evarcha culicivora would hunt down female mosquitoes, and imbibe the blood they’d collected from their latest feed. After catching the insects, the spiders would pierce the abdomen of the mosquitoes and suck out the hematological treat. When this discovery was announced, it made big waves in the arachnid-studying community.
There had been further anecdotal evidence to suggest that jumping spiders might actually be much more prolific hunters than people had realized, and so one group of researchers set about conducting a search to see how much information they could find relating to the group of arachnids preying on vertebrates.
They trawled through scientific literature, books, and crucially in today’s world, social media posts, to aggregate all recordings. Despite the tiny spiders weighing just 2 grams at their largest, some were found to be able to tackle frogs and even lizards up to three times their weight.
In the eight incidents they found of the species Phidippus regius, which is the largest species of jumping spider, chowing down on the invasive Cuban tree frog, all occurred in one of seven Floridian counties. They also found another case of an unknown Phidippus species taking on a juvenile anole lizard in Costa Rica. Publishing their results in the Journal of Arachnology, this is the first time vertebrate predation by jumping spiders has been documented in scientific literature.
The behavior has probably remained hidden for so long as the spiders are pretty shy. They suspect that it is only the largest species of jumping spider, like P. regius, that can do this with any regularity, as they others tend to be too small and are therefore often on the receiving end of the frogs and lizards.