More Than 300 Spiders Pretend to Be Ants
Some spiders are such ant wanna-be's that they resemble, act like, and hang out with ants, even forming mini colonies to foil ant-hating predators.
Tarantulas and black widows may cause human Miss Muffets to get off their tuffets, but several studies show that many spiders themselves run for their lives if they encounter Myrmarachne melanotarsa, a gregarious jumping spider that pretends to be an ant.
The jumping spider is not the only faux ant. A new Phys Org report notes that there are more than 300 species of spider that mimic the outward appearance of ants.
The jumping spider looks like, acts like, and hangs out with ants, even forming mini, colony-type gangs to foil their own predators.
Most spiders are afraid of ants, and they even fear these fake ants that are really spiders.
"Ants are very dangerous to arthropods," Ximena Nelson, of the University of Canterbury, told Discovery News. Nelson is one of the world's leading experts on myrmecomorphy, or resembling an ant.
Nelson said ants "are social and can mount a strong response if alerted to potential danger, and they have strong mandibles and are extremely lethal to many spiders. Many ants also contain formic acid, which they can use for defense by squirting it on potential predators, causing considerable harm."
Spiders that make the mistake of putting an ant in their mouths, she added, often spit them out immediately, suggesting that "ants don't taste good either."
What's an ant-loathing spider to do, then, to avoid being bullied? Mimicry comes into play, because it's a case of "if you can't beat them, join them."
Many animals impersonate other species temporarily. Some birds, for example, copy avian songs that aren't their own. Cats sometimes chatter like birds, presumably to fool their potential prey. Even hunters sometimes don camouflage clothing to disguise themselves.
Evolving a permanent new body to facilitate mimicry, however, takes deception to a whole new level.
Nelson believes the ant-resembling jumping spider evolved its ant-like ways over a long period of evolution "in which each morph that resembled ants more was selected for and morphs that did not resemble ants were selected against."
The deception works better if the fake ant behaves like an actual ant too, so natural selection appears to have also selected for spiders within this species that act like ants. The end result is a spider that is the spitting image of an ant.
Spider expert Paula Cushing, of the Denver Museum of Nature & Science, told Discovery News that insects and spiders that mimic ants "are well protected from their own potential predators" since "ants are often unpalatable prey for arthropod predators or are not attractive as prey due to their aggressive behavior towards intruders and their ability to sting and bite animals that attack them."
There's yet another perk to looking like an ant, at least for M. melanotarsa. This ant mimic spider is so feared that female spiders from other species will flee when they see it, even abandoning their broods, which the fake ant then consumes as an easy snack.
Ant mimic jumping spider (
Insects and other creepy crawlies may be tiny, but their lineages are mighty, finds a new study that determined the common ancestor of mites and insects existed about 570 million years ago. The study, published in the latest issue of the journal Science, presents an evolutionary timeline that settles many longstanding uncertainties about insects and related species. It found that true insects first emerged about 479 million years ago, long before dinosaurs first walked the Earth. Co-author Karl Kjer, a Rutgers entomologist, explained that mites are arthropods, a group that's distantly related to insects. Spiders and crustaceans are also arthropods.
Spiders such as the huntsman spider can, like mites, trace their lineages back to about 570 million years ago, according to the new study. The researchers believe that the common ancestor of mites, spiders and insects was a water-dweller.
Millipedes, such as the one shown here, as well as centipedes are known as myriapods. The most recent common ancestor of myriapods and crustaceans lived about 550 million years ago. Again, this "mother of many bugs" would have been a marine dweller. Kjer explained, "You can't really expect anything to live on land without plants, and plants and insects colonized land at about the same time, around 480 million years ago. So any date before that is a sea creature." Moving forward in time, the most common ancestor of millipedes and centipedes existed a little over 400 million years ago. The leggy body plan has proven to be extremely successful.
"This is an early insect that evolved before insects had wings," Kjer said. Its ancestry goes back about 420 million years. The common ancestor of silverfish living today first emerged about 250 million years ago. Dinosaurs and the earliest mammals likely would have then seen silverfish very similar to the ones that are alive now.
Dragonflies and damselflies have family histories that go back about 406 million years. Kjer said that such insects looked differently then, however. "For example," he said, "they had visible antennae." Their distant ancestors were among the first animals on earth to fly.
"Parasitic lice are interesting, because they probably needed either feathers or fur," Kjer said. As a result, they are the relative newbies to this list. Nonetheless, the researchers believe it is possible that ancestors of today's lice were around 120 million years ago, possibly living off of dinosaurs and other creatures then.
Crickets, katydids and grasshoppers had a common ancestor that lived just over 200 million years ago, and a stem lineage that goes back even further to 248 million years ago. A trivia question might be: Which came first, these insects or grass? The insects predate the grass that they now often thrive in.
Dinosaur Era fossils sometimes include what researchers call "roachoids," or wing impressions that were made by ancestors to today's roaches, mantids (like the praying mantis) and termites. "Some cockroaches are actually more closely related to termites than they are to other cockroaches," Kjer said, explaining that this makes tracing back their lineages somewhat confusing. He and his colleagues determined that the stem lineage goes back about 230 million years, while the earliest actual cockroach first emerged around 170 million years ago.
Termites and cockroaches have a tightly interwoven family history. Termites similar to the ones we know today were around 138 million years ago. Now we often think of termites as pests, but they are good eats for many different animals, which back in the day would have included our primate ancestors.
Flies like houseflies that often buzz around homes belong to the order Diptera, which has a family tree that goes back 243 million years ago. The most recent common ancestor for modern flies lived about 158 million years ago, according to the study. There is little doubt that the earliest humans, and their primate predecessors, had to contend with pesky flies and all of the other insects mentioned on this list. All of these organisms are extremely hardy. The researchers determined that, in the history of our planet, there has only been one mass extinction event that had much impact on insects. It occurred 252 million years ago (the Permian mass extinction), and even it set the stage for the emergence of flies, cockroaches, termites and numerous other creepy crawlies.