Bed Bugs Have Fave Colors, Dislike Others
Bed bugs are attracted to the colors red and black, but dislike yellows and greens, new research shows. →
Bed bugs favor the colors red and black, but tend to avoid green and yellow, finds new research on the parasites.
The study is the first to show that bed bugs have color preferences. The findings could improve ways of controlling the pest, whose bites can cause itching, inflammation and allergic reactions.
For the experiments, outlined in the Journal of Medical Entomology, scientists created tent-like "harborages" for the bugs, to see which ones they gravitated to or avoided. Outside of the lab setting, bedding and luggage often function as bed bug retreats.
"It was speculated that a bed bug would go to any harborage in an attempt to hide," the authors wrote. "However, these color experiments show that bed bugs ... will select a harborage based on its color when moving in the light."
Co-author Corraine McNeill of Union College said in a release: "We originally thought the bed bugs might prefer red because blood is red and that's what they feed on. However, after doing the study, the main reason we think they preferred red colors is because bed bugs themselves appear red, so they go to these harborages because they want to be with other bed bugs."
McNeill and her colleagues determined that many factors influenced which color the bed bugs chose. For example, the bugs' color preferences changed as they grew older, and they chose different colors in groups than when alone. Whether the bugs were satiated or hungry also affected their choices. Males and females additionally seemed to prefer different colors.
Despite the variation, favoring red and black and avoiding yellow and green hues remained mostly consistent.
According to the "Bugs Without Borders" survey conducted last year by the University of Kentucky and the National Pest Management Association, the top three places where pest professionals report finding bed bugs are apartments/condos (95 percent), single-family homes (93 percent), and hotels/motels (75 percent). Bed bugs have also been found in nursing homes, college dorms, offices, schools and daycare centers, hospitals and public transportation.
While a CDC fact sheet maintains, "Bed bugs should not be considered as a medical or public health hazard," clearly the parasite's prevalence is a concern and bites could pose more of a threat to children, the elderly and those already weakened by illness. So creating more effective traps for the bugs is one of the researchers' goals.
"We are thinking about how you can enhance bed bug traps by using ... a specific color that is attractive to the bug," McNeill said. "However, the point isn't to use the color traps in isolation, but to use color preference as something in your toolkit to be paired with other things such as pheromones or carbon dioxide to potentially increase the number of bed bugs in a trap."
She and her team advise not to throw out your red and black bedding and luggage just yet.
McNeill said, "I always joke with people, ‘Make sure you get yellow sheets!' But to be very honest, I think that would be stretching the results a little too much."
"I think using colors to monitor and prevent bed bugs would have to be specifically applied to some sort of trap, and it would have to be used along with another strategy for control," she said. "I don't know how far I would go to say don't get a red suitcase or red sheets, but the research hasn't been done yet, so we can't really rule that out completely."
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.