Bedbugs’ dinosaur age origins


This April 2017 video from the USA says about itself:

Bedbugs have pestered us for centuries. These bedbug fossils were recently recovered from Paisley Caves, Oregon, the site of the oldest dated archaeological human remains in North America, and are approximately 9,400 years old.

Bedbugs nearly vanished in the United States during the 1940s and ’50s due to improved hygiene … but are on the rise again due to global travel and a increasing resistance to common pesticides.

A new study finds that bedbugs — just like flies and other insects — have favorite colors. They really like dark red and black, and they shun dazzling white and bright yellow. These apple seed-sized insects probably instinctively prefer black and red shelters over white and yellow ones because they offer better protection from predators such as ants and spiders, Pereira said.

By Jennifer Leman, 1:47pm, May 16, 2019:

Bloodthirsty bedbugs have feasted on prey for 100 million years

New genetic analyses reveal the insects evolved from at least the Cretaceous

The first bedbug infestations may have occurred in the beds of Cretaceous critters.

Scientists previously assumed bloodsuckers’ first hosts were bats. But a new genetic analysis of 34 bedbug species reveals that bedbugs appeared 30 million to 50 million years before the nocturnal mammals, says Michael Siva-Jothy, an evolutionary biologist at the University of Sheffield in England, and his colleagues.

The analysis, published online May 16 in Current Biology, pegs the emergence of ancient bedbugs at more than 100 million years ago. It also fleshes out more of the pests’ history. For instance, two bedbug species that humans are most familiar with didn’t evolve just to plague us. The common bedbug (Cimex lectularius) and the tropical bedbug (C. hemipterus) emerged around 47 million years ago, long before early human ancestors meandered into bedbug-infested caves, the team found (SN Online: 4/10/17).

The new study “puts the Cimicidae family on the map in terms of understanding its diversity, understanding its evolutionary history in a way that no other previous studies had,” says Zach Adelman, a molecular geneticist at Texas A&M University in College Station, who was not involved in the study.

To build a collection of bedbug specimens, a global network of scientists plucked insects from damp caves and dusty museum exhibits over 15 years. For each species, researchers looked at four genes known to mutate at a constant rate, like an evolutionary timekeeper. The team then calibrated that data with the known fossil records from two insects — an ancient species of bedbug and a closely related insect species — to create its timeline.

The genetic analysis can’t say what Cretaceous critters ancient bedbugs snacked on. But a computer simulation and modern-day behavior — bedbugs prefer hosts that sleep for long periods in one place — suggest that the insects probably fed on small mammals and birds.

Using the feeding habits of modern bedbugs, the team also mapped the likeliest hosts their ancestors would have preyed on. It found that bedbugs were initially picky eaters that preyed on only one type of mammal or bird. Some bedbug lineages continue to dine on a single host. But over time, some swapped furry for feathered prey, and a few even broadened their palate to include a variety of hosts, including humans.

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Paper wasps’ logical reasoning? New research


This 2012 video is called Polistes metricus life cycle – from beginning to end.

From the University of Michigan in the USA:

Paper wasps capable of behavior that resembles logical reasoning

May 8, 2019

A new University of Michigan study provides the first evidence of transitive inference, the ability to use known relationships to infer unknown relationships, in a nonvertebrate animal: the lowly paper wasp.

For millennia, transitive inference was considered a hallmark of human deductive powers, a form of logical reasoning used to make inferences: If A is greater than B, and B is greater than C, then A is greater than C.

But in recent decades, vertebrate animals including monkeys, birds and fish have demonstrated the ability to use transitive inference.

The only published study that assessed TI in invertebrates found that honeybees weren’t up to the task. One possible explanation for that result is that the small nervous system of honeybees imposes cognitive constraints that prevent those insects from conducting transitive inference.

Paper wasps have a nervous system roughly the same size — about one million neurons — as honeybees, but they exhibit a type complex social behavior not seen in honeybee colonies. University of Michigan evolutionary biologist Elizabeth Tibbetts wondered if paper wasps’ social skills could enable them to succeed where honeybees had failed.

To find out, Tibbetts and her colleagues tested whether two common species of paper wasp, Polistes dominula and Polistes metricus, could solve a transitive inference problem. The team’s findings are scheduled for online publication May 8 in the journal Biology Letters.

“This study adds to a growing body of evidence that the miniature nervous systems of insects do not limit sophisticated behaviors,” said Tibbetts, a professor in the Department of Ecology and Evolutionary Biology.

“We’re not saying that wasps used logical deduction to solve this problem, but they seem to use known relationships to make inferences about unknown relationships,” Tibbetts said. “Our findings suggest that the capacity for complex behavior may be shaped by the social environment in which behaviors are beneficial, rather than being strictly limited by brain size.”

To test for TI, Tibbetts and her colleagues first collected paper wasp queens from several locations around Ann Arbor, Michigan.

In the laboratory, individual wasps were trained to discriminate between pairs of colors called premise pairs. One color in each pair was associated with a mild electric shock, and the other was not.

“I was really surprised how quickly and accurately wasps learned the premise pairs,” said Tibbetts, who has studied the behavior of paper wasps for 20 years.

Later, the wasps were presented with paired colors that were unfamiliar to them, and they had to choose between the colors. The wasps were able to organize information into an implicit hierarchy and used transitive inference to choose between novel pairs, Tibbetts said.

“I thought wasps might get confused, just like bees,” she said. “But they had no trouble figuring out that a particular color was safe in some situations and not safe in other situations.”

So, why do wasps and honeybees — which both possess brains smaller than a grain of rice — perform so differently on transitive inference tests? One possibility is that different types of cognitive abilities are favored in bees and wasps because they display different social behaviors.

A honeybee colony has a single queen and multiple equally ranked female workers. In contrast, paper wasp colonies have several reproductive females known as foundresses. The foundresses compete with their rivals and form linear dominance hierarchies.

A wasp’s rank in the hierarchy determines shares of reproduction, work and food. Transitive inference could allow wasps to rapidly make deductions about novel social relationships.

That same skill set may enable female paper wasps to spontaneously organize information during transitive inference tests, the researchers hypothesize.

For millennia, transitive inference was regarded as a hallmark of human cognition and was thought to be based on logical deduction. More recently, some researchers have questioned whether TI requires higher-order reasoning or can be solved with simpler rules.

The study by Tibbetts and her colleagues illustrates that paper wasps can build and manipulate an implicit hierarchy. But it makes no claims about the precise mechanisms that underlie this ability.

In previous studies, Tibbetts and her colleagues showed that paper wasps recognize individuals of their species by variations in their facial markings and that they behave more aggressively toward wasps with unfamiliar faces.

The researchers have also demonstrated that paper wasps have surprisingly long memories and base their behavior on what they remember of previous social interactions with other wasps.

The other authors of the new Biology Letters paper — Jorge Agudelo, Sohini Pandit and Jessica Riojas — are undergraduates.

The work was supported by the National Science Foundation and the Doris Duke Conservation Scholars Program at the University of Michigan, funded by the Doris Duke Charitable Foundation. All experiments complied with the laws of the United States and international ethical standards.

Eight new bug species discovered on Texel


This November 2018 video says about itself:

This video is exploring the general characteristics of the insect order Hemiptera.

The blog of wildlife warden Erik van der Spek on Texel island in the Netherlands reports today (translated):

Bug researchers Dik Hermes and Berend Aukema have found eight bug species new for Texel in 2018, four of which are also new for the Wadden Sea area. Meanwhile, 342 of the 641 bug species known from the Netherlands are also known from Texel.

Beetle-ant symbiosis in the dinosaur age


Detailed photos of the newly discovered Promyrmister kistneri beetle's morphology through its amber encasement. Credit: Courtesy of the Parker laboratory / eLife

From the California Institute of Technology in the USA:

These beetles have successfully freeloaded for 100 million years

Ancient beetle infiltrated earliest-known ant colonies like its modern relatives

April 17, 2019

Summary: An ancient and rare beetle fossil is the oldest example of a social relationship between two animal species.

Almost 100 million years ago, a tiny and misfortunate beetle died after wandering into a sticky glob of resin leaking from a tree in a region near present-day Southeast Asia. Fossilized in amber, this beetle eventually made its way to the desk of entomologist Joe Parker, assistant professor of biology and biological engineering at Caltech. Parker and his colleagues have now determined that the perfectly preserved beetle fossil is the oldest-known example of an animal in a behaviorally symbiotic relationship.

A paper describing the work appears on April 16 in the journal eLife.

Symbiotic relationships between two species have arisen repeatedly during animal evolution. These relationships range from mutually beneficial associations, like humans and their pet dogs, to the parasitic, like a tapeworm and its host.

Some of the most complex examples of behavioral symbiosis occur between ants and other types of small insects called myrmecophiles — meaning “ant lovers.” Thanks to ants’ abilities to form complex social colonies, they are able to repel predators and amass food resources, making ant nests a highly desirable habitat. Myrmecophiles display elaborate social behaviors and chemical adaptations to deceive ants and live among them, reaping the benefits of a safe environment and plentiful food.

Ants’ social behaviors first appear in the fossil record 99 million years ago, during the Cretaceous period of the Mesozoic era, and are believed to have evolved not long before, in the Early Cretaceous. Now, the discovery of a Cretaceous myrmecophile fossil implies that the freeloading insects were already taking advantage of ants’ earliest societies. The finding means that myrmecophiles have been a constant presence among ant colonies from their earliest origins and that this socially parasitic lifestyle can persist over vast expanses of evolutionary time.

“This beetle-ant relationship is the most ancient behavioral symbiosis now known in the animal kingdom,” says Parker. “This fossil shows us that symbiosis can be a very successful long-term survival strategy for animal lineages.”

The fossilized beetle, named Promyrmister kistneri, belongs to a subfamily of “clown” beetles (Haeteriinae), all modern species of which are myrmecophiles. These modern beetles are so specialized for life among ants that they will die without their ant hosts and have evolved extreme adaptations for infiltrating colonies. The beetles are physically well protected by a thick tank-like body plan and robust appendages, and they can mimic their host ants’ nest pheromones, allowing them to disguise themselves in the colony. They also secrete compounds that are thought to be pacifying or attractive to ants, helping the beetles gain the acceptance of their aggressive hosts. The fossilized Promyrmister is a similarly sturdy insect, with thick legs, a shielded head, and glandular orifices that the researchers theorize exuded chemicals to appease its primitive ant hosts.

Depending on another species so heavily for survival has its risks; indeed, an extinction of the host species would be catastrophic for the symbiont. The similarities between the fossilized beetle and its modern relatives suggest that the particular adaptations of myrmecophile clown beetles first evolved inside colonies of early “stem group” ants, which are long extinct. Due to Promyrmister’s remarkable similarity to modern clown beetles, Parker and his collaborators infer that the beetles must have “host switched” to colonies of modern ants to avoid undergoing extinction themselves. This adaptability of symbiotic organisms to move between partner species during evolution may be essential for the long-term stability of these intricate interspecies relationships.

New wasp species discovery on green roof


The newly discovered wasp species Diasta dichrocera. Photo: Kees van Achterberg

Translated from Dutch Vroege Vogels radio, 14 April 2019:

Student discovers new wasp species

An investigation into insects on green roofs unexpectedly found a new species for the Netherlands in Rotterdam, in the roof garden of Erasmus Medical Center: a Braconidae family wasp species. The tiny wasp is called Idiasta dichrocera, and does not yet have a Dutch name.

There is a proposal to call it Erasmus wasp.

To find out whether green roofs actually contribute to biodiversity, the Natural History Museum Rotterdam is researching which plants and animals are found there. Particular attention has been paid to the insects that can be found. The first results are starting to show.

Eva Drukker, a master’s student at Wageningen University, did the fieldwork. She has placed insect traps on various green roofs and roof gardens throughout the Netherlands. These samples must show which factors make a green roof a success for insects and other small animals.

It is a coincidence that the new roof garden of Erasmus MC in Rotterdam, the neighbours of the Natural History Museum Rotterdam, produced the special find. There, Eva found a little insect that was unknown to her: a small wasp-like creature that at first sight looks more like an ant than a wasp. Thanks to expert Kees van Achterberg, the animal could be named.

Idiasta dichrocera is only 4 millimeters in size. It had never found in the Netherlands before. It was in other European and Asian countries, including Germany, Sweden, Russia and China. Almost nothing is known about its way of life. It is suspected that the wasp is a parasite of fly larvae. Just what the wasp was looking for on the hospital roof is a mystery.

The wasp is included in the collection of the Natural History Museum Rotterdam under collection number NMR 9970-137370. Enthusiasts are welcome to come and admire the insect. A loupe is recommended.

Eva Drukker, discoverer of the new wasp species

This wasp was a female. Also other interesting insect species were discovered during the research.

New Australian wasp species named after Doctor Who


This 9 April 2019 video from Australia says about itself:

New species of wasps named after Oreos and Doctor Who

Read more here.

From the University of Adelaide in Australia:

New wasps named after biscuits and Doctor Who aliens

April 9, 2019

University of Adelaide researchers were inspired by everything from chocolate biscuits and Doctor Who aliens when choosing names for 10 new species of wasps.

“I named one wasp Sathon oreo as the antennae are dark brown with a thick white stripe in the middle… like an Oreo chocolate biscuit,” says Dr Erinn Fagan-Jeffries from the University of Adelaide’s School of Biological Sciences.

While the new species Choeras zygon is named for the Zygon race of aliens in Doctor Who.

“Zygon aliens consume their host whilst inhabiting them, a trait particularly relevant to parasitic wasps,” says Dr Fagan-Jeffries.

These wasps inject their eggs into live caterpillars, and the baby wasps slowly eat the caterpillar from the inside out. As gruesome as it sounds, they are very important in ecosystems for regulating native caterpillar populations.

One of the new wasps, Choeras bushblitz, takes its name from the Bush Blitz species discovery program, a unique multi-million dollar partnership between the Australian Government … and Earthwatch Australia to document plants and animals across Australia.

“Less than 10% of this group of wasps have scientific names, which is why programs like Bush Blitz are so vital. We have discovered over 1,660 new species since 2010, and 17 of those are wasps”, says Jo Harding, Bush Blitz Manager.

Taxonomy, the scientific discipline of describing new species, is vital for understanding and documenting the living things around us. “Until taxonomists name and formally describe a species, it is difficult for other researchers, such as those working in conservation, or biological control, to do anything with it,” says Ms Harding.

Inspirational taxonomists and entomologists that helped Dr Fagan-Jeffries collect vital specimens for this research, as well as those who feature prominently throughout her career, were also honoured with species named after them.

“I always loved insects in school, and I had a lot of incredible support from entomologists, back then and also during my PhD, who fuelled my passion for following a scientific career path,” Dr Fagan-Jeffries says. “Naming species after those people is just a tiny way of saying thank you.”

Species named after researchers include Dolichogenidea brabyi, Dolichogenidea garytaylori, Dolichogenidea forrestae and Dolichogenidea kelleri, after entomologists Michael Braby, Gary Taylor, Jan Forrest and Michael Keller.

Blue stick insects discovery in Madagascar


Achrioptera manga, one of two new Madagascan stick insect species discovered by Drs Glaw, Bradler and colleagues. Manga means 'blue' in the Madagasy language. Credit: Dr. Frank Glaw

From Frontiers in Ecology and Evolution:

Love Island: Flamboyant males get the girls on Madagascar

In two new species of rare giant stick insects, males turn livid blue or multicolored at sexual maturity — but why?

April 2, 2019

Summary: Scientists have discovered two new species of giant stick insect on Madagascar, whose males become dazzling blue or multicolored at sexual maturity. The researchers describe their rare and exciting findings, and wonder at the reproductive success of the least stick-like stick insects on the planet.

Biodiversity hotspot Madagascar is one of the world’s biggest islands, and home to some of its biggest insects. Now German scientists have discovered two new species of giant stick insect, living only in the dry forests of Madagascar’s northernmost tip.

One giant female measures a whopping 24cm — but it is the smaller males that are most striking. At sexual maturity these daredevils abandon their stick-like camouflage for dazzling blue or many-colored shining armor.

Writing in Frontiers in Ecology and Evolution, the researchers describe their rare and exciting findings, and wonder at the reproductive success of the least stick-like stick insects on the planet.

When two become four

“Nearly all of the 3000+ known species of stick insects try to be inconspicuous and just look like twigs,” says senior author Dr. Sven Bradler of the University of Göttingen, Germany. “There are a very few, very large exceptions — and we have just discovered a couple more of them.”

The authors re-examined specimens they’d previously identified as odd-looking examples of two existing giant stick insect species, whose adult males remarkably are bright blue or multicolored.

“These were similar in size — 15 to 24cm — but generally less spiny and a bit differently colored than typical examples of their kind,” explains Bradler. “Now genetic tests confirm that the quirky individuals are in fact two new species, distinct from the original two but part of the same group.” explains Bradler.

Bradler’s reclassification places members of this group of species as close evolutionary relatives to other Madagascan stick insects, rather than cousins from overseas as previously thought. This is a potentially major finding, as it challenges the prevailing view that sticks insects colonized Madagascar multiple times.

He who dares, wins

The discovery also prompted the researchers to wonder: what reproductive advantage do these males gain from their bright colors, that is worth exposing themselves to predators?

The first author Dr. Frank Glaw of the Bavarian State Collection of Zoology in Munich, and colleagues bred the new giant stick insect species in captivity to observe their behavior.

“Males of one species started mating attempts only when they achieved their bright blue color.”

This might suggest that the males use their bright coloring to attract a mate. However, it is hard to believe the males could find a mate before being eaten — unless their bright coloring acts as a deterrent to predators.

“Males searching for a mate have to move about more, so pretending to be a stick becomes tricky. Better perhaps to plump for the opposite: a brightly colored warning.”

Bright colors — suggestive of toxicity — keep safe vivid members of other typically camouflaged species, like lividly colored Madagascan frogs.

“In support of this, all stick insects have neck glands that [produce] repellant substances, and these are typically well-developed in brightly colored species. Alternatively, like the Madagascan frogs some giant stick insects may have developed the ability to accumulate toxins from their food.”

But testing these hypotheses will be tough, admits Glaw.

Bradler adds “More than one factor may have played a role in the evolution of this remarkably conspicuous coloration. So even with more data on mate selection, habits, predators, natural food plants, toxins produced by defense glands and possible accumulation of toxins among giant stick insects, finding evidence for these ideas may prove difficult.”

Colorful stick insects have a bright future

Whatever its function, the splendid coloring of the male giant stick insects could make them a strong flagship species to promote the unique biodiversity of Madagascar, and the need for its protection.

“Already the once-uncertain future of these two new species seems secured, with their forest habitat in northern Madagascar a hotspot for conservation priorities”, says Glaw. “It is vital to maintain awareness and motivation to keep logging at bay. This precious area also harbors the highest density of critically endangered reptiles in Madagascar and is home of one of the most threatened primate species in the world, the lemur Lepilemur septentrionalis.”