Tropical bedbugs back in Florida, USA


This video from Florida in the USA says about itself:

Tropical bed bugs emerge after 60 years

11 November 2016

In 2015, a Brevard County family reported finding tropical bed bugs in their home.

From Science News in the USA:

Now there are two bedbug species in the United States

by Sarah Zielinski

9:00am, November 23, 2016

Bedbugs give me nightmares. Really. I have dreamt of them crawling up my legs while I lie in bed. These are common bedbugs, Cimex lectularius, and after largely disappearing from our beds in the 1950s, they have reemerged in the last few decades to cause havoc in our homes, offices, hotels and even public transportation.

Now there’s a new nightmare. Or rather, another old one. It’s the tropical bedbug, C. hemipterus. Its presence has been confirmed in Florida, and the critters could spread to other southern states, says Brittany Campbell, a graduate student at the University of Florida in Gainesville, who led a new study that tracked down the pests.

Tropical bedbugs can be found in a geographic band of land running between 30° N latitude and 30° S. In the last 20 years or so, they’ve been collected from Tanzania, Sri Lanka, Malaysia, Australia, Rwanda and more. Back in 1938, some were collected in Florida. There were more reports of the species in the following years, but none since the 1940s.

Then, in 2015, researchers at the Insect Identification Laboratory at the University of Florida identified bedbugs sent to the lab from a home in Brevard County, Florida, as tropical bedbugs. To confirm the analysis, researchers went to the home and collected more samples. They were indeed tropical bedbugs, the team reports in the September Florida Entomologist.

The family thought that the bedbugs must have been transported unknowingly into the house by one of the people who lived there. But no one living in the home had traveled outside the state recently, let alone outside the country. This suggests that tropical bedbugs can be found elsewhere in Florida, the team concludes.

Additional evidence comes from the Florida State Collection of Arthropods, which holds two female tropical bedbugs that, according to their label, were collected in Orange County, Florida, on June 11, 1989, from bedding. “Whether this species has been present in Florida and never disappeared, or has been reintroduced and remains in small populations, is not currently known,” the researchers write.

Why hasn’t anyone noticed? Well, people don’t usually send bedbugs to entomologists when they have an infestation, and your average victim isn’t going to notice the difference between the two species. “Both species are very similar,” Campbell says. Not only do they look alike, but they also both “feed on blood, hide in cracks and crevices and have similar lifestyles.” Plus, there’s been little research directly comparing the two species, she notes, so scientists don’t know how infestations might differ.

Just to give us all a few more nightmares, Campbell points out something else: While there’s probably no reason to worry that the creepy critters will spread as climate change warms the globe, she says that there is a potential for the species to move north “because humans provide nice conditions for bedbugs to develop.”

New mosquito species discovery in the Netherlands


Culiseta bergrothi

From Nature Today, 14 November 2016 (translated):

During a European study on diversity and dynamics of mosquitoes, a mosquito species new for the Netherlands was found. The discovery of the mosquito Culiseta bergrothi brings the total number of mosquito species known in the Netherlands to 40. Whether the new species is actually established in the Netherlands should be examined further.

From July 2014 to July 2015 monthly mosquitoes were caught near Wageningen for a European study. The aim of the study was the identification of insect diversity on farms, wetlands and urban fringe in three European countries (Sweden, the Netherlands and Italy). In total, in the Netherlands were caught 14 types of mosquito species, amongst whom Culex pipiens and Culiseta annulata were the most common.

Unknown species

In June 2015 on the organic farm Veld en Beek in Doorwerth were found some mosquitoes that did not look immediately like a well-known species. After identification and verification in collaboration with the Centre for Monitoring of vectors (CMV) of the NVWA, they turned out to be a new mosquito species for the Netherlands: Culiseta bergrothi (Edwards, 1921). In the same study, this species was also found on farms in Sweden. It is a relatively unknown species which has been found so far mainly in northern parts of Japan, Russia and Europe such as Norway and Sweden. The catch in the Netherlands is remarkable, as with increasing temperatures more southern species are expected.

As far as is known, Culiseta bergrothi does not transmit diseases.

Wasp makes nest, video


This 2016 video from the Netherlands shows an Odynerus spinipes wasp making its nest.

Bush-cricket video


This 7 October 2016 video shows two dark bush-crickets in the Ridderkerkse Griend nature reserve in the Netherlands.

Wasp lays egg, video


This 18 October 2016 video by Michael Grobbe from the Netherlands shows a female parasitoid wasp, boring a hole into wood and then laying an egg on a longhorn beetle larva.

Shrew and wasp, video


This 4 October 2016 video shows a greater white-toothed shrew trying to eat a wasp, which is not so easy.

Bo Andernach in the Netherlands made this video.

Spiders hear better than expected, new research


This video says about itself:

13 October 2016

In a test of hearing airborne noises, a small dark jumping spider stops moving abruptly (red pointer appears) when researchers broadcast a tone similar to the scary droning of the wings of a predatory wasp.

Video: G. Menda, Hoy Lab at Cornell

From Science News:

Be careful what you say around jumping spiders

Arachnids hear airborne sounds over greater distances than thought

By Susan Milius

8:00am, October 15, 2016

Accidental chair squeaks in a lab have tipped off researchers to a new world of eavesdroppers.

Spiders don’t have eardrums, though their exquisitely sensitive leg hairs pick up vibrations humming through solids like web silk and leaves. Biologists thought that any airborne sounds more than a few centimeters away would be inaudible. But the first recordings of auditory nerve cells firing inside a spider brain suggest that the tiny Phidippus audax jumping spider can pick up airborne sounds from at least three meters away, says Ronald Hoy of Cornell University.

During early sessions of brain recordings, Hoy’s colleagues saw bursts of nerve cell, or neuron, activity when a chair moved. Systematic experiments then showed that from several meters away, spiders were able to detect relatively quiet tones at levels comparable to human conversation. In a hearing test based on behavior, the spiders also clearly noticed when researchers broadcast a low droning like the wing sound of an approaching predatory wasp. In an instant, the spiders hunkered down motionless, the researchers report online October 13 in Current Biology.

Jumping spiders have brains about the size of a poppy seed, and Hoy credits the success of probing even tinier spots inside these (anesthetized) brains to Cornell coauthor Gil Menda and his rock-steady hands. “I close my eyes,” Menda says. He listens his way along, one slight nudge of the probe at a time toward the auditory regions, as the probe monitor’s faint popping sounds grow louder.

When Menda first realized the spider brain reacted to a chair squeak, he and Paul Shamble, a study coauthor now at Harvard University, started clapping hands, backing away from the spider and clapping again. The claps didn’t seem earthshaking, but the spider’s brain registered clapping even when they had backed out into the hallway, laughing with surprise.

Clapping or other test sounds in theory might confound the experiment by sending vibrations not just through the air but through equipment holding the spider. So the researchers did their Cornell neuron observations on a table protected from vibrations. They even took the setup for the scary wasp trials on a trip to the lab of coauthor Ronald Miles at State University of New York at Binghamton. There, they could conduct vibration testing in a highly controlled, echo-dampened chamber. Soundwise, Hoy says, “it’s really eerie.”

Neuron tests in the hushed chamber and at Cornell revealed a relatively narrow, low-pitched range of sensitivity for these spiders, Hoy says. That lets the spiders pick up rumbly tones pitched around 70 to 200 hertz; in comparison, he says, people hear best between 500 and 1,000 Hz and can detect tones from 50 Hz to 15 kilohertz.

Spiders may hear low rumbles much as they do web vibes: with specialized leg hairs, Hoy and his colleagues propose. They found that making a hair twitch could cause a sound-responsive neuron to fire.

“There seems to be no physical reason why a hair could not listen,” says Jérôme Casas of the University of Tours in France. When monitoring nerve response from hairs on cricket legs, he’s tracked airplanes flying overhead. Hoy’s team calculates that an 80 Hz tone the spiders responded to would cause air velocities of only 0.13 millimeters a second if broadcast at 65 decibels three meters away. That’s hardly a sigh of a breeze. Yet it’s above the threshold for leg hair response, says Friedrich Barth of the University of Vienna, who studies spider senses.

An evolutionary pressure favoring such sensitivity might have been eons of attacks from wasps, such as those that carry off jumping spiders and immobilize them with venom, Hoy says. A mother wasp then tucks an inert, still-alive spider into each cell of her nest where a wasp egg will eventually hatch to feed on fresh spider flesh. Wasps are major predators of many kinds of spiders, says Ximena Nelson of the University of Canterbury in Christchurch, New Zealand. If detecting their wing drone turns out to have been important in the evolution of hearing, other spiders might do long-distance eavesdropping, too.