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Watch how battles with bats give moths their flashy tails

Bats and their prey are in a constant arms race. Whereas the winged mammals home in on insects with frighteningly accurate sonar, some of their prey—such as the tiger moth—fight back with sonar clicks and even jamming signals. Now, in a series of bat-moth skirmishes (above), scientists have shown how other moths create an “acoustic illusion,” with long wing-tails that fool bats into striking the wrong place. The finding helps explain why some moths have such showy tails, and it may also provide inspiration for drones of the future.

Moth tails vary from species to species: Some have big lobes at the bottom of the hindwing instead of a distinctive tail; others have just a short protrusion. Still others have long tails that are thin strands with twisted cuplike ends. In 2015, sensory ecologist Jesse Barber of Boise State University in Idaho and colleagues discovered that some silk moths use their tails to confuse bat predators. Now, graduate student Juliette Rubin has shown just what makes the tails such effective deterrents.

Working with three species of silk moths—luna, African moon, and polyphemus—Rubin shortened or cut off some of their hindwings and glued longer or differently shaped tails to others. She then tied the moths to a string hanging from the top of a large cage and released a big brown bat (Eptesicus fuscus) inside. She used high-speed cameras and microphones to record the ensuing fight.

Moths with no tails (such as polyphemus) were easy quarry for the bats, escaping only about 27% of the time, Rubin, Barber, and colleagues report today in Science Advances. But when Rubin enlarged the polyphemus hindwing lobe, twice as many escaped the bat’s sonar, or echolocation system.

Bats going after long-tailed African moon moths got a mouthful of tail 75% of the time as the moths flitted away. Shorten the tail, and the African moon moths escaped only 45% of the time. With no tail at all, that percentage dropped to 34%. When Rubin’s colleagues Chris Hamilton and Akito Kawahara at the Florida Museum of Natural History in Gainesville built a family tree of silk moths and their relatives, they realized that long tails had evolved independently several times. That’s further evidence that they are an important life-saving feature for these moths.

“The authors have demonstrated a powerful approach for understanding the diversity of moth shapes,” says Aaron Corcoran, an animal ecologist at Wake Forest University in Winston-Salem, North Carolina, who was not involved with the work. “There appear to be many different ways to trick a bat’s echolocation system.” The study also revealed how hard it was for bats to work around this deception, he adds. “The fact that the bats in the study never learned how to catch these moths, despite ample time to do so, shows how hard-wired this blind spot is in the bat’s perception.”

The findings could benefit other fields such as robotics, says Martin How, a sensory ecologist at the University of Bristol in the United Kingdom. Because the study examined the bat-moth dogfights at such a fine scale, the results could help engineers design the “bio-inspired technologies of the future,” he says, including deftly flying drones.

*Correction, 5 July, 1:45 p.m.: This article has been updated to reflect that although Juliette Rubin was the lead author of the paper, some of the work was done by other researchers.

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A “superb” southwestern Missouri cicada, Neotibicen superbus

Back in the summer of 2015, I made an early August trip to the White River Hills region of extreme southwestern Missouri. I was actually looking for one of Missouri’s more uncommon cerambycid beetles – Prionus pocularis, associated with shortleaf pine in the mixed hardwood/pine forests across the southern part of the state. I did not encounter the beetle in either my prionic acid-baited pitfall traps or at the ultraviolet lights I had set up the evening before, but while I was in the area I thought I would visit one of my favorite places in the region – Drury-Mincy Conservation Area in Taney Co. Sitting right on the border with Arkansas, the rolling hills of this area feature high-quality dolomite glades and post oak savannas. I’ve had some excellent collecting here in the past and hoped I would find something of interest this time as well. I didn’t arrive until after midnight, and since there are no hotels in the area I just slept in the car.

Neotibicen superbus

The next morning temperatures began to rise quickly, and with it so did the cacophony of cicadas getting into high gear with their droning buzz calls. As I passed underneath one particular tree I noticed the song was coming from a branch very near my head. I like cicadas, but had it been the song of a “normal” cicada like Neotibicen lyricen (lyric cicada) or N. pruinosus (scissor grinder cicada) I would have paid it no mind. It was, instead, unfamiliar and distinctive, and when I searched the branches above me I recognized the beautiful insect responsible for the call as Neotibicen superbus (superb cicada), a southwest Missouri specialty—sumptuous lime-green above and bright white pruinose beneath. I had not seen this spectacular species since the mid 1980s (most of my visits to the area have been in the spring or the fall rather than high summer), and I managed to catch it and take a quick iPhone photograph for documentation. A species this beautiful, however, deserves ‘real’ photos, so I spent the next couple of hours attempting to photograph an individual in situ with the big camera. Of course, this is much, much easier said than done, especially with this species—their bulging eyes give them exceptional vision, and they are very skittish and quick to take flight. Most of the individuals that I located were too high up in the canopy to allow a shot, and each individual that was low enough for me to approach ended up fluttering off with a screech before I could even compose a shot, much less press the shutter. Persistence paid, however, and I eventually managed to approach and photograph an unusually calm female resting – quite conveniently – at chest height on the trunk of a persimmon tree.

Sanborn-Phillips_2013_Fig-16

According to Sanborn & Phillips (2013, Figure 16 – reproduced above), Neotibicen superbus, is found in trees within grassland environments primarily in eastern Texas and Oklahoma, although records of it exist from each of the surrounding states – especially southern Missouri and northern Arkansas (Figure 16 below, Sanborn & Phillips 2013). Later the same day I would see the species abundantly again in another of the region’s dolomite glades – this one in Roaring River State Park further west in Barry Co., suggesting that dolomite glades are the preferred habitat in this part of its range. Interestingly, I think the Missouri records at least must be relatively recent, as Froeschner (1952) did not include the species in his synopsis of Missouri cicadas. This was all the information I had back in the 1980s when I first encountered the species in southwestern Missouri, its apparent unrecorded status in the state making it an even more exciting find at the time.

Neotibicen superbus

REFERENCES:

Froeschner, R. C.  1952. A synopsis of the Cicadidae of Missouri. Journal of the New York Entomological Society 60:1–14 [pdf].

Sanborn, A. F. & P. K. Phillips. 2013. Biogeography of the cicadas (Hemiptera: Cicadidae) of North America, north of Mexico. Diversity 5(2):166–239 [abstractpdf].

© Ted C. MacRae 2018

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From PestNet

Updated fruit fly identification handbook

Welcome resource for alert Australians

As there were several fruit fly outbreaks declared across the country in 2018, the release of an updated Australian Handbook for the Identification of Fruit Flies will be welcomed by the agricultural sector. The publication will make sorting and identifying the thousands of tephritid ‘true’ fruit flies affecting a wide variety of crops grown in Australia much easier.
The handbook is accompanied by additional online information, developed via the companion website Fruit Fly Identification Australia (fruitflyidentification.org.au) and is a handy reference for all primary producers, not just those producing commercial quantities of fruit.

Dr Mark Schutze, from the Queensland Department of Agriculture and Fisheries: “We’ve updated all the fruit fly images using fresh material and produced new, tailor made, molecular diagnostic tools that have emerged from our investment in next generation genomic research.”

According to farmingahead.com.au, over 60 target species of fruit flies are included in the handbook and website, shown both as individual flies and in groups of flies that look similar to each other. Importantly, the range of variation within species is also captured.
Find the Australian Handbook for the Identification of Fruit Flies

Publication date: 6/20/2018

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T. S. Park et al./Nature Communications, 10.1038

This ancestor of today’s insects, spiders, and crustaceans had a simple brain, but complex eyes

Although it’s hard to believe that delicate nervous tissues could persist for hundreds of millions of years, that’s exactly what happened to the brains and eyes of some 15 ancestors of modern-day spiders and lobsters, called Kerygmachela kierkegaardi (after the famous philosopher Søren Kierkegaard). Found along the coast of north Greenland, the 518-million-year-old fossils contained enough preserved brains and eyes to help researchers write a brand-new history of the arthropod nervous system.

Until now, many biologists had argued that ancient arthropods—which gave rise to today’s insects, spiders, and crustaceans—had a three-part brain and very simple eyes. Compound eyes, in which the “eye” is really a cluster of many smaller eyes, supposedly evolved later from a pair of legs that moved into the head and was modified to sense light.

But these new fossils, which range from a few centimeters to 30 centimeters long, had a tiny, unsegmented brain, akin to what’s seen in modern velvet worms, researchers report today in Nature Communications. Despite the simple brain, Kerygmachela’s eyes were probably complex, perhaps enough to form rudimentary images. The eyes, indicated by shiny spots in the fossil’s small head, appear to be duplicated versions of the small, simple eyes seen today in soft, primitive arthropods called water bears and velvet worms.

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This legless insect can jump 30 times its body length

SAN FRANCISCO, CALIFORNIA—U.S. figure skater Nathan Chen may wow crowds with his endless quadruple jumps, but the Olympic hopeful can’t hold a candle to the legless gall midge larva (Asphondylia sp). The 3-millimeter-long larva—which startled scientists when it started hopping out of its lab dishes—plants its rear end on the ground, slides its head toward its nether regions, and latches its body into a loop, which it then flattens by shifting fluids inside its body. After enough pressure builds up, the midge releases the latch, straightens, and flies into the air at 1 meter per second for a jump as much as 30 times its body length. On a human scale, that distance would be 60 meters. (Consider: The current long jump record is less than 9 meters, with a running start.) Researchers discovered the feat with super–high-speed video cameras that shot 20,000 frames per second. The secret to the midge’s success is power amplification—the ability to build up force and then release it all at once, they report here today at the annual meeting of the Society for Integrative and Comparative Biology. It’s like an archer pulling back a bowstring, temporarily storing the energy for shooting the arrow in the elastic string. No one knows yet why the midge larva jumps—until it matures into a fly, it never leaves its home, an abnormal growth on a type of goldenrod called silverrod. But documenting its Olympian performance could help scientists understand the movements of similar larval flies—and design better robots.

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Researchers find moth last seen 130 years ago

A moth masquerading as a shimmering blue bee has been rediscovered after 130 years. A damaged museum specimen collected in 1887 is the only previous evidence such a creature existed, The Guardian reports. Now, Polish researchers have spotted 12 of the oriental clearwing moths in Malaysia’s lowland rainforest collecting salts and minerals among the bees they look, act, and sound like. But how much longer this lost species lingers is tenuous, the researchers suggest in Tropical Conservation Science. The moth’s habitat is disappearing from rapid deforestation.

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22 November 2017 10:42:18 22 November 2017 10:42:18 |Agri Safety,Crops and Cereals,News

Crop damaging ‘super pest’ now capable of surviving wintry conditions

Resistant diamondback moths now capable of surviving winter

Resistant diamondback moths now capable of surviving winter

A ‘super pest’ moth resistant to a class of common plant protection is now also capable of surviving through the UK’s cold winter conditions, according to new research.

Diamondback moth (DBM) caterpillars feed on crops including cabbage, broccoli, swedes and Brussels sprouts, causing cosmetic damage, which could result in the loss of up to 100 per cent of the crop. Brassicas were worth more than £200m to UK agriculture last year.

The pests, which have developed resistance to the pyrethroid class of plant protection products often have reduced fitness levels so don’t survive through winter.

However, experts from Rothamsted Research and AHDB are concerned because this is not the case with this new strain of moth.

Growers are being asked to submit samples of the DBM either when seen through winter, or in spring when numbers start to rise, to aid the continued monitoring and development of control strategies to manage the pest.

Dr Dawn Teverson, Knowledge Exchange Manager at AHDB, said: “This new research reconfirms what we found last year. It’s important that Brassica growers are aware of this pyrethroid resistance and plan their crop protection programmes to treat against diamondback moths, accordingly.

“If pyrethroids are used, not only does this now fail to control DBM but it could also kill beneficial insect predators which would naturally help control the pest, further exacerbating the problem.”

Surviving winter

Pyrethroid resistant DBM have been found overwintering on swede crops grown under insect netting.

Dr Steve Foster, research entomologist at Rothamsted Research, said: “We have seen in aphids that those which have developed resistance may not survive the winter, however this doesn’t seem to be the case with this new strain of DMB.

“The identification of pyrethroid resistance in this season’s population of moths suggests that they are descendants of 2016’s migrating diamondbacks and therefore that the resistance hasn’t stopped them from surviving over winter.”

Andrew Rutherford, farm and agronomy manager at K. S. Coles, said: “This study has been extremely helpful to growers, allowing them to increase their understanding of the pests they are trying to control and which actives will be effective.”

The diamondback moth is often described as a ‘super-pest’ because it has a rapid lifecycle, providing more opportunities for resistance to develop through gene mutation.

In 2016, Steve Foster at Rothamsted Research tested three diamondback moth samples for resistance from Lincolnshire, Suffolk and Scotland. All three samples were resistant to pyrethroids

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