Moth takes advantage of defensive compounds in Physalis fruits

August 26, 2016

Researchers from the Max Planck Institute for Chemical Ecology found that the specialist moth Heliothis subflexa benefits from secondary plant components by turning the original defensive function of these compounds into its own advantage. Withanolides, which are present in Physalis plants, usually act as immune suppressants and feeding deterrents in insects. Surprisingly, Heliothis subflexa uses these plant defenses as immune-system boosters. Moreover, withanolides protect the moth from harmful effects caused by pathogenic bacteria. The new study demonstrates a unique benefit to host-plant specialization.

In order to survive and to repel herbivores, many plants defend themselves by producing toxic or deterrent substances. In the course of evolution, many insects have succeeded in adapting to the defensive chemistry of their host plants and thereby circumventing plants' defence mechanisms. However, the plants have also adapted their defensive system to further protect themselves against their enemies, which, in turn, generated counter-adaptations in the insects; biologists refer to this phenomenon as an "evolutionary arms race" between plants and insects. Many insects are plant pests which can be categorized as "specialists" and "generalists." Whereas generalists feed on many different plants, specialists have adapted to one or few closely related plant species as their food. The moth species Heliothis subflexa analysed in this new study is such a host specialist.

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Snapping Turtle killed by exploding M-80 firecrackers on its shell; 3 charged - via Herp Digest

by Barbara Miller, 8/24/16, pennlive.com

The explosion happened at 6:55 p.m. Aug. 3 in the 1100 block of North Penryn Road, Penn Township, Northern Lancaster County Regional Police said Wednesday.

The suspects are accused of placing two M-80 firecrackers on the shell of the turtle and lighting the fuse, causing the death of the reptile, police said.

A crater was found, in what appeared to be remains of a large turtle, including bone fragments and biological remains. Witnesses provided a description of a truck seen at the scene, and police were able to identify three suspects.

Charged were Taylor James Geib, 21, of the first block of North Colebrook Road, Manheim; Austin Mathew Garner, 21, of the 2000 block of Mountain Road, Manheim; and a 17-year-old juvenile, whose name was not provided by police.

The turtle wasn't a pet, but a wild turtle, possibly a snapping turtle, Lt. George Pappas said. It was larger than a box turtle, but not a full-grown turtle, he said.

"They found it in a rural area, saw it and decided to do this," he said. Pappas said he doesn't know the motive for the stunt. "Young and poor judgment," he surmised.

The suspects were charged with prohibited offensive weapons and criminal conspiracy.

Pappas said animal cruelty charges can only be filed for domesticated and zoo animals under the Pa. Crimes Code.

The Pa. Fish and Boat Commission has been notified, and further charges could be filed, Pappas said. Turtles, which are reptiles, fall under that agency, rather than the Pa. Game Commission.

Eric Levis, Fish & Boat Commission spokesman, said they are reviewing the case, and charges could be filed.

In the ocean, clever camouflage beats super sight

Even animals with super sight fail to spot this underwater disappearing trick

Date: August 22, 2016

Source: Duke University

In a matchup of animal superpowers, a clever form of camouflage might beat super sight -- at least in the ocean.

There's nowhere to hide in the open ocean, far from the shore or the seafloor. But some fish have a clever disappearing trick. The silvery skin of fish like herring, sardines, mackerel and tuna act like mirrors, reflecting their watery surroundings to better blend in. The effect serves as a kind of underwater invisibility cloak that helps them hide in plain sight.

Researchers have long assumed that some animals could see through this silvery disguise, thanks to a superpower of their own: the ability to detect a property of light -- called polarization -- that humans can't see.

Octopuses and squid, shrimp and other crustaceans, and some fish such as trout and salmon all have the gift, called polarization vision.

"It's kind of like wearing polarized sunglasses," said Sonke Johnsen, biology professor at Duke University and the first author on a new study of how well animals see reflective camouflage in the ocean.

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The cave bear: A vegan gone extinct

Date: August 23, 2016

Source: Senckenberg Research Institute and Natural History Museum

Senckenberg scientists have studied the feeding habits of the extinct Cave Bear. Based on the isotope composition in the collagen of the bears' bones, they were able to show that the large mammals subsisted on a purely vegan diet. In the study, recently published in the scientific publication Journal of Quaternary Science, the international team proposes that it was this inflexible diet that led to the Cave Bear's extinction approximately 25,000 years ago.

Today's Brown Bears are omnivores. Depending on the time of year, they devour plants, mushrooms, berries and small to larger mammals, but they will also take fish and insects. "The Cave Bear is a very different story," says Professor Dr. Hervé Bocherens of the Senckenberg Center for Human Evolution and Palaeoenvironment (HEP) at the University of Tübingen, and he continues to explain, "According to our newest findings, these extinct relatives of the Brown Bear lived on a strictly vegan diet."

Cave Bears (Ursus spelaeus) lived in Europe during the most recent glacial period, approximately 400,000 years ago, until they became extinct about 25,000 years ago. With a length of 3.5 meters and a height of 1.7 meters at the shoulder, these bears, which ranged from Northern Spain to the Urals, were noticeably larger than their modern-day relatives. Despite their name, they did not actually live in caves but only used them for hibernation. Nevertheless, the occasional death of animals in various European caves over several tens of thousands of years eventually led to enormous accumulations of bones and teeth from these large fur-bearing animals.

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Monster slugs are attacking birds in Europe

Slugs aren't usually considered predators.

BRYAN NELSON

August 29, 2016, 5:28 p.m.

An orange slug from the Arion genus. (Photo: Guillaume Brocker/Wiki Commons)

Death by slug: It's not a good way to go, but that's exactly what's happening to baby birds in Poland. Researchers there have witnessed a surprising pattern of large slugs of the Arion genus crawling into the nests of birds and eating the hatchlings alive, reports New Scientist.

A trail of slime is the only evidence remaining from such attacks. The behavior is so unusual that the birds' parents don't even try to defend them, possibly because they don't see the slugs as a threat until it's too late. One parent bird was even witnessed incubating a slug feeding on its dead chicks.

“The actual moment of slugs predating on nestlings isn’t easy to observe,” explained Katarzyna Turzańska from the University of Wroclaw in Poland, one of the researchers in the study. "You are more likely to come across the traces of the ‘tragedy’: dead or alive nestlings with heavy injuries, covered in slime – and often slugs’ droppings found nearby."

The researchers' work appeared in the Journal of Avian Biology.

Turzańska and colleague Justyna Chachulska have been researching this behavior since they observed it for the first time while studying whitethroat birds near Wroclaw, in Poland. Although predation by slugs has been recorded before across Europe, almost all of these reports pertain to bird species that nest close to the ground. That giant slugs would seek out treetop-nesting birds as food is a surprise, however. It appears unprecedented.

Slugs in the Arion genus can grow quite large, and they'll eat almost anything. While most slugs spend their time dining on leaves and rotting plants, they have been known to devour earthworms and other smaller slugs. Decomposing animals are certainly on the menu as well. And, apparently, now they've expanded their appetite to include live chicks.

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