New parasitoid wasp species discovered in Costa Rica


The new parasitoid wasp species, Dendrocerus scutellaris. Credit: Carolyn Trietsch

From ScienceDaily:

New parasitoid wasp likely uses unique saw-like spines to break out of its host body

January 31, 2018

Summary: A newly discovered parasitoid wasp species from Costa Rica might be only slightly larger than a sesame seed, yet it has quite vicious ways when it comes to its life as an insect developing inside the body of another. Most likely, it uses its unique saw-like row of spines on its back to cut its way out of its host.

About the size of a sesame seed, a new species of wasp from Costa Rica, named Dendrocerus scutellaris, has elaborate branched antennae that could be used for finding mates. Or hosts.

The new insect is described by PhD candidate Carolyn Trietsch, Dr. István Mikó and Dr. Andrew Deans of the Frost Entomological Museum at Penn State, USA, together with Dr. David Notton of the Natural History Museum in London, UK. Their study is published in the open access Biodiversity Data Journal.

The wasp is a parasitoid, meaning that its larvae feed on a live host insect. There are two types of parasitoids: ectoparasitoids, which lay their eggs on or near the host, so that the hatchling larvae can attach to and feed on the insect from the outside; and endoparasitoids, which lay their eggs directly inside the host, so that the larvae can eat them from the inside out.

Unfortunately, to puzzle out the new wasp’s lifestyle, the researchers could only rely on specimens collected back in 1985, which had spent the past few decades stored in the collections of the Natural History Museum of London before being loaned to the Frost Museum at Penn State for research.

What can you learn about a wasp’s lifestyle from specimens that are over 30 years old? Even though the new species has never been observed in the wild, researchers managed to learn a lot by looking at the wasps’ morphology, concluding that the species is likely an endoparasitoid.

The larva of an endoparasitoid wasp needs a safe place to develop and mature, so when it is done feeding on its host, it may stay inside the host’s body where it can develop undisturbed. Once it is fully grown, the adult wasp either chews or pushes its way out, killing the host if it isn’t already dead.

Unlike its close relatives, the new species does not have pointed mandibles for chewing. Instead, it has a series of spines along its back. While the wasp is emerging, it may rub these spines against the host and use them like a saw to cut open the body. Once emerged, it flies off to mate and continue the cycle.

“While their lives may sound gruesome, parasitoid wasps are harmless to humans and can even be helpful,” explain the scientists. “Depending on the host they parasitize, parasitoids can benefit agriculture by controlling pest insects like aphids that damage crops.”

It is currently unknown what the new species feeds upon, but naming the species and bringing it to attention is the first step in learning more about it.

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Flies’ dinner at mushroom


This 23 November 2017 video from the Netherlands shows flies having dinner at a common stinkhorn mushroom.

This way, the fungus’ spores stick to the flies’ legs, spreading them.

Fly diving in toxic lake


This video from California in the USA says about itself:

A tiny fly can ‘scuba dive’ in a salty and toxic lake

21 November 2017

Alkali flies plunge into the salty and alkaline Mono Lake, to feed and lay their eggs, but until now it has been unclear how they manage to survive. Read more here.

Grasshopper discovery on Vincent van Gogh painting


This video from Missouri in the USA says about itself:

7 November 2017

The 127-year-old grasshopper found by crews at the Nelson-Atkins in Kansas City is the buzz of the art world.

Translated from Dutch daily De Volkskrant today:

He has become world-famous for his sunflowers and self-portraits. But Vincent van Gogh also liked to paint olive trees. The Dutch painter made at least eighteen works between May and December 1889 about the olive groves in the vicinity of Saint-Rémy-de-Provence. In one of these paintings, the Nelson-Atkins Museum of Art curators in Kansas [no, Missouri] in the USA have now discovered a real grasshopper.

‘Landscape with olive trees’ is a painting from June 1889. It was painted in a period when Van Gogh, often plagued by illness and emotional depression, finally could come outside the walls of the hospital. Van Gogh also preferred painting outdoors. He was captivated by the whimsical growth patterns and ever changing colors of the ever-present olive trees. So much so that Van Gogh probably never noticed that the grasshopper ended up on his canvas. …

But it was curator Mary Schafer who recently discovered with a magnifying glass the grasshopper between the green and brown colours in the foreground of the painting. A paleo-entomologist then knew that the animal missed his abdomen and chest cavity and that no traces of movement were visible in the paint. Conclusion: The grasshopper was already dead when it landed on the Van Gogh painting, presumably by the wind. …

And Van Gogh himself talked about similar things in his letters to his brother Theo. “When painting outside, many things happen. I think I removed one hundred flies from my four canvases that I sent you”, wrote the painter in 1885.

Remarkable detail: British behavioral scientists at Queen Mary College in London let bumblebees in 2005 fly around variegated reproductions of paintings by Van Gogh, Paul Gauguin, Fernand Léger and Patrick Caulfield. During the research, the bumblebees appeared to fly more often to Van Gogh’s sunflowers than to the works of the other painters. Also the bumblebees stayed longer at Van Gogh’s paintings.

And the grasshopper? The Nelson-Atkins Museum of Art has decided to keep the animal in the painting.

See also here.

Beewolf wasp buries bee alive


This 4 August 2017 shows a beewolf wasp burying a bee alive.

The female wasp does that to provide food for her youngsters. The smaller male wasps of this species don’t do that, they feed on nectar.

Albert Jacobs made this video near Venhorst village in North Brabant province in the Netherlands.

Female grasshopper lays eggs


This 27 October 2017 video shows a female grasshopper. First, she makes more space between two tiles. Then, she lays her eggs there.

Janny Rijkse made this video in her backyard in Utrecht city in the Netherlands.