Posted tagged ‘insects’

Butterflies, beetles and dragonflies declining in Europe!

25 March 2010

The Violet Copper Lycaena helle (Endangered) is a rare and threatened butterfly in Europe. Photo : Chris van Swaay

Habitat loss is having a serious impact on Europe’s butterflies, beetles and dragonflies, the International Union for the Conservation of Nature (IUCN) said today. Nine percent of butterflies, 11 percent of saproxylic beetles (beetles that depend on decaying wood) and 14 percent of dragonflies are threatened with extinction within Europe, the Switzerland-based conservation organization said in a news release.

Read more on Vijay Barve’s Biodiversity India blog post here.

Download the section of the IUCN Red List on European butterflies here.

The situation is far worse in India. Even worse our scientific footprint is so weak, we don’t even have comparable data. God preserve my beloved country’s wildlife!

Image credit : IUCN. Displayed under “Fair use”.

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Love still unrequited (55 Fiction)

23 March 2010

He was her first mate. Never had she met such a virile, handsome male. He had wooed her and charmed her; they had just made love. To her dismay, her true nature emerged. She couldn’t stop from turning and eating him while they were still entwined in love.

Praying mantids always do such things.

Mantis mates - deadly for one!

Bizzare behaviour - of the male for passive acceptance of being eaten.

Image credit

Postscript

Why do male mantids allow themselves to be eaten? One theory says that sex has got nothing to do with the female’s foraging. In other words, she multi-tasks! 😉

Another theory, based on a view of ethology that an organism is nothing more than a vehicle for genes, states that animals will follow lifestyles which will maximise their fitness and success of getting offspring. In this case, the male mantis by allowing himself to be eaten improves the female’s fecundity by providing quality nutrition and correspondingly improving the chances of successfully passing on his genes.

Yet another disputed theory says that the eating of the head of the male results in a longer, vigorous sex act with increased chances of fertilisation.

Some experiments suggest that sexual cannibalism is observed laboratory behaviour caused by human presence. There have been indications that in the field sexual cannibalism may not be so rampant.

The mystery here is not the cannibalism, which is perfectly understood as an adaptive female strategy to maximise her reproductive success, but the male’s complicity in doing so.

Read more about sexual cannibalism in insects here.

Oh and don’t forget to read “Unrequited Love“.

Insect talk shows!

11 January 2010

If  you would like to listen to interesting, light-hearted talks about hexapods – those fascinating six-legged creatures you and I commonly refer to as  ‘insects’, then…

……Insectapod is for you.

You can rest your pods, put on your iPod and listen to insect podcasts.

Now, if I were you a few months ago, I would have said ‘waszat’ to the term ‘podcast’.

Well Wikipedia (almost) says …

podcast is a series of  audio or video files that are released episodically and downloaded through web syndication

So, a insectapodcast would therefore mean a series of interesting talks about insects, recorded as mp3 files in this case, and available as a series from Insectapod.

The insectapodcast is brought to you courtesy the Entomology Deptt, Michigan State University.

Each podcast, there are nine available as of date, talks on a folksy subject. The very first one (find it here) should find you right at home with its subject.  It is titled…

There’s no place like home

and has the byline…

“We share our homes with bedbugs, we manipulate the home lives of honey bees.”

Some other titles are :-

Insectapodcasts are well presented – they are nice to listen to (despite the American accents 😉 ). They permit you to listen, download, read the transcript and have a iTunes and RSS feed buttons.

They recently featured in the Spring 2009 volume of American Entomologist. You can find their article on Insectapod here.

So many of us own iPods or other mp3 players today. Most cellphones have this facility to. In addition to our music,  it is easy to listen to something different such as an educational talk or two.

The master list for all podcasts is of course found at  SpokenWord.org.

And if you would like to hear something very interesting about insects, check out the Insectapod talk list here.

Happy podcasting!

The beetle which changed colours

9 January 2009

One comes across the wonders of natures almost accidentally. In June 2006, on the thirteenth to be precise, my son Aashay and I had driven along the Pokaran – Jaisalmer road to look at Tawny Eagles, who are easily found every few hundred metres perched on the wires or poles. On the way back, we stopped to say hello to a local acquaintance. He stood at his present place of labour, a dolomite mine the concession of which he had taken. The mine, near Chacha village, some 20 odd kms from Pokaran, consisted of an area approx 200 yards in diameter in the middle of which there was a large pit some ten yards across and about ten feet deep. Inside, the pit had tunnels leading from the sides which my friend claimed were quite long and winding and undermined almost all the area of the mine. On the surface, occasional holes with large piles of white dolomite stones around the entrances hinted at the warren below.

The dolomite quarry where we found the beetle.

The dolomite quarry where we found the beetle.

As fathers are prone to do, conversations turn to worldly matters or ‘shop’ so Aashay went wandering around the mine. A fatherly warning followed Aashay that he should stick to the beaten tracks only.

Fifteen minutes later, I walked upto Aashay to fetch him. It was 8.30 and time that we made our way back home for breakfast. Aashay was bent over, peering at something on the ground. It was a beetle scurrying on the ground.

”Pappa” he said, ”there’s something strange about this beetle!”

We followed it as it meandered amongst through the broken stone and sand. It was beautiful, almost completely white with a few black markings. A white beetle being a novelty, I was keen to get close and take a photograph but the beetle did not cooperate. Realising it was being pursued, the beetle changed tack and now hurried along on a twisting path towards some Aak bushes (Calotropis spp). A picture on the ground was difficult to get so Aashay chased it trying to scoop up the dodging creature. This he did, only to lose it a few seconds later. We did however succeed in taking a few snaps.

What was truly amazing was that the beetle, which was almost completely white when Aashay had spotted it, gradually turned darker and darker until finally it was almost completely black with only a very thin white edging.

The creature finally reached sanctuary – a cluster of Aak roots with twisted branches, dried leaves and small crevices into which it disappeared. The Rajasthani locals who worked the mines told us that the beetle turned black with fright but would recover to its original pattern after 15 minutes or so.

Immediately after we encountered the beetle it began turning black.

Immediately after we encountered the beetle it began turning black.

Scooped up in Aashay's hands for taking a good snap, it has almost turned completely black.

Scooped up in Aashay's hands for taking a good snap, it has almost turned completely black.

Later I put up the images on Wikipedia WikiProject Arthrpods talk page, hoping for an identification. Doug Dynega, an entomologist and museum curator in the States, responded whith what appears to be the key to the mystery:

”It’s a Tenebrionid, but I can’t be certain of the subfamily. From what I can see in the photos, the white “markings” are, like in many desert Tenebs, not markings, but fine cuticular wax deposits. I’d never heard of the beetle being able to change the amount of wax on it, so I have a better explanation, based on what one can observe; the wax layer is hygroscopic (absorbs moisture), and when it does so, it loses its reflectivity. Holding the beetle in your hand will greatly increase the humidity in the airspace near the beetle. This makes some sense as a desert adaptation; when humidity is low, the beetle reflects more sunlight, and when humidity is high, it reflects less. I’ve just never heard of the phenomenon, and can’t confirm it myself. What you need to do is catch one, kill it, and experiment. If it’s that sensitive, even breathing on it should have a noticeable effect. If it can be confirmed, it might even be something to publish, assuming no one has documented it before.”

Sadly, we left the area soon after and could not go back to explore this mystery any further. A pretty little puzzle waiting for someone to unravel it!

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Notes.

1. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License“.

2.  Comment by Doug Dynega published under GFDL copyright from Wikipedia at the Talk page of WikiProject Arthropods on Wikipediaaccessed on 08 Jan 2009: