Tag Archives: insects

Chrysis inaequidens, the jewelled cuckoo wasp

Chrysis inaequidens, the jewelled cuckoo wasp

Look at this gorgeous North American solitary wasp (click the image for a bigger version if you like). Now wonder about its name – why is it named after a bird? After all, cuckoos are hardly known for their brightly coloured plumage. The answer lies in its lifestyle. Cuckoo wasps are so named because they breed by surreptitiously laying an egg in the nest of another (usually) wasp or bee – just as cuckoos do to other birds. Then the young cuckoo wasp larva hatches out, eats the larva of the host animal, and then enjoys the provisions the mother has left behind for her own offspring. From the cell emerges not the expected bee or wasp, but another species entirely – the adult cuckoo wasp.

The cuckoo wasps (and there are many species, including quite a few in the UK) have some special adaptations to help them do this. They have a really long egg-laying ovipositor, that can extend telescopically to let them insert an egg deep into a host cell. They also have the ability to curl up into a protective ball, like some woodlice do; with strong armour on the back, and gaps underneath where they can tuck their legs and antennae safely. It must be a hazardous life being a parasite – those host bees and wasps can bite and sting!

Reference

Why are there no really big insects any more? Blame birds.

It’s no secret that 300 million years ago, the largest insects were a lot bigger than they are now. The largest known insect that ever lived is an ancient griffenfly Meganeuropsis permiana. This creature belongs to the extinct order of griffinflies (Protodonata) – related to dragonflies -  and measured an impressive 71 cm across, larger than most birds. There were a variety of other megainsects in prehistoric times, but these days, the biggest ones are considerably smaller. So what happened?

Vespa mandarinia (c) Gary Alpert

Vespa mandarinia, the Asian giant hornet

One fact which is widely considered to be relevant is the limitation of insect respiration. As insects don’t have lungs like us vertebrates, they rely upon oxygen entering their body through many tiny tubes. They can help it on its way with various tricks but in essence, if the tube is too long the oxygen can’t get down it far enough. So an insect that got too big would soon run out of oxygen and find it difficult to fly or run. So how did those huge ancient insects get around that limit? The answer is that they didn’t. In Permian times the atmosphere was more than 30 percent oxygen, compared with 21 percent today. So insects had more oxygen available, and could grow larger.

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Buglife squished

If you’ve been following the story of small charity Buglife on this blog you will recall its legal challenge intended to prevent development on West Thurrock Marshes, a former industrial site now very rich in invertebrate biodiversity.

Buglife logo

After a long trek through the courts it seems as though the final act may now have been played out in this drama, as Buglife retires to lick its wounds following a comprehensive rejection of its arguments by the Court of Appeal. Continue reading

Buglife rides forth yet again

It really does seem to be like the butterfly that stamped. If you’ve been following the story of small charity Buglife on this blog you will recall its legal challenge intended to prevent development on West Thurrock Marshes, a former industrial site now very rich in invertebrate biodiversity.

Spider stamp © Buglife

Buglife made its own alternative stamps showing species threatened by the Royal Mail development

The original site developer, Royal Mail, has now pulled out and Buglife suggests that this is because “Buglife pressure forced Royal Mail to scrap its plans“. However the planning consent still stands, so some other body could still do the works and damage the site. So Buglife took the matter to court. Continue reading

The butterfly that stamped… Buglife sees off Royal Mail at West Thurrock?

The most ironic marketing gaffe ever, and then an apparent u-turn by Royal Mail: did plucky little conservation charity Buglife really pull off this campaign coup? For those who haven’t been keeping up, see this post – or here’s a summary: Royal Mail have been planning to build a depot on a marshland full of scarce invertebrates in West Thurrock, and invertebrate charity Buglife has been campaigning to stop them. But a High Court bid by the charity to have the development halted was rejected in February. Buglife have been considering whether or not to appeal.

Spider stamp © Buglife

Buglife made their own alternative stamps showing species threatened by the Royal Mail development

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What is the purpose of wasps?

What use are wasps? A perennial question. “Why did God make wasps?” is even asked as a theological poser – usually as a rhetorical question that can’t be answered. It is a question that comes with its own implied criticism – after all, nobody would ask “what is the purpose of butterflies?” (zero Google results at time of writing, vs. 838 for “what is the purpose of wasps?”). The suggestion is that as wasps are no use to humans, their existence is puzzling. A rather human-centric view. It also goes without saying that there are far, far more mysterious creatures than wasps upon this earth – and they don’t all seem to benefit humans either.

The Asian Giant Hornet, Vespa mandarinia
The Asian Giant Hornet, Vespa mandarinia

 

Anyway – now wasps do have a purpose. What a relief! Entomologist Joe Lewis, and agricultural engineer Glen Rains at at the University of Georgia have devised a pleasingly low-tech method to use wasps to sniff out all sorts of chemicals.

“So far, they’ve been able to detect, to some level, any chemical that we’ve trained them to,” Rains tells DBIS. Training is simple and quick. The wasps are fed sugar water. At the same time they’re introduced to a smell for 10 seconds. The process is repeated two more times. Lewis says, “We can train a wasp within a matter of 10 to 15 minutes.” For example, a set of wasps is trained to detect the smell of coffee. When they are put into a simple container, a tiny web camera watches their actions. When the smell of orange is pumped into the pipe, nothing. But when it’s coffee, the wasps crowd around the smell. So far, Rains and Lewis have not found anything the wasps cannot be trained to detect. They can be trained to detect everything from drugs to human remains to fungi on crops. They could one day even be able to detect deadly diseases like cancer.

This is obviously pretty useful – and pretty easy. Watch out, dogs – wasps are on your tails! See a video demonstration of this technique in action here.

Invasion of the giant hornets… or is it?

There’s a buzz going about… and it’s created by a load of hornets. Regular readers will know about the Asian Giant Hornet, Vespa mandarinia, which has been causing a bit of debate. Quite a few people emailed The Ranger or posted to the blog, worried (or interested) that they might have found a specimen of V. mandarinia in their house or garden. One of these was Ranger reader Dave Wall, who said:

I have just seen a massive hornet in my garden. It was hovering just above an ants nest. It only stayed around for a few seconds before flying off. I have seen ordinary hornets fairly commonly in and around our house, but nothing like this. It was not the European Hornet ! I would estimate it to be about 60mm in length. It’s bright yellow head and huge abdomen were the most striking features. We are in a very rural fruit growing area in Warwickshire.

The Ranger rather optimistically requested photos, and splendidly, Dave was able to comply. A few days later he gamely captured one of the beasts and took some great photographs – here’s one:

European hornet (c) Dave Wall

Dave Wall’s hornet – the ruler has been added in from another part of the photo, but the scale is correct.

We can see from Dave’s ruler that the body length of this creature is a somewhat less scary 35mm, which is well within the range of the European hornet V. crabro. Indeed, this is no Asian monster but our native European hornet, and as such is little to worry about. If you need convincing perhaps the simplest way to tell them apart is the colour of the thorax (the bit of the body between the head and the abdomen) which is very clearly brown in UK hornets (less so in other European races), but definitely black in the Asian one. This one, as you see, is quite gingery-brown. This is a worker although it’s on the big side. Queens and workers have seven segments to the abdomen, whereas males have only six. The queen can be up to 50mm in length, so quite possibly that’s what Dave saw the first time. The European hornet is actually less aggressive than the common wasp, and although it looks fearsome, is less likely to sting. And although it will nest in urban and suburban situations, it prefers the countryside. So you don’t need to be too worried, if you leave them alone they will probably not bother you and go away. Interestingly, it’s not just The Ranger who has had these enquiries. The Ranger’s correspondent Stuart Hine, who is manager of the Natural History Museum’s Insect Identification Service, explains more:

The Insect Identification Service at the Natural History Museum is receiving unprecedented enquires from the public about the insect. Most people are concerned that they are seeing the giant Oriental hornet or the Asian ‘killer’ hornet, probably due to recent media attention these species have received. But this is not the case. What people are seeing are queens of our native European hornet, Vespa crabro, our largest species of social wasp. Queen hornets are formidable looking insects with a body length of up to five centimetres. In the UK emerging queens are not usually seen until about early-mid May. However, the unseasonable mild spring we have experienced this year appears to have roused them from their slumber earlier with the first sightings in early March.

You can also see a great video of Stuart talking about this, with some (dead) examples of both the European and Asian hornets. Read this post if you think you have got an Asian Hornet.

Check out this massive wasp

We heard you wanted to see a picture of a simply gigantic wasp. So here it is.

The Asian Giant Hornet, Vespa mandarinia
The Asian Giant Hornet, Vespa mandarinia

 

Q. Have I got one of these?

A. Lots of people have emailed and commented (see below) worrying that they have a specimen of V. mandarinia in their garden or house. Unless you live in temperate or tropical Eastern Asia the answer is “definitely not!”. Continue reading