Posted by: lensweb | May 26, 2016

We’re going on a Beetle Hunt……….

Who else could lure us away from the TV on a Monday night but LENS, with a beetle hunt at  Nottingham Wildlife Trust’s beautiful Attenborough Nature Reserve?

attenborough memeChris Terrell- Nield who has a PhD in ecological entomology, was our guide for the evening. He is a real naturalist and arrived armed with spreaders and sweep nets and a huge box of books and other essential equipment in a big blue box. Dragging a huge trolley and laden with essential insect collecting equipment, we started out in glorious sunshine. Chris had set out 20 pitfall traps in two different habitats 3 days previously and we were going to check them all.

pitfall meme

The first habitat to be surveyed was grassland. Chris first had to locate the traps and then tip out the gravel and water contents onto a white tray to see what treasure was within. It was very exciting as we all crowded around to get a piece of the action. Let’s cut a long story short. There were not many beetles in the traps, I think we caught 2 small black carabid beetles. This was a bit of a disappointing return on a lot of effort by Chris but he was clearly pleased with his haul of centipedes, woodlice, millipedes and springtails and we joined in his pleasure. You can laugh but it had been such a sunny day that I wasn’t wearing a coat, you can guess what happened: A very cold shower of rain. Glad to say, the second set of pitfall traps were in dry shelter, under a tree, but once again there was not a lot to show.

name beetle meme

We were then set a challenge to find as many ladybirds as we could as we walked back over the bridge to the car park. It had stopped raining by now so we took our duties seriously, searching for and recording all sorts of ladybirds and also getting distracted by green and golden weevils, reed beetles and all sorts of spiders. David Attenborough would have been proud of our efforts as we found so many copulating invertebrates, even the millipedes were closely coupled.

millmeme

Most ladybirds are carnivorous, and prefer to eat aphids. This makes them particularly popular with gardeners, as aphids can be a real pest in the garden. They also eat scale insects, another species often harmful to plants, which further reinforces the ladybirds’ reputation as a gardener’s best friend! If you handle a ladybird, it may release small drops of yellow liquid from its leg joints. This is actually blood, which can stain your hand and smell quite pungent. This defensive ‘reflex bleeding’ is intended to ward off predators. Ladybirds are often named after the number of spots they have.

It was soon apparent that the number of spots on a ladybird is inversely proportional to the size of the ladybird. The 24 spot ladybird is only 3-4mm and is vegetarian.  The fourteen-spot ladybird, is larger, 3.5-4.5mm and is often called the clown faced ladybird, as its markings are often joined up to make a smiley face.

The seven spot is thought to be our most common ladybird, but it may just be our most commonly recognised ladybird. It is large, 5-8mm, and has black legs. It is usually red. Its colour pattern varies little. There are always seven black spots arranged three on each wing case and one on top of the back.

The Harlequin is large, 5 – 8mm with brown legs. It is an invasive alien species from Asia which spread rapidly after its introduction to Britain in 2004. http://www.harlequin-survey.org/ It eats aphids and other insects including ladybirds. Once thought to outcompete other ladybird species and be a major threat to various insect groups, numbers now thought to be levelling out as ecological harmony is re-established via control mechanisms such as good old British weather (too cold) and also parasitic wasps. It’s basic colour form is orange red with 0-21 black spots but the Melanic (black) form is common. It varies greatly in colour and spots.

The 2 spot seems to be an exception to the inverse rule as it is only 4 – 5mm.  It is a small and very common ladybird with black legs, which feeds on aphids. There are two main colour varieties, red with two black spots and commonly found are some which are black with red spots. The black versions are most common in the north where it is thought it may help the insect to absorb heat from the sun. The overall winner of the LENS ladybird survey was definitely the 2 spot at Attenborough with over 20 counted by sight (it was too wet for sweeping) in a short distance.


‘Ladybird, ladybird, fly away home,
Your house is on fire, your children are gone’

Marion Bryce 26 May 2016
 

 


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