Showing posts with label entomology. Show all posts
Showing posts with label entomology. Show all posts

Wednesday, 28 August 2019

Working with a live specimen

On Friday I found this potter wasp (one of the small, solitary nesting wasps) running around on the landscape contractor's bright green car. I thought I'd have a crack at identifying it to species using just a hand lens, which turned out to be an arduous way to spend a Saturday...


Step 1:  Put wasp in tube into the fridge to anesthetise


Step 2: Take out the book on solitary wasps



Step 3: Turn to first key in book, take chilled wasp out the fridge, start keying...



It seems that everything pretty well matches the family Eumenidae, which takes me to the next part of the book...

Step 4: Keying from the Eumenidae, following on until we get to couplet 7, which is over to the next page.



Oh no!


Ah jeez.


Step 5: Get stool from kitchen, retrieve tiny wasp from ceiling.


She's back in the tube and she's angry.

Quickly, to the next page....



It looks like she's an Ancistrocerus! We are getting there.

Step 6: Continuing on to try to get her down to species...


Hmm, a groove or step on 2nd ventral plate.... Is this it?

To me it looks like there is a step, but then a bulge. It's very difficult to get a decent picture in the hand and at the correct angle. Even after putting her back in the fridge for a while, she simply warms up again very quickly and dashes about.


Might she be Ancistrocerus nigricornis?

I'm just not sure whether this is simply the normal join between two ventral plates on the abdomen. Looking ahead in the rest of the key, it refers to the underside of the 2nd ventral plate, but my pictures are not clear enough. This is where we get stuck without using a microscope and other preserved specimens for comparison.


For many small invertebrates, photographs can only really take you so far in terms of identification, so I'll be told by entomologists that I should have kept the specimen. But seeing as I have a backlog of other material to microscope...

See ya Ancistrocerus sp., back to caterpillar hunting you go. 

Friday, 10 January 2014

Malaising stuff

I am always amazed by the amount of rubbish appearing on shop shelves at Christmas; an annual bloom of crap. Where does it all go after it has been unwrapped and politely chuckled at? No wonder the retailers are working up a sweat every year, we are all running out of cupboard space.
   But this year, Secret Santa did good... I discovered a secondary use for my Xmas-tat in the form of a new invertebrate sample test-tube stand. So ta very muchly, whoever you were!

Wasp tequila slammer, anyone?

Back to our Malaise Trap: Gatwick Greenspace Partnership (GGP) helped install this tent-like apparatus last July in a small open area in the Land East of the Railway Line. This is an energy-saving way of collecting invertebrate samples because despite their fantastic physiology, refined adaptations and resilience, insects are actually pretty dumb. When meeting this in the field, the insect hits a central wall of fabric and instinctively flies upwards, being directed into a funnel at the apex then eventually dropping down into a collecting pot at the top. 

Assembling a malaise trap - People and Wildlife Officer Kev and volunteer Eloise from GGP

It might look gruesome and destructive, but we collect this way in just one small area for one season, minimising any impact on the local invertebrate populations. Some mini-beasts need to be very closely examined to determine the particular species and identification can involve pulling apart teeny-tiny genitalia, comparing the diverse shapes and structures under a microscope while referring to technical books. For the time being I'm passing that work onto someone else, instead just sorting these guys into orders such as flies (Diptera), bees and wasps (Hymenoptera) and beetles (Coleoptera), then from there into smaller groups such as families.

Collecting pot from the malaise trap. This haul was in the peak of summer after just one day

A pitfall trap - these were sunk into the ground nearby to target the trundling invertebrates

Natural history is a subject open to absolutely anyone with an inquiring mind, and entomology has an increasingly accessible side through online resources for identification such as iSpot, plus your local wildlife and conservation groups. You could perhaps start with the larger, more obvious things such as bees or butterflies, carefully collecting them into pots without causing them harm. Take a look, snap photos on your macro setting or test yourself online. Work away at that over a couple of seasons, getting to know the species which occur locally. Then you might decide you need more of a challenge, moving onto things requiring as closer look such as beetles and spiders. 

1 down, only 19 to go...

Invertebrate diversity is mind-blowingly huge, so getting to know the different species is an ongoing journey with always more to discover. Even if you don't know what it is you are looking at, its still bloody fascinating. As an entomologist from the NHM put it on Radio 4 the other day: its not rocket science, but it is value science! 
   There are some brilliant blogs out there with excellent macro photography of the small and unique, such as the very readable The Lyons DenMark Telfer's Blog and particularly the Cabinet of Curiosities for a window into that under appreciated part of our world.