Cut and run

While continuing to sort my malaise trap-trawl, I've found another blast from my past Zoology lectures... Cleg flies or Horseflies.

Microscope close-up of a Cleg Fly head (x5)

I'm seemingly better at recalling the darker, gruesome side of zoology. I also got to know these insects rather intimately while working in damp Sussex woodland gardens; prime Deer, Human and Cleg habitat. These stealthy, bitey beasties are blood feeders and for them, pretty much any large mammal will do.

Palp and the sponging labella (x10), protecting the nasty

 pointy bits which can just be made out in silhouette 

Only the females partake in blood meals as they need the nourishment to produce their eggs (the males are nectar feeders). The mandibles and maxillae (mouth parts) of the female are brilliantly adapted into pointy, hardened, stabbing structures. These are shoved through the skin and then rapidly scissor back and forth like the blades of a tiny, hellish hedgetrimmer. The fly then injects an anti-coagulant and sucks up your life's fluid.

The stunning psychedelic banding of the eyes fades after death but can still show up in good light

This less-than-subtle eating habit apparently works just fine for them; the theory being the pain-inflicted victim will be more concerned with assessing the wound than swatting the culprit. However, I am a vengeful being and I recall the book The Wasp Factory graphically documents some pretty inventive ways to dispatch insects...

A live Notch-horned Cleg I caught last summer. 

After freezing to photograph it some more, the colours faded.

In all seriousness, I only dispatch the ones I need to photograph and identify (and perhaps a few others for self-protection). Going by the brownish colour of the wings and the dented antennal segment, the above species is the Notch-horned Cleg, Haematopota pluvialis. Even if they do make my skin crawl (or run about flapping my arms), these little.... ahem, guys are awesome-looking and resilient; when one lands and you give it a full-on whack, even if your aim is only slightly off, it casually flies off unscathed. But beware, for it has not likely to have gone far...

Chrysops relictus - Twin-lobed deerfly. Distinguishable from a similar species C. caecutiens by the reddish tibia (leg segments) and the black chevrons on the abdomen

All Deerflies, Clegs and Horseflies belong to the family Tabanidae and in the UK we have about 30 species. Another type I regularly come across is the Twin-lobed Deerfly. These are agile and difficult to catch, but just last summer I rescued the botanist Giles and our volunteer Georgina from certain doom by potting one on Giles' head. 

This one also died by freezing; it got off lightly.

To be honest, I don't really have time for a Wasp Factory, plus freezing is much less messy.

Ichneumon

...is not a type of Pokemon, but actually a tiny parasitic wasp.

An ichneumonid or braconid wasp. Difficult to photograph through the microscope lense, 

my old camera was better for this!

I got excited when I first saw this under the microscope; I remember lectures on them at uni and how interesting they were. However, as they are very numerous in the malaise trap samples, the novelty has quickly worn off! Still, they are very beautiful and diverse.

Relatively big parasitic wasp (1cm in length) vs. small parasitic wasp

Parasitic wasps are an incredibly diverse group of insects with thousands of species in Britain alone. Like all other wasps, they have the three body segments, but the abdomen, antennae and stinger (ovipositor) are usually very long. The ovipositor is adapted for injecting eggs into other invertebrate eggs or larvae.

The ovipositor is maneuverable; here it is tucked under the abdomen. 

The sheaths or 'guides' normally enclose the ovipositor and help to guide and support it.

The wasp larva hatches out and feeds either within or on the body of the host; some sci-fi movies were almost certainly inspired by these little guys. Even poor ol' Darwin was quite darked-out by them, questioning why a benevolent god would ever create something with such a cruel lifestyle.

Their taxonomy (classification) is very difficult and instead of attempting to identify them, I'll be storing them indefinitely, saving them up for my retirement (which for my generation might be never). As well as ichneumon wasps, related groups such as braconids, chalcids, and eurytomids are likely present in our malaise trap samples, all of which make up a huge group with the general name 'Parasitica'. Some of these are used on a commercial level as biological control agents, keeping down your agricultural and greenhouse pests. Here is a selection of parasitic wasps I've come across so far:

This last one is possibly a gall wasp (Cynipidae). They are actually herbivorous and lay their eggs in host plants, often causing swollen growths called galls on leaves and stems.

Looking at stuff under the microscope is addictive and I've been putting in quite a bit of my free time sorting these trap samples. My make-shift portable invertebrate lab is coming along in leaps and bounds - I have most recently acquired a great big cardboard box!

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 Den, Mark Telfer's Blog and particularly the Cabinet of Curiosities for a window into that under appreciated part of our world.