A macrochelidae mite

I am an amateur naturalist trying to identify everything living in my garden.

On a whim, I recently got out my trusty Baermann funnel (which sounds far more technical than it actually is, namely, a sieve for sieving tiny critters out of soil) and was pleased to discover a host of new-for-my-blog creatures in a handful of old grass clippings. One, a mite, is shown in Photo 1 (click on photo's to enlarge)

Readers of my blog will know I make some effort to research the species of any creature I find in my garden. In the case of my mite however, this turned out to be no small challenge. Before this posting I knew nothing about mites. As I discovered, there are at least three factors mitigating against the amateur seeking to identify one to species level.

Firstly, there is the obvious minute size of mites' physical features. Identification to species can depend on close examination of some minute gland on the body or joint in the jaw-parts ('chelicerae'). With only one specimen and the type of microscope equipment typically available to the amateur, such features can be a challenge to view. The professional may perhaps turn to an extensive university collection of carefully dissected and permanently mounted specimens or examine their find by electron microscope. Sadly however, I don't have a electron microscope in my garden shed (I'm open to donations!).

A second challenge is the sheer number of mite species. More than 45,000 (here) have been recorded and some sources estimate this may be only 5% of the number awaiting discovery. To make matters worse there seems to be a dearth of elementary texts or online keys in the area. A number of advanced texts are available (at suitably advanced cost!) but there seems to be little along the lines of a field guide aimed at the amateur (I'd be pleased to be corrected on this matter).

Attempting to work through academic journal papers and keys brings one to a third difficulty, namely the dense jargon that accompanies the study of mites (acarology). The amateur must wrestle with references to such arcane structures as pretarsal condylophores, filiform corniculae and Claperede's organs. To complicate matters still further, acaralogists refer to the hairs (setae) that decorate mites' bodies in code ('h1', 'pg3' etc.) and not only does there seem to be no simple online explanation of how this code works (anyone?) but there is more than one system in use amongst the professionals.

Thankfully however, there are some notable exceptions to the comments above. On his excellent web site David Walter Evans has put together a Glossary of Acarine Terms, indispensable for making sense of the jargon of acarology. For discussion of some current research topics in acarology and some superb images see Macromite's blog. My searches turned up very few online keys but notable exceptions are the one on David Evans' site above and the interactive key here on the site of the North American Bee-Associated Mites project.

It was the latter that enabled me to make some progress with my mite. I spent some time inputting various features into the key with limited success, but then noticed my mite had 'brush like arthropodrial processes on the chelicerae' (in English: a fringe of hairs on its pincer-like mouthparts). You can see these in photo 2. In the key above this immediately narrows things down from my mite being in any of 36 possible families, to it being in the single family macrochelidae. (As always my identifications come with a health warning - I'm happy for them to be corrected)

Unfortunately that is as far as the key takes me and from the webpages of Dr G.W. Krantz I learn there are still well over a hundred individual species in the macrochelidae family. The book to consult would appear to be A Review of the Macrochelidae of the British Isles by Hyatt and Emberson, but this is out of print and seems generally unavailable.

In the course of my searches I pleased to discover that I am not the only UK amateur taking an interest in the fauna beneath our feet. Over at Alan Hadly's splendid site he too is busy studying macrochelidae mites (together with a host of other critters).

I must end this posting here. My intention in writing my blog is to learn something of the natural history of the creatures I encounter. It may not have escaped the attention of the observant reader however, that in this article I have largely failed to say anything about the natural history of mites. I feel relaxed! With 44,999+ species potentially still at large in my garden, I suspect this will not be the last time I have an opportunity to study these tiny creatures...

Dasineura urticae galls on a nettle leaf

I am an amateur naturalist trying to learn something about everything living in my garden.

I've previously blogged the nettles (Dioica urticae) growing in my garden (indeed, I guess some of you reading this may even now be tucked up in your nettle bed sheets!) and also described some of the capsid bugs (Liocoris tripustulatis) I found living on them.

Recently I've noticed evidence of a second lifeform feeding off my nettles, namely the galls in photo 1.

I am fortunate enough to be in possession of a set of a dozen-or-so volumes of Field Studies, a journal that was at one time published by the Field Studies Council. This admirable UK charity runs a wide range of residential study courses aimed at the amateur naturalist. The Field Studies journal is no longer printed which is a pity as it commonly used to feature keys for the amateur wanting to identify some of the trickier plants and animal in our fields and gardens, including (for present purposes) a key to British Plant Galls by Redfern, Shirley and Bloxham in the October 2002 issue. Fortunately, for those of you without old copies of the journal to hand, this key has been reprinted. You can purchase a copy along with various other gall guides from the British Plant Gall society here.

Redfern, Shirely and Bloxham list five arthropods and one fungal rust capable of causing galls on British nettles. The pouch-like swellings with slit-like grooves in their surfaces on the leaf in photo 1 indicate these are galls caused by the small fly, Dasineura urticae. Had I cut open some of the galls (I didn't) I might have been lucky enough to find some of the white grubs of this fly. Indeed, as I learnt from the very nice 'A Nature Observer's Scrapbook' site, I might even have found some predatory grubs from another species, laid there to eat the Dasineura urticae grubs.

I'm very far from being an expert in diptera (flies). From the Bioimages site however it seems there are several dozen British species in the fly genus Dasineura. This site has pictures of the grubs and galls of some of them.

I have only found one description of an adult D.urticae fly: My copy of Insects on Nettles (Davis, Richmond Publishing) describes a "very small fly with long antenna. Under a microscope an antenna looks like a string of beads...". Unfortunately I haven't been able to find a photograph on the web, although the Bioimages site does carry a photo of another Dasineura species (D. sisymbrii) which I guess may be rather similar since it too has bead-like antenna.

Sadly, that is as much as I have managed to learn about my mysterious fly. How and when the adults mate, how a female locates a host patch of nettles, whether she lays eggs or live grubs, how long the grubs remain inside their gall... I can only guess at the answers to these and a host of other questions. Another garden study-project to add to my burgeoning list!

A Blood-Vein Moth (Timandra comae)

I am an amateur naturalist trying to discover everything living in my garden.

What with photography, microscopy and literature searching, my self-imposed mission to catalogue my garden's life places lots of demands on my free-time. When I've a chance however I'm still making an effort to set out my home-made moth trap at night. I did so recently (on the 22nd August for the record) and it yielded a good haul of new species to add to my garden list, amongst them the attractive moth in photo 1.

My moth's common name is The Blood-Vein, for reasons that I imagine are obvious. It is a member of the large (several hundred species in the UK) geometridae family of moths, so called because of the caterpillars of these moths walk with a measuring (=hence 'geometer'), 'inch-worm'-like, gait.

From my copy of Moths of Great Britain and Ireland (Townsend and Lewington) I understand Blood Vein caterpillars feed on dock, sorrel, knotgrass and common orache. I've not been able to find a picture of one on the web (anyone?). Price, Goldstein and Smith studied the suitability of the Blood Vein for introduction into the States as a biological control agent against 'Mile a Minute' Weed (their paper is available here). (They found it was unsuitable)

Adult Blood Vein's are fairly common in Mid- and Southern Britain, but get rarer in the North.

The Blood Vein gets but a single mention in my copy of the excellent Moths (Michael Majerus). One might expect that such small and fragile creatures as moths might tend not to fly about in severe weather such as during heavy downpours. Surprisingly this seems not to be the case however: Majerus reports setting up a moth trap during a severe thunderstorm and trapping several hundred moths, undaunted by the driving rain, within hours. A dozen or so Blood Veins were among them.

The Blood Vein's scientific name is Timandra comae. There seems to be some confusion over the the relationship between this moth and the closely similar Timandra griseata. At various times the two have been lumped together as a single species, and at other times split out as two. Current work suggests they are indeed two separate species.

In Greek mythology Timandra was one of the daughters of the Spartan King Tyndareus and his wife Leda (she of swan-fame). Timandra's sister was Helen of Troy. King Tyndareus managed to upset the goddess Aphrodite and was punished with a curse that all his daughters would be adulteresses. Daughter Timandra duly obliged, eventually marrying one King Echemus only to later desert him for King Phyleus.

Now, whether in fact my moth has a particularly adulteress streak to its nature I really can't say. Indeed, aside from the snippets of information above, I've been failed to find any significant written accounts of the biology and behaviour of The Blood Vein. Whether this is because I've not looked in the right places, or whether it is that The Blood Vein, in common with so many other insect species, has simply not been studied in detail, I do not know. I'd be delighted to find out a little more about this pretty moth however, so do leave a comment if you can help.