As usual with most investigations, my observations of gorse mites around Westleton left me with more questions than answers. The colonies of mites, so vigorous and active at the beginning of spring, were completely destroyed by the small black ladybird ( Stethorus punctillum, White Admiral 55 , 17 – 18) and the larvae of a gall midge ( Feltiella acarisuga ) which appeared later in the season. Had any mites left the colonies and evaded the predators and was the gorse mite not a significant factor in the interplay between the growth of gorse and other heath vegetation?
In any case, was the study worth pursuing from a natural history perspective? The emphasis these days seems to be on the census of animals and plants with the information being passed up to experts, eventually to appear as dots on a map, support for management grants, or dire warnings about ultimate demise. In the world of high-tech and wealthy conservation bodies with call on modern methods and expert consultants, can the amateur make any contribution? Undeterred by these considerations, and convinced that study of a particular organism as well as recording, is a relevant subject for the SNS, I determined to press on. Perhaps, one day the gorse mite may become an endangered species and information about its biology may be needed to save it.
Had any mites survived the onslaught and what had happened to them? Bushes which had colonies in spring 2003 were searched for survivors, a peculiar form of masochism. In some bushes, which had had strong colonies with large webs none at all were found. In other, similar bushes small colonies were found in September, clustered around twigs deep in the canopy. The colonies were composed solely of adult mites and viewed in situ with a hand lens (a hazardous pastime) they were moving slowly: clearly not hibernating. At the time writing (mid-January) on sunny days they are beginning to move to the top of the canopy and as Stephen Duck observed in 1736:
The little things, elate with Pride,
Strut to and fro, from side to side:
In tiny Pomp and portly vein,
Lords of their pleasing Orb, they reign.
To
see more clearly what they are up to a digital camera is just the thing. This
has a macro function (focus to about 40 mm) and a video function providing 40
seconds of recording. Using these settings to photograph the colonies in the
field shows that they are in constant motion and by playing the clip one frame
at a time and tracking individual mites, they do indeed ‘strut to and fro’ moving back and forth over a short distance
as they spin a dense complex web. 
Occasionally one sets off purposefully,
presumably spinning a long strand to form scaffolding for the web.
What about these overwintering mites? They all appear to be females and therefore are presumably fertilised. To try and check this some were mounted in lactic acid, which clears the tissue and allows observation of internal structures such as eggs.
(An initial problem was to obtain lactic acid - enquiries at High Street chemists were not helpful; one advised trying health shops! Help came eventually from the Editor who, in another guise, found me some). The preparations (photograph) show, among other things, structures tentatively identified as food balls (fb) and an oviduct with eggs (ov). Observing these structures until eggs are laid in March will confirm, or otherwise, their identity.
[If you see any gorse mite colonies, especially large ones where the web can spread over a metre square or more, I would be grateful to hear about them]
Michael Kirby, The Studio, Blythburgh Road, Westleton, Saxmundham, IP17 3AS
