Tain and District Field Club held its AGM on Tuesday 15th Sept 09 and afterwards hosted the first lecture of the Winter season given by Dr Alan Bowman of Aberdeen University.
“Secrets of Tick – The Problems and Potential” was an excellent talk, which riveted the audience. The disease transmission capabilities of these little blood suckers is well known, and it has been getting worse, e.g. there has been a 17-fold increase in Lyme cases in humans over the last 10 years.
To understand some of the reasons, Dr Bowman introduced the audience to the biology of these creatures. Ticks are not insects, but related to spiders. The “head” is in fact just mouth parts. There are backward pointing barbs which anchor the tick in place, and it also secretes liquid cement over 1 to 2 days, which is why ticks become so difficult to remove. They inject chemicals such as pain killers, anti-inflammatories and immuno-suppressants, so that the host does not know the tick is there.
It is this injection/regurgitation process that transfers disease to the host. But it is also these chemicals which represent the tick’s potential as well, because they are of considerable interest to the pharmaceutical world. Tick spit is remarkable.
The Sheep Tick is best known. There are 3 stages of the life-cycle: larva, nymph, and adult. It is the nymph stage that is the most important for disease transmission. The larvae that hatch from eggs are clean of disease, and it is only if the nymph feeds off an infected animal that it becomes a carrier.
In the economy of the Highlands it is sheep and grouse, especially chicks, that are potentially worst affected by “Louping Ill”. A dilemma for estates that manage for both deer and for grouse is that red deer blood seems to cleanse ticks of disease, so the deer themselves are not seriously affected. The problem is that the large numbers of deer help to keep tick populations high in these habitats which, apart from grouse, otherwise support quite small numbers of alternative host such as small mammals and birds.
It is very difficult to clear an area of ticks, even with burning, as animals and birds just bring it back in again.
Dr Bowman finished with some practical tips on avoidance and especially on how NOT to remove ticks. Importantly, do not squash the body or use chemicals such as nail varnish remover, as the tick will react and regurgitate its stomach contents into you. Incentive indeed!
University of Aberdeen – Macaulay Institute Scottish Tick Survey
Further information about ticks and Lyme Disease can be found HERE. If you have had Lyme disease please complete the response form on the site.