The main method of collecting specimens in the past has been sweeping the vegetation and beating the foliage and this has produced many records and will be continued in the future. However there are many spider species whose habitat is on the ground and pitfall trapping is a convenient method for finding these spiders many of which are only 1-2 mm in length.

The traps, which are plastic cups of the coffee dispenser variety, are inserted into the ground, in this survey 3 cups per site at approx 1 metre apart, and contain a solution of 25% Ethylene Glycol (Anti-Freeze) in water with a dash of Teepol (Washing up liquid) to reduce surface tension. These are left for periods of a week or more, then the contents are sieved out for identification and the cups replenished. In this survey the traps were installed at the end of March 2004 and serviced every week or two until they were lifted and trapping ceased on 09/11/2004.

Three sites were chosen in places where there would be little or no disturbance to the bird life of the reserve. Site A was in woodland to the left of the main path fairly close to the perimeter fence. Site B was at the western extremity of the reserve in undergrowth near to the brook and Site C was in the wild flower meadow.

A total of 37 species were identified over the trapping period and are listed in Tablet. This is a somewhat disappointing result, I would have expected more species, but my traps seemed to lose their efficiency after some weeks of use and needed replacing but suitable replacement cups could not be found the design having changed.

The complete list of species identified over the last 12 years is shown below and on Table 1 and the reserve list totals 64 species of spiders and 6 species of harvestmen. All these are reasonably common spiders, only Philodromus albidus is a Nationally notable B species and this designation may not now be justified as it turns up in lots of places in Herts. There are undoubtedly many more species to be discovered on the reserve including some very common ones, and significant areas of the reserve, particularly beyond the Shell hide, remain to be investigated. I would expect a list in excess of 100 species to be the final result and I hope to be able to continue to my search to add to the knowledge of the invertebrate fauna of the reserve.