Amateur arachnologists, or spider experts, at the Woodland Trust's newly created wood at Cefn Ila near Usk have clocked up a Welsh first, a breeding record of the rare and beautiful wasp spider.

Out surveying for moths last autumn, biologist Michael Kilner, a volunteer for the Woodland Trust at Cefn Ila, near Llanbadoc, Usk, noticed and recorded over 25 of the rare arachnids, including two males. What's more, some were engaged in breeding behaviour. It is unusual to see this, as it is only during a short period, while female's jaws are still soft after moulting, that the much smaller male is able to mate without being eaten by the female.

Probably named for the black and yellow stripes on its abdomen, the fearsome but beautiful wasp spider, or Argiope bruennichi, preys on flying insects and grasshoppers and has even been known to capture and devour wasps. These spiders are still very rare outside the south east of England but have been gradually increasing their range over the past two decades, possibly due to climate change.

The Woodland Trust acquired Cefn Ila in 2007 and has already planted over 36,000 trees to create 24 ha (59 acres) of new woodland. Now, with the help of a £25,800 development grant* from the Heritage Lottery Fund, the charity plans to develop the new wood so as to help and encourage the local community to make the most of it, organising a programme of events and activities for schools, local people and visitors, and restoring the site's natural and built heritage. The aim is to recruit local volunteers to lead activities and to work with local people to propagate the rare heritage fruit trees growing in the site's historic orchard.

Barry Embling, who manages the site for the Woodland Trust says: "I'm finding that local people are drawn to Cefn Ila. Many of them, including Michael Kilner who recorded these rare spiders, were actually born here, as there used to be a maternity hospital on the site, which actually burnt down in 1973.

"It's a wonderful place. As well as the new woodland, it includes a historic walled garden and orchard and an arboretum that has been described by the expert Ivor Stokes as 'amongst the finest in Wales'. I'm really looking forward to working with the local community to make more of the site and to encourage more people to enjoy and appreciate it."