Of particular interest to both conservationists and farmers are the pollinators. In the last decade or so populations of the UK's pollinating insects, including honey bees, have crashed and there is serious concern about the viability of our crops if pollinating insects continue to decline.
Surveying nine areas of the Southern Block over several days in 2015 and 2016, Dave Goulson - Professor of Biology at Sussex University, and author of ‘A Sting in the Tail’ and ‘Bee Quest’ - recorded 62 species of bee and 30 species of wasp, including seven bee and four wasp species of national importance.
Some of the rarer species, like the Red Bartsia Bee, are specialists in particular flowers now present at Knepp. Other lesser-known species like the Ridge-cheeked Furrow-bee need desiccation cracks in the soil to nest in – something amply provided by our clay in summer. One unusual bee (Melitta europaea) likes to nest in damp or even partially flooded soils. It visits exclusively Yellow Loosestrife for pollen but also for floral oils with which it waterproofs its nest. Other species were more surprising to find in our clay landscape. One, Crabro scutellatus, is associated with damp heathland; another – a very scarce sand wasp (Gorytes laticinctus) – with light soils.