FOOD-PLANT FAMILIES OF BRITISH INSECTS AND MITES - THE INFLUENCE OF LIFE FORM AND PLANT FAMILY

The dissimilarities between 107 British plant families with respect to the insect and mite species which feed on them were analysed using a principal co-ordinates analysis. The relationships between the plant f amilies were strongly influenced by the plant life forms. Major groups were woody plants (trees and shrubs), aquatic plants and herbs. A wet to dry gradient was distinguished, as were evergreen plants, and earl y successional plant families with weeds and annuals. Taxonomically, p lant families of the same order were closer together if they were pred ominantly of the same life form. Fagales and several orders of monocot yledons formed particularly clear groups. The three 'nearest neighbour s' of each plant family based on the dissimilarities measures were lis ted. These provide some interesting, but conjectural, data on evolutio nary aspects of plant families. This was illustrated briefly by the Co rnaceae and Euphorbiaceae. The underlying progressive evolution of pla nts from woody species and wetter areas to herbs and annual plants of dry and cold places may be reflected by insect and mite food plant fam ily associations.