Importance of lichen secondary products in food choice of two oribatid mites (Acari) in an alpine meadow ecosystem.

In an alpine meadow ecosystem in the Swiss National Park, the lichensCetraria islandica andCladonia symphycarpa occur in small vegetation patches dominated byCarexfirma (Cyperaceae) andSesleria coerulea (Gramineae). Laboratory food-choice experiments with two oribatid mitesFuscozetes setosus andCarabodes intermedius show that the thallus structure and secondary products ofC. islandica are repellent factors against herbivorous mites. In contrast, secondary products ofC. symphycarpa may be an attractant for the mites.