Entomofauna of Centaurea sp. and their economic importance

Abstract

The different species of Centaurea are host of numerous insects: among the most important some are pollinating (Apis melifica L.), the most of them are phytophagous (Larinus obtusus...,Agonopterix liturella Den. et Schiff., Chaetorellia jaceae R. D., Crophora quadrifasciata Meig.) and others are zoophagous (Exeristes roborator F. and Zeuxia cinerea Meig.). The plant root is harmed by the larvae of Pelochrista medulana Stgr., the stalk is mined by the caterpillars of Agonopterix liturella Den. et Schiff., and the flowers and seeds are destroyed by the larvae of Larinus obtusus Gyll., Eucosoma hohenwartina Den. et Schiff., E. aemulana Schlang., Chaetorellia jaceae R.D. and Urophora quadrifasciata Meig. Due to the population density and to the caused damages, the species Agonopterix liturella Den. et Schiff., Larinus obtusus Gyll., Chaetorellia jaceae R.D. and Urophora quadrifasciata Meig., are these who present a practical importance as agents of biological control of the knapweed species, especially Centaurea phrygia. On the whole, considering the seed losses caused only by the seed weevil (Larinus obtusus Gyll.) and by tephritids flies of the knapweed seeds (Chaetorellia sp. and Urophora sp.) these are estimated to 50-60 %.