Full-text - Norsk entomologisk forening

Melaletrarrychus ulmi 4211050- 5-1 0-15- 20-251050-5-1 0-1 5-20-25-35-35-4 0I05ULLENSVANG0- 5-10-151 15 31 15 31 15 20 15 31DEC. JAN FE B MAR.Fig. 1. Afaximum and minimum temperatures from December 1965 toMarch 1966 at As, Nes and Ullensvang.The eggs were collected at a time when diapause normally isbroken (S~mme, 1965). To study survival rates twigs with aknown number of eggs were placed on moist filter paper in PetriLdishes at room temperature in the laboratory. Each twig wassurrounded by a ring of Vaseline to prevent the escape of anymites. The number of hatched mites was counted at regularintervals, until hatching ceased.