Cold hardiness of larvae of the summer fruit tortrix moth, Adoxophyes orana (Fischer von Rosslerstamm) (Lepidoptera: Tortricidae) was examined in the laboratory. Supercooling point of field collected larvae increased significantly from a mean value of -23.9°C in February 1998 to -16.9°C in June 1998. Mean supercooling points for laboratory diapause and non-diapause larvae were -20.7°C and -17.2°C respectively. Short period of acclimation (10 days at 0°C) significantly decreased supercooling point to -24.7°C for laboratory diapause larvae. Acclimation for 12 days at 5°C decreased supercooling point to -19.4°C for non-diapause larvae. Pre-freeze mortality for diapause and non-diapause larvae was also studied. Constant exposure of diapause larvae at -5°C resulted in high mortality (63.1%) after a period of 30 days. in contrast, only 6 days at -5°C were sufficient to cause 100% mortality of non-diapause larvae. Mortality of non-diapause larvae reached 100% after 12 and 18 days at 0 and 5°C respectively. The importance of these findings for the overwintering strategy of A. orana is discussed., Panagiotis G. Milonas, Mathilde Savopoulou-Soultani, and Lit
Ex ovo larvae of Lobesia botrana were reared on flowers and fruits of known and potential host plants. both in the laboratory and in the field. Development rates indicated a wide range of host suitability. In the laboratory, larvae of L. botrana had higher survivorship and shorter development time when reared on Vitis vinifera, Prunus persica (nectarina), Taraxacum officinale or Prunus domestica than when reared on Malus pumila, Pyrus amygdaliformis, Prunus armeniaca, Prunus cerasus, Syringa vulgaris or Papaver rhoeas. Similar results were obtained in the field. In no-choice tests in the laboratory, more eggs were laid on fruits than on flowers. Fruits of Prunus domestica, Vitis vinifera and Prunus persica (nectarina) were most preferred as oviposition sites.