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
Cistus salvifolius L. is the most widely spread Cistus species around the Mediterranean basin. It colonizes a wide range of habitats growing from sea level to 1,800 m a.s.l., on silicolous and calcicolous soils, in sun areas as well as in the understory of wooded areas. Nevertheless, this species has been mainly investigated in term of its responsiveness to drought. Our aim was to understand which leaf traits allow C. salvifolius to cope with low-light environments. We questioned if biochemical and physiological leaf trait variations in response to a reduced photosynthetic photon flux density were related to leaf morphological plasticity, expressed by variations of specific leaf area (SLA) and its anatomical components (leaf tissue density and thickness). C. salvifolius shrubs growing along the Latium coast (41°43'N,12°18'E, 14 m a.s.l., Italy) in the open and in the understory of a Pinus pinea forest, were selected and the relationships between anatomical, gas exchange, chlorophyll (Chl) fluorescence, and biochemical parameters with SLA and PPFD variations were tested. The obtained results suggested long-term acclimation of the selected shrubs to contrasting light environments. In high-light conditions, leaf nitrogen and Chl contents per leaf area unit, leaf thickness, and Chl a/b ratio increased, thus maximizing net photosynthesis, while in shade photosynthesis, it was downregulated by a significant reduction in the electron transport rate. Nevertheless, the increased pigment-protein complexes and the decreased Chl a/b in shade drove to an increased light-harvesting capacity (i.e. higher actual quantum efficiency of PSII). Moreover, the measured vitality index highlighted the photosynthetic acclimation of C. salvifolius to contrasting light environments. Overall, our results demonstrated the morphological, anatomical, and physiological acclimation of C. salvifolius to a reduced light environment., G. Puglielli, L. Varone, L. Gratani, R. Catoni., and Obsahuje bibliografii