We evaluated net photosynthesis, respiration, leaf conductance, xylem pressure potential (XPP) and cold hardiness in red spruce (Picea rubens Sarg.) seedlings exposed to either a continuous thaw (CT) or a daytime thaw with freezing nights (FN) for 8 days during mid-winter. Physiological differences between CT and FN seedlings were evident for all measured parameters. However, the temporal expre...

The method of evaluating cold injury in woody plants by the use of triphenyl tetrazolium chloride has been refined to eliminate bias associated with visual differentiation between varying degrees of tetrazolium reduction and to predict tissue survival at a later date. An advantage of the method described here is that a small amount of tissue (50-100 mg) is required; this, therefore, allows for ...

The codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae), a worldwide apple pest, is classified as a freeze-intolerant organism and one of the most cold-tolerant pests. The objectives of this study were to examine the supercooling point of overwintering and non-diapausing larvae of C. pomonella as an index of its cold hardiness, and to assess larval mortality following 24 h exposure to e...

Strong tolerance of freezing is an important strategy for insects living in extremely cold regions. They produce highly effective cryoprotectant systems consisting of ice-nucleating proteins and polyols, which enables tolerable freezing of the body fl uid. Therefore, the measurement of the concentrations of polyols and the activity of ice nucleators in the haemolymph is an essential tool for de...

This study was conducted to obtain information on the cold hardiness of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), in Florida and to assess upper and lower temperature thresholds for oviposition. The psyllid is an important pest in citrus because it transmits the bacterial pathogens responsible for citrus greening disease, Huanglongbing, considered the most seri...

the beet moth, scrobipalpa ocellatella is recognized as a widespread agricultural pest. cold hardiness strategy of the beet moth larvae was investigated through monitoring seasonal changes at supercooling points and lower lethal temperatures. furthermore, the role of microhabitat in winter survival was studied. the mean scps of the last instar larvae was not significantly different from novembe...

must endure cold and severely desiccating conditions, but most studies of adaptations for winter survival have focused primarily on survival at low temperature, with little consideration of water conservation. However, several authors have emphasized that certain adaptations affect not only coldhardiness but also resistance to water loss (Ring and Danks, 1994; Block, 1996; Danks, 2000), suggest...

Cold climate interspecific hybrid grapevines (CCIHG) selected for their superior midwinter cold hardiness have expanded grape production to regions. However, extreme weather events, such as polar vortexes and the high frequency of fall spring freezes, often result in yield vine losses. The main objective this study was evaluate changes bud five CCIHG cultivars grown upper Midwest identify relat...