EFFECTS OF GLYCEROL ON COLD-HARDINESS IN INSECTS

1964 ◽  
Vol 42 (1) ◽  
pp. 87-101 ◽  
Author(s):  
Lauritz Sømme
Keyword(s):  
Seasonal Changes ◽  
Cold Hardiness ◽  
Polyhydric Alcohol ◽  
Melting Points ◽  
Glycerol Content

The effects of glycerol on cold-hardiness in insects and seasonal changes in glycerol concentrations were investigated. The presence of this polyhydric alcohol was demonstrated in overwintering stages of 10 species. Larvae of one species also contained sorbitol, and eggs of two species another polyhydric alcohol, probably mannitol.Evidence gathered from various diapausing species showed that glycerol accumulated during the fall. This increase in concentration was observed in eggs of one species at temperatures ranging from −5° to 20 °C. No decrease in glycerol content was observed in any species as long as it was in diapause. After diapause was broken glycerol was lost in all species, in some even at temperatures down to −5 °C. Increase in concentration was never found in postdiapause insects. In two species, which do not have a diapause, the glycerol content increased below a certain temperature and decreased at higher temperatures.Three species were freezing-tolerant, although one contained less than 3% and another no glycerol, whereas eight species, most of which contained more than 15%, were killed by freezing. Thus glycerol alone cannot protect against freezing injuries.In several species the cold-hardiness was increased by the presence of glycerol because supercooling points were depressed. These depressions were more than those of the corresponding melting points. The regression of amount of supercooling on concentration of glycerol was linear in five species.

Seasonal changes in cold hardiness, sucrose and sorbitol in apple trees treated with plant growth regulators

1992 ◽  
Vol 67 (3) ◽  
pp. 429-435 ◽  
Author(s):  
W. K. Coleman ◽  
E. N. Estabrooks ◽  
M. O’hara ◽  
J. Embleton ◽  
R. R. King
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Seasonal Changes ◽  
Cold Hardiness ◽  
Apple Trees

Studies on insect dormancy. II. Relationship of cold-hardiness to diapause and quiescence in the eastern tent caterpillar, Malacosoma americanum (Fab.), (Lasiocampidae: Lepidoptera)

1974 ◽  
Vol 52 (5) ◽  
pp. 629-637 ◽  
Author(s):  
Ajai Mansingh
Keyword(s):  
Cold Hardiness ◽  
Physiological Adaptation ◽  
Malacosoma Americanum ◽  
Glycerol Content ◽  
Supercooling Point ◽  
Mature Embryos ◽  
Glycerol Level ◽  
Carbohydrate Level ◽  
Cold Tolerant ◽  
Tent Caterpillar

Studies were conducted on the relationship between levels of glycerol and carbohydrates, supercooling points, and the relative abilities of diapausing and developing eggs and of larval instars of Malacosoma americanum to withstand various periods of chilling at 5° and −15 °C.Diapause in the mature embryos was associated with very high glycerol content (112 mg/g), low carbohydrate level (13 mg/g), and the ability to supercool to −35 °C. During diapause termination, the glycerol level was reduced lo 11 mg/g with a slight rise only in carbohydrate level while the supercooling point was raised to −14 °C. When quiescence was induced in the larvae by chilling them at 5 °C for 1 to 7 weeks, their wet weights and carbohydrate and glycerol contents decreased gradually. However, the supercooling point remained constant around −14 °C.Diapausing embryos could survive several weeks of chilling at −15° and 5 °C. However, only a few weeks of exposure to 5 °C was fatal to quiescent larvae.It is concluded that there is a direct relationship between glycerol content, supercooling points, and the relative abilities of developing and diapausing stages of the tent caterpillar to withstand low temperatures. The developing stages were naturally "cold-tolerant" with the ability to supercool to −14 °C and survive a few weeks of quiescence at 5 °C, which is well below their range of physiological adaptation. Induction of diapause enhanced the supercooling ability and increased cold-hardiness in the mature embryos.

EXTENT OF ICE FORMATION IN FROZEN TISSUES, AND A NEW METHOD FOR ITS MEASUREMENT

1955 ◽  
Vol 33 (6) ◽  
pp. 391-403 ◽  
Author(s):  
R. W. Salt
Keyword(s):  
Cold Hardiness ◽  
Bound Water ◽  
Fish Muscle ◽  
Theoretical Background ◽  
Ice Formation ◽  
Dehydration Melting ◽  
Salt Solutions ◽  
Melting Points ◽  
Insect Cold Hardiness

Use of the calorimetric and dilatometric methods for determination of ice in frozen tissues is criticized, and a method based on terminal melting points determined after various degrees of drying is proposed. The theoretical background of such a method lends support to it, and experimental work with gelatin is especially convincing. Use of the dehydration – melting point method on blood of Loxostege sticticalis gave results conforming in general to those obtained by other workers with calorimetric and dilatometric techniques, and also to those obtained with salt solutions. The amount of water that is bound is shown to be very low, as in mammalian, frog, and fish muscle. The possible influence of bound water in insect cold-hardiness is discussed and the conclusion is reached that it has little if any protective effect.

Modeling seasonal changes in intracellular freeze-tolerance of fat body cells of the gall fly Eurosta solidaginis (Diptera, Tephritidae)

1997 ◽  
Vol 200 (1) ◽  
pp. 185-192 ◽  
Author(s):  
V Bennett ◽  
R Lee
Keyword(s):  
Cell Survival ◽  
Seasonal Changes ◽  
Cold Hardiness ◽  
Fat Body ◽  
Freeze Tolerance ◽  
Cellular Level ◽  
Eurosta Solidaginis ◽  
Freeze Tolerant

Although seasonal changes in the freeze-tolerance of third-instar larvae of Eurosta solidaginis have been well documented for the whole organism, the nature of this cold-hardiness at the cellular level has not been examined. Seasonal changes in the survival of fat body cells from E. solidaginis larvae were assessed using fluorescent vital dyes after freezing at -10, -25 or -80 °C for 24 h both in vivo and in vitro. Cells frozen in vitro were frozen with glycerol, with sorbitol (both of which enhanced cell survival) or without cryoprotectants. Both cellular and organismal survival were low in August when larvae were not freeze-tolerant, then increased dramatically during September and October before leveling off from November to January. This observation for cells frozen without cryoprotectants indicates that the cells themselves have adapted. The single most important factor influencing cell survival, as determined by logistic regression modeling, was the time of larval collection, which reflects the level of cold-hardiness achieved by field acclimation. Cells frozen in vivo exhibited greater survival than did those frozen in vitro, even with the addition of cryoprotectants. Since no differences were observed between cells frozen with glycerol or sorbitol, the role of the multi-component cryoprotectant system present in E. solidaginis should be investigated.

scholarly journals Seasonal cold adaptation dynamics of some carabid beetle species: Carabus granulatus, Pterostichus oblongopunctatus and Platynus assimilis

2012 ◽  
Vol 57 (1) ◽  
Author(s):  
Angela Ploomi ◽  
Irja Kivimägi ◽  
Eha Kruus ◽  
Ivar Sibul ◽  
Katrin Jõgar ◽  
...  
Keyword(s):  
Seasonal Changes ◽  
Cold Adaptation ◽  
Cold Hardiness ◽  
Carabid Beetle ◽  
Carabid Beetles ◽  
Beetle Species ◽  
Supercooling Point ◽  
Pterostichus Oblongopunctatus

Abstract Cold-hardiness can be measured by supercooling points – the temperature at which spontaneous freezing occurs. Seasonal changes in supercooling point were assessed in field-collected predacious carabid beetle species: Carabus granulatus L., Pterostichus oblongopunctatus L. and Platynus assimilis Payk. (Coleoptera: Carabidae). Supercooling ability of these beetles changed seasonally. The tested carabid beetles proved to belong to freeze-avoiding cryotype.

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