-3.— 
     
    
   
   
    
     Outdoor insects of northern latitudes have had to solve the problem of winter 
     
    

    
     survival. Entomologists do not know all about the devices which temperate insects 
     
    

    
     use to help them withstand the cold of winter, for these devices are founded within the 
     
     physiology, or bodily functions, of the insects. 
     
    
   
   
    
     Surviving a Long Cold Winter, Insect Style 
     
    
   
   
    
     For example, diapause (an obstinate state of arrested development) enables some in- 
     
     sects to pass the winter safely. Common white cabbage butterflies have at least two 
     
     broods per season, but when the caterpillars are exposed to daylengths of l2 hours 
     
     or less, the pupae which form enter diapause and do not develop further until the 
     
     following spring. The tent caterpillar, on the other hand, goes into diapause as 
     
    

    
     an egg. Other species may enter diapause as larvae or as adults. Diapause is under 
     
     the influence of light, which affects the hormonal system of the insect and results 
     
     in profound physiological changes. We should not, therefore, make too close a 
     
     parallelism between diapause and cold survival. 
     
    
   
   
    
     Some insects survive the winter without diapausing; what is the nature of cold 
     
     hardiness in these insects? 
     
    
   
   
    
     One alternative is supercooling; that is, as the temperature drops below the freezing 
     
     point, body water becomes more ice-like in its molecular arrangement but nucleation 
     
     (centres of ice formation) is absent. Some insects will supercool in this way to 
     
     -hO°C without harm. However, should nucleation and freezing occur, these insects 
     
     will usually die because of cell damage. Insects which supercool usually have a 
     
     lowered freezing point of body fluids, the result of a high solute concentration 
     
     and/or the presence of glycerol in their bodies. In effect, they produce their own 
     
     antifreeze! 
     
    
   
   
    
     Finally, a lot of insects are unharmed by freezing. Such insects show a buildup of 
     
     glycerol in their tissues as cold weather approaches and insect physiologists 
     
     generally agree that glycerol-containing cells can be frozen without injury. However, 
     
     the nature of the freezing-tolerance conferred by glycerol is still unknown. 
     
    
   
   
    
     R. W. Salt, the foremost Canadian researcher on cold hardiness in insects, summed 
     
     up our knowledge of winter survival of insects as follows "Diapause may have 
     
     attributes that favour winter survival but the two factors that really determine 
     
     coid hardiness are supercooling potential and presence of glycerol.” 
     
    
   
   
    
     - Lawson Drake 
     
     Biology Department 
     
     Univ. of P.E.|. 
     
    
   
   
    
       
     
    
   
   
    
     Notes on an Osprey Nest 
     
    
   
   
    
     On September 18, l975, while returning from a day in the field, my eyes, lower than 
     
     usual, spied an unusual “blob” on the horizon. Unusual since I had been on that 
     
     particular road many times before and the blob went unnoticed. On closer examination 
     
     with binoculars and telescope, it was decided that the “blob” consisted of an osprey 
     
     nest and one osprey repairing the nest. In the days that followed,the now quite 
     
     obvious nest was checked daily for activity. 
     
    
   
   
    
     On September l9, it was noted (by Kathy Martin) that a second osprey was utilizing 
     
     the tree and until September 24 our notes suggested that two osprey were simply 
     
     maintaining or repairing a nest, possibly for next year's breeding season. Calling 
     
     could be heard from the road but this vocal activity did not seem one of alarm. 
     
    

    
     On September 24, the first hint that the nest had been active all summer was noted 
     
     when 2 adults were observed as well as movement of a third object in the nest. It 
     
     was later confirmed that the family consisted of two adults and two young. 
     
    
   
   
    
     The nest was located in Chelton not far from Central Bedeque. It was within a mile 
     
     of Northumberland Strait which provided the ospreys with its usual diet--fish. This 
     
     nest as well could be home base for osprey sighted several times along the Dunk 
     
     River. The nest 60 feet high in a dead white pine, towered above the mixed woodlot 
     
     by 20 feet. The nest, 2.5 - 3 feet in diameter and about two feet high, was made 
     
    

    
     of twigs and old branches. 
     
    
   
   
    
     Nelson Hurry arrived on September 25 to band the young osprey. As he climbed the 
     
     tree, two young osprey flew from the nest scolding and calling. What had earlier 
     
     been considered as flightless young turned out to be quite able flyers. The nest