Table 4 



Mortality during hibernation 



earth, but perished on the surface. Such a strong effect of the photoperiod 

 took place when hght or darkness were directly acting on the beetles, however, 

 the influence of food grown in different conditions of light did not manifest 

 itself at all. 



The influence of the photoperiod was unusually strong on the fertility of fe- 

 males. This is seen in Table 3 Avhere the number of eggs is given laid by 100 

 females bred on different food and in different light conditions. 



10 pairs of beetles are in 2 days 1105 cm^ of potato leaves grown in a normal 

 day and 2202 cm- of leaves grown in diffused light. In this manner, the insects 

 compenate the unsubstantial food lacking nutritive compounds by the quantity 

 of eaten leaves. 



Table 4 shows the mortality of beetles during hibernation. The biochemical 

 analyses of beetles given in Table 5 explain the differences in winter mortality. 

 The beetles, immediately after metamorphosis, had a rather balanded bio- 

 chemical composition of the body characterized by high contents of free water 

 and a low lii^ocytic coefficient (the relation of the quantitj^ of lipoids to protein 

 nitrogen) amounting generally to below 1. 



During the period of descending for hibernation the biochemical composi- 

 tion distinctly differentiates, namely the beetles bred in a short day always 

 have the least free water and the most lipoids, their li])ocytic coefficient 

 amounts to 6 — 8. The beetles bred in a long day have considerably more free 

 water and the relation L/N about 3,5. 



During the period of hibernation insects lose considerable quantities of fat 

 and the percentage of free water increases from about 45% to about 55% of 

 the body weight. 



It is a very characteristic fact that the quality of the food did not influence 

 at all the biochemical composition of the beetles body. 



233 



