genesis in mesonymph a small increase in respiratory quotients has been found 

 лл'ЫсЬ may be explained probably by the influence of protein metabolism. 



Changes in the total metabolism were studied also in connection with the 

 generation cycles. In sawflies there occur polyvoltine, bivoltine and mono- 

 voltine species and diapause lasts sometimes as much as 2 to 3 years beside 

 extreme cases with even a 6 years long diapause. In most sawflies the prepupal 

 diapause takes place through the winter period but there are species, too, e. g. 

 Neodiyrion sertifer Geof f r. with a summer diapause. In the family Dolerinae 

 larvae live predominantly in spring. Diapause begins here in the eonymph 

 and continues throughout summer. In autumn diapause is interrupted, the 

 pupa moults falling again into diapause which lasts during the winter. It is 

 one of the few instances of pupal diapause in sawflies. In bivoltine species 

 the minimal respiratory metabolism in eonymphs during the nondiapause 

 development never reaches such a low value as in the case of diapause (Fig. 4). 



Many authors explain the rapid fall of metabolism rate during metamorpho- 

 sis of holometabola by means of the histolysis (see e. g. Fink, 1925). But 

 experiments made with different sawfly species show that this decrease is 

 not necessarily connected with histolysis, as we have supposed before and 

 depends most probably chiefly on the activity of respiratory enzymes. As these 

 two processes run almost simultaneously in the pupae of holometabola it has 

 not been possible as yet to distinguish them properly. In sawflies they are 

 clearly separated because of the said shift of organogenesis into the prepupal 

 stages. In many sawflies decrease in metabolism appears to be equally rapid 

 in the developing individuals as in those reaching diapause, even if the histolytic 

 — histogenetic processes in the latter case do not begin before the one year 

 diapause delay. During histolysis-histogenesis processes in mesonymph we 

 can observe a slight increase of the total metabolism and succinodehydro- 

 genase activity. This increase, however, is very small, only about 10 to 20 1эег 

 cent of the total diapause metabolism, even if at this period the imaginai organs 

 are quickly formed from the imaginai discs. Presumably the morphogenetic 

 processes alone need not necessarily cause a large increase of respiratory meta- 

 bohsm. 



A considerable decrease of respiration and reduced activity of respiratory 

 enzymes during diapause are accompanied by an increased resistance against 

 inhibitors of the cytochrome system — this is the well known cyanide — resist- 

 ant respiration shown from many diapausing insects (see Lees, 1956). 

 A very high resistance against cyanide was ascertained in diapausing pupae 

 of cecropia silkworm (Schneiderman and Williams, 1954). As an exception 

 to this cyanide-resistant respiration the sawfly Pristiphora erichsonii is often 

 quoted, its diapausing prepupal stages being scarcerly more resistant against 

 cyanide as the normal developmental stages, according to McDonald and 

 Brown (1952). I have made measurements of cyanide — resistance by means 



200 



