NUTRITIONAL-ENDOCRINE REGULATION OF INSECT 

 REPRODUCTION 



Пищевая и эндокринная регуляция размножения насекомых 



А. S. JOHANSSON 



(Zoological laboratory, University of Oslo, Norway) 



Reproduction of animals often has to be timed rightly, both as to the 

 individual's own state of development and to the environmental conditions, 

 this including the presence of individuals of the opposite sex. In insects this 

 regulation may be controlled by a variety of factors, such as temperature, photo- 

 period, mating, or nutritional uptake. 



The present paper will be concerned with certain aspects of the relation 

 between nutrition and reproduction. Food is generally required for two main 

 purposes: firstly to maintain the hfe and development of the individual, and 

 secondly to supply materials necessary for the production of offsprings. It is 

 Avell кполуп that in many species of insects, particularly in the females, these 

 two processes may have different requirements: the type of food which is able 

 to maintain hfe, as for instance carbohydrates, may not be sufficient for 

 successful reproduction. In the latter case a special diet of proteins may be 

 necessary. 



We have for some time used the American milkweed bug, ОпсщхИгш 

 jasciatus (Dall.), to illustrate how nutritional uptake by way of the central 

 nervous system and endocrine organs regulates egg production (Johansson, 

 1058). This heteropteran is very easily kept in the laboratory on water and 

 dried seeds of the milkweed plant. In sexually mature females the development 

 and growth of the oocytes go on as a continuous process even in virgin 

 specimens. The fecundity is, however, influenced by the nutritional state 

 of the individual. Daily access to an adequate food supply is normally neces- 

 sary. If food is withdrawn from an egg producing female, oviposition ceases 

 within few days. Similarly, if a newly emerged female is given Avater and no 

 seeds, egg production will usually not start at all. In such starving females 

 the oocytes degenerate shortly after reaching the state where yolk is normally 

 being deposited into the eggs. The same is observed when the females are kept 

 on glucose: no eggs are normally produced, although such individuals may 

 live for a month or more. On the луЬо1е, the egg output from a female is strongly 

 influenced both by the quantity and the quality of the food. 



In Oncopeltus, as in many other species of insects studied (Novak, 1959, 

 p. 80), the corpus allatum has proved to be an endocrine organ necessary for 



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