DEVELOPMENT AND FUNCTION OF DIAGINAL MALE 

 REPRODUCTIVE ORGANS OF THE COCKCHAFER MELOLONTHA 

 MELOLONTHA L. 



Разнитие ii функция мужских половых органов у взрослых майских жуков 



V. LANDA 



(Entomological Laboratory of Czechoslovak Academy of Sciences, 



Praha, Czechoslovakia) 



In these last years I made detailed studies of the development of male 

 reproductive organs of imagoes of the cockchafer from the emergence until 

 death. In this report I should like to mention some results of a general signifi- 

 cance. 



1. Spermatogenesis and spermateliosis 



Spermatogenesis and spermateliosis are not accomplished in the pupa as 

 it has been affirmed up to now, but they continue in the imaginai stage. 

 Thus we find various figures of meiosis also several days after the emergence. 

 The transition of spermatogenesis into imago as well as differences in lenght 

 of this first phase of testes are the proof that the development of reproductive 

 organs is to a certain extent independent on the development of the whole 

 body. At the end of their first evolutionary stage the testes contain bundles 

 of spermatozoa stretched with straight flagella. During the second, very 

 important stage the cyst cells are contracted, flagella of spermatozoa undulate, 

 the physiological state of spermatozoa changes (increased affinity towards 

 stains). The third stage is characterized by the exit of spermatozoa and cyst 

 cells. In the fourth stage during the feeding period the testes rapidly dege- 

 nerate. 



2. Cyst cells 



In beetles of the family Scarabaeidae the spermatocyte groups in various 

 developmental stages are covered up by cyst cells, as usual in insects. On the 

 transfer of spermatozoic bundles into the genital duct the cyst cells separate 

 forming large circular cells with further special functions which is on the whole 

 an exceptional case in insects. On the separation from sperm bundles the cells 

 develop their own activitj^ evident from photographs made with the phase 

 contrasts microscope by a short-term cultivation of testicle mass. The cyst 

 cell nucleus rounds vip, concentrates the remaining protoplasma in its own 



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