On the Mating Instinct in Moths. 183 



XXI. — On the Mating Instinct in Moths*. 

 By Alfred Goldsborough Mayer. 



During the past summer the author carried out a series of 

 experiments to determine the nature of tlie mating instincts 

 of CoUosamia proniethia. 



A hirge number of cocoons of this moth were kindly 

 collected for the author by W. L. Tower, Esq , in the neigh- 

 bourhood of Cambridge, Mas.^achusetts, and others were found 

 by the writer at Maplewood, New Jersey. Altogether 449 

 cocoons were olitained during the winter of 1898-99. These 

 were allowed to remain out of doors in Cambridge (Mas;".), 

 where they were exposed to the winter's cold, and then on 

 May 5 they were taken to Loggerhead Key, one of the Dry 

 Tortugas Islands, Florida. 



Tiiis situation was most favourable for the prosecution of 

 the experiments, for this insect does not extend south of the 

 Carolinas, and thus the moths were sej)arated many hundreds 

 of miles from others of their species. Moreover, Loggerliead 

 Key is a small sandy island surrounded by many miles of 

 ocean, and thus no interference with the experiments could 

 come from the outside. 



The cocoons were hung under the shade of some trees, 

 where they were protected from the direct rays of the sun. 

 It was remarkable that all but five of the moths (three females 

 and two males) issued from the cocoons during the early 

 morning hours between sunrise and 11 o'clock. 



The following table will show the rate at which the moths 

 issued from their cocoons : — 



Number Number 



Date. of males, of females. Total, 



May 18 12 3 



19 1 2 3 



20 1 2 3 



21 1 1 



22. 10 1 



23 



24 1 1 



25 1 1 2 



26 



27 1 1 2 



28 



Carried forward .... 8 8 1(3 



* This paper was delivered as the Presidential Address before the 

 Cambridge (Mass.) Entomological Society in January 1900, and pub- 

 lished in * Psyche,' the Journal of the Club, in February. 



