THE COURTSHIP OF PIERIS PROTODICE 



PHIL RAU 



The mating habits of Pieris protodice have been so uniform 

 in all of the cases which have come under my observation in 

 various times and places that I feel that this phase of their 

 behavior is fairly constant. The following cases are typical of 

 the usual performance. 



On June 12, at 5:10 p. m., many of these white butterflies 

 were fluttering about one of their favorite haunts, a patch of 

 white-flowered milkweed in a sunny, treeless pasture. A female 

 was at rest on the upper surface of a leaf, with its wings spread 

 flat and its abdomen turned directly upward into the air and 

 held thus rigidly. A male was hovering above her with more 

 than usual activity; frequently he would flutter very near to 

 the upturned abdomen. Presently he grew more bold; he 

 repeatedly approached and beat his wings against hers with a 

 flapping motion, and darted toward her and touched her abdomen 

 with his own, apparently in an attempt to mate, until the ex- 

 citement grew intense after several such advances, and both 

 arose on the wing and fluttered and danced and fussed in an 

 almost quarrelsome manner in mid-air for a few seconds, when 

 the female settled to rest on another leaf nearby in the very 

 same position, and the whole performance was repeated. When 

 the male again became too familiar the female flew away as 

 before, the male following and the two fluttering 'round and 

 'round each other, high in the air. Then the coquettish female 

 suddenly darted away and hid under a leaf near the ground, 

 this time eluding her suitor. 



Although there were hundreds of these white butterflies fly- 

 ing about and feeding upon the white flowers, only three pairs 

 were in copulo. Perhaps the late hour in the day might account 

 for the small number in mating. 



On three occasions I chanced to see the beginning of this 

 strange performance, but I was unable to ascertain at any time 

 which sex made the first advance in this courtship. In each 

 case the female was feeding or resting on the flowers, with closed 

 wings in a normal, placid manner in so far as I could see, when 



