22 BULLETIN 491, U. S. DEPARTMENT OF AGRICULTURE. 



cane leaf hopper (Perkimiella saccharicida Kirkaldy) on sugar cane, 

 by the green scale (Coccus viridis Green) on coffee leaves and fruit, 

 by the corn leaf hopper (Peregrinus maidis Ashm.) on corn tassels 

 and leaves, by the bean aphis (Aphis gossypii Glover) -on different 

 varieties of beans, or by the banana aphis on banana foliage and 

 flowers. Wherever honeydew is present the melon fly is among the 

 many insects attracted. 



The adults are particularly fond of the juices exuding from the 

 ruptures made by the female in the epidermis of the host while form- 

 ing the cavity in which to deposit eggs. Cucurbits in general exude 

 considerable juice when injured, and this is eagerly eaten by both 

 sexes of adults. Fruits broken in the field, crushed vines, and even 

 the decayed areas in infested fruits are attractive to adults. Although 

 adults have seldom been observed to visit the flowers of cucurbits in 

 search of food, they have been observed, apparently feeding, among 

 the flowers of Acacia farnesiana Willd., the banana (Musa spp.) , and 

 sunflower (Helianthus sp.). On numerous occasions they have been 

 seen drinking small droplets of moisture during the early morning 

 or after light showers. 



In the laboratory, in confining jars, the adults have been kept alive 

 by feeding with several fruit juices, but they thrived best upon 

 papaya pulp passed through cheesecloth and then diluted with about 

 twice its bulk of water. 



Of special interest is the attraction of the flowers of the orchid. 

 Phalaenopsis schilleriana Keichb. f. Mr. W. M. Giffard, of Hono- 

 lulu, first observed adults feeding upon the nectar of this orchid 

 during April, 1913. Dr. H. L. Lyon and Mr. Albert Waterhouse, 

 also of Honolulu, have observed many adults about their greenhouses, 

 into which they had been lured by the orchid flowers. One florist 

 feared that the adult melon fly might injure the blooms, but experi- 

 ments and observation proved that they were only after the nectar. 



PROPORTION OF SEXES. 



The sexes are quite evenly divided. The examination of 1,049 indi- 

 viduals emerging from 8 lots of fruit showed 524 to be males and 

 525 to be females. The proportion of sexes of each of the eight lots 

 is as follows: 



Males 25 



Females 24 



20 



73 



70 



83 



44 



102 



107 



37 



HAT] 



65 



NG. 



60 



70 



45 



123 



101 



So far as the writers have been able to detect, neither sex of the 

 melon-fly adults gives off an odor. 



Inasmuch as adults of the Mediterranean fruit fly show at all times 

 during the day, particularly during the warmer months, indications 



