238 MANUAL OF TROPICAL AND SUBTROPICAL FRUITS 



set in the orchard or garden, and thereafter fruits and flowers in 

 all stages of development may be in evidence at all times of 

 the year. In the cool season the fruits are slow in ripening, 

 thus causing a short crop and high prices for a month or two." 



Sometimes the fruits are produced in such abundance that it 

 is necessary to thin them in order to avoid their remaining 

 small in size or becoming malformed by the pressure of neigh- 

 boring fruits. Thinning should be done when the fruits are 

 rather small. 



If the fruits are to be sent to market they should be picked 

 as soon as the surface begins to turn yellow. " Certain varieties 

 become ripe enough for serving while showing little yellow 

 coloring." It is difficult to ship the fully ripe fruit, since it is 

 large, heavy, and has no firm outer covering, but only a thin 

 membranous skin, to protect it. For this reason papayas 

 must be shipped before they are fully ripe, and even then great 

 care is necessary. Shipments have been made from Hawaii to 

 San Francisco in cold storage with good results. When shipped 

 from southern Florida to New York by express, the percentage 

 of loss is usually large, unless the fruit is picked while still 

 green; and in the latter case it does not ripen properly after 

 reaching the market. It is advised to encase the fruits in 

 cylinders of corrugated strawboard, and pack them in single- 

 tier cases holding four to six fruits. 



Pests and diseases. 



Two pests have become sufficiently troublesome in south 

 Florida to require attention. One, the papaya fruit-fly (Toxo- 

 trypana curvicauda Gerst.) threatened at one time to become 

 serious. This insect occurs in several parts of tropical America. 

 The female inserts her eggs into the immature papaya by means 

 of a long ovipositor, and the larvaB first feed in the central seed- 

 mass, but later work into the flesh of the fruit, frequently 

 rendering it unfit for human consumption. The only means 



