20 



BULLETIN 640,, U. S. DEPARTMENT OF AGRICULTURE. 



as soon as they began to turn white from green in the final ripening 

 process, and the larvae, numbering from 2 to 8, were able to become 

 nearly full grown by the time the cherries had turned red. The pulp 

 surrounding the beans varies from two to seven fifteenths of an inch 

 in thickness, or is scarcely thicker than the well-grown larva of the 

 fruit fly (see fig. 30, p. 39). Therefore, by the time the cherry is ordi- 

 narily ready for harvesting, the larvae have devoured practically all 

 the pulp, leaving the seeds hanging more or less loosely within a 

 sack comprised of the thin skin of the cherry. If the weather 

 happens to be dry, the skin shrivels and hardens about the beans 



and the cherry remains on 

 the branch indefinitely and 

 resembles those killed by 

 disease. However, should 

 the harvesting season be 

 rainy, the skin decays rap- 

 idly, and under the weight 

 of the beans the cherry falls 

 to the ground. A slight j ar 

 may at such times cause 

 many cherries to fall to the 

 ground, where they are 

 lost. This type of loss ne- 

 cessitates extra pickings 

 and greater cost for labor. 

 Since the successful intro- 

 duction of parasites the 

 fruit fly has been so re- 

 duced in the coffee field 

 that the infestation of 

 cherries occurs so late in the ripening process that extra pickings 

 are not necessary, and the cherries on reaching the pulping mills 

 during the height of the harvesting season contain chiefly eggs 

 or young larvse which have not had an opportunity to reduce the 

 pulp. 



Badly infested cherries do not pulp as readily when run through 

 the pulping mill, and naturally weigh much less than sound cherries. 

 (Fig. 16.) The loss in number of cherries in a given weight of badly 

 infested fruit has been found to vary at times from 27 to 59 per cent. 

 This loss in weight, which takes place only in the worthless pulp, and 

 in no way affects the bean, which alone is of commercial value, 

 brought about a financial loss to growers who sold their fruit by 

 weight according to prices obtained before the fruit fly was intro- 



Fig. 18.— Chinese orange sectioned to show damage by Medi- 

 terranean fruit fly. Chinese oranges, kumquats, tanger- 

 ines, satsuma oranges, and many limes are easily and gen- 

 erally infested because of their loose peel and lack of a thick 

 protective rag. (Original.) 



