THE MEXICAN ORANGE MAGGOT 



323 



time, apparently selecting a favorable spot in which to deposit her eggs. This 

 spot is usually found near the flower end, but sometimes on some other 

 part of the fruit. When the right spot has been selected the fly bends 

 down its long tube-like abdomen and forces it into the outside skin of the 

 fruit and there deposits some of her eggs. When this has been completed 

 she flies off to another orange to repeat the process. One female may infect 

 anywhere from four to ten oranges or mangoes and often more g^avas. 



The eggs hatch after a certain number of days, varying with the tem- 

 ]ierature. The entire injury is done by the larvae or maggots which eat their 

 way through the pulp and inner tissues of the fruit, reducing that part of the 

 fruit to a soft pulpy mass which soon decays and ruins the rest of the fruit 

 tissue. In the orange the worm often confines its eating, for a time at least, 

 to the inner pulp of the skin ; after that it wjprks its way on into the juicy 

 part and passes the rest of its existence immersed more or less in the fruit 

 liquids. The mango has a much thinner skin and therefore the boring is 

 almost entirely in the inner fruit tissues. The presence of the worm in the 

 mango is much more easily detected from the outside than in the orange, 

 for the boring in the former always makes a soft spot while in the latter it may 



Figure 120. 

 Larva, pupa and fly of Aiiastrepha ludens. (Copied from Eeport of Cal. Horti- 

 cultural Commission.) 



or it may not. The maggot attains a length of from one-third to one-half 

 of an inch and usually lives at least two weeks and often more before 

 passing into the pupal stage. Four to six worms living that long in one 

 orange work great havoc, rendering the fruit entirely useless. Before the 

 maggots are ready for their pupation the fruit is usually so decayed that it 

 falls to the grountj. When maturity is reached the larvae leave the rotten fruit 

 and become pupae either between the fruit and the ground or else slightly 

 under the surface of the ground. I found by digging down in several places 

 that the average depth to which the worm penetrates the earth before pupating 

 is between one-quarter and one-half of an inch, although many were found at 



