120 



Fig. 3. — Lantana seed fly (Agromyzidl. Hair line shows natural size. 

 (,\uthor's illustrarion). 



by its natural enemies, this fly has increased enormously since 

 its introduction. In course of the past year it was difficult 

 to find a lantana seed that was not either entirely destroyed or 

 seriously damaged by this fly. Such complete destruction of 

 lantana seed means that the plant can no longer be sown broad- 

 cast as was done formerly by mynah birds and doves. AVhile 

 in Makawao, Maui, last May, I was told by a farmer that 

 owing to the absence of lantana seed the mynah birds have 

 deserted the locality, as a result of which the Army-worm 

 {HeliopMla unipuncta, Haw.) was more destructive that spring 

 than it had been for the previous twenty years. It may pos- 

 sibly be, however, that the drought was the principal cause of 

 the migration. The fact remains that a stage has been reached 

 in the fight with lantana when a field once thoroughly cleared 

 of it may be depended upon to remain so indefinitely. We 

 must hope now that fields cleared of lantana are not overrun 

 by guava, which I was assured by growers of Kona, is far 

 more difficult and expensive to eradicate. "We must bear in 

 mind, however, that there will always be times and places, 

 when and where, after a complete extermination of lantana 

 seed, the flies will die out for want of food, and then the seed 

 is likely to get the start of the fly and some germinable seed 

 will be produced before the fly has again increased sufficiently 

 to check it. These ups and downs of host and parasite are a 

 common phenomenon in nature and are to be expected. 



