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The only parasite that has been found attacking this fruit-fly is a small 

 red braconid wasp, with a black head and dark-coloured wings, named 

 Cratosiptta rudibunda. Isaacs states in his report (1905) : "The parasite 

 has not as yet done any effective work on the Trypeta ludens, as investiga- 

 tions have shown that not over 10 to 15 per cent, of the maggots are 

 parasitised. Every effort is being made to encourage the propagation of 

 the parasite, and great hopes are entertained that it may yet overtake the 

 plague and keep it in check." 



Koebele, who gave me specimens of this parasite he had bred from mangoes, 

 obtained in the Mexican markets, told me he had never bred it from infested 

 oranges. Professor A. L. Herrera, the Chief of the Entomological Staff at 

 Mexico City, informed me that the parasites had made no difference to the 

 pest up to the time of my visit (October, 1907). 



In consequence of the presence of , this fly in Mexican orchards, the State 

 Board of Horticulture prohibited the importation of Mexican oranges into 

 the State, and the railways running between the two States refused them as 

 freight. Mr. Craw caused all cars used for transportation of Mexican oranges, 

 to be disinfected with steam before they could be again used in California. 



In Bermuda an Act on very similar lines came into law only last year, 

 and has, according to Mr. Harris, already made a marked difference in the 

 numbers and damage caused by their fruit-fly pest. 



There are no special laws in the southern countries of Europe and northern 

 Africa against fruit-flies, but in all countries where these pests are known, 

 all the entomologists have urged the orchardists to destroy as much as they 

 can of the infested fruit. 



In the Turkish village of Lefka, in Cyprus, where a large quantity of 

 oranges are grown, I found no traces of fruit-flies, probably because every 

 fallen fruit was eaten clean out of the skin by rats. 



Besides the destruction of the maggots in the fruit, we can also destroy 

 many of the adult flies, on account of their liking for certain oils. It was 

 discovered about two years ago in Western Australia that if a dish con- 

 taining kerosene was placed out in an orchard, the Mediterranean fruit-fly 

 was attracted by the scent and flew into the oil. This was confirmed when 

 suitable tins were placed among infested trees, for thousands were taken in 

 a few days ; and wherever tried it has had the same effect upon this species. 

 This oil, however, had no charms for the Queensland fruit-fly when it was 

 tried in Queensland. While experimenting in the orchards of India, where 

 a species closely allied to the Queensland fly was very abundant, Mr. Hewlett 

 discovered that citronella oil spread on some leaves, on a stone, or smeared 

 upon a handkerchief, attracted this and an allied species, but had no attrac- 

 tions for a third larger species that destroyed the melons and gourds. I 

 took a thousand specimens of this fruit-fly (Dacus ferrug ineus) with half-a- 

 dozen sweeps of my net over some leaves upon which we had placed oil the 

 previous evening. One remarkable thing was that when we came to examine 

 them we found that all the specimens were males. Further experiments 

 right through the season should prove whether this is always the case ; but 

 even so, the destruction of all the males would soon lead to infertile females. 

 If other oil can be found to attract other species, they can be mixed with 

 poison or used in traps, and will become a very effective aid in controlling 

 the pest. 



The Olive Fly (Dacua olea) is one of the most serious insect pests in the 

 world at the present time, for last year it destroyed so large a percentage of 

 the olive crop that it was estimated that the loss in olive oil due to the 



