DISTRIBUTION OF INJURIOUS INSECTS 7 



lines, and has been wrongly referred (so I am informed by Mr. 

 Austen, Dipterologist at the British Museum, by Mr. Froggatt 

 and others in Australasia) to the genus Tephritis; Ceratitis has 

 ornamented wings with a dense fine network of veins at the 

 base; whilst the last named has mottled wings with normal 

 venation. These Fruit Flies lay their eggs in both sound and 

 rotting fruits; the maggots live in the pulp, and can at once 

 be told from Codling Maggots by being apodal. Numbers are 

 frequently found in a single struck fruit. 



The great importance of these pests cannot be overesti- 

 mated, as we have no remedy for them. All that can be done 

 to guard against Fruit Flies is to protect the trees by means of 

 muslin tents, an operation too costly to be carried out in most 

 places. 



That these insects have been and are still imported with the 

 fruit we know quite well. The Mediterranean Fruit Fly {Cera- 

 titis capitata) has thus been distributed into Australia and Cape 

 Colony and elsewhere, and has become a serious pest in its 

 new homes. The various Australian Fruit Flies {Dacus tryoni, 

 Froggatt) and others are found in numbers in exported fruit. 

 As a result. New Zealand prohibits all fruit infested with Fruit 

 Flies from being landed. We find in the official records that 

 3,700 cases of fruit were destroyed in 1901 on account of the 

 presence of these enemies. 



Similarly, St. Helena has passed an Ordinance (1904) prohibit- 

 ing the importation of all fruits from South Africa, Mauritius, 

 Cape Verde, and Malta, and for the extermination of the Peach 

 Fly {Ceratitis capitata). 



Neither Ceratitis nor Dacus are likely to flourish here, if 

 imported ; but they may do so in many warm countries where 

 they are not yet known as pests, and might even exist in hot- 

 houses here. 



We find these insects also in Mexico and many other coun- 

 tries. During 1904 many cases of fruits were destroyed at the 

 Hawaiian Islands on account of the presence of Mexican Fruit 

 Flies. Recently they have been found attacking melons in the 

 Sudan {Dacus sp. ?). 



One species may easily be imported into Britain — namely, 

 the Apple Fruit Fly of America {Trypeta pomonella, Walsh). I 

 feel confident some apples sent me from the Isle of Thanet were 

 attacked by this pest ; but, unfortunately, the dipterous l&rvEe 



