DISTRIBUTION OF INJURIOUS INSECTS 61 



First, we will consider insects that attack fruit-trees in 

 orchards and gardens, which may easily be carried from one 

 country to another over sea, or from one state to another over 

 land. The following are some of the most important in this 

 category : l 



The Codling Moth (Carpocapsa pomonella)* ; the Bud Moth 

 (Tmetocera ocelland)\\ the Pith Moth (Laverna atra); Pistol and 

 Cigar Case-Bearers (Coleophoridce spp.) ; Bagworms (Thyrido- 

 pteryx, etc.); Lackey Moths (Clissiocampidce spp.) ; the Peach 

 Borer (/Egeria exitiosa, Say.) ; and Currant Borer (JEgeria 

 tipuliformis, Linn.) ; the Shot-borer Beetles (Xylcborus dispar, 

 etc.); Bark Beetles (Scolytus rugulosus and S. destructor, etc.)t ; 

 Currant Sawflies (Nematus spp.) ; the Pear Slugworm (Erio- 

 campa limacina). Various fruit flies, such as the Apple Fruit 

 Fly (Trypeta pomonelld)] ; the Mediterranean Fruit Fly (Ceratitis 

 capitata) ; the Australian Fruit Flies {Dacus tyrom', etc.) ; and 

 the Indian Fruit Fly (Dacus ferrugineus). Psyllidae, such as 

 the Apple Sucker (Psylla malt) of Europe and the Pear Sucker 

 (Psylla pyri) of America; the Woolly Aphis (Schizoneura 

 lanigerd)] ; the Currant-root Louse (Schizoneura fodiens) ; the 

 Phylloxera or Vine Louse (Phylloxera vastatrix). Various 

 aphides of all kinds, such as the Cherry Aphis (Myzus cerasi) ; 

 Apple Aphides (Aphis pomi, A. filchii, and A. sorbi). Of scale 

 insects or Coccidae, the most important are the Mussel Scale 

 (Mytilaspis pomorum)* ; the San Jose Scale (Aspidiotus perni- 

 ciosus) ; the Japanese Cherry Scale (Diaspis amygdali)t ; 

 the Peach Scale (Aspidiotus persicce) ; the Cottony and Egyptian 

 Cushion Scales (Icerya purchasi and /. wgypticd) ; and very 

 many Citrus Scales, such as Aspidiotus aurantice and Mytilaspis 

 citricola. 



Besides true insects we get the ova of Red Spiders (Bryobia 

 pretiosa) ; various gall-mites or Eriophyidae, such as the Currant- 

 bud Mite (Eriophyes ribis) and the Pear-leaf Blister Mite (Erio- 

 phyes pyri). 



These various pests may be carried in three different ways — 

 namely (i) in and on fruits and seeds ; (2) on living plants ; and (3) 

 in the cases and packages in which fruits and plants are sent. It 

 will at once be said that the first and last are of little importance, 

 as such cases of fruits are taken to large towns and markets. 



1 Those marked with an asterisk come in abundance to Britain ; those with a 

 dagger may do so now and again. 



