MICRO-LEPIDOPTERA. 



G7 



Opogona, three species, related together and probably developed from a 

 single immigrant form ; a considerable genus, cosmopolitan in warm latitudes, 

 but specially Indo-Australian, the larvae feeding on dead vegetable tissues, and 

 probably often having relations with Termites, sometimes feeding within their 

 nests. 



Spilonota, three species, one of these also in Fiji ; Indo-Malayan by origin, 

 but with more specific development in Australia, the larvae being commonly 

 attached to Myrtaceae. 



The remaining thirty-three genera include in each case only one or two 

 species, and all without exception are of Indo-Malayan type, the line of relation- 

 ship passing through the New Ireland group and not by way of Australia. This 

 explanation covers the whole Micro-Lepidopterous fauna, nor is there any 

 evidence of more than one period of immigration. 



Two cosmopolitan families, easy of observation, are absent from the indi- 

 genous fauna, viz. the Pterophoridae and Oecophoridae. The Pterophoridae 

 are obviously insects of very weak flying powers, but on the other hand their 

 structure is apparently specially adapted to favour wide distribution by the 

 wind, and in fact many of the species have exceptionally extensive ranges ; 

 they are, however, as I have pointed out elsewhere, a family of very recent 

 origin, and attached exclusively to the most modern and highly developed 

 orders of flowering plants, and this circumstance probably accounts for their 

 absence ; they have not previously succeeded in effecting a lodgment in Samoa 

 or Fiji, but are now filtering in with assistance. It should be noted, however, 

 that New Zealand is fairly well supplied with indigenous Pterophoridae, and 

 Hawaii also has species, the source of these being probably in both cases America. 



The Oecophoridae are a much more puzzling problem. The family is one 

 of the largest, being only exceeded by the Gelechiadae,* and though not one of 

 the earliest, it is certainly older than the Gelechiadae. It is numerous in all 

 regions, but particularly so in those adjacent to the Pacific, Australia and New 

 Zealand, in each of which it is the largest family, though in the main originating 

 separately, the New Zealand forms chiefly from South America, and the 

 Australian mostly from India. The family is equally at home in the moist 

 temperate climate of New Zealand and the dry heat of Australia ; from the 

 latter continent no fewer than 1,500 Oecophoridae are already known. There 



See note on p. 76. — E. E. Austen. 



