56 



ON THE DECREASE OF MANY SPECIES OF INSECTS AND 

 INCREASE OF SOME IN SOUTH AUSTRALIA. 



By Otto Tepper, Cork. Member. 



(Read February 5, 1878.) 



Long-con tiuued observations of the life and habits of insects in 

 general have produced the impression on me that, at least in the localities 

 I visited frequently in the course of my rambles, the number and variety 

 of many insect tribes were rapidly decreasing from year to year, while 

 some of them apparently maintained their position, and a few materially 

 increased in number. Many species of Coleoptera, as Longicornia, Bu- 

 prestidae, Lytta, &c, some butterflies, &c, have become scarce, while 

 some even seem to have died out altogether in some localities ; notably 

 those seem to be first and most frequently affected whose conditions of 

 life depend upon certain assemblages of trees and shrubs. This appears 

 not to be altogether due to the actual want of such trees and shrubs, 

 for I have seen and examined carefully patches of blooming mallee and 

 myrtle, many acres in extent, several times a week for months, but only 

 met with a few of the commonest beetles, flies, or wasps, though at other 

 places not far distant, and almost exactly similar, a great many of the 

 desired Coleoptera, &c, were taken upon these their favourite flowers. 

 Far less direct influences seem to furnish the main cause of this compara- 

 tive barrenness, the chief of which, I am disposed to consider, is the 

 browsing of cattle, sheep, &c. The woodcutter's axe and the farmer's 

 plough coming next in order. All these change the aspect of nature 

 greatly, amd alter very much the relations of vegetable and animal life. 



For illustration I will select Monarto on account of various reasons. 

 It is situated about seven miles east of Callington, and was, at the time 

 of my stay, a newly-formed farming settlement on the eastern slope of a 



