\Q The South Australian Naturalist. 



The layman may hear httle or nothing of these studies, but it 

 was through such observations and discoveries that the foundation 

 was laid, not only for the completion of the Panama Canal, but for 

 the yet unaccomplished health conquest of the tropics — a conquest 

 which will do more than anything else to restore economic stability 

 to the world. It may not be an impossible dream to look forward 

 to Nature Study as a most valuable agent in assisting to lead us 

 out of the labyrinthine mazes of the present social and industrial 

 conditions of the world. 



To come nearer home, everyone knows of the flood of criticism 

 poured upon the management of the "Wheat Scheme." Great losses 

 there have undoubtedly been. Yet even here Nature Study has saved 

 millions of bushels of v.heat frorn the ravages of the weevil. Their 

 damages have been checked, if not prevented, through the knowledge 

 of such workers as our Government Entomologist, Mr. Lea. Had the 

 Nature student been listened to in the beginning there is no doubt 

 that the amount of wheat saved from destruction would have been 

 enormously greater. There is no one thing in Nature of which the 

 importance to man is fully known. This is especially true of Aus- 

 tralia, where Nature has been studied for such a very short period, 

 and where plants and animals, known for ages in other countries, 

 show such unexpected responses to their new environment when in- 

 troduced here. 



It is to the study of Nature that we must look for the solution 

 of the many troubles that confront us. the pest pear, the rabbit, the 

 codlin moth, the rusts of wheat, weevils, and the numerous diseases 

 of plants and live stock, to say nothing of those of human kind. 

 In other countries it is reckoned that an average of over 10 per 

 cent, is lost from every crop through the ravages of insect pests 

 alone. Just one other instance may l>e quoted of an oft-told but 

 wonderful story of the successful study of an insect pest. When the 

 San Jose scale (Iceraya purchasi) invaded the orange groves of 

 California, it brought down the yield from 8,000 to 600 carloads in 

 a season. The life history of the parasite w-as worked out by Nature 

 students, and one of them, a Mr. A. Koebele, was sent round the 

 world to find an effective enemy of the scale. In Australia he found 

 our brilliant red ladybird, and specimens were sent to California. 

 From their_ knov.'ledge of the habits of the ladybird, the authorities 

 in California were able to breed it and supply it to the orangeries. 

 The result was that the pest was completely held in check, and 

 almost disappeared, so that now a supply of ladybirds is bred in 

 special glasshouses ready for dispatch to any orangery found to be 

 infected with the dreaded scale. 



Annual Report for the Year Ending September 30, 1919. 



EVENING MEETINGS. 



The Annual Meeting was held on the 17th September, 1918, and an 

 adjourned meeting on 1st Octo1)er, when the Chairman (Mr. W. J. Kim- 

 ber) delivered the annual address, entitled. "Attractions of Port Wil- 

 lunga to the Nature-Study Student." The lecturer took his hearers on an 

 imaginary trip to Port Willunga, first visiting the reefs, which contain 

 the most varied forms of marine life that can be found on any beach in 

 South Australia. The shells found in the various depths of water were 



