SHEEP MAGGOT FLY

Dominion, Volume 16, Issue 101, 15 January 1923, Page 11

SHEEP MAGGOT FLY

, EXACTS £1.000,000 STERLING ANNUALLY. One of the most expensive pests tb the farmer in Australia, and particularly in New South Wales, is the sheep maggot fly? which was the subject of an address delivered by Professor T. Harvey Johnston, of Australia, before the Biology Section at the Science Congress on Saturday. The industry, he said, was penalised to the extent of about one million sterling annually, as a result of tho attack upon sheep by various species of blowfly, which were probably first attracted by the presence of soiled wool. Not only was there a considerable direct loss of wool, but also an interference with the general health of affected animals, many of which d:od from tho intensity of infestation. Additional expense was necessary in order to treat fly-blown sheep. The various jxdsons and methods of' applying them were reviewed. The utility of traps was referred to, but their utilisation did not seem to have diminished the prevalence of the fly to any appreciable degree. Special attention was paid to. the biology z of the flies themselves and the life stages of the insects. The lecturer also gave an account of his investigations into the life history of a number of wasp parasites, which attack blowflies during either the larval or pupal condition, and dealt with the possibility of utilising certain of them in the campaign against the blowfly pest.