THE CONTROL OF BLOWFLIES.

Hokitika Guardian, 16 December 1929, Page 8

THE CONTROL OF BLOWFLIES.

SUCCESSFUL EXPERTEMENTS. NELSON, December 11. During the past 10 years one of the major problems engaging the attention of Dr. D. Miller, of the Gawtliron Institute, has been the establishment of a parasite for the control of blowflies. The need for some such control arose from the attacks of blowfly maggots upon living she.ep, causing very heavy mortality in many parts of the country. Statistics collected over a period of several t years show that throughout the Dominion the losses among sheep from maggot infestation averaged some £400,000 annually. Dr. Miller imported from England in 1926 the parasite alysia, and the first step was to develop a method by which it could be reared successfully for the purposes of liberation. This having been accomplished, a small scale of liberations was made at first, but owing to lack of funds the mass production of the parasite necessary for its' rapid establishment cou.ld not be undertaken. However, this difficulty was overcome by the New Zealand Sheep Owners’ Federation granting a sum. of money which has enabled the alysia to be developed on a large ,scale at the Cawthron Institute and extensively liberated during the present season. An examination. of the maggot on infested carcases in a field where ■ parasites were liberated last summer and autumn show that the alysia were busily engaged parasitising the maggots. Tho actual establishment of this parasite under field conditions is a matter of very great satisfaction, and the subjection of the blowfly now depends upon tho extent to which it acts in its new environment. In the meantime the liberation continues from the institute’s insectaries..