CONTROL OF BLOWFLIES.

Manawatu Herald, Volume L, Issue 40040, 17 December 1929, Page 2

CONTROL OF BLOWFLIES.

PARASITE LIBERATED IN MANAWATU:

About a month ago (Mr. W. E. Barber, of Motuiti, liberated a number of blowfly parasites in 'two different parts of the Manawntn and also at Tok-omaru. In conversation Avith our representative yesterday, Mr. Barber said that while in Nelson a short AA’hile ago he paid a visit to the CraAvthorn Institute and AA’hile there made arrangements for a supply of blowfly, parasites to be forwarded on to him for liberation in the ManaAvatu district at the earliest possible date. FeAV people (realise the very serious damage done by these flies, said Mr. Barber and the need for their control is most urgent. The blowfly does not confine itself to dead •animals but Avill bIoAV live sheep causing heavy mortality in many districts especially at this time of the year Avhen the danger is most acute when the sheep get moist in the hot Av-eather. Mr. (Barber said he had seen the thigh bone of a live sheep laid bare by blowfly maggots. It was Avith the object of trying to lessen this menace in this district that he liberated the parasite a month ago and hc\ would appre - ciate news of their success or otherwise from farmefrs. The parasite he described as being like a flying ant- but a little shorter. Statistics collected over a period of several years -slioav that throughout the Dominion losses among sheep from maggoty infestation average some £400,000 annually. Dr. Miller, of Nelson, imported from England in 1926 the parasite alysia and the first step Avas to develop a method by Avhicli it could be reared successfully for purposes of liberation. This having been accomplished, liberations on a small scale Avere made at first, but oaving to lack of funds the mass production of the parasite necessary for its rapid establishment could not be undertaken.

However, this difficulty was OA’ercome by the / NeAV Zealand Sheepowners’ Federation granting a sum of money Avliieh has enabled the alysia to be develops!! *on a large scale at the Cawthron Institute and extensively liberated during the present season. An'examination of the maggot-infested carcases in the field where the parasites were liberated last summer and autumn show the alysia to be present and busily engaged parasitising the maggots. The actual establishment of this parasite under field conditions is a matter of very great, satisfaction, and the subjection of the bloAvfly now depends upon the extent to which the parasite Avill effectively' develop in its neAv environment. In the meantime, the liberation continues from the institute’s insectaries.