NOXIOUS WEEDS CONTROL.

New Zealand Herald, Volume LXIV, Issue 19633, 11 May 1927, Page 13

NOXIOUS WEEDS CONTROL.

EXPERIMENTS WITH INSECTS. VALUABLE INFORMATION GAINED [Br TELEGRAPH. —OWN CORRESPONDENT.] WELLINGTON. Tuesday. The control of noxious weeds by means of insects is one of the problems which is the concerp of the Department of Scientific and Industrial Research at the Cawthron Institute. Dr. R. J. Tillyard and his assistants have been carrying on numerous experiments, and his first quarterly report lias just been issued. The report states that for the purpose of research six new insectaries have been built and equipped, each being 12ft. square. The insectaries are inspected regularly each morning and evening, and any damage noted is at once repaired. In the coarse of three months' work the only damage so far found has been the cracking of one or two panes of glass during a very violent storm. These wero at once repaired. In starvation and other tests the insects are enclosed in muslin or gau/,0 cages placed over or round plants or portions of plants inside the insectaries, thus affording additional protection. There are three main methods of testing, which are applied to all insects introduced for the control of noxious weeds. These are (1) oviposition tests; (2) starvation tests; and (3) preference tests. The report details the tests and the results which may be obtained. Naturally no finalitv has been reached as yet in these tests, but much valuable information has already been obtained, and there is every indication that in time some of the insects being experimented with will be found to be powerful agents in the extermination of noxious weeds.

Among the weeds being concentrated upon are the blackberry, foxglove, gorse and ragwort.