278 QUEENSLAND AGRICULTURAL JOURNAL, [1 Apriz, 1899. 
FRUIT FLY EXPERIMENTS. 
By ALBERT H. BENSON ayp S. VOLLER. 
Earty last spring the Department of Agriculture considered it advisable to 
conduct a series of experiments with a view of determining the best method or 
methods of dealing with the Fruit Fly, and we received instructions to carry 
out such experiments. 
In order to make the work as comprehensive as possible, we decided to 
carry out a complete series of experiments both in the coast and Downs 
districts, and, as no departmental orchards were available, arrangements were 
made with private orchardists for the use of their orchards. 
The orchards obtained were situated-—one near Sunnybank, on the South- 
port line; and the other at Birnam, near Toowoomba; the former belonging to 
Mr. O’Brien, and the latter to Messrs. J. and H. Roessler. No charges were 
made for the use of the orchards, and both Mr. O’Brien and the Messrs. 
Roessler gave us every assistance they could; and we consider that the thanks 
of the Department and of the fruit-growers of the colony generally are due to 
these gentlemen. 5 
The orchards selected were chosen, firstly, on account of their having been 
badly infested with the Fruit Fly in previous seasons ; and, secondly, on 
account of their being comparatively isolated, as we deemed that the latter 
consideration gave us a better control of the experiments, in that the orchards 
in which they were carried out were not so liable to infestation from outside 
sources, as would have been the case had there been adjacent infested orchards. 
The experiments at Sunnybank commenced on the 15th of September, and 
continued to the 14th of December, and were confined to peaches of several 
kinds and to red heart Japanese plums ; whereas those at Birnam commenced 
on the 28th of September, and continued to 24th of January, and included 
oranges, cherry plums, apricots, peaches, nectarines, apples, pears, plums, 
Japanese plums and quinces. 
At Sunnybank, some 300 individual experiments were carried out, and at 
Birnam over 1,000. 
The object of the experiments, as previously stated, was to determine the 
best method or methods of dealing with the Fruit Fly; and in order to do this 
we conducted experiments— 
1, To prevent or deter the fly from attacking the fruit. 
2. To attract and destroy the mature insects. 
The first series of experiments—viz., those in which we endeavoured to 
prevent or deter the fly from attacking the fruit—occupied by far the larger 
portion of our time, and the methods adopted were as follow :— 
1st. Spraying the fruit and trees with strong-smelling substances that 
were deemed likely to deter or repel the fly. 
The substances used as sprays were many and varied, and included the 
following :—Sulphide of lime, sulphide of soda, lime, sulphur, wood tar, bone 
oil, caustic soda, carbonate of soda, whale-oil soap, tobacco, pyrethrum, black 
leaf tobacco extract, nicotine, and Redwood’s specific. Most of these sub- 
stances were used singly, and, with the exception of Redwood’s specific, in 
various combinations. All the mixtures were applied in the form of a fine 
spray by means of a Figaro knapsack spray pump, fitted with an 8-foot 
bamboo extension, and using a triple cyclone nozzle. This outfit worked 
exceedingly well, and we had no difficulty in thoroughly spraying trees of all 
the kinds treated up to 14-feet in height. All of the mixtures were applied 
during the day, sometimes during a moderate breeze and bright sunshine, but 
