BENEFICIAL VERSUS INJURIOUS INSEOTS. 
Brazil he wrote of his success in finding Braconid parasites and a 
predatory Staphylinid beetle that would control the fruit fly, but even 
after his second trip there, in 1905, the material collected did not give 
much promise of success. It was in India that he had most success. 
There he searched for parasites of the genus Dacus (or Bactrocera). 
On his first return to Perth it was winter, and no hosts were available 
for his parasites, which died. He returned to India in 1907, and collected 
approximately 100,000 parasitized pupx and successfully transported 
them to Australia. In India he preserved his specimens in soil in small 
tins, packed in ice, which had to be renewed each day. The most impor- 
tant parasite that he secured was a Chalcid Syntomosphyrum indicun, . 
of which as many as thirty-six individuals were seen to emerge from 
a single pupa and the average was twenty. Of two other parasites only 
one of each emerged. At the same time six specimens of the adult 
fruit fly of India hatched out, but were said to have been promptly 
destroyed. The Government afterwards shipped some 20,000 to South 
Africa (1908), and some to Dr. Silvestri, in 1909. From this material 
Dr. Silvestri hatched out in Italy the same Chalcid, and also two male 
Braconids. The Syntomosphyrum were liberated in thousands in Cala- 
bria, but failed to-establish themselves. In 1906-7 W. W. Froggatt also 
went on a tour of the world in connexion with fruit flies, but parasites 
were not brought back. Both of the above entomologists omitted West 
Africa, which, according to Dr. Silvestri, is probably the original home 
of Ceratitis capitata, and he was employed by the Board of Agriculture 
at Hawaii to visit Africa and other places to obtain fruit fly parasites. 
Dr, Silvestri thus introduced into Hawaii different species of parasites 
of the genera Opius, Galesus, and Dirhinus from other species of 
Ceratitis, but all of which attacked (. capitata freely. From Australia 
he secured Diachasma Tryoni. Two species of the introduced African 
parasites produced males only, so that finally four active parasites were 
available. Such success has been gained that the number of larve of 
_ C. capitata parasitized averaged 33 per cent. in 1916, 47 per cent. in 
1917, and 56 per cent. in 1918. This has been of great benefit to Hawaii, 
and has decreased the danger of the introduction of the fly to California. 
What can be done in Hawaii could, no doubt, be repeated in Australia, 
notwithstanding the divided opinions of some of our entomologists. 
In Queensland also we find good progress being made with the con- — 
trol of the many sugar-cane pests. The Beetle Borer (Rhabdocnemis 
obscurus Boisd.) is a serious pest in Fiji and parts of Queensland. Mr. 
Tryon discovered a Tachinid parasite (Ceromasia sphenophori Vil) in 
‘New Guinea, and this was introduced into Fiji for the Colonial 
Sugar Company by Frederick Muir in 1911. There it quickly spread, 
and is now successfully combating the borer. Consequently, in 1914 it 
was also introduced into Queensland, and after several years it is now 
“making good” in the Mossman district, where 90 per cent. of the grubs 
of the borer were recently found to be destroyed. It was also success- 
