1 Ocr., 1897.] QUEENSLAND AGRICULTURAL JOURNAL. BBY 
Entomology. 
LADYBIRDS (VEDALIA CARDINALIS). 
Nature has two articles on the subject of the introduction of beneficial insects. 
to countries 1n which fruit trees and other vegetation are affected by insect 
pests, which are worthy of attentive perusal, especially by orchardists. 
The first is from notes on the result of introducing predatory and 
parasitic insects into the Hawaiian Islands for beneficial purposes, com- 
municated by the secretary of the committee appointed by the Royal Society 
and British Association for investigating the fauna of those islands. The 
writer says:—“ Few countries have been more plagued by the importation of 
insect pests than the Hawaiian Islands; in none have such extraordinary results - 
followed the introduction of beneficial species to destroy them. By far the- 
most conspicuous of the former class, and hitherto the most injurious, have 
been the Scale Insects. The number of species of this group which have been 
spread over theislands is remarkable, and no less so, the enormous multiplica- 
tion of individuals of many or of most of these species. The first importation. 
of Coccinellide to destroy these hordes was made in 1890, when Vedalia 
cardinalis, Muls., a native of Australia, was sént over by Mr. Albert Koebele. 
At that time many trees were in a deplorable condition from the attacks 
of Icerya, monkey pod trees being particularly badly infested—so much so 
that they were being largely cut down as the only resource. The Vedalia 
was a complete success; it became perfectly naturalised, increasing pro- 
digiously for a time; it practically cleared the trees, and then, as the Lcerya 
became comparatively scarce, decreased in numbers; while it is evident that 
the number of the scale and its destroyers has arrived at a fixed pro- 
portion. Previous to its introduction into the islands, the same Ladybird 
had done excellent service in the fruit orchards of Lower California. One of 
the most useful Ladybirds has been Coccinella repanda (from Ceylon, Australia,. 
China, &c.), which feeds on Aphides. The services of this species cannot be 
overrated. On Kauai recently, the cane was so much attacked by the Aphides 
as to cause considerable alarm. On visiting the locality, the Obvecinella was. 
found to be already present, breeding in such numbers as to leave little doubt 
that the plants would soon be clear. On the same island, on another occasion, 
I saw the fruit trees (especially oranges and limes), in a beautiful garden, in a 
most deplorable condition from the attacks of Aphis and Scales. Very few 
Ladybirds could be found after a careful search. ‘The owner was for spraying. 
the trees, but, seeing that their condition could not be worse, I advised him to: 
wait and give the beetles a chance. In a few weeks these were swarming, and 
when I returned, after six months, the infested trees were all in perfect 
condition, full of fruit and flower. No less useful than the preceding is. 
the Cryptolemus (O. montrouziert) introduced from Australia, and thoroughly 
naturalised.* It attacks the injurious species of Pulvinaria. When I visited 
the Kona district of Hawaii in 1892, many of the trees were literally festooned 
with masses of these pests, and appeared on the point of being totally 
destroyed. In 1894, the Ladybirds were sent over there, and very soon had 
entirely changed the condition of things. The attacked trees speedily 
recovered. ‘To show the vast increase of this species of Ladybird, I may state 
* The predaceous Ladybird (Oryptolemus montrouziert) was first made known to the scientific 
world by Mr. Henry Tryon, Entomologist to the Department of Agriculture, Queensland, in a 
paper issued by that Department; and its useful work in Hawaii is so pronounced as to show 
that Mr. Tryon was fully justified in entertaining the opinion regarding its important services. 
that he formerly expressed.— Ed. Q..4.J. 
