338 QUEENSLAND AGRICULTURAL JOURNAL. [1 Ocr., 1897. 
that in June of the present year (1897) many large trees in the city of 
Honolulu had several square feet of their bark entirely hidden by the Jarve, 
which formed great white masses, presenting such an extraordinary appearance 
that I much regretted not having been able to obtain photographs of some of 
the trees. Other introductions were Orcus chalybeus trom Australia, feeding 
on Lecanium, Pulvinaria, Diaspis, &c.; Rhizobius ventralis from China and 
Ceylon attacks that very abundant scale, Lecanium Longum. Ohilocorus 
circumdatus, introduced from China and Ceylon, breeds freely on scales in 
Honolulu. Trees literally covered with J/ytilaspis were entirely cleaned. 
Even the dead, dry scales were turned over in the search forfood. Before the 
introduction of the species above mentioned, the only Hawaiian Coccinellidx 
were a few species (probably endemic) of Scymnus and C. abdominalis ; the 
Jatter no doubt accidentally imported from Australia many years ago. 
Unfortunately, this species is attacked by a hymenopterous parasite, a 
Braconid (Centistes americana, Riley), which might interfere with the splendid 
work of O. repanda. The presence of this parasite is the more to be deplored, 
as such care was taken to exclude parasitised specimens when the introductions 
were made. This was very necessary, as the Ladybirds seem very liable to the 
attacks of parasitic Hymenoptera, especially the Australian species.” 
Further information is given on the subject by Mr. C. L. Morlatt, in the 
“ Year Book of the United States Department of Agriculture.” He describes 
the various methods of combating the ravages of injurious insects in Cali- 
fornia, and says that the possibility of control of insects, by introducing and 
fostering their natural enemies, has been thoroughly tested. A very notable 
instance of the entire eradication of the White Scale insect by the introduction 
from Australia of its Ladybird enemy, Vedalia cardinalis, demonstrated the 
possibilities in this direction in the most striking way. This one experiment 
saved the State its citrus industry, ‘and gave the greatest confidence in man 
quarters in this means of controlling insects on a much larger scale. It led the 
State of California in 1891 to grant $5,000 for the purpose of sending an 
expert to Australia, New Zealand, and the adjacent colonies to collect, and 
import into this State, parasitic and predaceous insects. Mr. Albert Koebele, 
who had previously been instrumental in introducing Vedalia cardinalis, was 
selected for the work. ‘The chief object was to obtain predaceous insects which 
might exterminate the Black Scale, the Red Scale, and the San José Scale. 
Mr. Koebele’s mission lasted upwards of a year, and during this time he 
imported into California some 60,000 specimens, representing very many 
species, chiefly Ladybirds. [Five or six of these species took hold well from 
the start, and two or three of them are still represented abundantly in the 
orchards of California, others having practically disappeared, but the important 
ones remaining include the very efficient predatory enemy of the Black Scale, 
in the Rhizobius ventralis, and two much similar species, RP. debilis and R. 
toowoombe, which attack the Black Scale, and also the Red Scale, and San José 
Scale to a less extent, 2. ventralis was easily colonised, and during the last 
three years has been distributed in enormous numbers to different parts of the 
State, 300,000 to 400,000 having been colonised in Lower California alone. 
This beetle has been far the most useful of the recent importations, and has 
already done much good; in several instances, it has effected the entire reduc- 
tion of Black Scale in badly infested orchards. The disappearance of the scale 
may, in some cases, be due to other natural causes, but there seems to be no 
doubt that the chief credit belongs to the Ladybird. Once the Ladybirds have 
established themselves in sufficient numbers, it seems best not to spray or 
fumigate the trees, as these treatments are very prejudicial to the multiplication 
of this beneficial beetle. 
