♦ 31 
The bag spread to Natal witkiu the last few years, and last year I received speci- 
mens of them, found on the common black wattle. Only yesterday I was sorry to 
receive a lot -found there on the orange. 
No public action in the matter has been taken since the legislative assembly, in 
1887, threw out the attempted legislation on the subject. [Roland Trimen, South 
African Museum, Cape Town, Cape of Good Hope, February 8, 1887. 
F. S. Crawford, Adelaide, to Professor Filey. 
Last year I entirely lost my colony of Icerya, owiug to the attacks of a fly. A rough 
tracing of an unfinished drawing of the same I also forward. I know nothing about the 
Diptera and should be obliged if you can determine the insect from the drawing. I 
may say that I sent Miss E. Ormerod specimens of the fly about two months back, but, 
of course, have not had time to hear what she makes of it. This is the only instance 
I know, or have read of, of a true Dipteron being a Coccid parasite. [Frazier S. Craw- 
ford, surveyor-general's office, Adelaide, South Australia, February 21, 1887. 
Letter from Baron von Mueller, of Melbourne, to Professor Piley. 
, * * * -I beg to inform you that the Icerya purchasi (or a closely allied species) 
although occurring on Acacia mollissima and some congeners in the colony Victoria, has 
not attacked here (so far as I can learn or had occasion to observe), destructively at- 
tacked, the orange orchards. I will, however, make further inquiries as well in this 
colony as in New South Wales, South Australia, New Zealand, and lei; you know the 
results. 
Possibly the Icerya develops more readily in a moister clime than that of Victoria, J 
and thus becomes more mischievous in California than here. 
The introduction of this destructive insect into your States by means of Acacia seems 
to me very unlikely, because the various species of Acacias are so easily raised from seeds 
that no one will think to introduce them by living plants. Moreover, it could not have been 
the Acacia latifolia, which was the host of Icerya, because that species is a native only of 
the north coast of Australia, and as yet nowhere existing in horticulture. Acacia armata 
certainly is grown for hedges, but always raised from seed, chiefly obtained from North 
Australia. It seems, therefore, more likely that when Acacias are grown anywhere, 
they would afford — particularly in humid climes — a favorable opportunity for the 
Icerya to spread. A similar circumstance occurred in Ceylon, and another in some 
parts of Brazil, where an indigenous insect plague became aggravated, when Euca- 
lyptus, on which that insect preferably seized, became reared.* Whether the Icerya 
was originally an inhabitant of Victoria or merely immigrated, I will endeavor to 
ascertain ; but such a subject of inquiry is surrounded with difficulty now after half 
a century's existence of the colony, particularly as the Icerya drew no attention here 
by any extensively injurious effects on any cultivated plants, though it may have 
caused on some plants minor or transient inj ury. [ Ferdinand von Mueller, Melbourne, 
Australia, March 21, 1887. 
Letter from L. M. Kirk, of Wellington, New Zealand, to Professor Riley. 
On returning from it protracted tour of forest inspection in the South, I find your 
letter of 22d December awaiting reply. My friend Baron von Mueller is mistaken in 
supposing that I have written recently on the Icerya purchasi. In a report on Fruit 
Blights printed two years ago, I drew attention to the pest,*intending to treat at 
greater length at an early date; but my duties as forest conservator have prevented 
the intention from being carried out. 
The insect is a native of the Fiji and other Pacific islands, from whence it has migrated, 
probably with orange trees, to Australia, New Zealand, and California. Mr. Maskell states, 
* Always from seed. 
