81 
for their depredations than are purely native or indigenous species. It is for 
this reason the introduced insects naturally engage such paramount attention 
when the pests of vegetation of any country or district come to be coped with, 
or even considered as a preliminary to that act. 
A mere list of the destructive insects for which we are indebted to our 
commercial relations with other countries, or which other countries may — 
similarly place to our credit, to which has been appended some indication of 
the manner in which the insects specified comport themselves in the countries 
of their birth and of their adoption respectively, would serve to fully substan- — 
tiate these propositions. It is not, however, the purpose of this communication 
to enter into this phase of the subject, but rather to point out the manner in 
which injurious insects are wont to find their way hither, and also to indicate 
some kinds not already occurring in the colony that we may expect to receive, — 
Pernicious insects such as are alluded to-may be distributed into two 
classes, the first of which comprises those that are injurious to animals, whilst 
the second embraces those harmful to plants. Each of these groups may, again, 
be subdivided into—(L) pests that determine chemical and other transforma- 
tions in living organisms; (2) pests that limit the vitality of, or even kill such 
organisms; and (3) pests that consume or damage stored products, whether 
manufactured or not.* +i 
From this consideration, relating to the comprehensive nature of the term 
“destructive insect,” it must be abundantly evident that the subject to be 
dealt with, as defined in the title of this paper, is a very extensive one. 
Recognising this, attention is henceforth almost exclusively restricted to those 
forms of animal life that are injuriously related to cultivated plants yielding 
marketable products, and whether harmful to the plants as a whole that they 
attack or exclusively so to their fruit. 
As to the probability of our receiving destructive insects from sources 
beyond the limits of the colony, it may be stated, as the outcome of a review 
of the plant pests already operating in Queensland, that with the exception of 
the common Kruit-Fly, cane grubs (Scarabeide), and a few other insects, it 
is almost entirely beholden to foreign lands for their presence. ‘This fact it.is 
proposed to further enlarge upon on some future occasion. And, moreover, 
there are a large number of varieties of destructive insects, many of them 
allied to those already introduced into the colony and for which similar 
favourable conditions for importation and for naturalisation are forthcoming, 
but which have not yet reached°our shores and become established here, or 
which, if they have already done so, have not been remarked. 
_ With regard to the circumstances that mainly contribute to their intro- 
duction, it may be stated that these consist in the unrestricted importation of 
merchandise yielding them food or shelter, or the latter only, from countries in 
which they already exist. That traffic in injurious insects is attendant on this 
form of commercia! enterprise will appear from the following incident :—In 
the State of California, U.S.A., there is a statute creating a State Board of 
Horticulture, and amongst the regulations framed in accordance with the F 
provisions of that Act are ones that empower that body to either absolutely 
stay the introduction of insect-infested plants or portions thereof, or to permit 
it only after certain measures of disinfection have been effectually carried out. 
These restrictive measures are enforced through the agency of a quarantine 
officer and entomologist in the person of Alexander Craw, whose special 
attainments are of the highest order. The report of that officer for the period 
intervening between 2nd July, 1894, and 29th August, 1895, on “ Inspection of 
* These groups, it must be remembered, are, however, not altogether mutually exclusive, thus 
certain insects—e.g., water beetles belonging to the family Hydrophilida—consume both living 
animal and vegetable organisms, deriving their subsistence from the former when in the larva 
condition, and from the Satter when adult; but more remarkable still, there are insects that are, 
when adult, indifferently animal and vegetable feeders, an instance of which has lately been 
brought to light through the researches of I’. H. Chittenden, of the United States Department of — 
Agriculture, relating to the habits of a dermestid beetle, belonging to the genus Attagenus, and | 
which is exemplified in more than one family of Hymenoptera. 
