500 QUEENSLAND AGRICULTURAL JouRNAL. [1 Jun, 1898. 
or fully grown condition (Smith, IV., p. 11). And it would appear that in 
Queensland also there is a similar winter resting period, though probably a 
much less protracted one than in the former region. Thus it has been remarked 
that on the Darling Downs no young were being produced during the months 
of April and May of the present year—1898. 
INTRODUCTION, DISSEMINATION. 
As already stated, the female insect at a very early stage in its existence 
has not only Jost all vestiges of organs of locomotion, but has also become 
permanently attached to the plant whereon it occurs. It is therefore itself 
incapable of moving a single inch. Jt is not, however, the case with its young 
or larvee; these crawl from beneath the parent scale at birth, and continue to 
move restlessly about for some time, but very slowly; moreover, the active 
stage that they represent has probably very rarely a duration exceeding forty- 
eight hours. It may thus sometimes happen, owing to the limited extent 
of their excursions, that sn entire tree may become covered with the scale 
from the ground upwards to the tips of its branches, before an adjacent 
one in the same orchard has become at all infested.* The larve “ get along 
readily enough on a smooth surface, but are helpless on rough or powdery 
land, tending to bury themselves in the soil rather than to crawl over 
it. In most instances they do not get over 6 inches from their hatching- 
point, provided they have a chance to settle down and are not carried away.” 
(Dr. J. B. Smith, XIT., p. 445.) This amount of activity is, however, compatible 
with their spreading from plants when these occur growing close together, as 
in the case of nursery stock. Hence it has happened that thousands of youn 
trees have become uniformly infested in one of these establishments in the 
course of a comparatively short period—the scales appearing in the first 
instance upon the stems. 
With regard to other modes of dissemination it may be affirmed that the 
insect is passive, being borne from place to place by agencies that it cannot 
‘control. It is wont when still a crawling larva ‘to attach itself readily to 
objects that come in contact with it by means of the so-called tenent (holding) 
hairs with which its feet are provided. (Plate XLI., fig. 5a.) Other insects 
have been found with the tiny young insects attached to their bodies, 
especially ants, and even so certain beetles, amongst others those that prey 
‘upon them. hey may also attach themselves to the feet of birds, which latter 
‘may also thus serye as agents for their spreading. Instances of this are 
given by L. O. Howard and ©. L. Marlatt (X., pp. 49-50), as already 
mentioned by the writer in this Journal (Vol. I., p. 120) and other writers. 
With reference to the work of birds in this connection, F. M. Webster 
writes as foilows :—‘“ That they are carried considerable distances and left upon 
the branches of trees by birds we have ample proof. On Catauba Island, 
where the birds were nesting in the badly infested osage hedge, and where other 
_birds were nesting in both infested and uninfested trees, isolated trees were 
found by the Fruit Commissioners with a single limb seriously affected, and 
located in the midst of orchards at considerable distances from either hedge 
or infested trees. In fact, one of the best places to search for isolated colonies 
of the scale in an infested district is about old birds’ nests.” [X1V., p. 204. ] 
Again, there are grounds for concluding that in some instances the wind 
may have contributed to their dissemination ; though the special organs that 
facilitate their attachment to the bodies of other insects and to the feet of 
birds enable them to maintain a firm foothold upon the bark of trees, and 
from this, therefore, they are not readily dislodged. Instances in which thig 
method of transportation must apparently be inferred to have operated are 
given by several writers, especially . M. Webster. [XILV., p. 204. ] 
3 *¥F.M. Webster has, however, mentioned an interesting exceptional instance to this general 
“rule XIV., p. 204]. : 
