32 
Crickets are also said to cause injury to the roots by gnawing 
the epidermis, but no instance of this kind came under my observation. 
The larve may readily attack the roots of oranges amongst other 
plants. In their perfect state crickets may be destroyed by mixing 
a small quantity of phosphoruswith flour, and placing it in their haunts. 
The larval state may be treated in the same way as the grass-grub 
(see “ Olive’). 
The New Zealand mantis is also stated to be injurious; but 
nothing is certainly known about it at present, and the insect itself is 
comparatively rare. 
CATERPILLARS. 
The larve of several small moths are frequently found feeding on 
the young leaves, but at present none of them are known in the perfect 
state so as to allow of their identification. Their ravages are seldom 
of a serious character; but any great increase in their numbers would 
be attended with a corresponding increase in the amount of injury 
effected by them. 
Syringing with strong tobacco-water, or with a solution of caustic 
potash containing sulphur, may be applied where necessary. 
GRASS-GRUB (Odontria zealandia). 
The grass-grub attacks the roots of citraceous trees as well as 
others, and when in large numbers causes a considerable amount of 
injury in a brief period. The larve feed upon the root-fibrils and 
epidermis of the more tender portions of the root, so that the tree is 
unable to procure a proper amount of nourishment, its growth is 
arrested, and it is unable to mature fruit. ‘The perfect insect has not 
been observed to attack the foliage, as in the apple. 
For a more complete account of this insect and for remedies, see 
under “ Olive.” 
THRIP. 
These minute insects may sometimes be found on neglected trees 
in vast numbers, especially when the trees are growing in dark damp 
situations. Careful pruning and the removal of all superfluous growth 
from the centre of the tree will do much towards preventing their 
attacks. Frequent syringing with a powerful syringe or garden-engine 
will usually be found sufficient to drive them away. Where they have 
been established for any length of time, it may be advisable to add a 
weak solution of caustic potash with sulphur. 
WOOD-LICE. 
These well-known pests are occasionally troublesome to the 
orange-grower, but their ravages are rarely of a serious character. 
They are usually found at the base of the trunk or in the forks of 
branches. Saturating the soil at the base of the trunk with a thin 
solution of lime and sulphur will be found beneficial, or Goodhue’s 
powder may be dusted over their habitat. 
