27 
enable him to identify. it as the mona hirta of Captain Broun’s 
“Manual of the New Zealand Coleoptera.” He informs me that he 
has observed the beetle for several years in connection with the fer- 
tilization of the Yucca, but its identity with the lemon-tree borer has 
not hitherto been suspected. 
In trees affected by the borer a few of the young branchlets pre- 
sent a withered appearance, the bark for an inch or more below the 
tip shrivels and turns brown, the leaves fall, and in a short time the 
twig breaks; at the point of fracture a few grains of wood-dust ma; 
be discovered, and on splitting the branchlet longitudinally below the 
fracture a small gallery will be found excavated in a downward direc- 
tion, and containing the larval insect ensconced at or near its lower 
extremity. 
The perfect female insect punctures the branchlet a short distance 
below the apex and deposits an egg; on being hatched the grub com- 
mences to bore its way downwards, taking advantage of the central 
pith. On reaching the base of the twig it continues its excavations 
into the branch, at the same time increasing the diameter of its gallery, 
and at intervals forming shallow expansions to the right and left. At 
length it reaches a stout branch, or possibly the main stem, when it 
bores through the bark, and after a longer or shorter periud enters upon 
its quiescent stage, the exact duration of which has not been ascertained. 
The largest specimens of the larval state that have come under my 
notice are about an inch and a quarter in length, and of a yellowish- 
white colour. The segments are thirteen in number, somewhat keeled 
or ridged; the mouth is small and slightly sunk in the head. Each of 
the three thoracic segments carries a pair of minute pointed feet 
turned outwards, and all the segments are more or less clothed with 
short, rigid, scattered hairs. 
The galleries vary greatly in length; the longest that I was able 
to trace uninterruptedly was under two feet, the average being from 
nine to fifteen inches; the greatest diameter was three-eighths of an 
inch. I was assured by one or two observers that the grub invariably 
makes its way to the main stem; this view, however, cannot be main- 
tained, as the apertures by which the beetle makes its exit may 
frequently be observed on the branches. The sudden increase in the 
diameter of the gallery as the borer passes from the branchlet into the 
adjacent branch is very striking; it is often marked by a small pellet 
of curved woody fibres, such as may be found near the shallow lateral 
expansions already mentioned. In rare instances the gallery is driven 
upwards, and the larva has the power of moving along its gallery either 
upwards or downwards with some degree of rapidity, the movements 
being doubiless facilitated by the short stiff hairs which are scattered 
over the segments. 
The perfect insect isfrom five- to seven-eighths of an inch in 
length, with a narrow body; the head is partially clothed with yellow 
hairs; antenne as long as the body, eleven-jointed, the terminal joints 
hairy ; body cylindrical or slightly flattened ; wing-cases reddish brown, 
somewhat truncate, i 
