DISEASES OF THE PEAR TREE ] 249 



directed downwards into the underground portion of the 

 base of the trunk and into the main roots, and its section 

 is elliptical with a longer diameter of 2 to 2| c.m. An 

 opening is made at the base of the trunk, through which 

 the excrements and wood dust are thrust up, the opening 

 being always kept well closed against possible enemies. 

 The larva continues its active life for about two years, 

 and then becomes a pupa, at first white, and when the 

 metamorphosis is complete the insect assumes its black 

 colour, but remains cosily esconched in its tunnel 

 waiting for the advent of spring. There are often as 

 many as twelve larvae in separate tunnels within the 

 same trunk, and when the insect visits the same tree one 

 year after another, in a few years the tree dies or is 

 blown down by the wind. 



The other borer is Capnodis tenebrionis L. of which 

 the female insect is about 3 c.m. long, but the male is 

 never longer than 2\ c.m. Both have the same shape 

 and colour. The shape is peculiar, being obtusely round- 

 headed with very -short antennae, the body tapering 

 behind abruptly almost to a point. The colour is dull 

 black or dirty black, but the head is white, with splashes 

 of white continuing over the thorax. The life history is 

 the same as that of Cerambyx miles, and the larva directs 

 its tunnels always downwards, but the insect is much 

 less frequent than Cerambyx so that for every 20 adult 

 Cerambyx caught in the same orchard it is not always 

 possible to find one Capnodium. The ravages caused 

 by these tree borers is incredible. The depletion of our 

 pear and apple orchards is due to them, and but for 

 them the cultivation of these kernel fruits would be 

 much more popular. Long^ before the introduction of 

 the fruit fly in these Islands' the older gardeners used to 

 say that "he who plants a pear-orchard will be planting 

 a bagful of sorrow", no doubt alluding to the short- 

 lived character of the plantation owing to the activities 

 of these insects. These borers can be kept in check only 



