164 THE GARDENER. [April 



Pear cultivator in Britain, and wliicli do no inconsiderable amount of 

 damage to the leaves and wood in some localities. The first of these 

 ■which we shall notice is the Selandria atra, which is perhaps the most 

 common as well as the most curious of them all. In its caterpillar 

 state it is of a black slimy appearance, resembling very much the little 

 black slug so familiar to all kitchen-gardeners — hence is it popularly 

 known as the slug-worm. Their depredations are always committed 

 during the night, for although they generally remain during the day 

 on the under part of the foliage, they never appear to do any injury 

 there, as all the eating is done upon the upper surface. They change 

 their appearance several times, giving off a greenish skin, which is 

 followed by one of a buff colour. In a week or two after this trans- 

 formation they descend into the soil, where they remain till the fol- 

 lowing June, when they appear in their fly shape, and at once begin 

 the propagation of a fresh generation. The most effectual cure is to 

 syringe the trees affected with a strong decoction of tobacco-water, and 

 the best time to apply it is towards midnight, when they are sure to be 

 upon the upper surface of the leaf, and consequently in a better posi- 

 tion to receive the water. 



Another of these most destructive insects is the Astyages hemero- 

 biella, but fortunately its visits are more limited than that of 

 the one just noticed. It may make its appearance once, and not 

 be seen again upon the same tree for years to come, or, at all 

 events, in very limited numbers. The caterpillar is of a lightish 

 brown colour, encased in a brown-coloured cylindrical case, from | 

 to f of an inch in length, from the under end of which the head of 

 the insect is from time to time thrust out. Its mode of attack is very 

 different from that of the Selandria. It attacks the upper surface of 

 the leaf, merely cutting through into the cuticle, when it places its 

 mouth upon the opening thus made, and, erecting itself into a standing 

 position, with its head down and at right angles with the leaf, it feeds 

 upon the parenchyma. In this manner it continues to work until it 

 has made an opening between the upper and under surface of the 

 leaf, when part of its body is introduced, so that it mines out the leaf 

 to a considerable distance round the place of its first entrance. Being 

 of a much larger size than the former one spoken of, it can be easily seen 

 and gathered by the hand ; but if they should be in great numbers, the 

 remedy recommended for the Selandria can be applied. These being 

 the two principal moths or caterpillars with which we are acquainted, 

 we shall refrain from enumerating any of the others, which are de- 

 scribed in many other garden works, and shall simply say that we 

 believe the most of those which attack the leaves of the Pear can be 

 destroyed, either by hand-picking, or syringing with tobacco-water. In 



