INSECT PESTS 



493 



These are very useful in gardens, and run with great rapidity. Woodlice, or slaters 

 (Onisid*), as they are sometimes called, are often very troublesome pests, and do much 

 mischief in greenhouses, Melon-pits, Mushroom-beds, and among Peaches and Straw- 

 berries. It is no use trying to kill them with insecticides, but when they are found, as is 

 often the case, in regular colonies at the base of a wall just below the surface of the soil, 

 they may be killed wholesale by pouring boiling water over them ; they may also be 

 trapped under slates, bricks, &c., and in small bundles of dry moss. Toads are very 

 useful in keeping woodlice and many other night-feeding pests under. 



"Prevention is always said to be better than cure," and this is very true in the case 

 of plants likely to be injured by insects, and fungi, weeds, stones, rubbish, &c. , which 

 harbour these pests, should never be allowed in gardens, even in out-of-the-way corners, 

 and any prunings of trees or refuse of a crop that has been infested by any pest should be 

 burned at once. Indeed, the old time-honoured rubbish heap should be turned into a 

 bonfire far oftener than it is, for even when its contents are well rotted they are not of 



FIG. 66. Black Currant Gall Mite. 



i. Black Currant Gall Mite (magnified 400 times). 2. Twig of Black Currant with 

 healthy buds. 3. Twig of Black Currant with infested buds. 



much value, and when spread over the ground often carry pests with them, and the ashes 

 from a bonfire that has not been allowed to burn too rapidly are of considerable value. 

 When garden ground is being dug a sharp lookout should be kept for any chrysalides 

 that may be turned up, particularly if the last crop was attacked by caterpillars. 



Leaf-Curl in Peaches and Nectarines. Beginners are generally puzzled about this 

 characteristic of the Peach and Nectarine. The injury it causes is generally attributed to 

 cold winds or draughts of some sort. No doubt certain conditions of the weather are 

 more favourable to the growth of this fungus than others, a sudden fall in the temperature 

 after mild weather, during which the leaves have opened, being particularly liable to 

 cause an attack. Still, if this fungus was not present in the tissues of the tree, no atmos- 

 pheric conditions would cause the disease. Peach leaves are often attacked by aphides, 

 which cause the leaves to curl more or less, and the two kinds of attack are sometimes 

 mistaken for the same, but the difference as a rule is easily detected. The "curl" is 

 rather of a different nature ; it has not the same puckered appearance, and though in 

 both cases the diseased part of the leaf may turn red at last if caused by aphides, it never 

 assumes the pale sickly green colour that it does from being infested by the fungus, nor 

 has it the almost velvety appearance. It happens not infrequently that a tree may be 



