INSECT PESTS 347 



to attract the pests, or to take up the plants and carefully pick out 

 the insects from the roots, and destroy those that are in the soil. 

 Nearly all the insects that feed on the roots of plants are in the grub 

 or caterpillar state. There are a few exceptions, one or two species of 

 aphides feeding on the roots of plants. It is often stated that ants 

 injure the roots of plants. In one sense this is quite true, as they 

 make their nests among them at times, but not with any intent of 

 feeding on them, or injuring them in any way ; but when they find a 

 plant infested by one of these underground aphides, they make their 

 nest so that they can easily obtain the sweet matter which these, like 

 all other aphides, secrete, and the presence of the ants laying bare 

 some of the roots, and the interference with their supply of moisture 

 consequent on the nest surrounding them, is naturally very harmful to 

 the plant. The ants in this respect are of a certain amount of use, as, 

 when one of their nests is found at the roots of the plant, it is an 

 almost sure sign that the latter are attacked by one of these aphides, 

 which would seriously injure the plant if means were not taken to 

 destroy them. Under these circumstances the plant should be lifted 

 out of the ground, and its roots carefully washed so as to free them 

 from the aphides, and the hole from which it was taken filled with 

 boiling water so as to kill any of the pests which might be in the soil. 

 This will also kill the ants if plenty of water be used so that it 

 thoroughly fills the nest ; boiling water is a most useful agent in kill- 

 ing all kinds of insects, it is absolutely sudden death to them. There 

 are a great number of different kinds of 



Grubs and Caterpillars that Feed on the Roots of Plants. The former may be 

 divided into two kinds, those with legs and those without. Those that have legs are the 

 grubs of beetles, but they have only three pairs of legs, which are placed near the head ; 

 the caterpillars that may be found at the roots of plants have eight pairs, so they may 

 easily be distinguished from grubs. Among the grubs of beetles, perhaps the best 

 known are the 



Wireworms, whose parents are the long, narrow, dull-coloured insects, belonging to 

 the family Elateridas, and commonly known as "skip-jack" or "click" beetles, which 

 live among grass and weeds, and may often be seen on the flowers of " cow parsley " and 

 other plants of that nature. These grubs have received the name of wireworms, on 

 account of their resemblance to a short piece of copper wire ; they vary in size according 

 to the species, but the largest is seldom more than f-inch long ; they are of a yellowish 

 colour, except the heads, which are dark brown, and the three pairs of legs, which are 

 just behind the head, are of the same colour. If these characteristics are borne in mind, 

 it is impossible to mistake any other insect for a wireworm. These pests may be trapped 

 by burying small slices of turnips, mangolds, carrots, or potatoes in the ground just 

 below the surface ; if a small wooden skewer be thrust into each they will be more easily 

 handled, and their position in the soil more easily seen. Small pieces of oilcake are also 

 very useful as traps, even if only placed on the ground. These traps should be examined 

 every morning. When ground is being dug that is infested with this insect, a sharp look- 

 out should be kept for them ; though small, their colour soon betrays their presence. 

 The grubs of the "common cockchafer" (Melolontha vulgaris] are also very injurious 

 to the roots of various plants, and as they are three years old before they attain their full 

 size, each grub has the opportunity of doing an immense amount of damage. The 

 grubs, when full-grown, are about 2 inches long and almost \ inch in diameter. They 

 are nearly white, but their tails, which are generally curled under their bodies and are the 

 thickest part of the grub, are bluish. Practically there is no way of destroying them 

 except turning them up out of the ground, and the easiest way of keeping this insect in 

 check is by killing the cockchafers. The grubs of several kinds of weevils feed on the roots 

 of plants, but unfortunately they cannot be caught in traps as the wireworms can, and 

 the best way when a plant is attacked is to take it up and pick out the grubs from among 

 the roots. The caterpillars of the "ghost" and "swift moths" (Hepialus humuli and 



