Insect Pests 171 



2. The maggot, larva, grub or caterpillar usually the most destructive 

 stage. 



3. The chrysalis or pupa the dormant and non-destructive stage. 



4. The perfect insect, which in many cases may possibly help to fertilize 

 certain flowers at times. 



The female insect is naturally more to be feared than the male, because 

 in many species she is capable of depositing numerous eggs, from which in 

 due course arise a devastating horde of hungry larvae. There are thus 

 two dormant stages in the life-history of an insect, namely, the egg stage 

 and the chrysalis stage, and two active stages, viz. the larva and perfect 

 insect. Some pests, however, notably the green fly or aphis, are not only 

 egg-bearing but also viviparous, i.e. at certain seasons they bring forth 

 young the females amongst which soon mature and bring forth families 

 with amazing rapidity. 



In the active stage it is sometimes difficult to catch and even to see 

 some of the pests, as they assume many forms closely resembling in appear- 

 ance and colour the leaves and shoots upon which they are feeding. The 

 cultivator, however, with a keen eye will often detect the presence of 

 insect pests when others may be oblivious to their presence. While washes 

 and spra}'s applied at this stage will no doubt disable a large number of 

 pests, many must escape destruction, being thus saved to do further mis- 

 chief at some future time. 



In the dormant stages of egg and chrysalis, however, the grower has 

 the pests at his mercy, and then is the time to make war upon them. By 

 destroying the eggs, future generations of caterpillars, &c., are suppressed, 

 and by destroying the chrysalides the future perfect insects are prevented 

 from giving rise to new families. 



Methods of Prevention. But how are these eggs and chrysalides 

 to be destroyed? Entomologists tell us that the eggs of many insect pests 

 are protected by a covering impervious to most, if not all, of the insecticides 

 on the market. If that is so it would be waste of time and money to apply 

 these washes. In a cold state possibly many washes may be harmless to 

 the eggs of insect pebfcs, but if applied hot or warm, in the form of fine 

 spray, the liquid would probably soften the coat of the eggs and render 

 them pervious to the destructive properties of the insecticide. The embryo 

 larva would thus be destroyed. It may be stated that there is absolutely 

 no danger in applying boiling-hot solutions to plants in the open air, pro- 

 vided they are applied in the form of a fine misty spray, and with as much 

 force as possible. Even tender leaves of plants under glass will not be 

 injured by hot washes applied in this way, because the minute globules 

 of liquid are considerably reduced in temperature almost immediately they 

 reach the surface of the plant. For outdoor work the only difficulty would 

 be to maintain a large supply of liquid at a sufficiently high temperature 

 to render it effective when applied to the eggs of insect pests. 



Chrysalides. In most cases these are to be found at rest in the soil. 

 The chrysalis, or pupa as it is also called, is the stage of development 



