INSECTS, FUNGI, PLANT DISEASES, ETC. 109 



is the character of the trouble, and then use the remedy 

 which experienced entomologists recommend. 



1. Insects which Attack the Leaves. — These are compara- 

 tively easy to destroy by spraying poisons on the foliage, 

 so that the insects will take the poison in their food; or 

 the plant may be enveloped with poisonous gas which 

 will cause death to the enemy. 



2. Insects which Suck the Juices from the Plants. — This 

 group contains the plant lice, which puncture the tender 

 bark and suck out the vital juices of the plant. They 

 belong to the order of insects known as Hemiptera, or 

 true bugs. Their bodies are pear shaped, and from the 

 upper part of the rear end are two projections from which 

 a clear, sweetish fluid exudes. Ants and bees are ex- 

 ceedingly fond of this exudation, and on those plants that 

 lice infest it is quite common to see ants climbing in con- 

 siderable numbers feeding on the honey thus manufac- 

 tured by these lice. One remarkable fact in the life 

 history of these animals is the reproduction of the young 

 without the intervention of the male, and also the fact 

 that the mother, while she is feeding, produces the 

 living young without first laying eggs. This process of 

 multiplication goes on until late in the fall, w T hen males 

 are produced, which fertilize the females, and eggs are 

 laid in secure places against the winter, and next spring 

 these hatch out into female lice, and the process of repro- 

 duction is continued without the laying of eggs. It can 

 be readily understood, therefore, how rapidly the multi- 

 plication of these animals will take place, and the plant 

 must soon succumb, unless measures are used to kill the 

 lice at once. During the winter months all rubbish must 

 be burned in order to destroy the eggs laid by the lice the 

 preceding season. When the plants are growing they must 

 be constantly examined and all lice killed. One female 

 deprived of her life early in the season is equivalent to 



