INSECTS AND THEIR CONTROL 



239 



beak-like mouth-parts. Some of the worst pests of orchards 

 belong to this group. Plants that are attacked by the aphids 

 are very often covered with ants, the reason being that ants 

 are very fond of the honey-dew which the plant-lice excrete. 

 Ants have been known to care for certain species of aphids 

 during the winter, taking 

 them into their nests and 

 placing them on their host 

 plants in the spring. 



The method of repro- 

 duction among this group 

 of insects is unusual and 

 interesting. Many of them Fl0 ' 122 "~ A P arasitized larva - 



spend the winter in the egg stage. In other seasons of the 

 year there is no egg stage and reproduction takes place 

 viviparously ; that is, living young are produced without any 



egg stage. Generation 

 after generation of these 

 lice are produced on 

 plants during the active 

 growing season and 

 some species continue 

 feeding throughout the 



1 HS&\ winter months. 



y| ||& The life history of the 



' h ^^^ Sh common woolly aphis 



of the apple is char- 

 acteristic of the mem- 

 bers of the entire group 

 and is as follows : Dur- 

 ing the summer time, 

 twigs, foliage, and roots 

 of apple trees may be 

 abundantly infested with this little woolly coated insect 

 which feeds by means of a beak inserted into the leaf or the 



FIG. 123. a, The Eyed Ladybird and b, Ash- 

 Gray Ladybird, predaceous on aphids; c, 

 the Black Ladybird predaceous on black scale; 

 d , the Mealy Bug destroyer. 



