THE APHIS. 309 



as Paris green and London purple, will be found efficient, 

 while for the sucking insects, which are more trouble- 

 some in the greenhouse, we shall need to rely upon kero- 

 sene emulsion, tobacco, whale-oil soap, pyrethrum and 

 other remedies that act upon the exterior, or the breath- 

 ing apparatus of the insects. 



THE APHIS. 



This insect and its allies embrace a great variety of 

 forms, all of which may be included under the common 

 name of plant lice or "fly." While most of them are of 

 a green color, some forms, such as chrysanthemum aphis, 

 are black in color, and in some cases 

 we find a blue aphis upon the roots 

 of plants. They have long, slender 

 antennas or feelers, a small head, a 

 full, round thorax or chest, and gen- 

 erally a very large, round abdomen. 

 From near the end of the abdomen, 

 two tubes project, from which the so- 

 called honeydew exudes (Fig. 105). 

 During the early part of the season, 

 the female aphides give birth to liv- 



"fkmaLb^hm* 88 in S femalc y° un g; these propagate 

 very rapidly until, as fall approaches, 

 when eight or ten broods have been produced, both 

 males and females appear. This brood, only, has wings 

 (Fig. 106). The eggs produced as a result of pairing 

 serve to carry the species over winter. It has been esti- 

 mated that from a single individual a quintillion could 

 develop in one season. 



Aphides seem to thrive, in particular, upon plants in 

 partial shade and poor ventilation. The best way of 

 destroying them is by means of tobacco smoke, extract, 

 or tea. All of these should be used upon the first 

 appearance of the aphides, as, if they are allowed to reach 



