182 



APHIDES, SCALE INSECTS, ETC. 



The number of remedies — such as solutions or 

 mixtures of tobacco, paraffin, quassia, or other appli- 

 cations in the form of washings or syringings — are 

 endless, and recipes are not given here, as these 



Fig. 140. — Hop Aphis : base of antennae and frontal tubercle of — 

 1, young form; 2, wingless female, magnified. 



applications lie in the special province of the Hop- 

 grower. It may, however, be noted that sometimes, 

 washes fail in efiect from the operator not being 

 aware that in the case of many Aphides the skin is 

 covered with a kind of mealy coating, which throws 

 off watery application. Consequently it often hap- 

 pens that unless the washing lodges amongst the 

 Aphides so as to kill them, or, again, the syringing 

 is given with such force as to knock them from the 

 plants, the insects are but little hurt. It is for this 

 reason that soft-soap is so largely used, especially by 

 Hop-growers, for the washes : it is sticky, and thus 

 adheres in some degree to the Aphides ; also it may 

 be made the vehicle of any other application, with 

 which it may be desired to poison the Aphides ; and, 

 thirdly, it is a good fertiliser, which, as we have 

 observed, is important in Aphis attack. 



The great thing, however, that we need to know, in 

 order to check Aphis attack, is where and how each 

 kind spends the winter. Meanwhile our best hope as 

 to prevention lies in allowing as few shelters as 

 possible on trees, or in neglected bark (in fruit or tree 

 attack), or at the roots of wild grasses round fields, for 

 possible shelter of grain Aphis, and (generally) being 

 alive to the necessity of not letting everything drift 

 without thought of the reasons how, or why, things 



