STATE HORTICULTURAL SOCIETY. 291 



fall web worm, the round-headed and flat-headed borers, the 

 bark louse and the codling moth, except that some new ways of 

 fighting them have been tried with more or less success. The 

 kerosene emulsions with milk or soap are coming more and more 

 into use, their principal recommendation being that they are 

 less dangerous to man and the higher animals than Paris green, 

 and are equally deadly in their effects on the "bugs." The only 

 difficulty is to get the oil so strongly mixed with the dilutants 

 that it does not fall in "splashes " on any part of the plant. For 

 use on large trees a force pump is necessary for its application, 

 and this also keeps the fluids well stirred. A tree syringe an- 

 swers very well for small trees and other plants. For use on 

 leaf- feeding insects a ten per cent mixture is strong enough, but 

 for scale insects a larger proportion of kerosene may be used, 

 and in all cases it must first be thoroughly emulsified with at 

 least an equal quantity of milk or strong soapsuds, and the 

 water added later. Before concluding I wish to say a word on 

 the aphis. This is an insect that ' ^ we have always with us " in 

 one form or another. Scientific entomologists have described a 

 great number t)f species, and make much of the differences be- 

 tween them, which they find in the way a vein in the wings 

 curves here in one, or branches off there in another, or is entirely 

 wanting in a third; whether the honey tubes are long or short, 

 or whether the skin is covered with cottony or waxy secretions, 

 or is smooth and polished. The main points of structure in 

 which the horticulturist and farmer are interested are the beaks 

 with which they abstract such large quantities of the sap that 

 was prepared for the nourishment of leaf and blossom and fruit, 

 and that they multiply at a rate beyond any ' ' arithmetical pro 

 gression" for which we can find rules in books. 



Most of the so-called "scab" on apples is undoubtedly due to 

 punctures and exudations of the common apple tree plant louse 

 (aphis inali). This insect hatches with the unfolding of the buds 

 in the spring, and swarms on the tender leaves. All the lice 

 hatched in the spring are agamic females which, in about a week, 

 begin to reproduce themselves, not by the usual and slower pro- 

 cess of laying eggs, but by a plan analogous to the propagation 

 of plants by buds and slips, by which the young lice are brought 

 forth alive and about half grown. In the course of a day or two 

 these are also adding to the population in the same way, and it 

 will be evident that in a very short time a single aphis will be 

 the original parent of an immense colony. Each louse, as soon 



