SCALE-INSECTS. 25 



jure, in every way, whether as regards ornamental or commercial 

 value, a number of trees and plants on which the people of the 

 country depend largely for subsistence or profit. In the South 

 of France the olive industry has been in some years greatly cut 

 down. In Florida, California, Australia, the Cape of Good 

 Hope, oranges and apples have been so damaged that the value 

 of an orchard or a grove has been reduced sometimes by 80 per 

 cent. It may be said, moreover, that even in tropical countries 

 the attacks of scale-insects are often most damaging : in Mauri- 

 tius the sugar-cane and in Ceylon the coffee plantations have 

 suffered from their ravages. The experience of American fruit- 

 growers is certainly not to be despised, and the fact that both 

 in California and Florida the people strain every nerve to get rid 

 of the insect pests on open-air trees would seem to be distinctly 

 against the notion that these little enemies can be neglected with 

 impunity. 



Nor, indeed, can it be said that in New Zealand itself 

 the attacks of scale-insects out-of-doors are harmless. Apple 

 orchards throughout the country bear evidence to the contrary : 

 lemon-groves can be seen about Auckland where, instead of the 

 thousands of fruit formerly grown, a few stunted lemons are all 

 that the withered trees afford ; and nobody can glance round 

 the plantations at Nelson or Napier without recognizing the 

 devastating powers of a scale-insect (leery a) . 



The opinion that Coccids are not likely to do much harm in 

 the open air is therefore scarcely tenable, and it will be of use 

 to inquire what remedies can be provided against them. 



There is a point, however, to be noted at the outset, and it 

 is, that in reality there is not, as far as is yet known, any cer- 

 tain remedy against scale-insects. Not that ingenuity and ex- 

 periment have not succeeded in inventing plans and substances 

 quite efficient in killing the insects when applied to them. It 

 is easy enough to kill an insect when you can get at it, in most 

 cases ; but the problem in this instance is not only to kill indi- 

 vidual insects, but to do more. What is wanted is to get rid of 

 whole communities of them, and, at the same time, to prevent 

 their eggs from hatching and a new brood coming forth. Many 

 of those who profess to know all about destroying " scale " 

 especially if they belong to that class which prides itself upon 

 being " practical men " being generally quite ignorant of the 

 habits and life-history of the insects, are satisfied when they 



