Injurious Insects and How to Control Them. TS « 



or Putnam's scale. It is represented at figure if. It can be 

 separated at once from the San Joe^ scale by the eccentricity and 

 the yellow or reddish color of the nipple. There is another 

 species, Aspidiotus ostreccfonnis (figure 4e), which resembles the 

 San Jos6 scale very closely indeed. If trees are infested by scale 

 insects or even present a suspicious appearance, it is by all means 

 advisable to cut off a small twig and submit the same to some 

 entomologist for examination. The San Jo&6 scale is dangerous 

 on account of its inconspicuousness and also because of its great 

 prolificacy. A tree may be nearly covered by this scale and noth- 

 ing be suspected. I have known such to be the case, even when a 

 bright and intelligent man and his two boys had endeavored to 

 keep posted and had been looking for the creature. Careful 

 studies have shown that in the latitude of Washington, D. C, four 

 and even five generations could be produced in a year and that the 

 descendants from one female might in one season reach the enor- 

 mous estimate of 3,216,080,400 individuals. In New York state 

 not over three generations annually would probably be the rule, 

 but even with our climatic conditions the insect is able to keep 

 up with a rapidly growing apple tree, as is shown by a twig fifteen 

 inches long of 1898 growth being nearly covered with the scale 

 at the end of that season. 



Very diverse opinions are held regarding this insect and its 

 destructiveness. It is at least a pest no man cares for and it 

 is much easier to exclude it from the farm than to maintain a per- 

 petual warfare to keep it in subjection. There are many sections 

 in the state where this pest has not become established and thou- 

 sands of farmers and horticulturists are in a position to prevent 

 the San Jos^ scale from gaining a foothold in their orchards. 

 To every such person I would say, buy only trees that have been 

 fumigated with hydrocyanic acid gas or else fumigate every tree 

 and shrub before it is set out. This measure is not only our most 

 practical method of safeguarding against the introduction of the 

 San Jos^ scale but is equally valuable against many other im- 

 ported insects. The importance of this latter has already been 

 emphasized. Nothing but the most heroic measures will stamp 

 out the pest after it has become established and these will be 



