The Pernicious Scale Insect in New Hampshire. 277 



The scales that are found through the winter develop in early spring into 

 mature insects that give birth to many young scale lice. These are tiny whitish 

 or yellowish white creatures that crawl about over the bark for about thirty 

 hours before they finally fasten themselves to it, inserting their curious beaks to 

 suck the sap. They then begin to secrete the scale which is so characteristic 

 of this family of insects. Certain definite stages have been observed in the 

 formation of this scale. At first there is a white or fluffy stage due to the se- 

 cretion of cottony threads ; then a tufted stage due to waxy threads ; then a 

 hiack stage during which the scale becomes thicker, and finally passes into the 

 mature form. These are the periods of the female scales. The male scales finally 

 develop into minute two-winged creatures which are able to fly about. 



When the San Jose scale occurs upon older trees it is most likely to be 

 found o. the twigs and smaller limbs, but upon young trees it may occur over the 

 whole surface. But it does not confine its attacks to the bark, for the leaves and 

 fruit are often infested ; upon the young bark and the leaves and fruit there is 

 a very characteristic purplish ring around each scale. When the leaves are 

 infested the insects are likely to be found along the midrib. 



This pest is most likely to bei ntroduced into new localities upon nursery 

 stock imported from infested regions. This is believed to be the way in which 

 it was first brought to the Eastern States. It is also likely to be carried upon 

 ■apples and pears sent to market, but this species never occurs upon oranges 

 or lemons. 



infestation in new HAMPSHIRE. 



A few years ago there seemed some reason for hoping that this pest would 

 not thrive so far north as New Hampshire, but this hope must be abandoned 

 in the face of the facts now known about its presence in our State. That it 

 can develop even as far north as our White Mountain region to an extent where 

 it is seriously destructive is beyond further question. 



Theinfestation first found was in the eastern part of Manchester, where 

 a young mixed orchard of about forty trees was very severely attacked by this 

 scale. The trees consisted of apples, peaches, pears, plums, cultivated cherries 

 and wild cherries, with gooseberry bushes planted between. All of these, except 

 the cultivated cherry, were very badly infested when we first visited the place 

 one year ago. The gooseberries were so seriously attacked that they were burned, 

 along with a large number of branches pruned from the other trees. The wild 

 cherries were badly infested, a discouraging indication of future trouble when 

 we think how generally these trees are distributed throughout the State. In a 

 •neighboring orchard of sixteen young apple trees two were practically dying from 

 scale attack and others were more or less infested. Larger apple- trees in the 

 neighborhood also showed occasional scales. 



The trees originally infested were sprayed in March, 1903, with undiluted 

 ■kerosene, which was then believed to be one of the best remedies for this insect. 

 The results obtained, however, were not satisfactory, only part of the insects 

 being killed, so that by last autumn the infestation was still seri( us, requiring 

 treatment this winter with a more effective insecticide. 



The next region of infestation of which we learned was at Dover Point, 

 where some peach, pear, and plum trees were very seriously attacked, and 

 neighboring apple trees less seriously. The pest had doubtless been introduced 

 through nursery stock, and had been developing for some years. The owner 

 promptly sprayed these trees with the lime, sulphur, and salt wash, with the 

 result that the nine worst infested trees were killed, though the lightly infested 

 •apple trees were not injured. I do not know just why this result should have 

 happened. 



Another infestation was found at Intervale, New Hampshire, where a row 

 of pears along the south side of a wall were badly infested. These were thor- 

 oughly treated with Calcothion, a trade mixture of the lime, sulphur, and salt 

 wash made by the Adler Color & Chemical Company, New York. This treatment 

 apparently eradicated the scale without Injury to the trees. 



