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look out for this pear aphis, and disinfect all imported stock. Since 

 then everything has been attended to, and I don't think we will have 

 any trouble with it. But it would be well for pear growers to make 

 investigation of sickly trees and see if the aphis has not got established. 



Last March, I received some pear leaves from a pear grower in 

 Tehama County. On the first inspection I thought they were affected 

 with a fungous growth. I placed them under a microscope, and I found 

 they were very minute mites, so small that hundreds of them were in a 

 single gall. They had the effect of blistering the leaf. Pear growers in 

 different sections have reported this pest, and it is very widely spread, 

 through all the counties of the Sacramento Valley, but in the coast 

 counties, so far, there has none been reported, nor in the southern part 

 of the State. It is comparatively new to the United States. About four 

 years ago was the first notice taken of it in New York State. It spread 

 throughout Canada and I had specimens from Lewiston, Idaho. The 

 gentleman who sent them was Horticultural Commissioner from that 

 section, and he said they had found it about three years ago. The Sec- 

 retary of the State Board of Horticulture in Oregon asked me to forward 

 him specimens, so they could determine whether they had it in Oregon. 

 He finds it distributed over Oregon. As a remedy, coal-oil emulsion is 

 recommended for spraying in the spring. That is expensive. Experi- 

 ments in this State tend to show that sulphur is a good remedy, applied 

 the same as for red spiders. I think it is one of our best remedies. Pear 

 growers everywhere, where they find the Phytoptus, or blister mite, should 

 dust their trees thoroughly in the spring twice or three times, just as they 

 would for red spider. The pest should not be allowed to spread in the 

 orchard. 1 think that thorough work, just as soon as the leaves push 

 out, will destroy it so that there will be no trouble. 



Mr. Lelong: Also as to stock coming into this State from foreign 

 countries — whether they come here affected by the root knot. 



Mr. Craw: We have not found anything very serious coming from 

 the outside, but from the East we frequently find root knot. Those are 

 all taken out and destroyed. 



Mr. Pryal: I would like to ask Mr. Craw if he knows whether the 

 codlin moth is disappearing, or not. 



Mr. Craw: I think probably there was less this year than some years 

 previous, but it is not disappearing. 



A Voice: I would like to ask Mr. Craw what success has been met 

 with in the use of gas lime on pear aphis. 



Mr. Craw: Gas lime has appeared to have no effect at all. There • 

 were trees that had been so seriously injured they were dug up and the 

 soil was removed and new soil w r as placed in the holes. Gas lime was 

 mixed in those holes and fresh trees planted. When I visited the 

 orchard about a month ago I found the trees very seriously affected 

 with the aphis. The experiments, however, with the rosin wash were a 

 little more successful. Where they had been thoroughly soaked I found 

 there were very few aphids left, and the trees had made a very good 

 growth. I hardly think that remedy would be practical for larger 

 orchards or for older trees, still, experiments could be conducted with 

 it. It would be quite expensive to irrigate with insecticides. The pear 

 aphis is a very serious pest, but it does not appear to injure the roots 

 like the woolly aphis on the apple. It does not produce any swelling. 

 It only appears to poison the roots and destroy the young fibers. 



