Page 20 



BETTER FRUIT 



June 



Hatching takes place in the spring. At 

 first the young mites are red in color 

 and have only six legs. Upon feeding 

 for a short time moulting takes place, 

 after which the mite is olive green or 

 brown in color, and has eight legs, more 

 or less tinged with red. It feeds prin- 

 cipally upon the leaves, occasionally 

 attacking the fruit, and may be detected 

 by the faded out, pallid appearance of the 

 foliage, dotted here and there with little 

 black specks of excreta. Figure 6 shows 

 two peach leaves which have been 

 attacked and two which are normal from 

 the same tree, and gives a good idea of 

 their appearance after this pest has been 

 feeding upon them. 



Experiments show that tobacco prepa- 

 rations are of little value in controlling 

 this mite; that they will kill the mites, 

 but not the eggs. As the latter are 

 almost always present on a tree where 

 the mites are feeding such sprays can 

 only be efTective when repeated applica- 

 tions are made. The sulphur spray was 

 again tested this season, this time at 

 Palisade, Colorado. Some badly infested 

 pear trees were treated, using ten pounds 

 of sulphur to fifty gallons of water. 

 Results of this test were perfect, and a 

 week after the trees had been sprayed it 

 was hard to find a living mite on them. 



An interesting point in connection with 

 the sulphur treatment for brown mite is: 

 The adult mites are not immediately 

 affected by the spray, but those newly 

 hatched die shortly after the application. 

 An examination of a tree the day after 

 spraying with sulphur is usually disap- 

 pointing, for the adult mites may be 

 alive and abundant. In all the tests made 

 a very few newly hatched, six-legged 

 mites have been found twenty-four hours 

 after spraying, and in a week's time 

 neither adult nor newly hatched mites 

 can be found. The sulphur adhering to 

 the bark and leaves undoubtedly kills 

 the young mites as they hatch from the 

 eggs. Whether the older ones are killed 

 by the sulphur or simply die a natural 

 death is a point that has not been deter- 

 mined definitely. As there are probably 

 only three broods of this mite, and thejf 

 are quite long lived, it would seem that 

 the sulphur really kills the adults, but 

 that it takes some days to do so. The 

 important fact remains that the young 

 mites never develop after the sulphur 

 treatment, whether hatched or in the egg 

 stage at the time of treatment, and that 

 the adult mites are either killed by the 

 sulphur or die a natural death within 

 seven or eight days after treatment, thus 

 ridding infested trees of the pest. In 

 bulletin 152 the following statement is 

 made: "Trees may be treated while dor- 

 mant with lime and sulphur. This spray 

 has no effect upon the eggs, but prob- 

 ably kills the young mites as they hatch." 

 The fact that the lime and sulphur kills 

 3'Oung mites as they hatch was def- 

 initel3- established last spring at Palisade, 

 Colorado. 



Three adjoining peach orchards, each 

 containing a great many brown mite 

 eggs — two of them sprayed with Rex 

 lime and sulphur 1-10 and one not 

 sprayed — were chosen as observation 



places to determine this point. The eggs 

 were found hatching in all three orchards 

 at the same time; in the orchards which 

 were sprayed a great many of the tiny, 

 red mites could be found where they had 

 died on the limbs very soon after hatch- 

 ing. In no case were any found alive, 

 except a few immediately hatched from 

 the eggs. In the unsprayed orchard all 

 the mites seemed to live, and the trees 



ROSE DOROTHY PERKINS 



were soon covered with them. Through- 

 out the season the sprayed orchards were 

 almost entirely free from mites, while 

 the unsprayed one, located between the 

 other two, had quite a serious infesta- 

 tion. As a result of the extensive use of 

 a lime and sulphur spray in the Palisade 

 section the past season the brown mite 

 was practically exterminated, except in 

 a few orchards where such a spray was 

 not used. 



The red spider mite differs from the 

 preceding one in its wintering habits; 

 instead of living over in the egg stage, 

 as the brown mite does, this species 

 hibernates in the soil as an adult, close 

 to trees upon which it has been feeding 

 or underneath rubbish of any kind. On 

 the 7th of November, last season, they 

 were found plentifully under burlap 

 bands that had been applied to trees for 

 the purpose of trapping the codling moth 

 larvae. Hibernation begins before the 

 cold weather sets in; the first downward 

 migration of mites to the soil was noticed 

 at Grand Junction last on July 2G. While 



a few of them may work on trees until 

 late in the fall their damage is usually 

 over by the 15th of August. Eggs are 

 laid in the spring by mites that have 

 lived through the winter. These eggs 

 are pearly white, and may be seen as 

 tiny specks on the under surface of the 

 leaves. 



When first hatched from the egg this 

 mite, like the species previously treated, 

 has only six legs, the fourth pair develop- 

 ing with the first moult. They are some- 

 what smaller than the brown mite, usu- 

 ally green in color while feeding upon 

 the foliage of trees, with minute black 

 dots on the dorsum of the abdomen. 

 When feeding ceases in the fall, and they 

 begin their downward migrations to the 

 soil, they become an orange or red color. 

 During my observations of this species 

 of mite, for the past three years, a red 

 one has never been seen on fruit trees 

 until feeding ceases in late summer. In 

 greenhouses this same species is very 

 often red in color. Unlike the brown 

 mite, the red spider has the power of 

 spinning a web, and may easily be 

 detected, when prevalent, by the pres- 

 ence of these webs on the foliage or 

 branches of infested trees. The appear- 

 ance of injured peach foliage is not unlike 

 the appearance of that injured by the 

 brown mite, but is more inclined to turn 

 yellow in patches. 



Sulphur is very successful in treating 

 this mite also, whether dusted upon or 

 applied as a liquid spray to infested 

 trees. When applied in water, by means 

 of a spray, sulphur should be very finely 

 screened and mixed with the water by 

 using a small amount of soap. Without 

 the soap the sulphur will remain on the 

 surface of the water, while with the soap 

 it will sink to the bottom of the spray 

 tank, and a good agitator will keep it 

 mixed. Lime and sulphur has not 

 proven a successful treatment for red 

 spider, and cannot be depended upon to 

 do effective work when used as a dor- 

 mant spray. The use of tobacco prepa- 

 rations, as with the brown mite, result 

 in little good. 



^ ^ 



FOREST FIRES, one of the greatest sources 

 of destruction to the most valuable resources 

 of the state, will soon be restricted and their 

 terrors largely reduced if the people will co-operate 

 with the state forester in the administration of the 

 new forestry law enacted by the last Legislature, 

 which will be ready for distribution in pamphlet 

 form in the near future. One of the most impor- 

 tant provisions of the law is that making a closed 

 season for burning from June 1 to October 1, 

 during which period outdoor fires of all kinds are 

 prohibited, except under most stringent regula- 

 tions and the probability of heavy penalties. 

 In this connection the state forester urges upon 

 every one the necessity of doing all possible burn- 

 ing before the closed season begins, and thus save 

 the trouble and risk of doing it by permission dur- 

 ing that season of greatest danger when fire 

 spreads so easily and rapidly. The state forester 

 desires the assistance and co-operation of every- 

 one in the protection of property from forest, grass 

 or brush fires, and to this end invites suggestions 

 and information calculated to assist in any manner 

 in the performance of his most important duties. 

 Copies of the law will be promptly furnished to 

 all who desire them. Requests and communications 

 addressed to F. A. Elliott, state forester, Capitol 

 Building, Salem, Oregon, will receive prompt and 

 appreciative attention. 



<S> 



Editur Better Fruit : 



I enclose one dollar for one year's subscription 

 for "Better Fruit." The sample copy I have is 

 the first one that I have ever seen, and I like it 

 so well that I must add my name to your sub- 

 scription list. H. G. Fitzsimmons, San Francisco. 



