-5- 



Rotary mower- shredders have been used by growers to cut brush and small 

 trees on land being prepared for an orchard. One grower reports that oak, maple 

 and birch trees ten feet in height can be knocked down and cut into small pieces 

 by a mower-shredder. 



--- W. J. Lord 

 I I I I I I I I I I I I I I I I 



BEV.'ARE'., San Jose Scale 



The threat posed by this insect should not be shrugged off'. San Jose Scale 

 is weakening and killing twigs and branches - even entire trees. Apples with tiny, 

 round scales or the red spots left where the insects settled and fed are being 

 found in more and more boxes. Growers and official workers in adjacent states 

 also report unexpected infestations. Scale-marked fruit is do\>m-graded for local 

 sales and may be refused for export. 



Why is this scale threatening to become an important pest again? 



Undoubtedly the upsurge in numbers of San Jose Scale has resulted from the 

 cumulative effect of several factors. The switch from lime sulfur to mild sul- 

 furs and then to the organics; a change to less frequent applications of oil; 

 methoxychlor and dieldrin in post-bloom sprays rather than sulfur- lead or DDT- 

 lead; a natural or possibly an insecticide-caused upset in the parasite-host 

 relationship; the series of mild winters (prior to 1956-57) and relatively warm 

 summers (except 1956) extending from the late 1940' s -- all of these added to 

 other unknown influences, have brought about the present situation. 



San Jose Scale has a tremendous potential for reproduction. Each over- 

 wintering female may give birth to 400 tiny living young. These latter scatter 

 widely over the tree making it difficult to attain 1007, kill with any material. 

 From three to four generations occur each year. Infestations on wild fruit trees 

 and other woody plants are spread into orchards by wind, birds, etc. Overwinter- 

 ing stages are found all over the bark, some well protected by flakes of loose 

 bark or other cover. 



Apple growers are urged to give full attention to the control of this scale 

 during 1958 and the next two or three years. If already known to infest any block 

 an oil application seems essential. Since a complete clean up from one treatment 

 is not expected, other measures should supplement the oil spray. A dormant DN 

 application could be one of these and would be especially useful on aphid-susceptible 

 varieties. Bofch oil and DN should be applied in dilute sprays to obtain the over- 

 all washing- drenching effect so necessary to get complete coverage of scale- 

 infested bark on trunks, larger limbs and even some spots on smaller branches. 



Summer sprays containing DDT or any one of the phosphates should be effective 

 against young active "crawlers". These appear first soon after bloom and then 

 again at intervals of about 4 weeks. However, it is extremely difficult to obtain 

 spray coverage in summer applications which is good enough to give adequate kill. 

 There are thousands, even hundreds of thousands, of these tiny crawlers on fruit, 

 leaves, new and old twig growth and branches. We must put our greatest reliance 

 upon delayed dormant oils and dormant DN's. 



