-16- 
Kearns and Martin (86) in 1939 discussed the use -of postdormant combined 
sprays on fruit crops in England. r, -otenone-containing sprays, excluding those 
containing high-boiling petroleum oil, give somewhat erratic results in red 
spider control at the petal-fall stage. Eggs are not killed. If most cf the 
spiders are active at the time of the application, control is satisfactory; hut 
should a large nunber of them he molting, the control is frequently unsatis- 
factory. The following spray is recommended for the control of . the plum saw- 
fly and fruit-tree red spider: 1 gallon of petroleum-oil emulsion (67 percent 
oil) enough rotenone-containing material to give O.COU percent of crystalline 
rotenone in the wash, and enough water to make 100 gallons of spray. 
Robertson (l2_9) in 1939 reported that Rotox with Stantex oil at 1:100 
was tried against the European red mite on Yellow Newtown apple trees, but 
was less effective than "Cosmic sulfur" at 1:200, and equally as effective as 
10-percent commercial summer oil. 
Paratetranychus yothersii McG. , the avocado red mite 
See He. r rdlton (695 under Bryobia ' praetiosa , on page 13. 
Paratetranychus sp. 
Petti t and Hutson (122) in 1931 reported that the red spider mite (belonging 
to the same. group as the Paratetranychus that was feeding on the Michigan holly, 
but distinct from it) infesting raspberry plants was finally controlled through 
the use of a Perrisol-soap solution (Derrisol about 1: SCO with Ivory soap 
U pounds to 100 gallons of water). As earlier tests in controlling this mite 
had apparently failed because of inadequate pressure* this application was made 
at a pressure of 200 pounds. 
Te.tranychus bi macula tus ilarv. 
See Hamilton (69)under Bryobia praetiosa, on page 13. 
Mclndoo, Sievers and Abbott (9^) in 1919 reported that derris applied as a 
dust was of no value against red spiders. 
"The California Agricultural Experiment Station (20) in 1923 stated that 
Derrisine (an extract of derris) was found to be inefficient against the red 
spider. 
De Ong and White (53) in I92U reported the results of tests with derris in 
v/hich a commercial derris extract of l6-percent concentration, diluted 1:300, 
gave a maximum control of 25 percent of the red spider. 
lienfest (91) in 1926 reported that lime-sulfur mixed with Derrisol will 
kill red spiders on citrus, . . 
