(>() ANNUAL REPORTS OF DEPARTMENT 01 AGRICULTURE, I 
Experiment Stations of California. Oregon, Washington, and Utah. 
In Washington it was conclusively proved thai three leafhop] 
Scaphytopius acutus, Fieberiella fiorii. and Keonolla confkiens, are 
vectors of the western X disease and little cherry disease. These three 
are in addition to the previously confirmed vector, the geminate Leaf- 
hopper, Colin, Inim. geminatus. The causal viruses have been trans- 
mitted from peach to peach, from cherry to peach, from chokecherry 
to peach, and from cherry to cherry. A tentative lead was obtained 
also in Washington that Gyponama kasta might be a fifth leafhopper 
\ ector of western K-disease virus. This latter species is considered to 
be of sparse distribution in area- thus far invaded by these dis 
More Effective Controls Developed for Pecan Pests 
Hickory shuckworm infestation in pecan shucks at harvest may be 
markedly reduced by means of late August and early September appli- 
cat ions of EPN and a few other insecticides, according to Held experi- 
ments in both Florida and Georgia. Under Florida conditions, in 
which 92 percent of the shucks on untreated trees were infested at 
harvest, the most effective control included three early- and two late- 
season applications of EPX. This treatment reduced infestation by 
45 percent. EPN was somewhat more effective than DDT and para- 
thion and much more so than Metacide. Under Georgia conditions. 
in which 73 percent of the shucks on untreated trees were infested at 
harvest, three Late-season applications of EPX reduced infestation to 
s percent. These late-season applicat ions were as effect ive as six appli- 
cat ions, three early and three late, or nine applicat ions made through- 
out the season. 
Dusts containing 1 percent parathion and 10 percent sulfur gave 
good control of the mite Tetranychus hicoriae on pecan when applied 
either with ground machinery or by airplane. It appeared more diffi- 
cult to obtain thorough coverage on large pecan trees with airplane 
application- of dusts than with either sprays applied by airplane or 
dusts applied with ground machinery. I lusts containing enough BHG 
to give 3 percent oi the gamma isomer and L2 percent of other isomers 
plus 1 ( » percent of sulfur gave good results against hicoriae. This 
treatment appeared to act more slowly against mature stages of the 
mite than concentrated parathion -prays and parathion-sulfur dusts. 
Dusting with 1 percent parathion was effective against the black 
pecan aphid over a period of several years in northwest Louisiana, 
Results obtained with parathion-sulfur dusts against hicoriou indicate 
that it will be possible to effect control of both of these pests through 
i he use of I his dust mixt ure. 
Vectors of Quick Decline Disease of ("itrus Sought 
Following the finding of "quick decline" or tristeza on Florida 
citrus, studies of possible insect vectors of the disease were Btarted at 
Orlando, Fla., in cooperation with plant pathologists of the Bureau 
of Plant [ndustry, Soils, and Agricultural Engineering. One natural 
grove transmission has \n-vw demonstrated from a mature diseased 
tree to a young lime seedling nearby. The rector responsible for this 
transmission could not be determined. Surveys of groves, both in 
central Florida and on the east coast, have disclosed three species of 
