956 EXPERIMENT STATION RECORD. 



The author here reports the results of investigations made during 190.S at 

 Lakeside, Ohio. 



The adults are said to produce the primary injury to healthy trees, the work 

 of the larvje being secondary. Healthy trees by repeated attacks of the adults 

 are reduced to a condition favorable to the formation of egg burrows. When 

 the beetles are ready to hibernate in the fall they fly to the healthy trees and 

 form their hibernation cells. These cells are injurious to the trees, since 

 through each cell there is a flow of sap during the following season. When 

 the beetles come out of hibernation they bore into the bark of healthy trees 

 from i to ^ in. either for food or to form egg burrows, many small channels 

 being thus formed in the bark. It is estimated that iu some instances from 1 to 

 3 or more gallons of sap flows from a single tree during a season. 



A description is presented of the life history of the pest. No parasites have 

 as yet been discovered. The details of experiments with remedies are reported. 

 It is recommended that trees severely injured be i)runed back and given an 

 application of barnyard manure or conuiiercial fertilizer. A thick coat of white- 

 wash should be applied 3 times during the season, the first to be made the 

 last week in March, the second the second week in July, and the third about 

 the first of October. Healthy trees but slightly attacked should be jiainted with 

 a thick coat of whitewash 3 times each season as prescribed for severely injured 

 ones, the applications to be made to the trunk and larger limbs. The whitewash 

 thus applied just prior to the emergence of the beetles acts as a repellant. The 

 addition of table salt at the rate of i lb. to a pail of whitewash makes the white- 

 wash more adhesive. It is recommended that all dead or nearly dead limbs 

 and trees be removed as fast as they appear iu the orchard, thus destroying the 

 breeding places. 



A bibliography is appended. 



The orange thrips, D. Moulton (U. S. Dept. Agr., Bur. Ent. Bui. 12, tech. 

 ficr., pt. 7, pp. 119-122, pi. 1). — The author presents a description of Euthrips 

 citri, a species new to science which has become a very important orange 

 pest in the .southern San Joaquin Valley of California. Curled and thickened 

 leaves and scab-like markings on the oranges have been known for from 10 to 

 15 years, but these injuries have only recently been attributed to the thrips. 

 While the quality of the fruit does not appear to be afl'ected, yet as oranges 

 are graded and sold largely on appearance, many thousands of dollars have 

 been lost annually. 



There are apparently two broods of E. citri. " Adults of the first brood appear 

 just before the blossoms in February, March, and April, and a second brood 

 appears in July, August, September, and October. Adults and larvte of the first 

 brood feed on the small oranges just as the petals are being thrown off, the 

 larvje usuallj^ under the protection of the sepals, and on the first growths of 

 the foliage. The second brood feeds on the nearly mature oranges and on the 

 third and fourth growths of the foliage. All varieties of oranges and lemons 

 are attacked, but the very noticeable scabbing on the fruit is common only on 

 the navel orange; it is less conspicuous on the Valencia." That the thrips are 

 not so prevalent on trees planted in sedimentary or loam soils as where the soil 

 is of a clayey or adobe texture is explained in the protection afforded by the 

 latter soil to the larval, pupal and early adult life stages, which are presumably 

 passed in the soil. 



A strong tobacco extract and the cheaper soap washes are suggested as 

 remedies. 



The citrus whitefly of Florida consists of two species, E. W. Berger (Jour. 

 Econ. Ent., 1 {1908), Vo. ;>, pp. 32-). S2.'i). — The author considers the citrus 

 whitefly of Florida to represent two distinct and well-defined species. 



