U. S. D. A., B. E. Bui. 80, Part VIII. D. F. 1. 1., November 28, 1910. 



PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



TESTS OF SPRAYS AGAINST THE EUROPEAN FRUIT 

 LECANIUM AND THE EUROPEAN PEAR SCALE. 



By P. R. Jones, 

 Engaged in Deciduous Fruit Insect Investigations. 



INTRODUCTION. 



Attention appears to have been first called in California to the 

 brown apricot scale by Mr. Alex. Craw° in 1891, at which time the 

 insect was described by him under the name Lecanium armeniacum. 

 The investigations of Mr. J. G. Sanders b while an agent of this Bureau, 

 however, have unmistakably shown that the brown apricot scale 

 of California is identical with Lecanium corni Bouche, known in 

 Europe since 1844, which Mr. Sanders has appropriately named 

 "the European fruit Lecanium." 



The European pear scale (Epidiaspis pyricola Del Guer.) was first 

 recorded as occurring in the United States by Prof. J. H. Corn- 

 stock in 1883, from Sacramento, Cal., under the preoccupied name 

 Diaspis ostreseformis. Since their introduction these two scale 

 pests have been the subject of considerable attention on account 

 of their injuries, and at the present time in the Santa Clara Valley 

 are by far the most important scale insects with which orchardists 

 have to contend. The European fruit Lecanium is now especially 

 abundant and the copious honeydew excreted by the scales upon 

 the leaves and fruit, with the accompanying sooty fungus, leaves 

 the fruit in an unsightly condition for market. 



In connection with other work in the deciduous fruit insect inves- 

 tigations of the Bureau of Entomology, carried on at the laboratory 

 at San Jose, Cal.; experiments have been made to determine an 

 effective treatment for both of these insects, with the results recorded 

 in the following pages. The work during 1908 was carried out by 

 Messrs. Dudley Moulton and Chas. T. Paine. 



aRept. Cal. State Bd. Hort., p. 12, 1891. 



&Journ. Econ. Ent., vol. 2, p. 443, 1909. 



c2d Kept. Ent. Dept. Cornell Univ., p. 94, 1883. 



147 



