894 



SCIENCE 



[N. S. Vol. XXVIII. No. 729 



secretary, Dr. Lorande Loss Woodruff, Yale Uni 

 versity. New Haven, Conn. Central Branch, De 

 cember 28-30. President, Professor E. A. Birge; 

 University of Wisconsin; acting secretary, Pro 

 fessor Thomas G. Lee, University of Minnesota, 

 Minneapolis, Minn. 



The Entomological Society of America. — De- 

 cember 29, 30. President, Professor W. M. 

 Wheeler, Harvard University; secretary, J. 

 Chester Bradley, Cornell University, Ithaca, N. Y. 



The Association of Economic Entomologists. — 

 December 28, 29. President, Professor S. A. 

 Forbes, University of Illinois; secretary, A. F. 

 Burgess, Washington, D. C. 



The Botanical Society of America. — December 

 29-31. President, Professor W. F. Ganong, Smith 

 College, Northampton, Mass.; secretary, Professor 

 D. S. Johnson, Johns Hopkins University, Balti- 

 more, Md. 



American Nature Study Society. — December 30, 

 31. President, Professor L. H. Bailey, Cornell 

 University; secretary. Professor M. A. Bigelow, 

 Teachers College, Columbia University, Nev? York 

 City. 



Sullvvant Moss Chapter. — President, Dr. T. 

 C. Frye, Seattle, Wash.; secretary, Mr. N. L. T. 

 Nelson, St. Louis, Mo. Address: Mrs. Annie Mor- 

 rill Smith, 78 Orange St., Brooklyn, N. Y. 



Wild Flower Preservation Society. — President, 

 Professor Chas. E. Besaey; secretary. Dr. Charles 

 Louis Pollard, New Brighton, N. Y. 



The American Psychological Association. — De- 

 cember 29-31. President, Professor G. M. Strat- 

 ton. University of California; secretary. Professor 

 A. H. Pierce, Smith College, Northampton, Mass. 



The American Philosophical Association. — De- 

 cember 29-31. President, Professor Hugo Miinster- 

 berg. Harvard University; secretary, Professor 

 Frank Thilly, Cornell University, Ithaca, N. Y. 



Southern Society for Philosophy and Psychol- 

 ogy. — Convocation week. President, Professor J. 

 MacBride Sterrett, The George Washington Uni- 

 versity; secretary, Professor Edward Franklin 

 Buchner, The Johns Hopkins University, Balti- 

 more, Md. 



The American Anthropological Association. — 

 December 28-January 2. President, Professor 

 Franz Boas, Columbia University; secretary. Dr. 

 Geo. Grant MacCurdy, Yale University, New 

 Haven, Conn. 



The American Folk-lore Society. — ^Week of De- 

 cember 28. President, Professor Koland B. Dixon, 

 Harvard University; secretary. Dr. Alfred M. 

 Tozzer, Harvard University, Cambridge, Mass. 



SOCIETIES AND ACADEMIES 



THE BIOLOGICAL SOCIETY OF WASHINGTON 



The 446th meeting was held October 17, 1908, 

 with President Stejneger in the chair. A paper 

 on " The Pear Thrips Problem in California " was 

 read by Mr. A. L. Quaintance. The so-called pear 

 thrips (Euthrips pyri Daniel) first came to notice 

 in the spring of 1904 in the Santa Clara Valley in 

 California. Since its first appearance, its in- 

 juries have constantly increased, and it has now 

 spread to the principal deciduous-fruit growing 

 regions in the San Francisco Bay region. The 

 losses brought about by the pear thrips the past 

 year have been perhaps not less than half a mil- 

 lion dollars. 



The insect was first investigated by Mr. Dudley 

 Moulton, beginning in 1904, at that time Santa 

 Clara County entomologist, and a fairly complete 

 account of it was published in a bulletin from 

 the office of the state commissioner of horticulture. 

 The increased destruetiveness of the thrips led to 

 provision by congress for an investigation of the 

 insect by the Bureau of Entomology, and Mr. 

 Moulton, who in the meantime had been employed 

 by the bureau, was assigned to the work beginning 

 July 1, 1907, with headquarters at San Josfi, Cal. 



The pear thrips attacks various deciduous fruits, 

 as almond, apricot, peach, prune, cherry, pear, 

 apple, etc. The life history is briefly as follows: 

 Early in the spring, as in late February or early 

 March, the adult thrips begin to make their ap- 

 pearance from the soil, at once attacking the 

 opening buds or blossoms, and by their feeding 

 soon cause these to blight, literally nipping the 

 fruit crop in the bud. Oviposition occurs soon 

 after emergence, the eggs being placed in soft 

 tissues, especially fruit and leaf stems or in the 

 midribs of leaves. The young larvse feed upon the 

 tender tissues of the leaf or flower, requiring some 

 three or four weeks to reach their full size. They 

 then leave the plants and work their way below 

 the soil from three to four or even ten to twelve 

 inches, depending upon whether this is hard or 

 soft, as resulting from frequent cultivations. In 

 the soil, the thrips larvae construct small oblong 

 cells where they remain the balance of the season. 

 In late fall and early winter, transformation to the 

 pupa stage occurs, from which the adults develop, 

 to appear above groxmd about the time fruit trees 

 are beginning to bloom in the spring. There is 

 thus but one generation each year, and the insect 

 spends practically ten months in the ground. 



The pear thrips has proved to be a very difficult 

 insect to combat, and its practical control has not 



