462 EXPERIMENT STATION RECORD. (Vol.37 



The cost of spraying' in tlie control of the pear thrips in British Columbia, 

 A. E. Cameeon, R. C. Trehebne, and E. W. White {Agr. Gaz. Canada, 4 (lyil). 

 No. 1, pp. 13-16). — These data are based upon spraying work in the spring of 

 1916 with hand and power outfits in which some 138 acres, comprising 11,569 

 bearing fruit trees of mixed varieties, were treated. 



The green apple bug- in Nova Scotia. W. H. Bbittain (Nova Scotia Dept. 

 Agr. Bui. 8 {1917), pp. 56. pis. 8, figs. 6). — This bulletin relates to a form pre- 

 viously described by Knight as Lyyus coinmunis novascotiensis (E. S. R.. 36. p. 

 550), one of the most serious pests of apples and pears in Nova Scotia. It 

 contains much data based upon work during 1916 in addition to that for 1915 

 noted from another source (E. S. R., 30, p. 457). 



" The young begin to emerge several days before the blossoms open, the 

 maximum emergence coinciding with the period of full bloom of the Bartlett 

 pear, or just as the Gravenstein blossoms begin to open. The nymphal stage 

 is of about 32 days duration. The adults l)egin to die off within a couple of 

 vk'eeks after reaching maturity, but are found in diminishing numbers through- 

 out the summer and early autumn. The winter is passed in the egg state, be- 

 neath the bark of the twigs. 



" The young bugs or nymphs are very active and elusive in their habits, and 

 us they increase in size, exhibit an incrcasetl tendency to drop to the ground. 

 Leaves, stems, blossoms, and fruit are freely attacked, but blossoms and fruit 

 are preferred. They are occasionally predacious in habit, and though ai> 

 parently fragile, can exist for sveral days without food and are able to make 

 their way over the ground for comparatively long distances. The adults are 

 active insects and strong fliers, though under ordinary conditions they do not 

 appear to wander far from the orchard in which they have develoi)etl. In 

 feeding, the adults prefer a diet of fruit, and that of pears is most attractive 

 to them wht'U they first reiab maturity." 



The spiny citnis white fly. — A potential pest of citrus trees, J. C. HuTSON 

 (Agr. Neics [Bnrbado.'i]. 16 (1917), A'o. 384, PP- iO, 11). — An account is here 

 given of Aleurucanthus icoylumi, a species recently described by Quaintance 

 and Baker (E. S. R., 35, p. 552), which is already attracting considerable at- 

 tention in Jamaica, the Bahama Islands, and Cuba. 



The author reports observations of the past in the Guantanamo Valley. Cuba, 

 where it was discovered in Augu.st. i;)15, attacking a few citrus trees in a 

 grove of about 8.O11O. During the course of an insiiection made in the early 

 months of 1010. it was found that this aleyrodid had spread so rapidly In the 

 infested grove that practically all the trees were infested. It wjis prevalent 

 in the neighboring town of Guantanamo. and an inspection of the main por- 

 tion of the valley showed that practically all the citrus trees within a well- 

 defined area of the valley and foothills were more or less infested by It. In 

 addition to attacking oranges and grapefruit, it occurs on other species of 

 citrus, mango, coffee, guava, sapodilla. star-apple, etc. 



The spiny citrus white fly and means for its control in Cuba {i^ec. .Agr. 

 Com. y Trnh., Com. Sanid. Vrg. Cuba. Cirr. 1 [1916], pp. 6). — This gives a brief 

 description of .\t( urotontliiis uoijlumi and nn'tbods of combating It. 



On the supposed varieties of Chry.omphalus dictyospermi, E. Malenotti 

 media. 12 {l'.>16). No. 1, pp. 109-123. figs. 6; abs. in Rev. Appl. Ent., Ser. A, 

 4 (1916), No. 11, p. 468). — The author takes the view that tliere are no true 

 varieties of C. dictyospermi, a scale which infests at least 80 different six-cles 

 of plants belonging to about 25 quite dissimilar families in both tropical and 

 temperate climates. 



