260 



twig to twig and feeding a little in each. Many of them pupate in 

 the dead leaves found fastened at the tip of the twig. The duration of 

 the larval stage at Corvallis is from 10 to 11 months, and of the pupal 

 stage, from 8 to 12 days. The results of spraying experiments 

 conducted in 1914 are given in a table, and after an application of 

 arsenate of lead, 2-50, and lime-sulphur, 1-12, only 0"1 of the buds were 

 destroyed by the pest. Contrary to the opinion of W. T. Clarke {Cat. 

 Agric. Expt. Sta., Bull. 144, 1902), who recommends the application 

 in the spring just as the buds are swelling, it was found that the 

 lime-sulphur is effective at any time until the buds open. 



Wilson (H. F.). An Apple Leaf Miner, Phyllonorycter {Lithocolletis) 

 crataegella, Clem.; pp. 119-120, 1 fig. 



This insect is quite common throughout the orchards of Western 

 Oregon, where it has become well established on the apple ; apparently 

 its native food-plants are the native ha\\'thorn and wild crab-apple. 

 Hundreds of leaves on a single tree may have from one to a dozen 

 mines, but exactly how much injury results cannot be estimated. 

 Although the vitality of the trees must be more or less decreased, it 

 does not seem that they have suffered in any appreciable degree. 

 The mines vary in size and, except that they are always included 

 between two of the larger cross veins, are not at all regular. The 

 number of generations a year is not definitely known, but if the 

 supposition that there are two be correct, the winter is spent in the 

 pupal stage and the adults emerge in the spring. The eggs are probably 

 laid on the underside of the leaves, and pupation apparently occurs 

 within the leaf. Control measures, so far as known at present, consist 

 of ploughing the dead leaves under so as to bury the pupae deep 

 enough to prevent the emergence of the adults. Arsenate of lead, 

 applied to the under sides of the leaves, may prove efficient, but it is 

 not thought that this insect is a sufficiently serious pest to warrant 

 special spraying. 



Wilson (H. F.). A New Cherry Pest, Simplemphytus pacificus, 

 MacGillivray ; pp. 121-122, 1 fig. 



This sawfly has only recently been discovered [see this Review, 

 Ser. A, iii, p. 77] and very little is known of its life-history. During 

 the winter of 1913, it was said to be causing some little damage 

 to cherry trees, but it was found that, while some damage might 

 result from the burrows made, the insect in itself was not a serious pest, 

 the chief danger being from such fungus diseases as may settle in the 

 open burrows after the insect emerges. Continued studies show that 

 the larvae bore down the pith of stubs left from pruning, and except 

 in cases where the stubs are short, they do not bore below the junction 

 of the nearest branch. Where the stubs are longer than the pupating 

 burrow, the insect does not work down to the first shoot. Knowledge 

 of the habits of this insect begins with its migration to the cherry stub 

 in the autumn ; as the insect is always found with its head towards 

 the opening, and as the burrow is only slightly larger than the insect 

 itself, the insect must make the burrow and then back into it. After 

 turning about in the burrow, the insect, now a mature larva, constructs 

 a partition across the burrow just beyond its head ; this partition 



