760 EXPERIMENT STATION RECORD. [Vol.43 



set out, about a teacupful being poured around each plant. In using the oakum 

 a small amount was pressed about the base of the plant. The tar-felt disk, 

 which has in the past been found the best preventive, gave a slightly larger 

 number of heads in 1918, but the other methods were easier to follow. From 

 60 plants set out on May 25 for each method, 52 marketable heads were obtained 

 from the oakum plat, 54 from the tar-felt paper disk plat, 47 from the cori'osive 

 sublimate plat, and 21 from the improtected plat. / 



The life histories of some Kansas Lachnosterna, W. P. Hayes {Jour. 

 Econ. Ent., IS {1920), No. 3, pp. 303-S18, figs. 2).— "The life histories of seven 

 species of Lachnosterna, found in the vicinity of Manhattan, Kans., are herein 

 considered. Five of these, L. crassissima, L. rubiginosa, L. futilis, L. rugosa, 

 and L. impUcata, in the order named, are the most abundant in this locality. 

 The other two, L. vehemens and L. suhmucida, ranked eighth and sixteenth, 

 respectively. Their flight periods begin about April 18 and may last, as in the 

 case of L. suhmucida, until August 17. 



" The egg stages were found to average from slightly over 14 to 29.8 days. 

 The larval period varied, 2 and 3 year life cycles occurring for the five impor- 

 tant species. Only a 3-year cycle was observed in the case of L. vehemens, and 

 grubs now living in rearing cages indicate a 3-year cycle for L. suhmucida, 

 besides the 2-year cycle discussed. The prepupal stage averaged from 6.6 to 9 

 days for the 'different species, and the mean pupal stage varied from 21.9 to 

 30.5 days. The averages of the 2 and 3 year life cycles for the different species 

 were 478.3 and 807.7 days for L. crassissima, 475.9 and 805.3 for L. ruhiginosa, 

 462 and 827 for L. futilis, 461.3 and 813.9 for L. rugosa, 411.7 and 750.7 for L. 

 impUcata, and 845 days for L. vehemens. L. suhmucida pupates in the spring 

 instead of the fall, and thus a 2-year cycle is produced which nearly equals the 

 period of development of the 3-year individuals. The average period for the 

 species was slightly over 711 days. 



"A list of food plants of the adults and situations apparently preferable to 

 the grubs are given, as is also a list of natural enemies found or reared during 

 this study." 



Roundheaded apple tree borer: Its life history and control, F. E. 

 Beooks {U. S. Dept. Agr. Bui. 8^7 {1920), pp. ^2, pis. 9, figs. 7).— This is a 

 report of investigations conducted from 1911 to 1918 at a field station at French 

 Creek, W. Va., also at Elkins, Pickens, Weston, and Great Cacapon, W. Va., 

 Demorest, Ga., Biltmore, N. C, Winthrop, Me., and Munising, Mich. This borer 

 is a native American insect which has been recognized as a serious pest of the 

 apple, pear, and quince since the early days of orcharding in this country, 

 occurring as it does in the United States and Canada over most of the apple- 

 growing east of the Rocky Mountains. 



" In addition to the cultivated fruits named, it breeds also in such wild trees 

 as wild crab, hawthorn, mountain ash, and service. These native trees growing 

 in woods or neglected fields often serve as centers in which the adults develop, 

 and from which they fly to near-by orchards to deposit their eggs. In the woods 

 and in orchards the insect is inclined to colonize, families or communities living 

 in the trees of somewhat restricted localities. Often infestation in an orchard 

 or in native woods will be confined for years to rather definite areas or spots. 

 This habit is due largely to the inclination of the adult female to deposit her 

 eggs near the place where she developed. . . . 



"About 95 per cent of the eggs from which the borers hatch are deposited in 

 the bark within a few inches of the ground. The incubation period is about 16 

 days. The borers feed in the bark and wood for from one to four years and 

 finally pupate at the end of an ascending gallery which extends up the trunk 

 from a few inches to approximately 2 ft. above the ground. The burrows made 



