ECONOMIC ZOOLOGY — ENTOMOLOGY. 453 



" Experiments with infested ripe apples show that the San Jose scale may- 

 live and reproduce freely on such fruits plucked from the tree and kept at 

 ordinary room temperatures, and that living young may continue to be born 

 under such conditions during a period of eight weeks. Infested apples taken 

 from cold storage in December gave similar results, young being produced on 

 these apples for 25 days. 



" Exact breeding experiments conducted at Urbana in 1906 in a way to dis- 

 tinguish throughout the season the descendants of the first born from those of 

 the last born of each generation, gave two successive generations of the hist- 

 born series in the complete year and four such generations of the first-born 

 series. A computation based on data thus obtained yielded a possible rate of 

 multiplication under optimum conditions of 32,791,472 to 1 for the year. This 

 total is only the ninety-eighth part of that of other investigators, who took no 

 account of diminished numbers of generations x^roduced by late-born individuals. 



" Spraying operations with various preparations of lime and sulphur and 

 with two brands of miscible oils justify the usual preference for the sulphur 

 solutions, especially because of their more prolonged effect when applied in 

 spring. The homemade solutions were equally effective with those ready- 

 made, requiring only dilution for use. These experiments also Illustrate the 

 great advantage of early spraying, before an orchard becomes heavily Infested, 

 and furnish evidence that spraying in spring is much more effective than spray- 

 ing in fall, the ratios of benefit being some 20 per cent greater. The possibility 

 of redeeming and restoring a badly Infested orchard and maintaining It in good 

 condition, with one or two sprayings a year, was well established by these 

 operations." 



Food plants of the gipsy motli in America, F. H. Moshee (Z7. S. Dept. Agr. 

 Bui. 250 (1915), pp. 39, pis. 6). — This is a report upon investigations conducted 

 during the years 1912, 1913, and 1914, with a view to determining the favorite 

 food plants of the gipsy moth. A brief statement is given of the i*esults secured 

 with each plant tested. The work leads to a division of the food plants into 

 four classes: (1) Species that are favored food for the gipsy moth ; (2) species 

 that are favored food for the gipsy moth after the early larval stages; (3) 

 species that are not particularly favored, but upon which a small proportion of 

 the gipsy moth larvae may develop; and (4) species that are unfavored food 

 for the gipsy moth. The species in the first of these classes are at present 

 the dominant species in the woodlands in the area now infested with the gipsy 

 moth, but the encouragement of coniferous growth is recommended, provided 

 the class (1) trees can be eliminated. 



The sugar cane moth stalk borer (Diatraea saccharalis), T. H. Jones (Porto 

 Rico Bd. Agr. Expt. Sta. Bui. 12 (1915), pp. 30, pU. 3, fig. 1). — ^A summarized 

 account of this borer, which is distributed throughout Porto Rico, its biology, 

 control measures, etc. A report of investigations of the injury by this pest in 

 Porto Rico by Van Dine has been previously noted (E. S. R., 27, p. 659). 



Two parasitic enemies occur in Porto Rico, one an egg parasite (Tricho- 

 gramma minutum), the other a tachinid fly, probably Hypostena sp. A parasitic 

 fungus (Cordyceps 'barheri) attacks the larva and pupa. 



" The preventive methods of control advised to reduce injury by the borer 

 include planting of noninfested ^eed, simultaneous planting and harvesting of 

 large areas of cane land, and clean cultivation before and after planting. The 

 remedial measures of control Include the collection of egg clusters and the cutting 

 out of dead hearts. The burning of trash as a means of reducing injury is not 

 to be recommended and the use of trap lights as a means of capturing the adults 

 does not seem advisable. At the time of harvesting, all stalks cut in the field 



