271 



tested, the larvae being killed only by a 70 per cent. dose. The most 

 efficient means of control is the appUcation of water under high pres- 

 sure, emphasis being laid on the necessity for thorough appUcation. 

 The pressure should not be less than 175 lb., while considerably higher 

 pressure would be advantageous. The form of stream used should 

 be such as to give a spread of not more than 6 or 8 inches at a distance 

 of 6 feet from the nozzle. From 50 to 100 U.S. gals, are necessary to 

 clean a medium- sized tree. Treatment should be repeated whenever 

 the injury produced by the insect becomes sufficient to warrant the 

 expense. Other spraying materials mentioned are kerosene emulsion, 

 distillate emulsion, kerosene-Hme mixture and carbohc acid emulsion. 

 Kerosene-lime mixture, prepared according to the formula, kerosene 

 (42° Be.) 20 gals., unslaked lime, 40 lb., and water, 200 gals., has been 

 found to be the most satisfactory of all composition sprays tested, and 

 is to be recommended in cases of heavy infestation in which the use 

 of large quantities of water is not possible. The use of Ume instead of 

 soap is found to increase the penetrating and adhesive power of the 

 spray, so that a thorough washing or brushing of the fruit must follow 

 each application [see also this Review, Ser. A, ii, pp. 434-437, and iii, 

 p. 621]. 



BiOLETTi (F. T.). Control of Raisin Insects.-— California Univ. Agric. 

 Coll., Berkeley, Circ. no. 134, July 1915, 11 pp., 6 figs. [Received 

 8th May 1916.] 



Stored raisins are liable to attack by various insects, the most com- 

 mon being the Indian meal moth [Plodia interpunctella]. This species 

 is abundant in summer and autumn ; the eggs are laid on the outside 

 of exposed fruit or in cracks in the packing boxes, and the larvae feed 

 on the outside of the fruit until mature. Pupation takes place within 

 a cocoon, the average duration of the pupal stage being 16 days at 

 80° F. At 70° F. the duration is more than 32 days. Winter is passed 

 in the pupal or larval stage, according to the temperature. The fig 

 moth [Ephestia cautella] is less abundant than the preceding species, 

 but is similar in habits. The saw-toothed grain beetle [Silvanus 

 surinamensis] is present throughout the year, though not in large 

 numbers. The rust-red flour beetle [Triboliiim castaneum] is 

 occasionally found. Infestation of a packing house is due primarily 

 to insects brought in on the raisins from the vineyard or other storing 

 place. Insects removed in cleaning can be prevented from escaping 

 by the use of a moveable frame, having on its under side a cloth pad 

 saturated with coal oil or crude carbohc acid, which can be fitted over 

 the edge of the refuse box. The contents of the box as well as all 

 refuse of stems and injured fruit should be burned, especially between 

 March and September, when breeding is rapid. More perfect control 

 can be obtained by methods aiming at the complete prevention of 

 multiplication in both vineyard and packing house. All raisins should 

 be removed from the vineyard by 1st May ; this will prevent breeding 

 during the summer. These methods will prevent infestation in the 

 packing house during the early part of the season. From February 

 to April no raisins should be kept in the house for more than four days, 

 and then only in quantities sufficient for current needs. Fumigation 



