233 



During the month there were bred a total of 14,925 of the following 

 parasites of fruit-flies : Teirastichus giffardi, Diachasma fullawayi and 

 D. tryoni. These and other parasites were distributed to a total of 

 14,819. The breeding of the mealy bug parasite, Paraleptomasiix 

 abnormis, was maintained, but none were liberated on account of the 

 heavy rains. 



WooDWORTH (C. W.). A new spray nozzle. — Jl. Agric. Research, 

 Washington, D.C., v, no. 25, 20th March 1916, pp. 1177-1182, 

 1 fig., 2 plates. 



A new principle has been discovered in nozzle construction. When 

 two streams meet across half their section, the resulting sheet of spray 

 will be of practically uniform thickness throughout, occupying a plane 

 45° from the plane of the streams and finally breaking up into drops 

 of great fineness and uniformity. This flat spray is comparable to the 

 hollow cone of spray from a cyclone nozzle as regards a uniform 

 distribution of the water, with the advantage of better aim proper to 

 the flat spray. The new nozzle allows some variation in the size of 

 the spray and can also be made into a long or short-distance nozzle. 

 It can be easily constructed by modifying existing nozzles and may be 

 adjusted if it becomes worn. The plates in this paper illustrate, from 

 kinematographic photographs, various phases in the production of 

 sprays from three kinds of nozzles. 



Pierce (W. D.). A new interpretation of the relationships of 

 temperature and humidity to insect development. — Jl. Agric. 

 Research, Washington, D.C., v, no. 25, 20th March 1916, 

 pp. 1183-1191, 2 figs. 



The effect of temperature on insect development has often been 

 inadequately recorded, especially the higher limits, largely owing to 

 the fact that most work on the subject has been done in the north 

 temperate zone where temperatures sufficiently high to affect develop- 

 ment do not occur, while it is only quite recently that attempts have 

 been made to correlate the humidity factor. The author used as 

 material the records of thousands of individual boll-weevils, Anthonomus 

 grandis and A. grandis thurberiae, obtained in Texas, Louisiana and 

 Arizona between 1902 to 1915. It is generally held that the activities 

 of a species reach a maximum of efficiency at a certain definite 

 temperature, but the author suggests a zone of humidities and tempera- 

 tures of more or less restricted area as more probable, and in the case 

 of the boll- weevil this lies near 83° F. and 65 per cent, relative humidity. 

 The relation of the stages of hibernation, activity and aestivation to 

 temperature, and the upper and lower fatal temperatures, have been 

 constantly recorded without reference to the humidity factor. A 

 diagram is given showing a combination of the temperature and 

 humidity records, which results in a series of concentric elliptical 

 areas, each of which represents a stage in the progress from maximum 

 efficiency to dormancy and death. Details are given as to the methods 

 of calculation used. One of the results of this method of record will 

 be the necessity for discarding the conception of separate zones of 

 aestivation and hibernation. The author has repeatedly noticed the 

 impossibiUty of differentiating between a boll-weevil larva killed by 



(C268) c 



