ECONOMIC ZOOLOGY ENTOMOLOGY, ■ 265 



turn yellow and drop early, while the fruit is small often not maturing suffi- 

 ciently to be salable. The mite passes the winter in the ground, within 10 ft. 

 of the base of the affected trees, and usually near to the trunk. The eggs are 

 deposited chiefly on the under surface of the leaves. In 1909, hibei'nation be- 

 gan as early as August 9, myriads of the mites being found in the ground at 

 Palisade on that date. 



The lace-winged flies and a small black species of lady beetle (Seymmisi puiic- 

 tum) are mentioned as natural enemies. 



The sulphur spi-ay as mentioned for the brown mite is recommended for use 

 in comI);iting this pest in summer. 



Arachnida of Cuba, N. Banks (Estac. Cent. Agron. [C»6rt] Rpi. (English 

 Ed.), 2 (1905-1909), pt. 2, pp 150-11.',, pi. /).— In this paper 100 species are re- 

 corded from Cuba and 10 others have previously been recorded from the island. 

 Of these species 16 are described as new, 5 of the new forms being among the 

 daddy-long-legs. The author believes that 200 or 300 species will be found in 

 the Island. 



Fumigation scheduling, C. W. Woodworth (California 81a. Circ. 50, pp. 2-',, 

 figft. l.'i, cliarts 3). — The author first discusses the development of methods for 

 determining the tented space as re(piired in the fumigation of citrus fruit trees. 

 If the tent or tree is calculated as a regular figure, the volume may be reckoned 

 from any combination of any two of its four dimensions except the circumference 

 and diameter. All of these dimensions may be determined optically from the 

 ground except the circumference, and all of them can be measured directly. 



The author refers briefly to direct measurements, which may be made l)y 

 pacing, by the use of a pole, or by a tape. The distance over the tree is con- 

 sidered to be best secured by graduating the tent and making it in effect a tape. 



Optical methods are based upon the comparison of similar triangles and de- 

 pend upon the fact that the sides of such triangles are exactlj- proportional to 

 each other. Four methods are suggested as available for optical measurement. 

 These consist in the application of the principle of the photo camera, the magic 

 lantern, displacement mirrors, and direct vision. 



Two methods of direct vision are recommended for use. one. more accurate 

 for experimental work, the other very rapid for practical fumigation. The 

 first or so-called accurate method depends upon the use of a tape to measure the 

 distance from the tree to the scheduler. The apparatus used consists of a 

 sighting diagram, and a specially graduated tape reading in oiuices. A dif- 

 ferent diagram is required for each different basis of calculation. " The proc- 

 ess of measuring a tree when done by one person consists in attaching one end 

 of the tape to the nearest point on a tree or tent, then backing off until the 

 width of the tree just fills the diagram. If the top of the tree also corresponds, 

 the graduation on the tape indicates the oiuices that should be used. A series 

 of marks on the diagram indicates the amount to add or subtract for high or 

 low trees." The most convenient means of holding the chart at a constant 

 distance from the eye is by the use of a light wire around the hat band, the end 

 of the wire being bent into a hook against which the chart will I'est when mak- 

 ing an observation. 



The apparatus u.sed in the second or so-called rapid aiethod consists of an 

 arrangement for holding at a constant distance from the face a loop or steel 

 wire, which can be so bent as to conform with the shape of the tree, being 

 adjustable both for height and width. In order to obtain uniform readings 

 with this instrument, it i.s necessary to hold the chart at a constant distance 

 from the eye as with the so-called accurate method, and one must also stand at 

 a uniform distance from. the tree to be measured. In the two methods of 

 measurement described, a difference iu dosage is provided for in the adjust- 



