50 



BULLETIN 536, U. S, DEPARTMENT OF AGRICULTURE. 



356 eggs hatched after a period of from 84 to 91 hours, 216 after 91 

 to 92 hours, 127 after 92 to 93 hours, 33 after 93 to 94 hours, 8 after 

 94 to 95 hours, 5 after 95 to 96 hours, and 3 after 104 to 106 hours. 

 Eighty-eight eggs hatched between 4 and 4.5 days after deposition 

 at a mean temperature of 68.7° F. 



Table XII. 



-Duration of the egg stage of the Mediterranean fruit fly at Honolulu under 

 normal conditions. 



Number 

 of eggs 

 under 



observa- 

 tion. 



Eggs deposited. 



Eggs hatched. 



Average 

 mean 



temper- 

 ature. 



350 



102 



695 



28 



3 



176 



243 



44 



90 



77 



63 



134 



128 



20 



12 



208 



79 



3 



47 



101 



10 



356 



216 



127 



33 



8 



5 



3 



437 



227 



Jan. 21-22, 4 p. m. to 10 a. 

 Mar. 9, 10 a. m. to 12 m. . . 

 Mar. 27, a. m. to 1 p. m . . 

 do 



.do. 

 .do. 



May 12-13, 3 p. m. to 12 m. 



do 



June 18, 1.30 to 3. 30 p. m. . 

 June 19, 10 a. m. to 1 p. m . 

 June 20, 9 a. m. to 4 p. m . . 

 June 24, 1.30 to 4.30 p.m.. 

 July 15, 3.30 to 4.30p.m... 



do 



do 



do 



Aug. 24, 10.30 to 11.30 a. m. 

 do 



do 



Sept. 9, 3 to 4 p. m 



Nov. 13-14, 4 p. m. to 9 a. 



do 



Dec. 15, 11 a. m to 1 p. m . 

 do 



Dec. 16, 11 a. m. to 1 p. m. 

 do 



Jan. 26, 6 a. m. to 3 p. m 



Mar. 12-13, 4.30 p. m. to 8 a. m . . 



Mar. 30, a. m 



Mar. 30, a. m., to Mar. 31, a. m.. 

 Mar. 31-Apr. 1, 9 a. m. to 8 a. m 



Apr. 1, 2 p. m. to 8 a. m 



May 15, a. m 



May 15-16, 2 p. m. to 8 a. m 



June 20-21, 6 p. m. to 8 a. m 



June 21-22, 6 p. m. to 8 a. m 



June 22-23, 6 p. m. to 7.30 a.m.. 

 June 26-27, 4.30 p. m. to 6 a. m . . 



July 17, 4.30 to 6 p. m 



July 17, 6 to 8 p. m 



July 17, 9 to 10 p. m : 



July 18, 10 a. m. to 4 p. m 



Aug. 26, 11.30 a. m. to 1 p. m. . . . 



Aug. 26, 1 to 2 p. m 



Aug. 26, 2 to 3 p. m 



Sept. 11, 3 to 9 p. m 



Nov. 16, 2 to 6 a. m 



Nov. 16, 6 to 11 a. m 



Dec. 18-19, 11 p. m. to 6 a. m. . . . 



Dec. 19, 6 to 7 a. m 



Dec. 19> 7 to 8 a. m 



Dec. 19, 8 to 9 a. m 



Dec. 19, 10 to 11 a. m 



Dec. 19, 11 a. m to 12 m 



Dec. 19, 8 to 10 p. m 



Dec. 19, 4 to 10 p. m 



Dec. 19-20, 10 p. m. to 6 a. m. . . . 



While eggs hatch in from 2 to 6 days after deposition in any fruit- 

 growing section in the Hawaiian Islands, they may require a much 

 longer period for development under colder weather conditions. In 

 the course of experimental work, the writers have secured data 

 showing that under varying conditions of temperature the duration 

 of the egg stage may be extended to at least 25 days. In Table XIII 

 data of special interest, as indicating how dependent embryonic 

 development is upon temperature, are recorded. 



All of 131 eggs one day old when placed at Puulehua, where the 

 temperature ranged between 39° and 89° F., with a mean of about 

 52° F., were still unhatched after 16 days at Puulehua, after which 

 they were taken to Kealakekua, where they hatched the following 

 day, or when 18 days old. 



Twenty-three eggs deposited in apples at Kealakekua, Kona, 

 Hawaii, at about 1,100 feet elevation, on February 9-10, 1915, and 

 taken on February 11 to the summit of Hualalai, 8,250 feet eleva- 



