﻿16 



BULLETIN" 1393, XT. S, DEPAETMENT OF AGRICULTURE 



Table 2. — Data concerning period of oviposition and adult longevity of the granary 



weevil 



No. 



Date 

 weevil 

 emerged 



Date 

 first egg 

 was laid 



Length 

 of pre- 



oviposi- 



tion 



period 



Date 

 last egg 

 was laid 



Length 

 of ovi- 

 position 

 tion 

 period 



Number 



of eggs 



laid 



Date of 

 death 



Length 

 of life 



1 



1920 

 Feb. 26 

 —do --- 



1920 

 Mar. 19 

 Mar. 18 

 Mar. 24 

 Mar. 20 

 Mar. 19 

 June 2 

 June 23 



Aug. 27 

 Sept. 4 



1921 

 Mar. 3 

 Feb. 24 



Sept. 18 

 Sept. 19 

 Sept. 15 

 Sept. 18 

 Sept. 15 



1922 

 Feb. 2 

 Jan. 28 

 Jan. 31 

 Feb. 1 

 Jan. 30 

 Feb. 1 



...do 



Feb. 2 

 Feb. 1 



.--do 



Feb. 2 

 Jan. 31 

 Feb. 5 

 Jan. 31 

 Feb. 1 

 Mar. 10 

 Feb. 18 

 Mar. 19 

 Mar. 6 



Days 

 22 

 21 

 27 

 23 

 22 

 8 

 6 



12 

 11 



137 

 130 



13 

 13 



9 

 12 



9 



148 

 95 

 98 

 99 

 97 

 99 

 99 

 100 

 99 

 99 

 100 

 98 

 103 

 98 

 99 

 123 

 102 

 131 

 118 



1920 

 June 14 

 May 29 

 June 11 

 — do- — 

 Aug. 30 

 Aug. 31 

 Sept. 15 



1921 

 June 10 

 Apr. 10 



June 30 

 July 22 



1922 

 Apr. 21 

 May 12 

 June 12 

 May 8 

 June 7 



May 7 

 Sept. 24 

 Apr. 21 

 July 24 

 June 5 

 July 28 

 June 9 

 July 7 

 May 27 

 Apr. 20 

 June ■ 9 

 June 26 

 Aug. 2 

 May 29 

 Apr. 13 

 June 14 

 Aug. 6 

 May 25 

 June 5 



Bays 

 87 

 72 

 79 

 83 

 164 

 90 

 84 



287 

 • 218 



119 

 148 



215 

 235 

 270 

 232 

 265 



94 

 239 



80 

 173 

 126 

 177 

 128 

 155 

 115 



78 

 127 

 146 

 178 

 118 



71 



96 

 169 



67 



91 



152 

 172 

 150 

 140 

 247 

 148 

 170 



254 



77 



141 



144 



65 

 71 

 145 

 128 

 130 



98 

 197 



36 

 135 

 126 

 234 

 181 

 184 



74 

 114 

 200 

 177 

 166 

 210 



95 

 130 

 242 



78 

 108 



1920 

 June 18 

 June 15 

 June 23 

 June 18 

 Sept. 1 

 Sept. 2 

 Sept. 20 



1921 

 June 27 

 May 18 



Sept. 15 

 Aug. 20 



1922 

 Apr. 25 

 May 24 

 June 30 

 May 15 

 June 16 



May 25 

 Oct. 8 

 May 1 

 Aug. 4 

 June 9 

 July 31 

 June 12 

 July 17 

 July 10 

 May 1 

 June 12 

 Aug. 7 

 Aug. 23 

 June 5 

 Apr. 20 

 July 21 

 Aug. 14 

 June 1 

 July 5 



Days 

 113 



2 



110 



3 



-_do 



118 



4 



...do- 



113 



5 



.-.do 



188 



6 



May 25 

 June 17 



Ang. 15 

 Aug. 24 



Oct. 17 

 do- .- 



100 



7 



95 



8 



316 



9 



267 



10 



333 



11 



307 



12 - 



1921 

 Sept. 5 

 Sept . 6 

 --do 



do 



232 



13 



260 



14 



15 



297 

 251 



16 



.do 



283 



17 



Sept. 7 



Oct. 25 



do .. 



260 



18-- 



348 



19 - 



188 



20 



.. do 



283 



21 



22 



23 



24 - 



—do 



—do 



...do 



do 



227 

 279 

 230 

 265 



25 



26 



27 



28.. 



—do 



—do 



-..do— - 

 do 



258 

 188 

 230 

 286 



29 



30 



31 -. 



32 



...do 



-..do 



---do 



Nov. 7 

 Nov. 8 

 -. do 



302 

 223 



177 

 256 



33 



279 



34 



205 



35 — - 



...do 



239 



METHOD OP EGG LAYING 



The beetles lay their eggs •within the seeds of most of our coniinon 

 grains. A hole is excavated within the grain equal to the length of 

 the slender proboscis of the female. Wlien this is completed to the 

 satisfaction of the beetle, she withdraws her proboscis and turning 

 around swings the abdomen about until the cavity is located. The 

 ovipositor is then thrust into the cavity and an egg deposited. 



Before the ovipositor is withdrawTi a translucent mass of gelat- 

 inous material is discharged on top of the egg and is tamped down 

 level with the surface of the seed. This plug of gelatinous material 

 quickly hardens, holding the egg in place and forming a protective 

 covering for it. 



The eggs are laid in all parts of the seeds but usually near one end. 

 It is probably mechanically easier for the weevil to bore a hole at 

 either end of the seed, owing to the need of a good foothold during 

 the operation. 



