BULLETIlSr 436, U. S. DEPAETMEISTT OP AGRICULTURE. 



Table I. — Combined length of egg, lannl, and pupal stages of the desert corn flea-beetle 

 {Chaetocnema ectypa) at Tevipie, Ariz., 1915. 



Cage No. 



Date 

 adults 

 placed 

 in cage. 



Date 



adults 



removed. 



Average 



date of 



oviposi- 



tion. 



New adults 

 emerged. 



Com- 

 bined 



length 

 of 



stages. 



Aver- 

 age 

 mean 

 tem- 

 pera- 

 ture. 



Date. 



No. 



T90 



Mar. 12 

 ...do 



Mar. 19 

 ...do.... 



Mar. 16 

 ...do.... 



...do 



May 13 

 (May 6 

 ■^May 14 

 [May 20 

 /May 13 

 \May 20 



...do 



/Jime 10 



iJtme 30 



/Jime 26 



\July 3 



June 26 



June 25 



June 26 



■ June 28 



June 30 



July 3 



/Jime 26 



June 30 



/June 25 



■June 26 



July 16 



•July 17 



July 20 



..do 



July 21 

 July 23 

 Aug. 23 

 Aug. 24 

 Aug. 25 

 /..do.... 

 \Aug. 26 



2 

 2 

 1 

 2 

 3 

 1 

 3 

 2 

 2 

 2 

 2 

 2 

 3 

 5 

 2 

 2 

 4 

 4 

 2 

 1 

 3 

 4 

 2 

 2 

 2 

 5 

 2 

 2 

 6 

 3 

 3 

 1 



Days. 

 58 

 51 

 59 

 65 

 58 

 65 

 34 

 43 

 63 

 59 

 66 

 31 

 30 

 31 

 33 

 35 

 38 

 30 

 34 

 29 

 30 

 24 

 25 

 28 

 28 

 29 

 31 

 32 

 33 

 34 

 34 

 35 



° F. 

 64 

 64 

 64 

 64| 

 64 

 64| 

 65 

 71 

 74J 

 73§ 

 75 

 791 



m 



79J 



791 



80 



80f 



80 



80| 



80 



80 



84J 



842 



84f 



84f 



84| 



85 



86 



86 



86 



86 



86 



T91 



T92. 



...do 



...do 



T. 117. 



Apr. 12 

 Apr. 26 



...do 



Apr. 19 

 Apr. 30 



...do 



Apr. 16 

 Apr. 28 



...do 



T 136 



T137 



T170 



May 25 

 ...do.... 



May 26 

 ...do 



May 27 

 ...do.... 



May 28 

 ...do.... 



Jime 24 

 ...do 



May 26 

 ...do.... 



May 27 

 ...do.... 



June 22 

 ...do 



T 171 



T173 



T175 





June 21 

 ...do 



T194 



T358 



July 21 

 ...do 



July 24 

 ...do 



July 22 

 ...do 



T3S9 



Total and average 









82 



37.50 















THE EGG. 



The eggs are deposited at or near the surface of the ground, either 

 on the stem of the host plant just below the surface of the ground, 

 and within the soil, or, as was found by Mr. Wilson, on the old shell 

 of the seed from which the plant germinated. They are usually de- 

 posited singly, but six or more may be placed at one location and at 

 the same time. It was very difficult to make observations upon the 

 natural place of oviposition under normal conditions because of the 

 minuteness of the eggs and the consequent inabihty to see them unless 

 the ground in which they were placed was very dark in color. In 

 confinement beetles deposited eggs quite readily through cheesecloth 

 upon any object which might be underneath, providing the surface 

 of the object was kept moist. This fact was made use of in securing 

 eggs, and cages (PI. I, figs. 1, 2) were constructed with cheesecloth 

 bottoms, having moist, dark-colored blotting paper beneath the 

 cloth. The eggs, being deposited on the dark blotting paper, were 

 easily counted and transferred to cages for records on the period of 

 incubation. 



