October, '22] mccolloch: attraction of corn for chloridea 335 



In a previous paper, the writer^ called attention to the fact that the 

 moths show a decided preference for the silks of com and, that when 

 these are not available, the upper surface of the leaves and the stalk are 

 selected. During the period 1913-1918, a total of 6867 eggs were found 

 on 128 plants under daily observation from germination to maturity. 

 Of these, 2100 or 30.6 percent were deposited on the silks. In order to 

 discover whether the moths showed a preference for the plants while 

 in silk, observations were begun in 1914 to determine the number of eggs 

 deposited on the plants while in silk in comparison with the total num- 

 ber of eggs found. These data are presented in Table I, while Table II 

 shows the location of the eggs deposited during the silking period. 



Table I. — Showing the Number of Eggs Deposited While the Pl.\nts Were in Silk in Compari- 

 son WITH THE Total Number of Eggs — ■1914-1918. 



Total No. eggs No. deposited while % deposited 



Year plants were in silk while plants were 



in silk 



1914 4646 2963 63.7 



1915 330 260 78.7 



1916 129 35 27.1 



1917 92 84 91.3 



1918 1091 459 42.1 



6288 3801 60.4 



Table II — Location of Eggs Deposited on Plants While in Silk — 1914-1918. 



No. of Leaf Surface p^ of eggs 



Year plants Upper Lower Silk Husk Tassel Stalk Total on silks 



1914 24 663 208 1546 89 164 293 2963 52 1 



1915 24 46 3 161 5 7 38 260 619 



1916 20 10 2 11 3 9 35 3l'4 



1917 20 8 1 56 5 4 84 666 



1918 25 109 37 211 23 20 59 4.59 460 



Total 113 836 251 1985 122 194 403 .3801 52*2 



From the data presented in the tables, it seemed apparent that the 

 silks offered some attraction for the moths, since over 60 percent of the 

 eggs were deposited during the period that the plants were in silk and 

 52 percent of these eggs were placed on the silks. In connection with 

 these tables it is well to mention that 1916 and 1918 were very poor 

 com years, due to drought and hot winds. As a result, many of the 

 plants did not produce silks and when they did appear they were soon 

 destroyed by the extreme climatic conditions. It is also worthy of 

 notice that under favorable conditions the silks are available for a short 

 period in comparison with the other parts of the plant. 



_ ^McColloch, J. W., A Study of the Oviposition of the Corn Earworm with Rela- 

 tion to Certain Phases of the Life Economy and Measures of Control. In Tourn 

 Econ. Ent., 13:242-255, 1920. 



