番茄田二代棉铃虫发生规律及药剂防治

Occurrence and chemical control of the second generation of cotton bollworm(Helicoverpa armigera) in tomato field.

第 2代棉铃虫Helicoverpaarmigera是危害番茄最严重的世代 ,95 %左右的卵产在番茄植株顶尖至第 4复叶层的嫩梢、嫩叶、果萼和茎基上 ,6月 2 0日至 7月 5日累计平均每株落卵 32 8粒。在番茄上第 2代棉铃虫的卵量和幼虫量与第 1代蛾量密切相关 ,卵量 (Y1)与第 1代蛾量 (x)关系式为 :Y1=-31 5 9+ 1 7783X ,n =6 ,r=0 85 6 2 ,幼虫量 (Y2 )与第 1代蛾量 (X)关系式为Y2 =31 3+ 0 1 34X ,n =6 ,r=0 86 5 2 。在第 2代棉铃虫产卵初盛期应用Bt菌剂含孢子 1 0 0亿个 mL ,2 0 0倍液喷雾 3次 ,或 1 8%阿维菌素 1 2 1 5g (a .i.) hm2 兑水喷雾 2次 ,防效显著。

The damage of the second generation cotton bollworm to tomato is much serious in Laixi, Shandong Province. 95% eggs is laid on the tender top, tender calyx and the base of stem. There are 32 8 eggs on average each plant from June 20 to July 5. The relationship among the density of eggs( Y 1 ), the number of the first generation larvae ( Y 2 ), and the number of the first generation moths ( X ) is as follows: Y 1=-315 9+1 7783X,r=0 8562 *,n=6; Y 2=31 3+0 134X,r=0 8652 *,n=6. The high control efficiency could be obtained by using Bt(200 times dilution, 10 billion/mL spore) spraying 3 times or 1\^8% avermection(12 15 g (a.i.)/hm 2) spraying 2 times in the early and peak time of laying eggs.