Abstract: Coleophora obducta (Lepidoptera: Coleophoridae), a kind of larch defoliators, is exclusively latent in the leaves. Seven kinds of environmental safe insecticides and larch volatiles, that were active to the insect females in the previous research, were sprayed to healthy larch seedlings to investigate the adult insect tendency, the olfactive and ovipositive responses. The results indicated that S-α-pinene 0.004 mol·L^-1 , S-β-pinene 0.000 4 mol·L^-1 , and 3-carene 0.04 mol·L^-1 attracted the females (P<0.05), whereas, S-α-pinene 0.04 mol·L^-1 and myrcene 0.8 mol·L^-1 repelled the females (P<0.01). Imidacloprid EC 3 000 times solution and emamectin benzoate microemulsion 2000 times solution repelled the C. obducta (P<0.01 or P<0.05). The seedlings sprayed with volatiles and seven kinds of environmental safe insecticides notably reduced eggs amount laid on by the insects. In comparison with mean 15.79～16.73 eggs per female on the control seedlings, mean 5.63 and 5.21 eggs per female were laid on the seedlings respectively sprayed with phellandrene 0.000 4 mol·L^-1 and myrcene 0.8 mol·L ^-1 , and mean 3.13 and 3.33 eggs per female were laid on the seedlings respectively sprayed with avermectin and imidacloprid oviposited.

Key words: Coleophora obducta, plant volatiles, environmental safe insectides, olfaction, oviposition