Table 1.

Mortality (%) of second instar gypsy moths on foliage of Oregon white oak and Douglas-fir treated with Bacillus thuringiensis Berliner (Bt) or diflubenzuron (DFB). Ground sprayed to point of drip. Corvallis, Oregon 1986.

Treatment^¹	Sample date post treatment (days)^²
Treatment^¹	1	6	14	21	28	47	58	64
Oregon White Oak
check	0a	0a	12a	48a	20a	28a	8a	56a
Bt once	100b	100b	100b	100b	100b	100b	100b	100b
Bt twice	100b	100b	100b	100b	100b	100b	100b	100b
DFB once	100b	100b	96b	100b	84b	100b	80b	100b
Douglas-fir
check	0a	0a	8a	64a	16a	4a	12a	54a
Bt once	100b	100b	100b	100b	100b	88b	88b	96b
Bt twice	100b	100b	100b	100b	100b	100b	100b	88b
DFB once	100b	100b	100b	100b	84b	76b	92b	92b

↵1 n = 25 larvae per treatment-sample day. Applied at a concentration of: Bt 4.22 BIU/1; DFB 15ml/1.
↵2 days are time of foliage collection post treatment. Different letters within a column designate significantly different results, LSDtest, p < 0.01.