Synergistic interaction of thymol with Piper ribesioides (Piperales: Piperaceae) extracts and isolated active compounds for enhanced insecticidal activity against Spodoptera exigua (Lepidoptera: Noctuidae)

Chemical and Biological Technologies in Agriculture

Table 2 Potential toxicity due to binary mixtures of thymol and P. ribesioides extracts against 2nd instar S. exigua after 24 h

Compound A	Compound B (P. ribesiodes extracts in respective solvents)	Sublethal dose (µg/larvae)	Laval mortality (%)				χ²	Effect
			Pure compounds		Binary mixtures
			Observed A	Observed B	Expected	Observed
Thymol (LD₁₀)	Hexane (LD₁₀)	1.21 + 0.65	13.33	23.33	33.56	53.33	11.66	Synergistic
Thymol (LD₁₀)	Hexane (LD₃₀)	1.21 + 3.21	13.33	26.67	36.44	6.67	24.33	Antagonistic
Thymol (LD₃₀)	Hexane (LD₁₀)	9.54 + 0.65	17.00	13.00	27.79	46.67	12.82	Synergistic
Thymol (LD₃₀)	Hexane (LD₃₀)	9.54 + 3.21	17.00	27.00	39.41	93.33	73.78	Synergistic
Thymol (LD₁₀)	CH₂Cl₂ (LD₁₀)	1.21 + 0.32	13.33	16.67	27.78	16.67	4.44	Antagonistic
Thymol (LD₁₀)	CH₂Cl₂ (LD₃₀)	1.21 + 1.73	13.33	20.00	30.67	86.67	102.26	Synergistic
Thymol (LD₃₀)	CH₂Cl₂ (LD₁₀)	9.54 + 0.32	17.00	17.00	31.11	56.67	20.99	Synergistic
Thymol (LD₃₀)	CH₂Cl₂ (LD₃₀)	9.54 + 1.73	17.00	20.00	33.60	96.67	118.38	Synergistic
Thymol (LD₁₀)	EtOAC (LD₁₀)	1.21 + 0.57	13.33	23.33	33.56	46.67	5.12	Synergistic
Thymol (LD₁₀)	EtOAC (LD₃₀)	1.21 + 1.60	13.33	27.00	36.44	10.00	19.19	Antagonistic
Thymol (LD₃₀)	EtOAC (LD₁₀)	9.54 + 0.57	17.00	23.00	36.09	43.33	1.45	Additive
Thymol (LD₃₀)	EtOAC (LD₃₀)	9.54 + 1.60	17.00	27.00	39.41	90.00	64.94	Synergistic
Thymol (LD₁₀)	MeOH (LD₁₀)	1.21 + 2.52	13.33	6.67	18.80	70.00	139.44	Synergistic
Thymol (LD₁₀)	MeOH (LD₃₀)	1.21 + 39.74	13.33	10.00	21.70	53.33	46.11	Synergistic
Thymol (LD₃₀)	MeOH (LD₁₀)	9.54 + 2.52	17.00	7.00	22.81	80.00	143.39	Synergistic
Thymol (LD₃₀)	MeOH (LD₃₀)	9.54 + 39.94	17.00	10.00	25.30	96.67	201.31	Synergistic