Toxicity, joint action effect, and enzymatic assays of abamectin, chlorfenapyr, and pyridaben against the two-spotted spider mite Tetranychus urticae

The Journal of Basic and Applied Zoology

Table 4 Joint toxic effect of technical (abamectin, chlorfenapyr, and pyridaben) and formulated (Agromectin, Challenger, and Sanmite) mixtures at LC₂₅ values of each acaricide against eggs of T. urticae by leaf-disk-dip technique

Acaricide		Conc. at LC₂₅ (mg/L)		Observed mortality (%) at LC₂₅		Expected mortality (%)	Observed mortality (%)	Co-toxicity factor	Results
1	2	1	2	1	2	∑ (1 + 2)	∑ (1 + 2)	∑ (1 + 2)	∑ (1 + 2)
Abamectin	Chlorfenapyr	22.79	26.40	32.47	30.84	63.31	62.12	24.23	Potentiation
Abamectin	Pyridaben	22.79	838.21	32.47	28.82	61.29	64.17	28.35	Potentiation
Pyridaben	Chlorfenapyr	838.21	26.40	28.82	30.84	59.66	72.81	45.63	Potentiation
Agromectin	Challenger	11.48	4.98	35.24	31.02	66.26	72.53	45.05	Potentiation
Agromectin	Sanmite	11.48	5.10	35.24	29.12	64.36	60.34	20.68	Potentiation
Sanmite	Challenger	5.10	4.98	29.12	31.02	60.14	53.71	7.42	Additive

Co-toxicity factor = [(OM − EM)/EM] × 100, where: OM is the observed mortality (%) and EM is the expected mortality (%). A positive factor of 20 or higher means potentiation, a negative factor of 20 or lower means antagonism and the values between + 20 and − 20 indicate an additive effect