Tetranychus urticae is a significant pest on cassava. Long-term use of abamectin has led to prominent resistance issues. Selecting mite-resistant cassava varieties represents a green, effective and straightforward approach to pest control. However, the effectiveness of resistant cassava varieties against resistant mite strains remains unclear, limiting its utility in supporting resistance management decisions. Accordingly, this study used mite-resistant cassava cultivar C1115, mite-susceptible cassava cultivar SC205 and the preferred host plant cowpea as test materials to investigate the effects on the development, reproduction and detoxification metabolism capabilities of abamectin-resistant (AB-R) and abamectin-sensitive (AB-S) strains. Results showed that compared to feeding on cowpea, feeding on SC205 did not significantly alter the developmental duration or population growth parameters [net reproductive rate (R₀), intrinsic rate of increase (r_m), mean generation time (T), population doubling time (DT)] of either AB-R or AB-S strains. In contrast, feeding on C1115 significantly prolonged the developmental duration and inhibited population growth (significantly decreased R₀ and r_m, significantly increased T and DT) of both strains. Furthermore, on C1115, the T and DT of the AB-R strain were also significantly lower than those of the AB-S strain. Regarding detoxification enzyme activities, compared to feeding on cowpea, feeding on both SC205 and C1115 significantly increased the activities of three detoxification enzymes-cytochrome P450 monooxygenases (P450s), glutathione S-transferases (GSTs) and uridine diphosphate-glycosyltransferases (UGTs) - in both mite strains. Enzyme activities were significantly higher in mites feeding on C1115 compared to those on SC205. Additionally, on all three host plants, the enzyme activities of the AB-R strain were consistently significantly higher than those of the AB-S strain. Detoxification genes associated with abamectin resistance exhibited different expression patterns. Although feeding on both C1115 and SC205 significantly upregulated the expression of six tested genes in both mite strains compared to feeding on cowpea, differences emerged when comparing strains on the same cassava variety. When AB-R and AB-S fed on the same cassava cultivar (C1115 or SC205), the expression levels of CYP389C10, UGT201D3 and UGT11 showed no significant difference. However, the expression of CYP392A16, GSTd01 and GSTm09 was significantly higher in the AB-R strain than in the AB-S strain. The results indicate that the AB-R strain of T. urticae, likely due to its enhanced detoxification capacity, might possess an advantage in neutralizing toxic secondary metabolites from the mite-resistant cassava, potentially compromising the pest control efficacy of this resistant cultivar. This hypothesis, however, requires further validation through subsequent field experiments. This study provides a preliminary theoretical basis for evaluating the application potential of mite-resistant cassava in the management of mite resistance to acaricides.