This study aimed to investigate the influence of environmental temperatures on the predation ability against Propylea japonica larvae and adults for Aphis sophoricola, and to identify the optimal temperature and instar for maximum pest suppression efficacy. Under controlled conditions of 20, 25 and 30 ℃, P. japonica and A. sophoricola were applied to quantify the predation rates of 1st to 4th instar larvae and adults on aphids at varying densities. Subsequently, the predation dynamics were analyzed by fitting the data to the Holling type II functional response model. At all tested temperatures, the functional response of P. japonica to aphid predation was conformed to fit assumption from the Holling type II model. At 25 ℃, the instantaneous attack rate of P. japonica （especially young larvae） was 2—5 times higher that at the other two temperatures, and the handling time was also shorter. At 30 ℃, P. japonica （especially old larvae and adults） exhibited the highest predation efficiency, and its theoretical daily maximum predation capacity was significantly higher than at other temperatures. At 20 ℃, the predation capacity and daily maximum predation were markedly reduced, which significantly inhibited predation efficiency. The 2nd instar larvae and adults are the optimal stages for P. japonica to exert the maximum control potential against A. sophoricola at 20 ℃ and 30 ℃, whereas the 3rd instar larvae are the optimal instar at 25 ℃. The 4th instar larvae and adults are the optimal instars and stages at 30 ℃. Overall, our study showed that pest control efficacy of P. japonica on A. sophoricola increased with its developmental maturity and reached its peak at higher ambient temperatures. In summary, this study provides a theoretical basis for releasing P. japonica in suitable life stages according to climatic conditions in field applications to achieve efficient aphid control.

Cinara bungeanae Zhang et Zhang is the primary piercing-sucking pest affecting Pinus bungeana Zucc. ex Endl, significantly compromising tree health and ornamental value. To facilitate rational pest management, this study evaluated the control efficacy of seven pesticides against Cinara bungeanae and assessed the safety of the three most effective compounds against five common natural enemy insects of piercing-sucking pests. Results indicated that 22% sulfoxaflor SC （30000× dilution）, 17% flupyradifurone SL （3000× dilution）, and 2% thiacloprid CS （1500× dilution） exhibited high efficacy and rapid knockdown against Cinara bungeanae. However, these agents also exert measurable impacts on natural enemies; therefore, their application should be timed to avoid peak activity periods of beneficial insects such as lady beetles and lacewings. Afidopyropen DC （50 g·L⁻¹, 12000× dilution） and 25% pymetrozine SC （6000× dilution） demonstrated lower immediate efficacy but are suitable for integration with biological control strategies under low pest population densities. Matrine SL （1%, 600× dilution） and 22.4% spirotetramat SC （6000× dilution） demonstrated suboptimal efficacy against the target pest and are not recommended for standalone use.