Predaceous ladybeetles are highly polyphagous predators that ingest supplementary food from flowering plants. Flowering plants widely grown in agroecosystems can sustain multiple natural enemies of agricultural pests, and the pollen and nectar resources from flowering plants may have a positive role in natural enemies.Cnidium monnieri(L.) Cusson, an annual herb with many flowers, blooms from May to July.C. monnierican support several predatory natural enemies, and the addition ofC. monnieristrips increases the density ofHarmonia axyridis(Pallas) and improves the biological control of apple aphids in an apple orchard.H. axyridisis also the most important natural enemy in wheat aphid biocontrol and is attracted to healthy and aphid-infestedC. monnieriplants. In addition, adultPropylaea japonicaThunberg survives significantly longer onC. monnieriflowers than on a water-only diet. In this study, a laboratory experiment was conducted to assess (i) the effect of nutritional supplements derived fromC. monnieriflowers on the development and reproduction ofH. axyridisunder a wheat aphids-only diet; (ii) the effect ofC. monnieriflowers onH. axyridisadult reproduction performance. We compared the larval durations, survival, weight, adult longevity, and reproduction ofH. axyridisreared on wheat aphids-only and aphids plusC. monnieriflower diets. The results showed thatH. axyridislarvae reared on aphids plus flowers had significantly greater weights and survival rates, shorter larval durations, and produced 1.62 times more eggs than those reared on wheat aphids-only diets.H. axyridisadults ingesting aC. monnieriflowers plus an aphid diet increased egg production 1.44 times compared to the aphids-only diet. Our study demonstrates thatC. monnieriflowers as a supplementary food positively affect the survival, development, and reproduction performance ofH. axyridis.