Effects of Differently Processed Hawk Tea on Aglossa dimidiata Larval Growth and Insect Tea Composition and Antioxidant Activity

Aglossa dimidiata (Lepidoptera: Pyralidae) is a polyphagous insect whose larval frass, after processing, constitutes insect tea. This study evaluated the effects of four processed hawk teas—traditional, black, oolong, and green—as larval diets on A. dimidiata development and the resulting insect tea quality. The survival rate, developmental duration, morphological traits, frass yield, and biochemical composition of the larvae and insect tea were systematically determined, and the in vitro antioxidant activity of insect tea was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, hydroxyl (·OH) radical, and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) radical scavenging assays together with the ferric reducing antioxidant power (FRAP) assay. The four processing methods had no significant effect on total larval developmental duration (52–53 d) or on head capsule width, body length, or body width within the same instar. By contrast, the green tea process markedly suppressed survival at every instar, with first-instar survival of only 72.29% compared with more than 89% in the other three groups, and reduced frass yield, reaching only 125.41 mg/larva at the eighth instar versus 191.68, 178.37, and 197.09 mg/larva under the traditional, black, and oolong tea processes, respectively. During instars 1–4, the traditional tea process produced the highest yield (0.497 mg/larva) and formed insect-tea particles with smaller minor diameters of approximately 94 to 180 μm. During instars 5–8, the three suitable processes gave comparable yields that were significantly higher than those in the earlier stage, reaching 178 to 197 mg/larva at the eighth instar, while the minor diameter of the particles increased markedly to approximately 303 to 312 μm at the fifth instar and 912 to 927 μm at the eighth instar. All hawk teas contained abundant flavonoids and catechins, and the differential fate of these compounds in the resulting insect teas suggests selective metabolism by the larvae. In the in vitro antioxidant assays, late-instar insect tea prepared by the traditional process showed the highest comprehensive antioxidant index of 93.00, followed by insect tea from the oolong and black tea processes at 84.10 and 74.28, respectively, and total flavonoid and catechin contents showed positive associations with ABTS and FRAP activities (descriptive, n = 3). Overall, traditional processing of hawk teas maintained high survival and frass yield while conferring the strongest antioxidant activity on the resulting insect tea, providing a reference for the production of high-quality insect tea.