Larvae-derived AMPs antagonize S. marcescens. (A) Representative images of surface slick with S. marcescens alone, with larvae, with secreta and with AMPs. (B) The prodigiosin production of S. marcescens alone, with larvae, with secreta and with AMPs. (C) Bacterial loads of S. marcescens alone, with larvae, with secreta and with AMPs. AMPs: cecropin A (40 μg/μl, 80 μg/μl). (D) Representative images of surface slick with S. marcescens alone, with wild-type larvae, with ΔAMP14 larvae, with AMPs, with ΔAMP14 larvae+AMPs and wild-type larvae+AMPs. (E) The prodigiosin production of S marcescens alone, with wild-type larvae, With ΔAMP14 larvae, with AMPs, with ΔAMP14 larvae+AMPs and wild-type larvae+AMPs. (F) Bacterial loads of with S. marcescens alone, with wild-type larvae, with ΔAMP14 larvae, with AMPs, with ΔAMP14 larvae+AMPs and wild-type larvae+AMPs. AMPs cecropin A = 40 μg/μl. (G, H) RT-qPCR analysis of the expression levels of downregulated and upregulated genes in the S. marcescens alone, with wild-type larvae, with ΔAMP14 larvae, with AMPs, with ΔAMP14 larvae+AMPs and wild-type larvae+AMPs. For B-C and E-F, n = 6 for each. Fo G-H, n = 3 for each. Means ± SEMs. All variables have different letters, and they are significantly different (p < 0.05). If two variables share a letter, they are not significantly different (p > 0.05). Kruskal- Wallis test followed by Dunn’s multiple comparisons test.