AICDA and infection: The results of RT–qPCR showed that, 6 h after infection, the expression of cecropin A (CEA), serine protease inhibitor (SP1-1/-2), chitin deacetylase (CDA-2/-3), immune-related protein (HDD-3) and serine protease (P1) was upregulated, and the expression of SP1-2 was upregulated 6.90 ± 0.26-fold (Figure 3A).