Table 1. Comparison of virulence between the wild type and mutants assayed on silkworm larvae.

Strains	LT50 (days)	Significance*
WT	4.0 ± 0.39	-
Mratg1Δ	5.0 ± 0.62	χ2 = 12.77; p = 0
Mratg4Δ	4.6 ± 0.34	χ2 = 4.86; p = 0.028
Mratg8Δ	NC	χ2 = 63.12; p = 0
Mratg15Δ	4.3 ± 0.16	χ2 = 8.51; p = 0.004
Comp	4.5 ± 0.21	χ2 = 0.38; p = 0.54
M8-3	4.0 ± 0.15	χ2 = 0.04; p = 0.85

^*Each mutant was compared with the wild type (WT), respectively and a Log-Rank test was conducted to examine the significance of difference between treatments. Comp, Mratg8Δ gene-rescued strain; M8-3, Mratg8Δ mutant complemented with mutagenized MrATG8 gene by deletions of protein C-terminal T117 and A118 residues. NC, not calculated due to mortality < 50%.