Table 1 Correlation of sample age and several library quality metrics when reads were aligned to the full Helicoverpa armigera reference genome

Total number of sequences

T₂₆₉ = 3.66; P < 0.01; R = 0.2180 (0.1015:0.3286)

Total duplication

T₂₆₉ = 2.95; P < 0.01; R = 0.1771 (0.0592:0.2901)

Mean genome coverage

T₂₆₉ = 5.93; P < 0.01; R = 0.34 (0.23:0.44)

Estimated library size

T₂₆₉ = 8.24; P < 0.01; R = 0.45 (0.35:0.54)

Adapter level

T₂₆₉ = -8.82; P < 0.01; R = -0.47(− 0.56:-0.38)

Total number of unmapped reads

T₂₆₉ = 4.60; P < 0.01; R = 0.27 (0.16:0.38)