Table 3. The life tables of the SEW and SEM strains of S. exigua.
| Development period | Strains | x2 | P-value | |
|---|---|---|---|---|
| SEW | SEM | |||
| Initial number of neonates | 384 | 433 | - | - |
| Mortality from first to third instars | 33% | 42% | 6.54 | 0.011 |
| Number of dead 1st-3rd instars larvae | 128 | 182 | - | - |
| Number of 4th instars larvae | 256 | 251 | - | - |
| Mortality from fourth to fifth instars | 8.59% | 16.73% | 7.612 | 0.006 |
| Number of dead 4th-5th instars larvae | 22 | 42 | - | - |
| Number of pre-pupae | 234 | 209 | - | - |
| Mortality during pre-pupation | 9.83% | 5.26% | 3.248 | 0.072 |
| Number of dead pre-pupae | 23 | 11 | - | - |
| Number of pupae | 211 | 198 | - | - |
| Mortality during eclosion | 2.84% | 1.29% | 0.838 | 0.360 |
| Number of dead pupae | 6 | 3 | - | - |
| Number of adults | 205 | 195 | - | - |
| Number of females | 116 | 86 | - | - |
| Sex ratio (female:male) | 1.3:1 | 1:1.26 | ||
| Average egg number per female1 | 257 | 637 | - | - |
| Hatching rate (%) | 96.2 | 97.8 | - | - |
| Predicted number of neonates of next generation2 | 32338.7 | 53576.8 | - | - |
| Net reproductive rate (R0)3 | 139.74 | 275.66 | - | - |
| Population trend index (I)4 | 74.69 | 123.73 | - | - |
| Relative fitness5 | 1 | 1.66 | - | - |
1Average egg number per female: average number of the fertilized eggs laid by female from single pair mating.
2Predicted number of neonates of next generation of SEW = Number of females × average egg number per female × hatching rate × initial number of SEM neonates/ initial number of SEW neonates; Predicted number of neonates of next generation of SEM = Number of females × average egg number per female × hatching rate × initial number of SEM neonates.
3net reproductive rate (R0) of SEW = Predicted number of neonates of next generation of SEW × female ratio/(number of female × initial number of SEM neonates/initial number of SEW neonates); net reproductive rate (R0) of SEM = Predicted number of neonates of next generation of SEM × female ratio/number of female.
4Population trend index (I) of SEW = Predicted number of neonates of next generation of SEW/initial number of neonates of SEW × initial number of SEM neonates/initial number of SEW neonates; Population trend index (I) of SEM = Predicted number of neonates of next generation of SEM/initial number of neonates of SEM.
5Relative fitness = ISEM/ISEW.