models and discuss a prospect for mode identification. An attempt to interpret the oscillation spectrum of HD 163899 is presented in Section \[hd163899\]. The last section contains Conclusions.

Theoretical models {#domains}
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![image](fig1a.eps){width="88mm"} ![image](fig1b.eps){width="88mm"} ![image](fig1c.eps){width="88mm"} ![image](fig1d.eps){width="88mm"} ![image](fig1e.eps){width="88mm"} ![image](fig1f.eps){width="88mm"}

The evolutionary models were calculated with MESA evolution code (Modules for Experiments in Stellar Astrophysics, Paxton et al. 2011, Paxton et al. 2013). MESA allows to follow the evolution of massive stars to the pre-supernova phase. Our previous calculations (D2013) were limited to the phase before core helium ignition due to the lack of helium burning in Warsaw-New Jersey evolution code we used. We considered the mass range of 13$-$18 $M_\odot$. All computed models have an initial hydrogen abundance of $X=0.7$ and AGSS09 metal mixture (Asplund et al. 2009). The initial metal abundance varies from $Z=0.005$ to $Z=0.02$. OPAL (Iglesias & Rogers 1996) and OP opacity tables (Seaton 2005) were used. All effects of rotation were neglected. Non-adiabatic pulsation analysis was performed using the code of Dziembowski (1977). In Fig.\[fig1\] we present evolutionary tracks including various effects: opacity, metallicity, overshooting, mass loss and element diffusion. They will be discussed in detail in the following subsections.

Treatment of convection and the blue loop 