Ia supernova rate has a strong dependence on stellar metallicity and examine the resulting observational implications. This is motivated by measurements of the nearby Type Ia supernova rates reported by the Lick Observatory SN Search (LOSS: @Leaman [@Li:2010ii; @Li:2010iii]). These measurements and their interpretation are discussed in Section \[section:ii\]. In Section \[section:iii\], we present a simple model that examines the SN Ia rate as a function of galaxy mass/age, and incorporate the effects of metallicity in Section \[section:iv\]. In Section \[section:v\], we extend this into a treatment of the cosmic SN Ia rate, including the relative effects on “prompt” and “delayed” SNe. We summarize our arguments and include further discussion on analogous observations, SNe Ia in galactic halos, galactic chemical evolution, and super-Chandrasekhar SNe in Section \[section:vi\].

The Type Ia Supernova Rate in Galaxies {#section:ii}
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At present, the most complete and systematic search for nearby supernovae was conducted over the past decade by the Lick Observatory SN Search, with results recently detailed in @Leaman and @Li:2010ii [@Li:2010iii]. Here, we briefly discuss the implications of the LOSS findings for our present study. Of particular interest are the results pertaining to Type Ia supernovae.

In Fig. \[Iarate\], we display the specific 