How do I compare mean mortality rates?

[#1]

I performed an experiment in which I subjected a few groups of insects to different treatments and then observed how long they survived. I want to see if there is a significant difference in the times it took for each group to reach 50% mortality. I was told a wilcoxon test is the best way to do this. I already have survival curves, I just don't know how to compare the means. How do I approach this?

[#2]

This sounds like a Reliability scenario to me. My approach would be to first use the Reliability...Life Distribution platform to understand the distribution of in insect curves, then use the Fit Life by X platform (specifying the distribution learned earlier) to understand the effects of the different treatments. This platform also includes the Wilcoxon Group Homogeneity Test and profilers.