aspnet_wp.exe using 80% of CPU usage

Question

Hi,

I am using web farm with load balancer, 2 server is their in web farm Application is very slow and my CPU usage is showing up to 85%. what is reason behind that ? how can I reduced CPU usage and make application faster. same application is working fine for Development server.any help will be appreciated. aspnet_wp.exe using CPU usage up to 83%

Application is asp.net 4.0 and IIS 7.5.

Thanks