I lost my iphone is it covered by insurance

Depends on the insurance. What do you have? AppleCare + Theft and Loss does. Also take a look here…

If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support

~ Katana-San~

It all depends on the details of your insurance plan.

In most cases, the insurance plan will send you a check for the current value of the phone. This will probably be less than the purchase price of the phone. Then, you can use the funds to buy a new phone.

If you have Apple Care Theft and Loss Insurance, Apple will send you a replacement phone.