BackgroundImage at the ContentPage doesn't works for iOS!

I'm using in my ContentPage the property BackgroundImage="Default.png"
in Android works fine, but in iOS doens't appear any image at my background!

code of content page:
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:controls="clr-namespace:Test.control;assembly=Test" x:Class="Test.Pages.Springboard" Title="Begin" Padding="10, 10, 10, 10" BackgroundImage="Default.png">

The source of the images are :
iOS -> Resources
Android -> Resources/drawable

anyone have any idea why this doesn't work ?