The Guide boxes are designed to make posing easier. However, you'll want to remove them before you render.
The first is to go to the Surfaces Tab (VIEW –> Tabs –> Surfaces). Highlight 'Guide A' and 'Guide B' under FX-Plane (or whichever HeroFX prop it is). Then go to the 'Advanced' tab below. Find the 'Opacity Property.' and change the value from 100% to 0%.
An easier way, depending upon which HeroFX add-ons you have, is to select the prop first. Then go to POSE –> MAT-HeroFXx-1 and double-click “+ Guides OFF.”
Relevant locations in DAZ Studio: