Select next shown parameters for the last made layer:
Blending mode-Color Burn 
On the last stage we’ll try drawing the reactive movers of the beetle, selecting the
Ellipse Tool (U).
The layer’s parameters:
Blending Options>Bevel and Emboss 
Blending Options>Gradient Overlay 
Gradient’s parameters: 
Using the last applied tool, try to make now the exit opening of the reactive engine. The layer’s color in this case should be white.
The layer’s parameters:
Blending Options>Outer Glow 
Merge down the layers composing the reactive engines (
CTRL+E). Make a copy of the new layer and select
Free Transform option to turn over the copy, placing it the way demonstrated next image.
The picture is finished!
View full size
here.
