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.