Bed bugs climb on the traps and fall into the gully, then no escape. You can fill the gully with diatomaceous earth for added protection. 

Printing settings

• Layer height: 0.20
• Walls loops: 5
• Bottom shell layers: 5
• Top shell layer: 5
• Infill: 50%+
• Supports: No
• Material: PETG, ASA, or ABS