3-D printed insect traps

The 3-D printed  insect trap in action
(Image credit Joshua Reid Carswell, FDACS)

If we want to monitor or reduce populations of insects or other arthropods we need to get our hands on them first. Everyone, that ever worked with insects had to handle an insect trap such as our famous Malaise trap or as simple as a sweep net. Not surprisingly, insect traps vary widely in shape, size, and construction, often reflecting the behavior or the ecology of the target species, and almost equally often the tight budget of scientists. The problem begins when your target species is not collected by the standard methods, or specimens are too damaged to provide any meaningful result. Another problem to consider is the maintenance of the traps. How often do we have to come back to the trap and check it? If you need a large array of traps or if you work in a remote location you will consider finding ways to collect less often.

All that considered the ideal trap would be unique and specifically designed to any particular research need. There are lot of modifications to standard traps out there and an even higher number of DIY versions created by desperate entomologists or ecologists.

But what if we could use modern technology to help with that? Researchers at the Florida Department of Agriculture and Consumer Services (FDACS) started to employ 3-D printing technology to build sophisticated, specialized and far more complicated contraptions.

Florida is currently battling the invasion of the Asian citrus psyllid (Diaphorina citri), a vector for bacteria that cause citrus greening disease. The sap-sucking hemipteran is infesting the famous state’s orange groves, and costing Florida an estimated $4.5 billion in lost economic output and more than 8,000 jobs during just a five-year period.

State inspectors are trying to monitor insect introductions into the state and mostly they are using simple sticky traps made with a glue known as tanglefoot. The glue is usually applied to some heavy duty tape that is wrapped around tree trunks. Insects walk over and are trapped in the glue but unfortunately specimens are often too damaged to do any further work with them not even molecular analysis simply because they don't contain any preservative. On the other hand its paramount to keep the insect intact, such that it is possible to isolate DNA and detect the pathogens.

The FDACS researchers studied the pest’s behavior for a long time which enabled them to tailor a trap to the insect. The trap is designed and drawn on a computer, and then someone just hits print. The plastic is then placed layer-by-layer to make the pieces that will form the insect trap. The new designs include such features as fake branches to fool insects. As an insect climbs along the fake branches, it falls into one of the small holes on the trap and immediately enters a pool of preservatives. 

The new 3-D printed traps seem to work better for disease monitoring because the insects can be recovered from a reservoir of preservative in which DNA of the specimens is conserved. Through its design the trap is also more selective.The costs in this case were actually fairly moderate. The 3-D printer with software was about $2300 and the traps cost $5 to $10 apiece to make. I think that is money well spend.