Could you feed a garden hose that’s twice as long as your height through a hole barely bigger than the hose itself? And in the dark? In essence that’s how many hawk moths sip their nectar, so research biologists are making artificial flowers by 3D printing to learn how they do it.
Graduate student Eric Octavio Campos and a team of biologists have been observing the feeding preferences of the hawk moth, Manduca sexta (also known as the tobacco hornworm as its larvae feed on tobacco) which has an extremely long proboscis. Campos says:
“Imagine being given a garden hose that’s almost twice your height in length. Now imagine trying to thread the other end through a hole that’s scarcely wider than the hose itself—at dusk as the sun is setting or at night during a full moon. It may seem like a silly proposition, but it’s not too far off from what night-flying hawk moths have to contend with to get a meal.”
Using a 3D printer the researchers created a variety of mathematically-specified printed plastic flower shapes, such as flat and trumpet-shaped, with a nectary filled with sugar water attached at the base. Moths were released and observed to see which flower shape they preferred.
The moths fed more easily from the curved, trumpet-shaped flower regardless of the nectary aperture size. Even a very slight curve in the disc shape improved the moth’s foraging ability, indicating that it uses the flower has a mechanical guide to locate its food source.
The use of 3D printed flowers to study pollinator behaviour now opens up possibilities for much more wide-ranging research about the relationships between pollinators and flowers.