|Watercolor and photo collage by M. Brummermann|
The throat of Datura flowers is extraordinarily deep. When completely unrolled, the proboscis of Manduca rustica is long enough for the moth to hover over the flower and reach the nectar. Still, most moths land and crawl laboriously into the depth. They stay surprisingly long wiggling among anthers and stigma, and when they emerge, they head directly for another one of those white funnels. It is assumed that chemicals in the nectar may be slightly addictive and keep the moths faithful - thus assuring that precious pollen reaches its goal and does not get wasted. Datura (like many plants) is a known chemical powerhouse that produces potent Alkaloids. These may protect the plant tissue from many herbivores, but not from the caterpillars of several Manduca species who seem immune. So the pollinating moths can lay their eggs right on their favorite plant to produce a new generation for this symbiotic relationship.