Just after sunset as the cooler night air began to flow into camp, the still September air was suddenly filled with sound of raindrops. There is no rain in the Lower Zambezi Valley during the hot dry months of September and October but there was no doubt about what I could hear – it was the sound of raindrops on the dry leaves that had been blown off the trees by the August winds.
I stepped out from under the thatched lounge area to feel the raindrops but instead felt nothing and only heard the rustle of leaves under my feet. The sound of raindrops hitting the ground stopped and now I was mystified! The following afternoon, just after sunset it happened again…
Pieter identified the tree that grows there as a “Rain Tree”, Lonchocarpus capassa . Early the next morning, I went to have a look at what the raindrops could have been but could not see anything. A few days later, to my delight there were thousands of tiny purple-blue flowers on the ground of which I have a picture to show you and for those interested, it’s not the flowers that are referred to as rain, but water from an insect…
“Many Africans are very superstitious about L. capassa for it is one of the so-called rain trees, and some specimens do ‘rain’ for a week or more during the hot dry months just prior to the actual breaking of the rains. This phenomenon is found in other unrelated genera and in this case is caused by the numph of a small insect, a species of frog-hopper, Ptyelus grossus, belonging to the order Hemiptera. As a protection against the sun, the nymph covers itself with a frothy substance similar to patches of foam, popularly called ‘cuckoo-spit’, caused by common, closely related species. The insects obtain nourishment by piercing the bark of the tree with their sucking mouth parts (stylets) and sucking up the sap at great speed. They eject almost pure water equally fast, and this drips from the tree in sufficient quantity to form pools on the ground below…
flowers from Loncocarpus
Tags: mystery-rain, rain-tree