Angracoid Orchids & African Moths

Darwin

• Charles Darwin was a 19th century British scientist who developed a theory of evolution based on the process of natural selection. Darwin believed the Angracoid orchid and the hawkmoth that pollinated it were an example of how plants and pollinators affect each other's evolution. Angracoid orchids have an extremely long nectar spur, which forces the hawkmoth to rub its face in the pollen while trying to reach the nectar, ensuring that the flower is pollinated. In order to reach the nectar, which is the moth's main source of food, it developed a longer tongue, which prompted the orchid to grow an even longer tube. When Darwin first suggested his hypothesis, only the orchid had been discovered. Darwin believed only one animal could pollinate it and predicted the existence of a moth with an equally long tongue. Forty years later, the hawkmoth was discovered and named Xanthophan morgani praedicta, which means "predicted moth." The hawkmoth's tongue was 10 inches long.

Orchid

• Aubert Du Petit-Thouars discovered the Angracoid Orchid in East Madagascar in 1822. It's also known as the Comet Orchid, Christmas Star or The Star of Bethlehem Orchid. The waxy-looking, star-shaped blossoms are ivory to greenish-white and reach up to 7 inches in diameter. Each flower contains a nectar spur that can be more than 12 inches in length. Only the bottom inch or so of the spur contains nectar. Star orchids are easy to grow. The plant prefers some shade, evenly moist soil with good drainage and humidity around 60 percent. It does not like direct sun. It starts producing menthol-scented flowers when it's only 10 or 15 inches tall.

Hawk Moths

• Hawk moths are some of the biggest moths in the world, and they have the longest tongues. The Giant Hawk moth of Madagascar's tongue can reach up to 14 inches in length. There are about 1,200 species of hawk moths worldwide but in a study done at the University of KwaZulu-Natal, only three species were observed pollinating the Star Orchid. These were Xanthopan morgani morgani, Coelonia fulvinotata and Agrius convolvuli. Hawk moths are fast flyers with long narrow wings and thick bodies.

Deja Vu

• In 1992, Gene Kritsky, Ph.D., of the College of Mount St. Joseph in Ohio, postulated the existence of another giant moth after finding a description of a rare orchid, called Angraecum longicalcar, with a 16-inch nectar tube in a natural history library. According to Kritsky, the predicted moth should have a wingspan of 6 inches and a tongue 15 inches long. Kritsky believes the orchid with the 16-inch tube must have co-evolved with its moth pollinator, as Darwin's orchid and moth did. Entomologists who heard him speak, agreed.