Tomato Hornworm Moths At Grand Canyon National Park
After a full day of activity at Grand Canyon National Park, Bob and I were returning late to our room at Maswik Lodge when a flicker of movement drew my eye towards the stunning night-blooming Moonflowers. We were not the only ones attracted by the glowing white flowers. Numerous Tomato Hornworm Moths, also known as Five-spotted Hawkmoths, were circling for a landing.
I was really intrigued by these nocturnal cousins of butterflies because they seemed to hover helicopter-style like small hummingbirds, which is why they are also known as Hummingbird Moths.
We had actually taken notice, early that morning, of the striking white blooms on the Moonflower plant, otherwise known as Datura wrightii. The large, trumpet-shaped corollas are usually withered by midday, having opened the evening before just as darkness cloaks the land, but we were up bright and early before the blooms wrapped into themselves.
Moonflower, or Datura Wrightii, is a native perennial wildflower in Arizona, and grows well in either a desert or upland environment. The plant is highly toxic and, if improperly handled, can be lethal. Since before recorded history, the narcotic qualities of the plant extracts have been known, and they once figured prominently in native religious ceremonies because of their hallucinogenic qualities. Hence, another name for the plant is Sacred Datura or Sacred Thornapple.
The highly-fragrant blossoms attract a variety of insects during the early part of the day,
and are a magnet for night-flying moths such as the Tomato Hornworm Moth.
In their caterpillar stage, the Tomato Hornworm Moths are plump, marvelously well camouflaged green caterpillars that feed voraciously on tomato plants, pepper and potato plants, chowing down on the leaves until branches are left bare. Among other plants in the Solanacaea family that the tomato hornworms favour are the Sacred Datura.
Tomato Hornworm Moths get their name from the fact that the caterpillars have a horn gracing the back end of their bodies. If a caterpillar is disturbed, it will raise its head and front third of its body into a contemplative stance and remain that way in what is referred to as a sphinx-like pose. Hence, the moths are also called Sphinx Moths.
It is hard to believe that the homely tomato hornworm caterpillar morphs into such a magnificent moth. The Five-spotted Hawkmoth is recognizable by the five pairs of yellow bands on its abdomen.
These moths have a wingspan of between 9-13.5 centimetres (3.5-5.5 inches). Maybe that is why a lot of people find them to be creepy and scary. Between its size , fuzzy antennae and the fact that it flies erratically at nighttime, some unsuspecting person prowling around in the dark might be spooked when one of these moths nonchalantly brushes against their skin.
For Bob and me, however, after a full day of hiking at the Grand Canyon,
and the promise of new blooms on the Datura plant opening at sunset, judging by the large, plump buds we saw that morning,
we were filled with anticipation when the last rays of sunshine kissed the upper reaches of the canyon walls.
Sure enough, fresh startling white flowers had opened and awaited the attentions of the Sphinx Moths. Sadly, we saw no sign of them the following evening. I guessed they had moved on to greener pastures.
For Bob and me, the Five-Spotted Moths had made a real impression, and we eagerly passed that way every night before retiring, on the off chance that the moths would be visiting the Datura plant again. They are magnificent insects!