Manduca Hawk Moth

Manduca sexta, the tobacco hornworm, is used for a variety of entomological studies. An artificial diet is available making it relatively easy to rear in the laboratory. It is a relatively large moth which makes it easier to do many physiological experiments. The adult hornworms are Sphinx Moths of the family Sphingidae. Sphinx moths are known for their ability to hover while collecting nectar from flowers.

Scientists who are interested in the aerodynamics and flight mechanics of hovering study Manduca as a model for developing flying mechanical robots with the the ability to hover. The ability to hover in a relatively small space allows the flight to be captured on video.

Hovering also allows entomologists to study the interactions between hawkmoths and the flowers they pollinate. The Manduca hawkmoth flies at night and often visits flowers in the nightshade family. Some flowers such as flowering tobacco (nicotiana) open at night to attract the night flying moths that pollinate them. These flowers are fragrant. Experiments have demonstrated that these hawk moths respond to both the odor and visual cues of the flowers.

Manduca Hawkmoth Resting on A Branch

The odors attract the moth to the flower location from longer distances. At short range, the moth uses visual cues provided by the flower to guide its proboscis (long sucking mouthpart) into the flower to contact the nectar. Some pollen from the flower sticks to the proboscis and is carried to neighboring flowers. It is possible to use artificial flowers baited with odor to investigate the visual cues used by the moths. The artificial flowers can be constructed with patterns or even be clear so the moth cannot see the flower. Seeing the flower is necessary to elicit extension of the proboscis by the hawk moth. Other patterns help the moth direct its proboscis to the source of the nectar.

Hawk moths can “learn” where to locate nectar in relation to the patterns. Hawk moths are also able to track flowers that are moving up to about 3 cycles per second. This ability is important when a breeze causes the flowers to move. The hawk moth can move while hovering and adjust its flight to hit the moving target.

The Manduca hawk moths are strong fliers. I have seen and heard them flying at night, attracted to flowering tobacco ornamentals in my front yard. Their low distinctive buzzing sound can easily be heard on warm summer nights.

About jjneal

Jonathan Neal is a retired Associate Professor of Entomology at Purdue University and author of the textbook, Living With Insects (2010). This blog is a forum to communicate about the intersection of insects with people and policy. This is a personal blog. The opinions and materials posted here are those of the author and are in no way connected with those of my employer.
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3 Responses to Manduca Hawk Moth

  1. Jill Owen says:

    I still find it really interesting to find how smart insects are and how valuable they can be to science. Often, people regard insects as annoying and rather dumb, which makes it really fascinating to hear about how insects like the Hawk Moth can learn where to feed and even track its food source. Now I’m curious about how intelligent some other insects are! I’m also kind of interested in trying to get some fake tobacco flowers and trying to lure in the Hawk Moths myself. It could be a really interesting experiment!

  2. Anonymous says:

    That is actually quite interesting. Those moths can track their food source from such a far distance. I always thought they were just really annoying and always getting in the way but actually learning how they interact with the odor of the flower and the visual sight of the flower is so amazing. I never really thought about how intense finding a food source was because with humans you always just have food in the refrigerator or go to the market. These moths actually use all of their resources such as their powerful wings to get an abundant amount of food.

  3. Ryan Straut says:

    It is interesting how the flower works to attract the moth, but how the moth has adapted so well to feeding on these particular plants. Nature really has a way of pairy organisms together for the benefit of eachother.

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