Skip to main content

Hornworms by Brionna McCumber

Gardeners in Colorado may find large green caterpillars with an iconic horn on their plants every summer—these are hornworms! Tobacco hornworms (Manduca sexta) feed on common garden crops, often leading to conflict with humans. These very hungry caterpillars are defoliators, damaging plants such as tomatoes, peppers, potatoes, and eggplant. While the caterpillars use crops as a food source, which could be seen as negative, the moths provide a critical step in reproduction for the plants via pollination.


Carolina Sphinx Moths (Manduca sexta), also called Hummingbird moths, are the adult form of hornworms. They are known for their unique ability to hover mid-flight. Combined with the use of a special elongated proboscis, these moths are especially important for plant species with long tubular flowers that other pollinators cannot access or pollinate. 
The Gardens on Spring Creek Butterfly House wants to highlight the importance of these specialized pollinators in our native Colorado ecosystems. We recommend that those who have hornworms in their garden attempt to relocate these creatures instead of bringing them into our facility. These animals eat many more things than just tomatoes! They are not picky and can host on a large variety of plants. Other plants that these caterpillars may find attractive:
  • Potatoes
  • Horse nettles
  • Eggplant (Solanum)
  • Peppers (Capsicum)
  • Jimsonweed
  • Thorn Apples (Datura)
  • Wild Tomatoes (Lycopersicon)
  • Tobaccos (Nicotiana)
  • Cape Gooseberry
  • Tomatillos
  • Husk Cherry (Physalis)
  • Petunias
  • and many more! 
You can help support local wildlife and pollinators by relocating hornworm caterpillars to a space where they can eat and grow without being a nuisance to your crops. Please help us keep wildlife, wild! 
Labels:

Popular posts from this blog

When Plants Fight Back

By Andrew Scott, Horticulturist for The Gardens on Spring Creek This is the second installment of a two-part feature on plant defenses. Read Part I online at North Forty News . Caffeine, nicotine, morphine, cocaine ... sounds like the ingredients label on an old-timey cold medicine, right? These molecules are actually all alkaloids, some of the most common chemical deterrents deployed by plants. As the adage goes, the dose makes the poison. While people can (and do) ingest these alkaloids for their psychoactive effects, they prove to be much more deadly to a small insect that weighs all but a few tenths of a milligram.  The sap of opium poppies ( Papaver somniferum ) contains morphine, a potent sedative (via Daniel Prudek , Hodder Education Magazines)   Still, alkaloids have a strongly bitter taste, which animals have learned to associate with the toxic effects they can have. Eating green potatoes isn’t likely to kill you, but solanine, the alkaloid that triggers this change...
Read more

Migrating Monarch Conservation Gardening

  Migrating Monarch Conservation Gardening  by Brionna McCumber This past winter, the U.S. Fish and Wildlife Service proposed a rule to list monarch butterflies as threatened under the Endangered Species Act. The iconic migration along the east side of the Rocky Mountains sees monarchs flying from as far north as Canada down to the Oyamel forests in Mexico. Most of these butterflies travel through the Great Plains region of the United States, with the Front Range serving as the western boundary of their migratory pathway. Starting in March, monarchs begin their journey north again, reproducing and laying eggs along the way. Their northward migration continues over multiple generations, limited by the availability of milkweed host plants and nectar sources for adult butterflies. This cycle persists throughout the summer until late August, when the migration south begins once more. In December 2024, the overwintering populations occupied 4.42 acres of forest in Mexico—nearly d...
Read more