Dr. Barbara Hass Jacobus, biology program coordinator and lecturer in the Division of Science at Indiana University-Purdue University Columbus (IUPUC) offers an effective and unique solution to the recent onset of gnats in the offices of faculty and staff on campus.
Within the Division of Science at IUPUC is a collection of unique plants that includes several carnivorous varieties. Jacobus provides the following elucidation, “Recently several offices have utilized our carnivorous plants for gnat control after I issued an invitation to all faculty and staff to “rent-a-plant” for offices plagued with gnats or fruit flies. Specifically, carnivorous plants called sundews, which are very effective in catching annoying little insects, were made available.”
Jacobus says the rental fee is nominal. She explains that participants are simply asked to learn a fact or two about the biology of the plant and share their new knowledge with others visiting their office. Jacobus hopes to eventually have a campus greenhouse, which would benefit the program with greater plant numbers and varieties allowing better education about the species beyond the IUPUC community and giving the program the ability to better assist people on and off campus with starting their own carnivorous plant collections.
Jacobus shares specific information about carnivorous plants
Sundews are a type of carnivorous plant. Carnivorous plants typically live in soils that are low in key minerals the plants need, and in very wet areas, such as bogs, where water carries away
the minerals. While photosynthesis will keep the plants alive, they won’t have enough extra energy to reproduce, so they have evolved a way to supplement their nutrition by eating animals, mostly insects.
There are many kinds of sundews. IUPUC has cape sundews, scientific name Drosera capensis. The plants in our collection were gifts from a colleague at Purdue to help start our collection. They are native to the Cape of South Africa.
We also have a variety from Queensland, Australia, scientific name Drosera adelae, also a gift from Purdue.
A third variety in our collection is the pygmy sundews, native to southwestern Western Australia. From this variety, we have Drosera x carburup, a natural hybrid.
How do sundews eat?
Sundew leaves are covered with stalked glands, called tentacles, which produce a tiny drop of a sticky, clear, dew-like substance. According to Peter D’Amato in his book The Savage Garden, when insects land on the leaves, they get caught in the sticky drops at the end of the glands. As they panic and struggle, they get captured by additional sticky drops. Some of the tentacles begin to move and curl inward to trap the insect and prevent its escape.
The prey either suffocates when its breathing holes get covered with the drops of glue or will die from exhaustion in its struggle to survive. Some species (such as the cape sundews) may also curl their leaves around the insect. Once prey is caught, the glands secrete digestive enzymes and acids that liquefy the soft parts of the insect. The plant is then able to absorb the nutrients from the digested juices. After digestion, the tentacles and leaves will generally return to normal (older leaves may die off). The insect carcass either remains or is washed away.
To learn more about the Division of Science at IUPUC visit www.iupuc.edu/science or phone: 812.348.7228.
You may also e-mail science@iupuc.edu.