03/14/2026
Have you noticed that smell?
Bradford pears, or *Pyrus calleryana*, are well-known for their white blossoms in spring, but they’re often criticized for their unpleasant odor. The smell is primarily due to the production of volatile compounds during blooming, particularly compounds like trimethylamine and hydrogen sulfide, which can give off a scent reminiscent of rotting fish or other decomposing organic matter. Here’s a deeper look into why they stink and their connection to flies:
Reasons for the Odor
1. Chemical Compounds: During the flowering period, Bradford pears emit certain sulfur-containing compounds. These are often produced as part of the plant's reproductive strategy to attract pollinators.
2. *lPollination: The strong smell is an evolutionary trait aimed at attracting specific pollinators, including flies. The scent mimics the smell of decaying matter, which can attract certain flies that are drawn to such odors for breeding purposes.
3. Flower Structure: The structure of the flowers can also contribute to the odor. The flowers are not very attractive to traditional pollinators like bees, so they rely on the foul smell to attract flies instead.
Connection to Flies
- Attraction: The foul odor attracts flies, particularly those that are scavengers or carrion flies, which are drawn to decaying organic matter. These flies help with pollination by transferring pollen from flower to flower as they feed.
- Reproductive Strategy: By attracting flies, Bradford pears ensure that their flowers are pollinated, even if the pollinators are not the typical ones associated with flowering plants.
Given their unpleasant odor, reliance on flies for pollination, and the fact that Bradford pears are considered invasive in Kentucky, this serves as another compelling reason to remove them. They can outcompete native species, disrupt local ecosystems, and contribute to biodiversity loss. Removing Bradford pears not only helps restore native habitats but also eliminates the nuisance of their foul smell and the attraction of unwanted flies.