Although bees are generally considered the most important, a number of other pollinators are also present in urban landscapes. Following are some other pollinators that have been observed in New York City.
After bees, the next most common visitors of New York City flowers are flies, especially syrphid or “flower flies” in the genera Toxomerus and Syrphus. The few studies of their ability to transmit pollen suggest that they can be effective pollinators of sweet peppers, strawberries, goldenrods, and many other plants. Bee flies (Bombylius species) are another interesting group of flies that are commonly seen in early spring and are excellent pollinators of spring wildflowers like the spring beauty (Claytonia species). It is unclear, however, how many species of pollinating flies are in the New York City area, or which ones are most effective at pollinating different flowers.
Wasps, which are often confused with bees, are sometimes observed on flowers. Bees can be considered “vegetarian” wasps because they feed their larvae pollen whereas many wasps feed their larvae insect prey. However, adults of both bees and wasps may visit flowers for nectar. Most wasps are not very hairy and thus probably have a relatively low likelihood of transmitting pollen. Common wasp flower visitors include social “yellow jacket” or “paper wasps” such as Vespula maculifrons and Polistes dominulus.
Butterflies and Moths
Butterflies are conspicuous when present but not nearly as abundant as bees, comprising just 6 percent of the flower visitors in New York City. Unlike bees, which actively collect pollen and nectar to feed to their young, butterflies as well as moths visit flowers only to seek nourishment from flower nectar for themselves. In addition, because most butterflies have long legs, the likelihood of their body contacting and transmitting pollen may be much lower than bees. Nevertheless, the diversity of butterflies in the New York City area is quite high—at least 110 species were documented in a 50 km radius of the city from 2001 to 2010. Some butterflies, such as the Bronze Copper and Silver-bordered Fritillary, are quite rare and worthy of conservation.
Although beetles are important pollinators of several plants in tropical regions, they are not commonly observed on flowers in the New York City area. Tumbling Flower Beetles (Family Mordellidae) and June Beetles (Family Scarabidae) are among the beetles that have been observed on flowers here. Other beetles in this area may be nocturnal pollinators (see below). In particular, magnolias, pond lilies, goldenrod, and spirea are visited and pollinated by beetles.
Most of the pollinators described thus far are active during the day. However, nocturnal pollinators such as moths, beetles, flies, and other insects may also be important for certain plants. Few studies of nocturnal pollinators in the New York City region have been done, so it is unclear exactly how abundant and important they are. Flowers dependent on nocturnal pollinators are often white, pale yellow, or pink. Hawk moths (Family Sphingidae), for example, are nocturnal pollinators of evening primrose and other Oenothera species.
The only resident species of hummingbird in the Northeast is the Ruby-throated Hummingbird, although several other hummingbird species sometimes move through the area. The tiny birds are actually summer residents, flying south as far as Central America for the winter. Hummingbirds are generally known for visiting tubular red or orange flowers such as orange jewelweed (Impatiens capensis), native coral honeysuckle (Lonicera sempervirens), scarlet bee balm (Monarda didyma), cardinal flower (Lobelia cardinalis), and trumpet creeper (Campsis radicans), which is self-incompatible and has been shown to greatly benefit from hummingbird pollination, relative to pollination by honey bees or bumble bees.