Are hummingbird moths good to have around?

Hummingbird moths, also known as hawk moths, are a group of insects that resemble hummingbirds in both appearance and behavior. With their fast, hovering flight and ability to feed on flower nectar while in midair using a long proboscis, these moths have earned the nickname of “hummingbird moths”.

Hummingbird moths can be found across many parts of North America, especially in the late summer months. If you have flowers or feeders in your yard, you may spot these interesting insects paying a visit. But are hummingbird moths helpful guests to welcome, or pesky intruders to shoo away? There are good reasons on both sides of the debate.

Arguments For Welcoming Hummingbird Moths

There are several benefits that hummingbird moths can provide:

• Pollination – Like hummingbirds, hummingbird moths play an important role as pollinators. As they move from flower to flower sipping nectar, they also transfer pollen from one bloom to another. This helps fertilize plants and allows them to produce fruits, seeds, and new flowers.
• Pest control – Hummingbird moth caterpillars have big appetites that often satisfy themselves by feasting on plant pests. The tomato hornworm for example, which can completely defoliate tomato plants if left unchecked, is the larval form of the five-spotted hawk moth.
• Garden interest – With their resemblance to tiny hummingbirds, the acrobatic flight displays of hummingbird moths can add excitement and natural wonder to your landscape.
• Occasional visitors – Hummingbird moths may stop by periodically to fuel up on nectar but they do not take up permanent residence. So you can enjoy their presence when in your yard without an ongoing responsibility.

Concerns About Hummingbird Moths

However, there are also some potential drawbacks of attracting hummingbird moths:

• Messy feeding – When collecting nectar, hummingbird moths plunge their long proboscis deep into each flower. This can sometimes damage blooms or leave behind messy drips of nectar residue.
• Nectar competition – Hummingbird moths share some of the same food sources as hummingbirds, butterflies, and bees. Large numbers of moths in your yard could potentially leave less nectar available for other desirable pollinators.
• Host plant damage – While caterpillars might munch on undesirable pests, they will also feed happily on valued garden plants if available. Caterpillars of some common hummingbird moth species are known to damage tomatoes, tobacco, grapes, and other crops.
• Difficult to control – Managing populations of hummingbird moths is not always easy. Their continual movement from one area to another makes containment and removal challenging compared to more sedentary pests.

Are hummingbird moths helpful or harmful to gardens?

Whether the overall impact of hummingbird moths is positive or negative depends on the specific circumstances:

Helpful Effects

Hummingbird moths are most likely to be beneficial when:

• They are present only transiently or in small numbers
• You have large numbers of pesky insect pests for the caterpillars to feed on
• You have abundant flowers suited to moth pollination that need fertilizing
• You do not grow vulnerable host plants like tomatoes, tobacco, grapes etc

In these situations, the helpful pollination services and natural pest control hummingbird moths provide will outweigh any minor drawbacks. Attracting small populations to pause briefly in your yard can add interest without causing issues.

Harmful Effects

On the other hand, hummingbird moth presence is more likely to be detrimental if:

• Many moths arrive and linger for extended periods
• You have few pesky insect infestations for the caterpillars to eat
• You grow tomatoes, grapes, ornamental plants or other vulnerable crops
• You notice damage to flowers or competition with other pollinators

With large, stable populations, the caterpillar damage, nectar robbing, and competition with other pollinators will become more apparent and outweigh benefits. Discouraging hummingbird moths or removing vulnerable plants may then be your best strategy.

Tips for managing hummingbird moths

If you are on the fence about whether to welcome hummingbird moths or ward them away, here are some tips that may help:

• Inspect plants regularly for caterpillar damage and remove any found
• Avoid planting known moth host plants near vulnerable crops
• Install mesh covers or netting on plants if caterpillar damage becomes excessive
• Remove flowers moths favor when numbers get very high
• Set up a nectar feeder some distance away to divert moths away from flowers
• Use traps baited with sugary liquids to capture and remove large numbers of moths

With some selective management, you can minimize negative impacts while still enjoying the benefits and fascination hummingbird moths provide. Achieving the ideal balance will take some tweaking over time and responses to changing conditions in your garden.

Key Facts About Hummingbird Moths

To further help assess if hummingbird moths are friends or foes for your yard, here are some key facts about these interesting insects:

Appearance and Behavior

• Over 120 species found in North America
• Most have fuzzy bodies and wings to resemble hummingbirds
• Long proboscis for reaching nectar at flower bases
• Wings beat up to 70 times per second, making a humming or buzzing sound
• Active during day and at dusk, especially in summer months
• Can hover in one spot and fly forwards, backwards, up, down, and sideways
• Drink nectar from deep, tubular flowers suited to their long mouthparts
• Visit hundreds of flowers per day seeking nectar

Life Cycle

• Adult moths live for a few weeks up to a couple months
• Females lay eggs on leaves of host plants
• Caterpillars eat leaves voraciously and grow rapidly
• Most species pupate underground; some spin cocoons on plants
• After metamorphosis inside cocoon/pupa, adults emerge and the cycle repeats
• Between one to three or more generations per year, depending on species and region

Key Host Plants

Conclusion

Hummingbird moths are interesting creatures that can provide benefits like pollination and natural pest control. However, large infestations can also damage crops and compete with other pollinators. By inspecting plants regularly, removing vulnerable species if needed, and monitoring moth populations, hummingbird moths can often be managed to provide ecological advantages without significant drawbacks in the garden. With some attentive tweaking to find the right balance, their fascinating presence can be enjoyed without major headaches.