Hummingbird moths, also known as hawk moths, are a group of insects that resemble hummingbirds when they feed. Their characteristic hovering behavior gives them their common name. There are over 1,200 species of hawk moths worldwide, with around 200 species native to North America. Hummingbird moths beat their wings rapidly, allowing them to hover in place while drinking nectar from flowers with their long proboscis. They are some of the fastest flying insects, reaching speeds over 12 mph. Knowing when these unique moths emerge in your area can allow you to plant flowers they prefer and watch their fascinating feeding behaviors.
When do hummingbird moths emerge?
The exact timing of when adult hummingbird moths first emerge varies by species and location. However, in most of North America, the majority of species will first appear between late spring and mid summer. Here is an overview of when common hummingbird moth species become active:
March-May
Some of the earliest hummingbird moth species begin flying from March through May. This includes:
– White-lined sphinx moth
– Five-spotted hawk moth
– Nessus sphinx moth
– Virginia creeper sphinx
These moths emerge early to take advantage of the first spring flowers. They have adaptations like thermal regulation and insulation that allow them to fly in cooler temperatures.
May-July
The peak hummingbird moth season across much of the United States and Canada is May through July. Some of the common species on the wing at this time include:
– Tobacco hornworm moth
– Carolina sphinx moth
– Ello sphinx moth
– Blinded sphinx moth
– Snowberry clearwing
– Hummingbird clearwing
The abundance of summer flowers allows large numbers of moths to emerge and find ample sources of nectar. Later summer emergence allows them to avoid the harshest winter conditions.
July-September
Some hummingbird moth species wait out the hottest summer conditions and don’t emerge until mid to late summer. Examples include:
– White-lined sphinx
– Lettered sphinx
– Wild cherry sphinx
– Azalea sphinx
– Rustic sphinx
These warmer climate adapted species time their emergence to coincide with the bloom period of flowers they specialize on. Their emergence often overlaps with southbound migrations of ruby-throated hummingbirds.
Migration
Most hummingbird moths cannot survive cold winters. Some species that emerge earlier in the year may go through two to three generations before winter. However, most only complete one generation per year. The adult moths that emerge in late summer or fall will migrate south to warmer climates like Mexico and Central America to overwinter. When spring returns, some of their offspring will migrate north again and repeat the cycle. This helps expand their range and utilize seasonal flower resources.
What affects when hummingbird moths emerge?
The timing of hummingbird moth emergence involves a complex interplay of environmental factors and evolutionary adaptations. Understanding what influences when they first appear can help us predict when they will show up each year.
Photoperiod
Photoperiod is the amount of daylight in a daily cycle. Many insects use photoperiod cues to begin pupation or trigger adulthood. For instance, shortening days may signal some hummingbird moth pupae to complete metamorphosis before winter. Increasing daylight in late winter motivates adults to emerge. The consistency of annual light level patterns makes photoperiod a reliable indicator of seasonal changes.
Degree days
Degree days are a measure of accumulated warmth over time. Hummingbird moth development depends on completing a certain number of degree days above a minimum temperature threshold. More degree days allow faster growth and emergence. Reaching adequate warmth is essential for the high-energy activities like flight in adults. Tracking degree days helps predict moth development and ideal conditions.
Climate
Regional climate differences create selective pressures that shape when local hummingbird moth populations emerge. For example, southern species may appear earlier to take advantage of long growing seasons. Northern species delay emergence until temperatures allow survival and plant resources are available. Migratory behavior in some species allows expanding ranges across varying climates.
Elevation
At higher elevations, colder conditions and shorter growing seasons delay hummingbird moth emergence compared to lower elevations. For instance, the same species may appear several weeks earlier in lowland areas than mountain sites. Some high elevation populations have adapted by having multiple generations in a year when possible.
Flowering plants
Hummingbird moths time their emergence to coincide with bloom periods of their nectar plants. This ensures adequate food resources for adult feeding and energy needs. The plants in turn benefit from increased pollination. If climate changes alter plant flowering, it could disrupt aligned moth life cycles.
Diapause
Diapause is a period of dormancy that helps many insects survive harsh seasons. Shortening photoperiods or cooling temperatures trigger diapause in some overwintering hummingbird moth pupae. Molting hormones resume activity when conditions improve, leading to emergence. Properly timing diapause exit is critical to emergence synchrony with flowers.
What flowers attract hummingbird moths?
To spot hummingbird moths in your own yard, you can plant flowers that these nectar-loving insects are powerfully drawn to. Here are some of the top flowers favored by foraging hummingbird moths:
Bee balm
Also called monarda, bee balm produce tubular red flowers that hummingbird moths find irresistible. They easily hover in place to sip nectar while pollinating the blossoms. Bee balm thrives in full sun and blooms from mid summer into fall, making it an ideal late season hummingbird moth nectar source.
Butterfly bush
As its name suggests, butterfly bush is a magnet for pollinators beyond just butterflies. Hummingbird moths will flock to the plant’s dense clusters of pink or purple flowers from summer through the first frost. It tolerates a variety of soils and requires little upkeep.
Trumpet creeper
Trumpet creeper vine has large orange tubular flowers that draw in hummingbird moths all season long. Once established, it grows aggressively to cover trellises, fences and more with its lush blooms. Caution should be used however, since trumpet creeper can become invasive in some regions.
Petunias
Popular annual bedding plants, petunias are hummingbird moth favorites. Their trumpet shaped blossoms invite moths to hover and gain quick energy. Growing different color varieties together creates an eye-catching display sure to attract moths.
Nicotiana
Also called flowering tobacco, Nicotiana produce clusters of tubular blooms ideal for hummingbird moth feeding. Their flowers open in the evening with a strong, sweet fragrance that specifically attracts moths. These annual plants come in varieties with both white and pink flower colors.
Verbena
Verbena bushes or trailing verbena varieties give hummingbird moths flat flower clusters rich in nectar. Their tiny, five-petaled blooms are easy for moths to probe. Verbena thrives in hot, sunny conditions. It blooms from early summer until frost, providing an ongoing nectar source.
Lantana
Lantana produces dense, colorful flowers in clusters called umbels. The abundant nectar draws in many hummingbird moths and butterflies. Trailing lantana varieties look particularly beautiful spilling over containers and garden edges. Lantana blooms best in full sun and hot conditions.
Fuchsia
Ornamental fuchsia offers versatile usage, and makes an excellent hummingbird moth plant. The hanging, tubular flowers provide accessible nectar. Fuchsia can be grown in containers or hanging baskets, trained as standards, or planted as ornamental edging. Flowering occurs repeatedly from summer until frost.
Zinnia
Long a favorite for bright floral displays, zinnias attract frequent hummingbird moth visitors with their wide range of flower forms and colors. The large, single flowered varieties seem to be their preferred choice. zinnias are easy to grow annuals that thrive in hot, sunny beds or containers.
Salvia
The tubular flowers of ornamental salvia perfectly match the long tongue extension of hummingbird moths. Red varieties seem to draw in the most moths, but other colors are also frequented. Salvia keeps flowering intermittently all season. There are varieties suitable for both full sun and partial shade conditions.
Conclusion
Hummingbird moths display a fascinating life cycle tied closely to seasonal flowering plant resources. By paying attention to key environmental cues like photoperiod, warmth, and food sources, the adult moths manage to emerge precisely when abundant nectar will allow feeding and reproduction. Their precisely adapted hovering ability provides reliable access to flower nectar across a wide range of plant shapes and sizes. Home gardeners can easily enjoy watching hummingbird moths by growing some of their favorite flowering plants and observing peak activity times during the warmer months. The moth’s speed, agility and beauty in flight make them a joy to observe. By supporting these important pollinator species in our gardens, we help preserve the magic of their unique ecological partnerships with flowers.
