How many species of hummingbird hawk moth are there?

Hummingbird hawk moths are a fascinating group of insects that resemble hummingbirds in their appearance and behavior. These day-flying moths beat their wings up to 70 times per second, allowing them to hover in front of flowers while feeding on nectar with their long proboscis. Their resemblance to hummingbirds is so convincing that they are sometimes mistaken for the birds at first glance.

There are over 1,400 species of hawk moths (family Sphingidae), but only a small subset are known as hummingbird hawk moths. These moths belong to the genus Macroglossum, which contains around 24 species. However, the exact number of Macroglossum species that should be classified as “hummingbird hawk moths” is up for debate among entomologists.

This is because several Macroglossum species closely resemble each other in appearance and behavior, making differentiation difficult. Additionally, some species have wide distributions across different geographical regions, leading to variations and uncertainty around defining separate species or subspecies.

So while reports sometimes list anywhere from 12 to 24 potential hummingbird hawk moth species, most experts agree that there are probably around 15 definitively identifiable species from this group found worldwide.

Major Species

Some of the most widespread and well-known hummingbird hawk moth species include:

• European hummingbird hawk moth (Macroglossum stellatarum) – Found across much of Europe, Asia, and North Africa. Usually considered the most common species.
• Hummingbird hawk moth (Macroglossum scribonia) – Found in North and South America. Often considered a subspecies of M. stellatarum.
• African hummingbird hawk moth (Macroglossum trochilus) – Found in sub-Saharan Africa. Closely resembles the European species.
• Oriental hummingbird hawk moth (Macroglossum sitiene) – Found from India and Sri Lanka to southern China and Indonesia.
• Madagascan hummingbird hawk moth (Macroglossum hirundo) – Endemic to Madagascar.

In addition to these widespread species, there are a number of more localized or rare hummingbird hawk moth species, such as:

• Chilean hummingbird hawk moth (Macroglossum joannisi)
• Annam’s hummingbird hawk moth (Macroglossum annamensis)
• Band-winged hummingbird hawk moth (Macroglossum avicula)
• Fraternal hummingbird hawk moth (Macroglossum fraternus)
• Purple hummingbird hawk moth (Macroglossum pygmaena)

Identifying Features

So what defines a hummingbird hawk moth and separates them from other Macroglossum species? There are a few key identifying features to look for:

• Size – They are medium sized, with wing spans ranging from 1.5 to 2 inches.
• Wings – Their wings are shaped like a hummingbird’s and beat rapidly, allowing them to hover.
• Color – Many have green or brown colored bodies with patches of red, orange, yellow, or purple.
• Proboscis – They have an exceptionally long proboscis (like a straw) used to drink nectar from flowers while hovering.
• Behavior – As their name suggests, they feed on the wing like hummingbirds and are active during the day.

These features distinguish them from other hawk moth species that may have drabber colored bodies, different wing shapes, and behavior focused on feeding at dusk or night. So if you spot a moth that seems to “hum” around flowers in daylight, casually inspecting it should reveal if it meets the criteria of a hummingbird moth!

Geographic Distribution

Hummingbird hawk moths are found on every continent except Antarctica. Here is an overview of where the different species can be found:

As this distribution shows, the majority are found in the Americas, Africa, Europe and Asia. Their range spans tropical to temperate regions, though they are most diverse in tropical locales.

Habitats

Hummingbird hawk moths occupy a variety of habitats across their broad global distribution. Some patterns in their habitat preferences include:

• Drawn to areas with plentiful nectar sources – fields of flowers, gardens, meadows, scrublands.
• Often found along habitat edges – forest margins, hedgerows, roadsides.
• Lowland to moderate elevations, though a few species live at higher elevations.
• Tropical species found in rainforests and wooded areas.
• Temperate species more common in open areas.

They are highly mobile and may wander widely through suitable feeding areas rather than occupy a restricted home range. Continuity of nectar sources is important to maintaining their populations. Some species migrate long distances to follow seasonal blooming patterns.

Feeding

As their appearances indicate, hummingbird hawk moths feed on floral nectar just like hummingbirds. Their long proboscis allows them to delve deep into tubular flowers to extract nectar while hovering in front for quick getaways. Some of their favorite food plants include:

• Lilies
• Thistles
• Petunias
• Nicotiana
• Jasmine
• Lavender
• Verbena
• Phlox
• Penstemon

They have excellent color vision to help them locate flowers and feed during the day. Most species get all of the nutrients they need from nectar, but a few tropical species have been observed eating pollen as well. Their nectar-feeding habitats make them important pollinators for many plants.

Life Cycle

Hummingbird hawk moths exhibit a complete metamorphosis with four life cycle stages: egg, larva (caterpillar), pupa (chrysalis), and adult moth. The stages proceed as follows:

1. Adult females lay eggs singly on host plants for larvae.
2. Caterpillars hatch and feed on host plant leaves.
3. When fully grown, caterpillars pupate, often on stems or in leaf litter.
4. Adult moths emerge from pupae in 1 to 4 weeks.
5. Adults feed on nectar and live for about 2 to 6 weeks while breeding.

In temperate climates there are usually 2 to 3 generations per year, compared to continuous breeding in tropics. Host plants for larvae vary, but some common groups include bedstraws, vines, and trees like ash.

Defense

Hummingbird hawk moth caterpillars have defenses to deter predators, including:

• Camouflage – cryptic greens help them blend into foliage.
• Body shape – tapered bodies with “horns” give a serpentine appearance.
• Regurgitation – they regurgitate irritating fluids when threatened.

Adult moths rely on speed and evasiveness to escape predators. They also employ Batesian mimicry, where a harmless species resembles a harmful one, by mimicking stinging insects.

Population Trends

Some hummingbird hawk moth species have experienced population declines in parts of their range due to habitat loss and pesticide use reducing food sources. However, they remain widespread and abundant overall, with a 2019 assessment of European species stabilizing their conservation status as Least Concern.

Steps to support their populations include planting nectar-rich flowers, limiting pesticide use, and preserving natural areas. Tracking moth distributions through citizen science programs can also help monitor trends over time.

Significance to Humans

Hummingbird hawk moths provide several direct and indirect benefits to people:

• Pollination services for crops and wild plants.
• Bioindicators of habitat quality due to their sensitivity to environmental changes.
• Control of undesirable plants since their larvae feed on some weed species.
• Aesthetic enjoyment from their beauty, unique behavior, and hummingbird resemblance.
• Inspiration for art and stories featuring these charismatic insects.

Their role in pollination and resemblance to beloved hummingbirds give these creatures appeal across cultures. People commonly delight in sighting them visiting gardens, where they may be confused for actual hummingbirds at first!

Research Uses

Scientists have leveraged hummingbird hawk moths for diverse research studies, including:

• Aerodynamics – Their wings have been analyzed to understand optimal designs for hovering flight. The aerodynamics principles were applied to develop more agile micro-air vehicles.
• Vision – How their vision interacts with hover-feeding was studied by tracking flower colors preferred across conditions.
• Energetics – Metabolic rates measured in flight revealed the energy costs of powering their rapid wing beats.
• Migration – Tracked individual migrations documented the incredible distances traveled between seasonal ranges.
• Pollination – Their effectiveness as pollinators for different crop flowers was tested for improving yields.

These insects make excellent model organisms due to their specialized adaptations and ease of observation. Research continues to provide insights into their biology while revealing principles applicable to engineering and technology.

Conclusion

In summary, there are an estimated 15 species of hummingbird hawk moth scattered across much of the world. These superficially bird-like insects captivate observers with their unique appearance and behaviors adapted for accessing floral nectar. Despite some local declines, most populations remain stable, allowing the continuation of these species’ important ecological roles along with their inspiration for human art and science alike. Careful stewardship of their natural habitats can ensure the persistence of these captivating creatures.