The hummingbird hawk-moth is a spectacular day-flying moth found in the UK, particularly in southern England. With its rapid wing beats and ability to hover while feeding on flowers, it lives up to its name, behaving remarkably like a hummingbird. This fascinating insect is a migrant species that cannot survive the UK winter, but flies here in the summer to breed.
What are hummingbird hawk moths?
Hummingbird hawk-moths (Macroglossum stellatarum) are large day-flying moths with a wingspan of 45-55mm. They get their common name from the way they feed – hovering in front of flowers and using their long proboscis to drink nectar. Their flight is very swift and hummingbird-like. These moths are sometimes attracted to bright colours and will feed from garden flowers.
Hummingbird hawk-moths belong to the Sphingidae family of moths, commonly called hawk moths. This group includes some very large species found in tropical regions. Hummingbird hawk-moths are relatively small in comparison, but are nevertheless one of the larger moths found in the UK.
The hummingbird hawk-moth has olive and pinky-brown forewings and hindwings with a black border and pink stripes. The abdomen has yellow-orange and black bands. The moths have a hairy thorax and head.
Where are hummingbird hawk moths found?
Hummingbird hawk-moths are widespread across central and southern Europe, North Africa and Asia. In hotter countries they can be resident all year round, but in cooler parts of their range they migrate to escape harsh winters.
In the UK, hummingbird hawk-moths are a regular summer migrant. They are unable to survive the cold winters here. Most sightings are in England, especially in the southern half of the country, but the moths also reach Wales and sometimes Scotland.
These moths tend to arrive between May and August, with numbers peaking in July and August. They fly during the day and regularly visit garden flowers.
Hummingbird hawk moth life cycle
Hummingbird hawk-moths which migrate to the UK fly in from southern Europe, often arriving already pregnant. On reaching the UK, the female lays eggs on the leaves of suitable food plants. Caterpillars hatch out and feed on plants before pupating.
In southern England there may be two generations per year. The first generation of adult moths emerges in June and July, lays eggs which hatch into caterpillars. These feed up quickly and pupate, emerging as a second generation of moths in late summer. Further north there is likely to only be a single generation.
The moths do not overwinter in the UK. As autumn approaches they migrate southwards back to southern Europe. Here they mate, hibernate as adults and re-emerge in spring to lay eggs and produce the next generation.
Hummingbird hawk moth life stages
Eggs – Very small, spherical and pale green, laid singly on leaves of food plants.
Caterpillars – Pale green with diagonal stripes and a horn on the rear. Up to 50mm long when fully grown.
Pupa – Formed in a loose cocoon made of leaves stuck together with silk. The pupa is dark brown.
Adult – Day-flying moth with long proboscis for drinking nectar while hovering. Distinctive markings of pink/orange stripes on olive brown wings.
What plants do hummingbird hawk moth caterpillars feed on?
Hummingbird hawk moth caterpillars feed on various plants in the Solanaceae family. Important food sources include:
- Deadly nightshade (Atropa belladonna)
- Potato (Solanum tuberosum)
- Tomatoes (Solanum lycopersicum)
- Woody nightshade (Solanum dulcamara)
- Jasmine – especially winter jasmine (Jasminum nudiflorum)
They will also feed on other garden and wild plants in this family. The caterpillars seem resistant to the toxins in these plants.
How to identify hummingbird hawk moths
Hummingbird hawk-moths are unlikely to be confused with any other moths or insects found in the UK. The combination of their large size, long proboscis, day-flying habit and hovering behaviour make them unique.
Points to look out for when identifying them include:
- Day-flying.
- Around 2 inch (5cm) wingspan.
- Olive brown forewings with pink and black markings.
- Orange-banded black and white abdomen.
- Rapid wingbeats and ability to hover in front of flowers.
- Very long proboscis which is curled up when not in use.
The moths fly during sunny weather throughout the day. They regularly visit garden flowers but also feed on wild flowers such as thistles.
When can you see hummingbird hawk moths in the UK?
Hummingbird hawk-moths are seen in the UK between May and September but peak in July and August. They tend to arrive slightly later in northern areas.
The first moths arrive in southern coastal counties in late May and early June. Their numbers build through July and peak in August. Reports tail off during September and they are unlikely to be seen after mid-October.
This pattern may vary slightly from year to year, depending on weather conditions. In hot summers higher numbers may arrive and peak earlier. Cool, wet summers may suppress numbers and delay peak sightings.
Month | Sightings |
---|---|
January | None |
February | None |
March | None |
April | Very rare |
May | Early sightings, usually late May in south |
June | Sightings increasing, spreading northwards |
July | Widespread, numbers increasing |
August | Peak sightings |
September | Numbers decreasing, mainly south coast |
October | Very rare late sightings |
November | None |
December | None |
Most reports are from May to August, with the peak months being July and August. However, in hot summers there may also be increased numbers recorded in late May and June.
Regional differences
The first moths arrive on the south coast, so the season starts earlier in southern counties like Cornwall, Dorset, Sussex and Kent. Sightings spread northwards through June and July.
By August hummingbird hawk-moths can be seen almost anywhere in England and sometimes southern Scotland, particularly during hot spells. The season lasts longer in the south, with moths lingering into September.
Sightings are more scattered in northern England, Wales and Scotland. However, in good summers reasonable numbers may reach southern parts of Scotland.
Why do hummingbird hawk moth sightings peak in summer?
Hummingbird hawk-moths migrate to Britain for the summer to take advantage of the long days and flower-filled countryside. The peak months of July and August provide ideal conditions.
Key factors include:
- Long daylight hours allow plenty of feeding time.
- Warm summer temperatures speed up their metabolism and life cycle.
- Flowers are abundant, providing lots of nectar.
- Two generations can be produced to boost numbers.
- Calm, sunny weather encourages the moths to fly.
The long, light and warm days of July and August are perfect for these day-flying moths. This influences both their abundance and behavior – they are noticeably more active on sunny days.
How to encourage hummingbird hawk moths into your garden
If you live in southern England, you stand a good chance of seeing hummingbird hawk moths in July and August. But you can increase your chances by making your garden more attractive to them.
Ways to encourage these moths include:
- Planting nectar-rich flowers they like, such as red valerian, honeysuckle, lavender and petunias.
- Choosing old-fashioned varieties with simple, open flowers.
- Having areas of long grass and native wildflowers.
- Avoiding spraying pesticides which reduce insect numbers.
- Putting out ripe fruit to attract them.
- Growing tomato or potato plants which their caterpillars feed on.
Providing nectar sources like buddleia, lavender and verbena is excellent for attracting the moths to feed. Allowing some areas to grow wild with long grass and native flowers is also beneficial.
Key plants to attract hummingbird hawk moths
Good garden plants to attract hummingbird hawk moths include:
- Lavender – especially english lavender.
- Buddleia.
- Red valerian.
- Petunias.
- Verbena.
- Honeysuckle.
- Phlox.
- Salvia.
These provide nectar for the adult moths. Having some host plants like tomatoes, potatoes or jasmine may result in breeding as well.
Conclusion
Hummingbird hawk-moths are a spectacular and unmistakable species seen in the UK from May to September, with peak numbers in July and August. They fly northwards, following the warmer weather. Gardens can be made attractive to them by planting nectar-rich flowers and providing some wilder areas. With a little thought, you can greatly increase your chances of seeing one of these mesmerizing moths hovering at your flowers through the British summer.