The Hawkmoths, Sphingidae are a widespread family of moths with more than a thousand species worldwide. They are usually large, broad-bodied strong flying moths whose caterpillars have a characteristic tail spike. Some members of the group have long tongues and feed extensively being able to use long tubular flowers as nectar sources, while others have reduced mouthparts and so do not feed as adults. In Britain there are 9 species that are resident and a further 8 others that are more or less regular immigrants, but which do not successfully over winter. In the Parish in the last few years 8 species have been seen that I have heard about, though only the Hummingbird and Elephant Hawkmoths are seen every year. Additionally, the Small Elephant Hawkmoth has been seen but not for a long time. The Hummingbird Hawkmoth was covered in this series on 5th August.
Elephant Hawkmoth
Elephant Hawkmoth: This characteristically ‘pink with olive markings’ moth has a long tongue and can feed easily from flowers like honeysuckle. It can be seen on the wing from May until early August. The usual caterpillar food plants are various willow-herbs and in gardens Fuchsias.
The large caterpillar, which is seen quite often, has two pairs of large eyespots on the segments just behind the small head, which, on being disturbed, it waves about, perhaps startling a would-be predator. The caterpillar forms a pupa in the leaf litter or in the soil below the food plant where it then over winters.
Privet Hawkmoth
Privet Hawkmoth: This is the largest of our resident hawkmoths with dark chocolate coloured forewings. It flies in June and July but does not feed. The caterpillar food plants are wild and garden privet, ash, and lilac. The caterpillar itself, is bright green with conspicuous purple edged white chevrons. It can be found from July through to September and overwinters as a pupa sometimes over two winters.
Poplar Hawkmoth
Poplar Hawkmoth: This moth flies between May and July and can have a small second generation in August or September. Its wings are a patchwork of brown and grey and at rest holds its wings such that the hind wing projects beyond the front edge of the forewing. The eyed hawkmoth. The food plants of the caterpillars is a variety of poplars and willows. The caterpillar is green with white diagonal striping also similar to the Eyed Hawkmoth. Pupae are formed buried in the soil at the bottom of the food plant, and which then overwinters.
Eyed Hawkmoth
Eyed Hawkmoth: This moth flies from mid-May into July. Its resting position resembles the poplar hawkmoth but if gently disturbed it reveals big ‘eyes’ on its hind wings and rocks too and fro. This seems to ward off insectivorous birds. The caterpillar food plant is predominantly apple but also crab apple and willows. The caterpillar is green with pale diagonal stripes resembling the poplar hawk moth and can be found from July through to September or October. It pupates underground near the food plant where it overwinters.
Convolvulus Hawkmoth found dead.
Convolvulus Hawkmoth: This is the biggest of the hawkmoths mentioned so far. It is an immigrant with very variable numbers arriving mainly in late August through into November. It has an exceptionally long tongue and can feed easily on long tubular flowers, white, nocturnally scented ones seem particularly attractive. The fore wings are mottled in ash greys and there are pink markings along the abdomen resembling those in the Privet Hawkmoth. The larval food plants are various bindweeds and larvae are regularly found along the south coasts of the UK. However, they do not survive to over winter.
full grown caterpillar
Death’s Head Hawkmoth: This is the rarest of Westbury’s Hawkmoths being seen only very occasionally. In 2019 11 caterpillars or pupae were found in Westbury and several were kept and emerged in captivity for people to enjoy seeing before release. This year, at least so far, none have been seen, but they have been seen in Westbury before, as they are shown in a photo of the Village postmaster in what is believed to be 1984.
Westbury Postmaster
As the largest British Hawkmoth, it is quite unmistakeable with dark patterned forewings and yellow underwings with black borders. The thorax has a very realistic looking skull like marking. Small numbers arrive in the UK from strongholds in North Africa and southern Europe every year. They lay eggs usually on potatoes but also on woody nightshade and the huge yellow caterpillars that grow rapidly can be found in August when lifting potatoes, or the large pupae may be found later buried in the soil amongst the potato plants.
Pupa
The 11 from Westbury and, for that matter, the 5 from Easton might represent eggs laid by a single fertile wandering female who has flown in from North Africa. She spreads here eggs out between potato patches. The adults emerge a month of so later in September and are occasionally seen. They can enter bee-hives without being attacked, where their short tongues are able to feed on honey stores. If the adult moth is disturbed it squeaks which may be part of its defences against attack by bees when it is in a hive. The squeak might resemble sounds made by queen bees. Neither the adults nor the pupae can over-winter in the UK and it is probably entirely wishful thinking to hope that the spectacular, newly emerged moths might fly southwards to return to southern Europe and North Africa.
in hand
Taking flight
Photos
Gill Cook
Liza Hobbs
Sylvia Healey
Ian Jones
Mike Jones
Peter Bright
Huge numbers have been recorded heading south and are able to once more return to the north African breeding grounds from which their great or great great grandparents left in the previous January. This strategy is so successful that the numbers estimated to return are much greater than the numbers that left. The benefit of this migration is believed to be related to a very effective wasp parasitoid that each year more or less exterminates any remaining north African Painted lady caterpillars. Migration means that the butterfly can evade this parasite and the successfully returning butterflies can take advantage once again of the ideal breeding conditions in north Africa over the northern winter before the wasp parasitoid multiplies once more. The extent to which sub-Saharan originating butterflies are part of the European annual immigration is not yet clear. While the occasional overwintering butterfly has been found e.g. in Cornwall, it seems clear that, as it has no ‘hibernation’ stage and caterpillars die when the temperatures fall below 5oC, it does not survive to any useful extent in the UK. The numbers that arrive in the UK each year are hugely variable and are, presumably, related to the particular conditions in the breeding grounds along their migration routes. 2009 and 2019 were the last ‘Painted lady years’ in which large numbers arrived in the UK.
