Let us get more closely acquainted with the largest, most massive and dynamic moths of Estonia—hawk moths, or more specifically Sphingidae.
The Sphingidae can be recognised by their long narrow forewings, much smaller hind wings and massive body, which reminds one of a cigar. Their flight is fast and vigorous, it is characterised by hovering over a bloom while feeding; at the same time the moth reaches its proboscis towards the nectar. As a rule, they do not land on a flower for feeding. In tropical countries they may be confused with hummingbirds or honeyeaters, both with regard to flight patterns and size, especially in dusk when all the aforementioned species are active.
The Sphingidae larvae have a characteristic appendix at the end of their body, shaped like a thorn or horn, about in the place where animals have tails. Overwintering in the pupa stage is crucial for the normal development of the moth in our climate for going through a successful life cycle. The pupae overwinter in the ground. As a rule, the Sphingidae produce one generation a year in Estonia.
The Sphingidae are mainly nocturnal or crepuscular but there are diurnal species as well.
There are more than 1,000 known species of Sphingidae in the world; 17 of those have been registered in Estonia. Let us firstly view the eyed hawk moth, who is one of the most common species of hawk moths in Estonia.
Eyed hawk moth (Smerinthus ocellatus) is very common in Estonia and one may encounter it all over the country from mid-May to August. The eyed hawk moth likes to fly toward the light and it is therefore quite easy to sight it. Its larvae feed on narrow-leaved willows.
When resting, the moth resembles a piece of bark but when disturbed it reveals the eye spots on its hind wings that are supposed to frighten the disturber. I met the eyed hawk moth on the picture early one morning at Hiiumaa where it was sitting in the light circle cast by a garden lamp and resting from its nocturnal journey. As can be seen, it tried to frighten me away, using its experiences that date back thousands of years. As the eyed hawk moth is widespread and its population is numerous, we have to admit that the characteristics acquired during evolution have brought success to the species. We do not have other species of Sphingidae with such pretty eye spots in Estonia, therefore, the species is easily recognisable for beginner lepidoptery enthusiasts.
Another common nocturnal guest on flowers is the privet hawk moth (Sphinx ligustri). It also likes to fly towards the light and its imagoes fly around from early June to mid-August in Estonia. The moth is the largest species of Sphingidae to live permanently in Estonia. A beginner lepidopterist may confuse the privet hawk moth with the convolvulus hawk moth (Agrius convolvuli), who may chance to journey here in favourable years and is therefore very rare. The privet hawk moth, however, is capable of going through its development cycle in our climate. The larva prefers to feed on lilacs in Estonia, as is indicated by its Estonian name sirelisuru. However, as the species is polyphagous, the larva may feed on other plants, e.g., ashes, currants, raspberries, honeysuckles, etc. Its larva also pupates in the ground so that it could emerge as a beautiful moth in the spring when there is enough food, and continue its life cycle.