A moth that hovers and hums like a hummingbird, yet evolved entirely separately
Spot what looks like a tiny hummingbird sipping from honeysuckle in Europe and you have probably seen a moth. The hummingbird hawk-moth hovers audibly in front of tubular flowers, probing them with a tongue up to 28 millimetres long. The likeness arose independently, a textbook case of convergent evolution.
Carl Linnaeus described the species in 1758. It ranges across the northern Old World from Portugal to Japan but breeds chiefly in warmer lands such as southern Europe and North Africa, producing three generations a year in Spain. Adults spend winter tucked into crevices in rock, trees or buildings and may emerge to feed on unusually warm midwinter days. In Britain and Ireland numbers keep rising, and warmer winters seem to be turning migrants into residents.
Unlike most moths it flies by day, favouring bright sunshine but also dusk, dawn and even rain. Free hovering costs a lot of energy yet gives fine control. In the hottest parts of its range, chest temperatures above 45 degrees Celsius have been measured, close to the ceiling at which insect muscles can still work. Its brown forewings carry wavy black lines, and the hindwings flash orange across a wingspan of 40 to 45 millimetres.
Its eyesight is remarkable. With three types of colour receptor, it can distinguish wavelengths just 1 to 2 nanometres apart, sharper than a honeybee, and chooses food mainly by sight. It prefers long, narrow flowers with generous nectar, which few rivals can reach, and tends to return to the same flower beds at roughly the same hour each day.
Females lay up to 200 pale green eggs, one per plant, which resemble the flower buds of bedstraw, the caterpillars' main food. The larvae sport a rear horn that turns from purplish red to blue with an orange tip. The moth has long been taken as a lucky sign; a swarm was reportedly seen crossing the English Channel on D-Day.
Source: Hummingbird hawk-moth
