Sphinx moth

The Sphingidae are a family of moths (Lepidoptera), commonly known as hawk moths, sphinx moths, and hornworms; it includes about 1,450 species. It is best represented in the tropics, but species are found in every region. They are moderate to large in size and are distinguished among moths for their rapid, sustained flying ability. Their narrow wings and streamlined abdomens are adaptations for rapid flight. The family was named by French zoologist Pierre André Latreille in 1802. Some hawk moths, such as the hummingbird hawk-moth or the white-lined sphinx, hover in midair while they feed on nectar from flowers, so are sometimes mistaken for hummingbirds. This hovering capability is only known to have evolved four times in nectar feeders: in hummingbirds, certain bats, hoverflies, and these sphingids (an example of convergent evolution). Sphingids have been much studied for their flying ability, especially their ability to move rapidly from side to side while hovering, called 'swing-hovering' or 'side-slipping'. This is thought to have evolved to deal with ambush predators that lie in wait in flowers. Sphingids are some of the faster flying insects; some are capable of flying at over 5.3 m/s (12 miles per hour). They have wingspans from 4 to over 10 cm (3.9 in). Antennae are generally not very feathery, even in the males. They lack tympanal organs, but members of the group Choerocampini have hearing organs on their heads. They have a frenulum and retinaculum to join hindwings and forewings. The thorax, abdomen, and wings are densely covered in scales. Some sphingids have a rudimentary proboscis, but most have a very long one, which is used to feed on nectar from flowers. Most are crepuscular or nocturnal, but some species fly during the day. Both males and females are relatively long lived (10 to 30 days). Prior to flight, most species shiver their flight muscles to warm them up, and, during flight, body temperatures may surpass 40 °C (104 °F). In some species, differences in form between the sexes is quite marked. For example, in the African species Agrius convolvuli (the convolvulus or morning glory hawk moth), the antennae are thicker and wing markings more mottled in the male than in the female. Only males have both an undivided frenular hook and a retinaculum. Also, all male hawk moths have a partial comb of hairs along their antennae. Females call males to them with pheromones. The male may douse the female with a pheromone before mating. Some species fly only for short periods either around dusk or dawn, while other species only appear later in the evening and others around midnight, but such species may occasionally be seen feeding on flowers during the day. A few common species in Africa, such as the Oriental bee hawk (Cephonodes hylas virescens), Macroglossum hirundo, and Macroglossum trochilus, are diurnal. In studies with Manduca sexta, moths have dynamic flight sensory abilities due to their antennae. The antennae are vibrated in a plane so that when the body of the moth rotates during controlled aerial maneuvers, the antennae are subject to the inertial Coriolis forces that are linearly proportional to the angular velocity of the body. The Coriolis forces cause deflections of the antennae, which are detected by the Johnston's organ at the base of each antenna, with strong frequency responses at the beat frequency of the antennae (around 25 Hz) and at twice the beat frequency. The relative magnitude of the two frequency responses enables the moth to distinguish rotation around the different principal axes, allowing for rapid course control during aerial maneuvers. Most species are multivoltine, capable of producing several generations a year if weather conditions permit. Females lay translucent, greenish, flattened, smooth eggs, usually singly on the host plants. Egg development time varies highly, from three to 21 days.