The Sphingidae are a family of moths commonly called sphinx moths, also colloquially known as hawk moths, with many of their caterpillars known as 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 agile and sustained flying ability, similar enough to that of hummingbirds as to be reliably mistaken for them. (an example of convergent evolution). Sphingids have been 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. They have wingspans from to over .

Description

Sphingid's antennae are not very feathery, even in males, Females attract males with pheromones. The male may douse the female with a pheromone

Flight

In studies with Manduca sexta, moths have dynamic flight sensory capabilities 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.

thumb|[[Vine hawk-moth larva (Hippotion celerio)]]

thumb|An example of the posterior "horn" seen on the [[Manduca quinquemaculata|tomato hornworm]]

Life cycle

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.

thumb|A [[Hyles gallii caterpillar seeking a place to pupate: the color of the caterpillar darkens before pupation.]]

thumb|[[Hyles euphorbiae pupa]]

Sphingid caterpillars are medium to large in size, with stout bodies. They have five pairs of prolegs. Larvae are quick to regurgitate their sticky, often toxic, foregut contents on attackers such as ants and parasitoids. Some species can tolerate quite high concentrations of specific toxins. Tobacco hornworms (Manduca sexta) detoxify and rapidly excrete nicotine, as do several other related sphinx moths in the subfamilies Sphinginae and Macroglossinae, but members of the Smerinthinae that were tested are susceptible. The species that are able to tolerate the toxin do not sequester it in their tissues; 98% was excreted. However, other species, such as Hyles euphorbiae and Daphnis nerii, do sequester toxins from their hosts, but do not pass them on to the adult stage.

Alfred Russel Wallace published a sort of "wanted poster" (properly, a drawing in a book) of what this lepidopteran might look like, and, concurring with his colleague, added:

The predicted sphingid was discovered 21 years later and described as a subspecies of the one African species studied by Wallace: Xanthopan morganii praedicta, for which, the subspecific name praedicta ("the predicted one") was given. The Madagascan individuals had a pink, rather than white, breast and abdomen and a black apical line on the forewing, broader than in mainland specimens. Molecular clock models using either rate- or fossil-based calibrations imply that the Madagascan subspecies X. m. praedicta and the African subspecies X. m. morgani diverged 7.4 ± 2.8 Mya (million years ago), which overlaps the divergence of A. sesquipedale from its sister, A. sororium, namely 7.5 ± 5.2 Mya. Since both these orchids have extremely long spurs, longspurs likely existed before that and were exploited by long-tongued moths similar to Xanthopan morganii praedicta. The long geological separation of subspecies morgani and praedicta matches their morphological differences in the color of the breast and abdomen.

Relationships and species

thumb|A sphinx moth, subfamily [[Macroglossinae (moth)|Macroglossinae, in Cibodas Botanical Garden, Java]]

The Sphingidae is sometimes assigned its own exclusive superfamily, Sphingoidea, but is alternatively included with the more encompassing Bombycoidea. Following Hodges (1971) two subfamilies are accepted, namely the Sphinginae and Macroglossinae. Around 1,450 species of hawk moths are classified into around 200 genera. Some of the best-known hawk moth species are:

  • Privet hawk moth (Sphinx ligustri)
  • White-lined Sphinx (Hyles lineata)
  • Death's-head hawk moth (Acherontia atropos)
  • Lime hawk moth (Mimas tiliae)
  • Poplar hawk moth (Laothoe populi)
  • Convolvulus hawk moth (Agrius convolvuli)
  • Catalpa sphinx (Ceratomia catalpae)
  • Hummingbird hawk-moth (Macroglossum stellatarum)
  • Elephant hawk moth (Deilephila elpenor)
  • Vine hawk moth (Hippotion celerio)
  • Spurge hawk moth (Hyles euphorbiae)
  • Oleander hawk moth (Daphnis nerii)
  • Pandora sphinx moth (Eumorpha pandorus)
  • Tomato worm (Manduca quinquemaculata)
  • Tobacco hornworm (Manduca sexta)

See also

  • Sphingidae species list

References

  • Sphingidae. Insecta.pro
  • Images of Sphingidae of Costa Rica
  • Images of Sphingidae species in New Zealand;
  • List of Sphingidae Types from Museum Witt München
  • Images from Flickr