Ghost moth

Female ghost moths have a wingspan of 50–70 mm. They have yellowish-buff forewings with darker linear markings and brown hindwings. Males are smaller, with a wingspan of 46–50 mm, and typically have white or silver wings. However, in H. h. thulensis, found in Shetland and the Faroe Islands, there are buff-coloured individuals.

The ghost swift aggregates in leks in order to attract female mates. Lekking occurs at dusk and typically lasts for 20–30 minutes.{{Cite journal|last1=Andersson|first1=S.|last2=Rydell|first2=J.|last3=Svensson|first3=M. G. E.|date=1998-07-22 |title=Light, predation and the lekking behaviour of the ghost swift Hepialus humuli (L.) (Lepidoptera, Hepialidae)|journal=Proceedings of the Royal Society B: Biological Sciences|volume=265|issue=1403|pages=1345–1351|doi=10.1098/rspb.1998.0440|issn=0962-8452|pmc=1689211}} During the lekking period, incident light intensities between 10.0 and 2.0 lux have been found to increase the brightness contrast between the background (grass/plants) and male moths' silver/white wings. It is thus believed that the male wing color may have evolved as a secondary adaptation to aid in the moth's visibility.{{Cite journal|last=Rydell|first=Jens|date=1998-08-07 |title=Bat defence in lekking ghost swifts (Hepialus humuli), a moth without ultrasonic hearing|journal=Proceedings of the Royal Society of London B: Biological Sciences|language=en|volume=265|issue=1404|pages=1373–1376|doi=10.1098/rspb.1998.0444|issn=0962-8452|pmid=9721686|pmc=1689220}}

The male ghost swifts display by hovering directly above vegetation, while occasionally shifting slowly horizontally. The displaying male only occasionally made vertical movements to shift display positions.{{cite journal|last1=Mallet|first1=James |title=Sex roles in the ghost moth Hepialus humuli (L.) and a review of mating in the Hepialidae (Lepidoptera)|journal=Zoological Journal of the Linnean Society|volume=80|issue=1|year=1984|pages=67–82|issn=0024-4082|doi=10.1111/j.1096-3642.1984.tb02320.x}} Females are attracted to the displaying males in leks, and once a female chooses a male she will pass within a few centimeters of him.{{Cite journal|last=Turner|first=John R. G.|date=1976-02-01 |title=Sexual behaviour: female swift moth is not the aggressive partner|journal=Animal Behaviour|volume=24|issue=1|pages=188–190|doi=10.1016/S0003-3472(76)80113-3|s2cid=53167316}} The male will follow the female, who will land and beat her wings, signaling that the male may approach her. The two moths will then copulate.

Males perform a flight display and use both chemical and visual signals to attract females to their mating sites.{{Cite journal|last=Mallet|first=James|date=1984-01-01 |title=Sex roles in the ghost moth Hepialus humuli (L.) and a review of mating in the Hepialidae (Lepidoptera)|journal=Zoological Journal of the Linnean Society|language=en|volume=80|issue=1|pages=67–82|doi=10.1111/j.1096-3642.1984.tb02320.x|issn=1096-3642}} While aggregating in leks, male ghost swifts use pheromones.. These are emitted in order to attract a female, but they are not known to be used as an aphrodisiac. The main component of the male pheromone (in the distantly related species Phymatopus hecta) is (E,E)-α-Farnesene.{{Cite journal|last1=Schulz|first1=S.|last2=Francke|first2=W.|last3=König|first3=W. A.|last4=Schurig|first4=V.|last5=Mori|first5=K.|last6=Kittmann|first6=R.|last7=Schneider|first7=D.|date=December 1990 |title=Male pheromone of swift moth, Hepialus hecta L. (Lepidoptera: Hepialidae)|journal=Journal of Chemical Ecology|volume=16|issue=12|pages=3511–3521|doi=10.1007/BF00982114|issn=0098-0331|pmid=24263445|bibcode=1990JCEco..16.3511S |s2cid=26903035}}

The olfactory substances used to attract females are produced on the male's hind tibial brushes, and were said to be "goat-like", meaning the smell of the Goat Moth caterpillar.R South 1909. The moths of the British Isles, volume 2. London, Frederick Warne. Males may also be attracted to stationary females by olfactory stimuli.

File:Hepialus humuli pair (7392024178).jpg

The ghost moth displays high levels of sexual dichromatism (see picture right). Female ghost moths are a yellow brownish color, while males have silver/white wings. It has been suggested that the difference in wing color between males and females is used for visual epidemic signaling. The upperside of males have un-pigmented scales with elaborate morphology and meshwork that allow for light reflection and may aid in attracting females.{{Cite journal|url=https://www.researchgate.net/publication/262048444 |title=Sexual dimorphism and geographical male polymorphism in the ghost moth Hepialus humuli (Lepidoptera: Hepialidae): Scale ultrastructure and evolutionary aspects (PDF Download Available)|journal=European Journal of Entomology|volume=106|issue=2|pages=303–313|language=en |access-date=2017-10-25|doi=10.14411/eje.2009.036|year=2009|last1=Kaaber|first1=Svend|last2=Kristensen|first2=Niels P.|last3=Simonsen|first3=Thomas J.|doi-access=free}} The females lack the intricate morphology of the males. The underside of both the male and female ghost moth is a uniform grey/brown color. It is believed that there is behavioral dimorphism as well, with one study showing that females were more attracted to light than males.

Common predators of ghost moths include several species of bats and birds. These predators are attracted to the moths during the male flight displays. Eptesicus nilssonii, the northern bat, has often been documented preying on lekking ghost moths. The ghost moth is a member of the family Hepialidae, an early branch of Lepidoptera. Species in the Hepialidae lack several predator defense systems, including ultrasonic hearing. The ghost moth lacks sophisticated predator defense systems, and instead restricts its sexual behavior to a short period during dusk to reduce its predation risk. Despite these precautions, the moth is still at a large predation risk, especially at high latitudes where twilight is prolonged.

It is believed that the deaf moths, such as the family Hepialidae, pre-date the predatory bats that may have driven the evolution of ultrasonic hearing. It is currently believed that the ghost moth's restricted flight patterns and low flight positions may be their main form of anti-predator defense. The ghost moth displays for only 20–30 minutes at dusk, which aids in predator avoidance, as most bats typically do not start feeding until after dusk, and most birds stop feeding well in advance of sunset.

On average, most female ghost moths will lay around 600 eggs over four days, but a female can lay anywhere from 200 to 1,600 eggs.{{Cite journal|last=Edwards|first=C. A.|date=May 1964 |title=The bionomics of swift moths. I.—The ghost swift moth, Hepialus humuli (L.)|journal=Bulletin of Entomological Research|volume=55|issue=1|pages=147–160|doi=10.1017/S000748530004935X|issn=1475-2670}}

Image:Buckler W The larvæ of the British butterflies and moths PlateXXX.jpg

The ghost moth larvae grow up to 50 mm long and have a white opaque body with a red/brown head. Their prothoracic plate is also red/brown, and their pinacula is dark brown. The young larvae feed on plant rootlets, while the older larvae feed on larger roots, stolons, and the lower regions of plant stems. The larval growth is very slow, and the developmental period can last for two to three years. The larva have at least 12 instars, but further research is needed to see if there may be more instars during higher temperatures. The larva cause damage to the plants they consume, with damage being the worst during the second summer of the larva's growth period. The larvae typically feed in grasslands, lawns, and pastures and have been known to cause significant damage to the host species. In the British Isles, the ghost moth larvae live in the soil and can commonly be found underneath the grass.

The ghost moth typically pupates during the April or May after the two to three year larval growth period has ended.

Adults are most commonly found in June and July, and they are typically active around dusk. In particular, lekking and mating occurs at dusk.

Ghost moth larvae are polyphagous—they are able to feed on multiple types of plants. Larvae born on crops will typically feed on the roots and can cause significant damage to the crops. Ghost moths frequently cause damage to strawberries, lettuce, and chrysanthemum plants.

{{columns-list |colwidth=15em |

• Arctium - burdock
• Asparagus
• Beta – beet
• Brassica
• Cannabis
• Chrysanthemum
• Dahlia
• Daucus – carrot
• Fagus – beech
• Fragaria – strawberry
• Fungi
• Helianthus – Jerusalem artichoke
• Humulus – hop
• Lactuca – lettuce
• Pastinaca – parsnip
• Phaseolus – bean
• Pisum – pea
• Poaceae – grasses
• Quercus – oak
• Rumex – dock/sorrel
• Solanum – potato
• Taraxacum officinale – dandelion
• Urtica – nettle

}}

Chinese authors retain a number of species in Hepialus. Most of these are placed in the genus Thitarodes by others. Species retained in Hepialus include:

Hepialus humuli was first described by the Swedish taxonomist, Carl Linnaeus in 1758. He named it Phalaena Noctua humuli — implying night moth of the hop vine. It was later allocated to the genus Hepialus (a fever), which was raised by Johan Christian Fabricius in 1775 and refers to its ″fitful, alternating flight″. The specific name humuli refers to the genus of hops (Humulus), on which Linnaeus wrongly thought, the larvae fed on its roots.{{cite book |last1=Emmet |first1=A Maitland |author1-link=A. Maitland Emmet |title=The Scientific Names of the British Lepidoptera. Their history and meaning |date=1991 |publisher=Harley Books |location=Colchester |isbn=0-946589-35-6 |pages=42, 43 & 197}}

• Hepialus humuli humuli
• Hepialus humuli thulensis Newman, 1865 (Great Britain, Faroe Islands)

It is believed that the common name of "ghost moth" for Hepialus humuli may have originated from European folklore, as there are numerous references to white moths being the souls of the departed. It is believed that the ghost moth is also referenced in the last passage of Wuthering Heights by Emily Brontë.{{Cite web|url=http://www.reaktionbooks.co.uk/display.asp?ISB=9781780235851 |title=Moth by Matthew Gandy from Reaktion Books|website=www.reaktionbooks.co.uk|language=en |access-date=2017-10-25}} Dead link

File:Faroe stamp 245 Hepialus humuli.jpg|Ghost moth on a Faroese stamp

File:Hepialus humuli f.jpg|Female

File:Hepialus humuli m.jpg|Male

File:Hepialus humuli, Ghost Moth, Trawscoed, North Wales, Nov 2013 (21418448681).jpg|Larva

{{Reflist}}

• Chinery, Michael (1986, reprinted 1991). Collins Guide to the Insects of Britain and Western Europe.
• Skinner, Bernard (1984). The Colour Identification Guide to Moths of the British Isles.

{{commons category|Hepialus humuli}}

{{Wikispecies}}

• {{cite web |last=Kimber |first=Ian |url=https://www.ukmoths.org.uk/species/hepialus-humuli/ |title=3.005 BF14 Ghost Moth Hepialus humuli (Linnaeus, 1758) |website=UKMoths |access-date=30 June 2019}}
• [http://www.lepiforum.de/lepiwiki.pl?Hepialus_Humuli Lepiforum e.V.]

{{Taxonbar |from=Q476878}}

Category:Hepialidae

Category:Moths described in 1758

Category:Moths of Europe

Category:Taxa named by Carl Linnaeus