Pollanisus nielseni
Encyclopedia
Pollanisus nielseni is a moth
of the Zygaenidae
family. It inhabits Western Australia
, mostly coastal areas, and has brilliantly shiny forewings. The diurnal adults are most active on sunny days. Eggs are laid on the plant Hibbertia
spicata, and females touch each egg after oviposition with a tuft of hair on their abdomen, which attaches protective spines. The larvae are brightly coloured and feed on H. spicata before pupation.
was collected 5 km east of Wedge Island in Western Australia by Gerhard M. Tarmann in 1995, and the species was formally described by him in 2005, in the work Zygaenid moths of Australia: a revision of the Australian Zygaenidae, (Procridinae: Artonini). Previously, P. nielseni had been considered a variant of the slightly larger moth Pollanisus cupreus
. The two species share habitat and possess similarities, but, among other visual differences, P. nielseni is smaller and has significantly more sheen to its forewings than P. cupreus.
The etymology of the specific epithet nielseni, given by Tarmann, is a tribute to his colleague Ebbe Nielsen, a leading Danish entomologist who had died four years before Tarmann described the species.
on the forewings of both sexes are brightly metallic, usually golden and green, giving the moth a brilliant sheen. The hindwings are opaque and dark-coloured. The moth's head, antennae, legs, and abdomen are usually bluish-green and a shiny metallic. The hair-tuft on the female's abdomen is yellow, which is used to attach protective scales to her pale yellow eggs following deposition. The emergent larvae are brightly coloured.
As with most primitive Lepidoptera, the frequency of the wing-beat is constant while the moth is in flight. When at rest, the wings are laid back on the abdomen and thorax. In this position, the wings are hooked to the metathorax
with very fine, hook-like hairs, present on both the undersides of the wings and the metathorax, which interlock in a "velcro" way. This wing-locking mechanism is referred to as "Haftfeld" (sometimes not capitalised) and is characteristic of the family.
singly on the leaves, sepals, or stems. The brightly coloured larvae feed on the plant and afterwards pupate in silken cocoons on leaves or stems, or in leaf litter on the ground. The cocoons contain minute crystals of whewellite
, produced by the larva's Malphigian tubule system. The adult moths are diurnal and most active on sunny days. They have been witnessed feeding on the flowers of Arctotheca calendula
and Phyllanthus calycinus.
In the Procridinae and Zygaeninae subfamilies of the Zygaenidae family, female moths typically have two glands near the ovipositor
that produce liquid poison. Referred to on occasion as "Petersen's glands", their function is to defend the eggs from prospective parasitoids. Three genera of these two subfamilies, however, including Pollanisus, have developed an alternative defence against predators. A tuft of hair at the end of the female's abdomen is brushed over each egg after it is laid, thereby attaching small spiny scales to its surface. The tips of these scales are presumably poisonous, as aphids have been observed dying following touching them.
Moth
A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...
of the Zygaenidae
Zygaenidae
The Zygaenidae moths are a family of Lepidoptera. The majority of zygaenids are tropical, but they are nevertheless quite well represented in temperate regions. There are about 1000 species. Various species are commonly known as Burnet or Forester moths, often qualified by the number of spots,...
family. It inhabits Western Australia
Western Australia
Western Australia is a state of Australia, occupying the entire western third of the Australian continent. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Indian Ocean to the south, the Northern Territory to the north-east and South Australia to the south-east...
, mostly coastal areas, and has brilliantly shiny forewings. The diurnal adults are most active on sunny days. Eggs are laid on the plant Hibbertia
Hibbertia
Hibbertia, or Guinea flower, is a genus of trees, shrubs, trailing shrubs and climbers of the family Dilleniaceae. The five-petalled flowers of all species are varying shades of yellow, with the exception of H. stellaris, H. miniata and H. selkii, a recently named species from the Stirling...
spicata, and females touch each egg after oviposition with a tuft of hair on their abdomen, which attaches protective spines. The larvae are brightly coloured and feed on H. spicata before pupation.
Taxonomy
The holotypeHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
was collected 5 km east of Wedge Island in Western Australia by Gerhard M. Tarmann in 1995, and the species was formally described by him in 2005, in the work Zygaenid moths of Australia: a revision of the Australian Zygaenidae, (Procridinae: Artonini). Previously, P. nielseni had been considered a variant of the slightly larger moth Pollanisus cupreus
Pollanisus cupreus
Pollanisus cupreus is a moth of the Zygaenidae family. It is found in Western Australia.The larvae probably feed on Hibbertia hypericoides.-External links:**...
. The two species share habitat and possess similarities, but, among other visual differences, P. nielseni is smaller and has significantly more sheen to its forewings than P. cupreus.
The etymology of the specific epithet nielseni, given by Tarmann, is a tribute to his colleague Ebbe Nielsen, a leading Danish entomologist who had died four years before Tarmann described the species.
Morphology
For adult males, the length of the forewings is 9 – and in females it is 8 –. The scalesScale (Lepidoptera)
The presence of scales on the wings of Lepidoptera, comprising moths and butterflies, characterises this order of insects. The name is derived from Ancient Greek λεπίδος and πτερόν . The wings of Lepidoptera are minutely scaled, which feature gives the name to this order...
on the forewings of both sexes are brightly metallic, usually golden and green, giving the moth a brilliant sheen. The hindwings are opaque and dark-coloured. The moth's head, antennae, legs, and abdomen are usually bluish-green and a shiny metallic. The hair-tuft on the female's abdomen is yellow, which is used to attach protective scales to her pale yellow eggs following deposition. The emergent larvae are brightly coloured.
As with most primitive Lepidoptera, the frequency of the wing-beat is constant while the moth is in flight. When at rest, the wings are laid back on the abdomen and thorax. In this position, the wings are hooked to the metathorax
Metathorax
The metathorax is the posterior of the three segments in the thorax of an insect, and bears the third pair of legs. Its principal sclerites are the metanotum , the metasternum , and the metapleuron on each side...
with very fine, hook-like hairs, present on both the undersides of the wings and the metathorax, which interlock in a "velcro" way. This wing-locking mechanism is referred to as "Haftfeld" (sometimes not capitalised) and is characteristic of the family.
Life cycle and behaviour
Observations suggest P. nielseni is a bivoltine species, with two generations per year, one in early spring and another in mid-summer. Females lay pale yellow eggs on the small flowering shrub Hibbertia spicata, ovipositingOviposition
Oviposition is the process of laying eggs by oviparous animals.Some arthropods, for example, lay their eggs with an organ called the ovipositor.Fish , amphibians, reptiles, birds and monetremata also lay eggs....
singly on the leaves, sepals, or stems. The brightly coloured larvae feed on the plant and afterwards pupate in silken cocoons on leaves or stems, or in leaf litter on the ground. The cocoons contain minute crystals of whewellite
Whewellite
Whewellite is a mineral, hydrated calcium oxalate, formula CaC2O4·H2O. Because of its organic content it is thought to have an indirect biological origin and this is supported by it being found in coal and sedimentary nodules. However, it has also been found in hydrothermal deposits where a...
, produced by the larva's Malphigian tubule system. The adult moths are diurnal and most active on sunny days. They have been witnessed feeding on the flowers of Arctotheca calendula
Arctotheca calendula
Arctotheca calendula is a plant commonly known as cape weed, cape dandelion, or cape marigold because it originates from the Cape Province in South Africa...
and Phyllanthus calycinus.
In the Procridinae and Zygaeninae subfamilies of the Zygaenidae family, female moths typically have two glands near the ovipositor
Ovipositor
The ovipositor is an organ used by some animals for oviposition, i.e., the laying of eggs. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly...
that produce liquid poison. Referred to on occasion as "Petersen's glands", their function is to defend the eggs from prospective parasitoids. Three genera of these two subfamilies, however, including Pollanisus, have developed an alternative defence against predators. A tuft of hair at the end of the female's abdomen is brushed over each egg after it is laid, thereby attaching small spiny scales to its surface. The tips of these scales are presumably poisonous, as aphids have been observed dying following touching them.