''Zorion guttigerum,'' commonly known as the flower long-horn beetle, is an endemic species of

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

in New Zealand. It is found on the flowers of many plant species and feeds on nectar and pollen.

Taxonomy

''Zorion guttigerum'' was first described as ''Obrium guttigerum'' by John Westwood in 1945, before it received the ''Zorion'' genus synonym. The ''Zorion'' genus currently includes 10 extant species, all of which are endemic to New Zealand. They belong to the family of long-horn Cerambycidae beetles, of which there are approximately 180 known endemic species. In New Zealand, long-horn beetles are important pollinators for our native plants, including harakeke (common flax).

Distribution

''Zorion guttigerum'' is widespread throughout the

North Island The North Island, also officially named Te Ika-a-Māui, is one of the two main islands of New Zealand, separated from the larger but much less populous South Island by the Cook Strait. The island's area is , making it the world's 14th-largest ...

and

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

Species description

Adults are variable in size and can range from 3-7mm in length. They are a dark purple brown colour with a bright golden spot on each elytron. They have been described as the most strikingly colourful beetle within our New Zealand fauna. Unlike most Cerambycinae species, where the antennae are elongate and extend past the body, ''Zorion guttigerum'' have antennae generally shorter than their body. Males tend to have longer antennae than females, although females are significantly larger in size ''Zorion guttigerum'' are diurnal beetles. They are good flyers and often fly between flower clusters. Adults mate and feed on the flowers of the many plant species they visit. Males may exhibit aggressive behaviour towards other males on the same flower cluster, even in the absence of females. After mating, females will leave the flowers to lay eggs, while males remain on the flowers. Feeding and mating will occur on flowers of many plant species usually between October and March. It has been found that the body colour of this species plays an important role in mating success in both males and females. Females will lay eggs in freshly cut and broken branches of both native and exotic plants. Larvae will feed internally on the bark and woody materials.

Plant visitation

''Zorion guttigerum'' are often found in great numbers near flowers and they may be important pollinators for many New Zealand native plants. They are a very generalist species and are known to visit a wide variety of plants. The species listed below are few selected examples of the plants visited by this beetle.

Native flowers

''Zorion guttigerum'' is known to visit the flowers of many native and endemic species. Some host species include: '' Discaria toumatou'' (matagouri), '' Phormium tenax'' (harakeke), ''

Schefflera digitata ''Schefflera digitata'', the patē, seven-finger, or umbrella tree, is a tree endemic to New Zealand belonging to the family Araliaceae. Māori names include: ''patē'', ''patatē'', ''patete'', and ''kōtētē''. It occurs in lowland to lower m ...

'' (patē), ''Pennantia corymbose'' (kaikōmako). They also visit the flowers of two beech species, ''

Nothofagus menziesii ''Nothofagus menziesii'', commonly known as silver beech ( mi, tawhai, tahina), is a tree of the southern beech family endemic to New Zealand. Its common name probably comes from the fact that its bark is whitish in colour, particularly in younge ...

'' (silver beech) and ''

Nothofagus fusca ''Nothofagus fusca'', commonly known as red beech (Māori: tawhai raunui) is a species of southern beech, endemic to New Zealand, where it occurs on both the North Island and South Island. Generally it is found on lower hills and inland valley fl ...

'' (red beech).

Exotic flowers

''Zorion guttigerum'' also visits flowers of exotic plant species, some of which include: ''

Physocarpus opulifolius ''Physocarpus opulifolius'', known as common ninebark, Eastern ninebark, Atlantic ninebark, or simply ninebark, is a species of flowering plant in the rose family Rosaceae, native to eastern North America. Description It is a mound-shaped deci ...

'' (ninebark), ''

Lagunaria patersonia ''Lagunaria patersonia'' is a species of tree in the family Malvaceae Malvaceae, or the mallows, is a family of flowering plants estimated to contain 244 genera with 4225 known species. Well-known members of economic importance include okra, c ...

'' (Norfolk Island hibiscus), '' Roldana petasitis'' (velvet groundsel), and some ''

Acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus na ...

'' species.

Other plants

Aside from flowers, ''Zorion guttigerum'' have been found on the foliage and branches of some plants including: ''

Pseudowintera colorata ''Pseudowintera colorata'', also known as mountain horopito or pepper tree, is a species of woody evergreen flowering trees and shrubs, part of family Winteraceae. The species is endemic to New Zealand. All Winteraceae are magnoliids, associated ...

'' (pepperwood), ''

Chamaecytisus palmensis ''Cytisus proliferus'', tagasaste or tree lucerne, is a small spreading evergreen tree that grows high. It is a well known fertilizer tree. It is a member of the Fabaceae (pea) family and is indigenous to the dry volcanic slopes of the Canary ...

'' (tree lucerne), ''

Sophora microphylla ''Sophora microphylla'', common name kōwhai, is a species of flowering plant in the family Fabaceae, native to New Zealand. Growing to tall and broad, it is an evergreen shrub or small tree. Each leaf is long with up to 40 pairs of shiny oval ...

'' (kōwhai), '' Galium palustae'' (marsh bedstraw), and ''

Olearia virgata ''Olearia'', most commonly known as daisy-bush, is a genus of flowering plants belonging to the family Asteraceae, the largest of the flowering plant families in the world. Olearia are found in Australia, New Guinea and New Zealand. The genus i ...

'' (twiggy tree daisy). Adults also visit orchards around New Zealand. Although the recorded orchards in New Zealand are dominated by

honeybees A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the current cosmo ...

as flower visitors, ''Zorion guttigerum'' was often a commonly reported flower visitor in kiwifruit (''

Actinidia deliciosa ''Actinidia deliciosa'', the fuzzy kiwifruit, is a fruiting vine native to Southern China. Other species of '' Actinidia'' are also found in China and range east to Japan and north into southern areas of Russian Far East. This species grows nat ...

'') and avocado ('' Persea americana'') orchards.

References

Endemic fauna of New Zealand Beetles of New Zealand Cerambycidae Endemic insects of New Zealand {{Beetle-stub