Hemiandrus pallitarsis

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Hemiandrus pallitarsis
Hemiandrus pallitarsis 111.JPG
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Orthoptera
Suborder: Ensifera
Family: Anostostomatidae
Genus: Hemiandrus
Species:
H. pallitarsis
Binomial name
Hemiandrus pallitarsis
(Walker, 1869)
Synonyms
  • Libanasa pallitarsis Walker, 1869
  • Hemiandrus furcifer Ander, 1938
Male Hemiandrus pallitarsis Hemiandrus pallitarsis.jpg
Male Hemiandrus pallitarsis

Hemiandrus pallitarsis is a species of ground weta endemic to New Zealand. This nocturnal species hides in burrows during the day, and can be an important food for kiwi. They can be identified by a single foretibial spine, three prolateral spines, and four retrolateral spines on the mesotibia, and their tibia lacks a tympanal membrane (they hear only through vibrations in the ground). The female has an unusual appendage on her abdomen, and the male has blackened hooks on his last tergite. They have a two-year life cycle, and their diet is largely unknown. Unusually for an insect, the female shows maternal care towards her eggs and nymphs.

Contents

Taxonomy

Hemiandrus pallitarsis was first described by Francis Walker in 1871 in the genus Libanasa, [1] and in 1906 W. F. Kirby moved it to the genus Ceuthophilus . In 1938, Kjell Ander erected the genus Hemiandrus , and moved this species to it, under the species name furcifer. [2] This species is therefore synonymous with both Libanasa pallitarsis Walker and Hemiandrus furcifer Ander. [3] [2]

Habitat/Distribution

Hemiandrus pallitarsis is endemic to the North Island of New Zealand. They are widespread throughout this distribution [4] [5] and are relatively abundant. [6] They are often found in burrows in the ground during the day, [7] as they are nocturnal . [8] During the night they are quite active on the ground, but are also found in vegetation such as beech trees, [9] kanuka bushes [10] and on leaves of plants such as kawakawa. [5] H. pallitarsis is often found at elevations below 200 metres. [10]

Conservation

The New Zealand Department of Conservation classified this species as "not threatened" in 2014. [11] These weta are widespread [4] [5] and relatively abundant, [6] therefore a species of least concern. Because they are nocturnal they are an important and accessible food source for kiwi, in areas where kiwi are present. [12]

Diet

The diet of this species is unknown; other Hemiandrus species vary from carnivorous, [13] to omnivorous (fruit, invertebrates, and seeds), [14] to herbivorous (apricots and grasses), [15] During the summer in the Ōrongorongo forest (southern North Island) this species of ground wētā is commonly caught climbing tree trunks, with large numbers climbing into hard beech trees ( Fuscospora truncata) . [16] At the same time of year moth caterpillars feeding on hard beech are abundant [17] which might explain this behaviour.

Morphology

Hemiandrus pallitarsis is morphologically identified by having a single foretibial spine, three prolateral spines, and four retrolateral spines on the mesotibia. [8] Males can be identified by blackened hooks on the last tergite. [10] Adult females have an elbow-like, forked appendage on their abdomen, formed from one of the sternites; this is the only Hemiandrus to have such an enlarged appendage. [18] Females are also distinguished by their short ovipositor, [19] [3] so short it can be overlooked and females mistaken for males, [14] The genus Hemiandrus contains species of widely varying overpositor lengths, which can distinguish between species. [5] H. pallitarsus has no tympanum, and instead can detect sound through its cuticle, which is adaptive for their underground lifestyle. [4] The tibia lack the tympanal membranes or vestiges of other Orthoptera legs. [4]

Breeding

Hemiandrus pallitarsis female Hemiandrus pallitarsis female.jpg
Hemiandrus pallitarsis female

Hemiandrus pallitarsis come out of their burrows at night and adults will often sit on top of leaves (such as kawakawa) and use pheromones and drumming to attract mates; it is on top of these leaves that most matings take place. [5] This drumming sound is produced by the drumming of the abdomen on a substrate, such as a plant leaf. [8] The special appendage on the female's abdomen is thought to function in acquiring nuptial gifts from the male: these gifts contain nutrients, allowing the female to lay more eggs. [18] There is a positive correlation between appendage size and nuptial gift size, and therefore between appendage size and the number of eggs laid by a female. [18] This suggest that this structure is sexually selected upon by males, as the larger the appendage, the larger the female's fitness. [18]

Females will burrow to create brood chambers under the ground (2.5 centimeters deep at most [5] ) to lay their eggs in, staying with the eggs until they hatch (most of the time, until they die). [20] They lay about 50 eggs at a time; the short ovipositor of this species aids in the laying of eggs within the underground brood chamber, rather than into the soil as in other Hemiandrus species. [14] H. pallitarsis shows maternal care, which is rare in Orthopterans. [20] There is continual care of the clutch (by covering the eggs with soil and even moving them should the burrow flood), but there is also physical, aggressive defense of the clutch. [5] Other species within this genus exhibit maternal care too, but only the species which have short ovipositors. [5] Eggs are laid in July, [15] and hatching occurs in September and October [5] (these are winter and spring months in New Zealand). Immature individuals are found most often between the months of December and March [21] and adults are found throughout the year. [19] Juveniles most likely take up to a year to develop into an adult. [19] They then live for approximately two years. [18]

Related Research Articles

<span class="mw-page-title-main">Anostostomatidae</span> Family of cricket-like animals

Anostostomatidae is a family of insects in the order Orthoptera, widely distributed in the southern hemisphere. It is named Mimnermidae or Henicidae in some taxonomies, and common names include king crickets in Australia and South Africa, and wētā in New Zealand. Prominent members include the Parktown prawn of South Africa, and the giant wētā of New Zealand.

<i>Hemiandrus</i> Genus of orthopteran insects

Hemiandrus is a genus of wētā in the family Anostostomatidae. In New Zealand they are known as ground wētā due to their burrowing lifestyle. Hemiandrus wētā are nocturnal, and reside in these burrows during the day. Ground wētā seal the entrance of their burrow during the day with a soil plug or door so that their burrow is concealed. This genus was originally said to be distributed in Australia and New Zealand, however, with recent molecular genetic methods, this is under debate. Ground wētā adults are smaller than other types of wētā, with the unusual trait of having either long or short ovipositors, depending on the species. The name of this genus comes from this trait as hemi- mean half and -andrus means male, as the species where the female has a short ovipositor can sometimes be mistaken for a male. This genus has a diverse diet, depending on the species.

<span class="mw-page-title-main">Northland tusked wētā</span> Species of orthopteran insect

The Northland tusked wētā, Anisoura nicobarica, is a rare monotypic wētā of the family Anostostomatidae, endemic to the northern half of Northland in New Zealand, and originally described in 1932. The type specimen was wrongly labelled as coming from the Nicobar Islands, so the species was named Anisoura nicobarica. It was erroneously described again in 1950 by a different author, who placed it in the ground wētā genus Hemiandrus.

Insulanoplectron is a genus of cave wētā in the family Rhaphidophoridae, with just one species: the Snares Island Wētā. Insulanoplectron spinosum is endemic to the subantartic Snares Island of New Zealand, where it is considered to be naturally uncommon. Wētā are nocturnal crickets found all around the world. During the day on the Snares, wētā can be found hiding in seabird burrows.

<i>Deinacrida parva</i> Species of orthopteran insect

Deinacrida parva is a species of insect in the family Anostostomatidae, the king crickets and weta. It is known commonly as the Kaikoura wētā or Kaikoura giant wētā. It was first described in 1894 from a male individual then rediscovered in 1966 by Dr J.C. Watt at Lake Sedgemore in Upper Wairau. It is endemic to New Zealand, where it can be found in the northern half of the South Island.

<i>Deinacrida connectens</i> Species of orthopteran insect

Deinacrida connectens, often referred to as the alpine scree wētā, is one of New Zealand's largest alpine invertebrates and is a member of the Anostostomatidae family. Deinacrida connectens is a flightless nocturnal insect that lives under rocks at high elevation. Mountain populations vary in colour. This species is the most widespread of the eleven species of giant wētā (Deinacrida).

<i>Hemideina ricta</i> Species of orthopteran insect

Hemideina ricta, known as the Banks Peninsula tree wētā, is an insect that is endemic to New Zealand.

<i>Hemideina thoracica</i> Species of orthopteran insect

Hemideina thoracica, commonly known as the Auckland tree wētā or tokoriro is a cricket-like insect. It is endemic to New Zealand and is found over most of the North Island, except for the Wellington region and regions 900 metres above sea level. This species is an arboreal, herbivorous generalist however, it is also thought to be polyphagous and is found in all wooded habitats, including forest, scrub and suburban gardens.

<i>Hemideina crassidens</i> Species of orthopteran insect

Hemideina crassidens, commonly known as the Wellington tree wētā, is a large, flightless, nocturnal insect in the family Anostostomatidae. This wētā species is endemic to New Zealand and populates regions in the southern half of North Island/Te Ika a Maui and the north-west of the South Island/Te Wai Pounamu. They forage arboreally during the night and are most likely polyphagous. There is obvious sexual dimorphism in adults. Individuals are reliant on tree cavities for refuge, social interactions and mating.

<i>Hemiandrus maia</i> Species of orthopteran insect

Hemiandrus maia, the Otago ground wētā, is a species of ground wētā endemic to New Zealand. Being a ground weta, they are often found in burrows in the ground during the daytime. The species is occurs on the South Island and is classified as "not threatened". This species of wētā is unusual for an insect in that the female looks after her eggs and nymphs, this is known as maternal care.

<i>Hemiandrus electra</i> Species of orthopteran insect

Hemiandrus electra, the Kahurangi ground wētā, is a species of ground wētā endemic to New Zealand. Being a ground wētā, they are often found in burrows in the ground during the daytime. The species is occurs on the South Island and is classified as "Naturally Uncommon". This species of wētā is unusual for an insect in that the female looks after her eggs and nymphs; this is known as maternal care.

<i>Hemiandrus bilobatus</i> Species of wētā endemic to New Zealand

Hemiandrus bilobatus, the wine wētā, is a species of ground weta endemic to New Zealand. Being a ground weta, they are often found in burrows in the ground during the daytime. The species is found in Wellington, on Mana Island and northern South Island and is classified as "Not Threatened". This species of weta is unusual for an insect in that the female shows maternal care. She lays about 50 eggs in the same burrow she uses during the day and looks after her eggs until they hatch.

<i>Hemiandrus nox</i> Species of orthopteran insect

Hemiandrus nox, the night ground wētā, is a species of ground wētā endemic to New Zealand. During the day, this wētā hides in burrows in the soil and is active only at night. The species is found in native forests in North and South Island. Females of this species have medium-long curved ovipositers to lay their eggs in the soil. Unlike some Hemiandrus species, H. nox does not show maternal care.

<span class="mw-page-title-main">Mary Morgan-Richards</span> New Zealand academic

Mary Morgan-Richards is a New Zealand biologist, and as of 2019 is a full professor at Massey University.

<i>Hemiandrus maculifrons</i> Species of orthopteran insect

Hemiandrus maculifrons is a species of ground wētā endemic to New Zealand. They are nocturnal, carnivorous, and flightless orthopterans belonging to the family Anostostomatidae. Being a nocturnal species, individuals remain in tunnels in the ground during the day and emerge from their burrows after sunset to forage and hunt for small invertebrates. H. maculifrons is one of the smallest New Zealand weta species, averaging 15 mm in length and weighing 1–3 g. Unlike the tree weta and tusked weta, where sexual dimorphism is found in the form of male weaponry, ground weta only exhibit sexual size dimorphism: the females are larger than the males.

<span class="mw-page-title-main">Wētā</span> Informal group of orthopteran insects

Wētā is the common name for a group of about 100 insect species in the families Anostostomatidae and Rhaphidophoridae endemic to New Zealand. They are giant flightless crickets, and some are among the heaviest insects in the world. Generally nocturnal, most small species are carnivores and scavengers while the larger species are herbivorous. Although some endemic birds likely prey on them, wētā are disproportionately preyed upon by introduced mammals, and some species are now critically endangered.

<i>Hemiandrus focalis</i> Species of orthopteran insect

Hemiandrus focalis is a species of ground wētā endemic to New Zealand. This flightless Orthoptera lives in the mountains of the South Island, New Zealand. This species can be distinguished from other ground wētā by their three superior retrolateral spines on their mid tibia and females have relatively long ovipositors. This omnivorous ground wētā species is listed as "not threatened" by the New Zealand Department of Conservation.

<span class="mw-page-title-main">Hemiandrus furoviarius</span> Species of wētā

The ground wētā population near Lake Tekapo New Zealand might represent a distinct species but it has not been formally described. The informal 'tag' name Hemiandrus'furoviarius' was given to this population by Peter Johns in 2001. Commonly known as the Tekapo ground wētā, it is a wētā of the family Anostostomatidae. They are a small, flightless, and nocturnal orthopteran endemic to the Mackenzie Basin of New Zealand's South Island.

<i>Hemiandrus celaeno</i> Species of wētā endemic to New Zealand

Hemiandrus celaeno is a species of endemic ground wētā in the family Anostostomatidae. H. celaeno is a small to medium-sized burrowing wētā found along the east coast of the South Island, New Zealand. Hemiandrus calaeno is a member of the short ovipositor ground wētā. H. celaeno is named for Celaeno of the Pleiades sisters in Greek mythology, whose name means "the dark one". Tag-named entity, H. ‘horomaka’, has been included under H. celaeno.

<i>Hemiandrus subantarcticus</i> Species of Orthoptera

Hemiandrus subantarcticus is a species of ground weta endemic to New Zealand.

References

  1. ↑ Walker, F.; Gray, J. E. (1869). Catalogue of the specimens of Dermaptera Saltatoria and supplement of the Blattari in the collection of the British Museum. Vol. pt. 5. London, England.: British Museum (Natural History), Department of Zoology. p. 24.
  2. 1 2 Johns, P. M. (1997). "The Gondwanaland weta: family Anostostomatidae (formerly in Stenopelmatidae, Henicidae or Mimnermidae): nomenclatural problems, world checklist, new genera and species". Journal of Orthoptera Research. 6 (6): 125–138. doi:10.2307/3503546. JSTOR   3503546.
  3. 1 2 Johns, P. M. (2001). Distribution and conservation status of ground weta, Hemiandrus species (Orthoptera: Anastostomatidae) (PDF). Wellington, New Zealand: Department of Conservation. Retrieved 7 June 2018.
  4. 1 2 3 4 Strauß, J.; Lomas, K; Field, L. H. (2017). "The complex tibial organ of the New Zealand ground weta: sensory adaptations for vibrational signal detection". Scientific Reports. 7 (1): 2031. Bibcode:2017NatSR...7.2031S. doi:10.1038/s41598-017-02132-1. PMC   5435688 . PMID   28515484.
  5. 1 2 3 4 5 6 7 8 9 Gwynne, D. T. (2004). "Reproductive Behavior of Ground Weta (Orthoptera: Anostostomatidae): Drumming Behavior, Nuptial Feeding, Post-copulatory Guarding and Maternal Care". Journal of the Kansas Entomological Society. 77 (4): 414–428. doi:10.2317/E-34.1. S2CID   86709108.
  6. 1 2 Chappell, E. M.; Webb, D. S.; Tonkin, J. D. (2014). "Notes on sexual size dimorphism, sex ratio and movements of adult ground weta (Walker) (Orthoptera: Anostostomatidae)". New Zealand Entomologist. 37 (2): 83–92. doi:10.1080/00779962.2013.856377. S2CID   4814697.
  7. ↑ Gwynne, D. T. (2014). "A secondary copulatory structure in a female insect: a clasp for a nuptial meal?". Naturwissenschaften. 89 (3): 125–127. doi:10.1007/s00114-002-0298-y. PMID   12046632. S2CID   28093747.
  8. 1 2 3 Chappell, E. M.; Trewick, S. A.; Morgan-Richards, M. (2012). "Shape and sound reveal genetic cohesion not speciation in the New Zealand orthopteran, Hemiandrus pallitarsis, despite high mitochondrial DNA divergence". Biological Journal of the Linnean Society. 105 (1): 169–186. doi: 10.1111/j.1095-8312.2011.01777.x .
  9. ↑ Brockie, Robert (1992). A living New Zealand Forest. Hong Kong: Bateman. ISBN   1-86953-039-X.
  10. 1 2 3 Chappell, E. M.; Webb, D. S.; Brown, A. J.; Tonkin, J. D. (2014). "A preliminary survey of altitudinal variation in two ground wētā species, (Walker) and (Walker) (Orthoptera: Anostostomatidae)". New Zealand Entomologist. 38 (1): 1–6. doi:10.1080/00779962.2014.922234. S2CID   4834193.
  11. ↑ Trewick, S.; Morris, S. J.; Johns, P.; Hitchmough, R.; Stringer, I. (2012). "The conservation status of New Zealand Orthoptera". New Zealand Entomologist. 35 (2): 131–136. doi:10.1080/00779962.2012.686318. S2CID   219564547.
  12. ↑ "Distribution and conservation status of ground weta, Hemiandrus species (Orthoptera Anostostomatidae)" (PDF). Department of Conservation. p. 15. Archived from the original (PDF) on 19 October 2008. Retrieved 8 April 2012.
  13. ↑ Cary, P. R. L. (1983). "Diet of the ground weta (Orthoptera: Stenopelmatidae)". New Zealand Journal of Zoology. 10 (3): 295–297. doi: 10.1080/03014223.1983.10423918 .
  14. 1 2 3 Tayolor Smith, B. L.; Morgan-Richards, M.; Trewick, S. A. (2013). "New Zealand ground wētā (Anostostomatidae: ): descriptions of two species with notes on their biology". New Zealand Journal of Zoology. 40 (4): 314–329. doi: 10.1080/03014223.2013.804422 .
  15. 1 2 Basri, W. M. (1978). The biology and economic impact of the weta, Hemiandrus sp. (Orthoptera : Stenopelmatidae) in an apricot orchard, Horotane Valley (Thesis). Lincoln College, University of Canterbury. hdl:10182/3201.
  16. ↑ Brockie, Robert (1992). A Living New Zealand Forest. David Bateman.
  17. ↑ Moeed (1985). "Seasonality of pitfall trapped invertebrates in three types of native forest". New Zealand Journal of Zoology. 12: 17–53. doi: 10.1080/03014223.1985.10428264 .
  18. 1 2 3 4 5 Gwynne, D. T. (2005). "The secondary copulatory organ in female ground weta (Hemiandrus pallitarsis, Orthoptera: Anostostomatidae): a sexually selected device in females?". Biological Journal of the Linnean Society. 85 (4): 463–469. doi: 10.1111/j.1095-8312.2005.00510.x .
  19. 1 2 3 Stringer, I. A. N. (2006). Distinguishing Mercury Island tusked weta, Motuweta isolata, from a ground weta, Hemiandrus pallitarsis (Orthoptera: Anastostomatidae) in the field, with observations of their activity (PDF). Wellington, New Zealand: Department of Conservation. Retrieved 15 June 2018.
  20. 1 2 Gwynne, D. T. (1995). "Phylogeny of the Ensifera (Orthoptera): A Hypothesis Supporting Multiple Origins of Acoustical Signalling, Complex Spermatophores and Maternal Care in Crickets, Katydids, and Weta". Journal of Orthoptera Research (4): 203–218. doi:10.2307/3503478. JSTOR   3503478.
  21. ↑ Barratt, B. I. P.; Patrick, B. H. (1987). "Insects of snow tussock grassland on the East Otago Plateau". New Zealand Entomologist. 10 (1): 69–98. doi:10.1080/00779962.1987.9722513.
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