Huhu beetle

The Māori name huhu is ultimately Austronesian in origin from root form *bukbuk₃, where cognates in related languages (like Tagalog bukbok) refer to weevils known to infest wood and rice across tropical Southeast Asia.{{cite web |title=*bukbuk₃ - weevil that infests wood, bamboo, and rice |url=https://acd.clld.org/cognatesets/25641 |website=Austronesian Comparative Dictionary |last1=Blust|first1=Robert|author-link=Robert Blust|last2=Trussel|first2=Stephen|date=2010|access-date=25 December 2024}}

In Māori, huhu has semantically evolved to refer explicitly to its larval form (also tunga haere, tunga rākau). As the huhu larva reaches maturity it ceases to bore in wood and casts its skin. This still edible stage is known in Māori as {{lang|mi|tataka}}. It then develops wings and legs, and while it is still white, it is known as {{lang|mi|pepe}} or pepe-te-muimui.{{Cite web|url=http://maoridictionary.co.nz/search?idiom=&phrase=&proverb=&loan=&histLoanWords=&keywords=pepe-te-muimui|title=pepe-te-muimui|website=maoridictionary.co.nz|access-date=3 September 2017}}{{cite journal|last=Best|first=Elsdon|title=Art. V.—Food Products of Tuhoeland: being Notes on the Food-supplies of a Non-agricultural Tribe of the Natives of New Zealand; together with some Account of various Customs, Superstitions, &c., pertaininy to Foods.|journal=Transactions and Proceedings of the Royal Society of New Zealand |year=1902 |volume=35|pages=64|url=http://rsnz.natlib.govt.nz/volume/rsnz_35/rsnz_35_00_000660.html|accessdate=20 August 2011}} Finally, it emerges and flies off to reproduce and is known as {{lang|mi|tunga rere}}.

File:Huhu beetle 01.ogv

Female adult huhu beetles oviposit their 3mm cigar-shaped eggs in clutches of 10–50, though up to 100 may be found.{{Cite book| title=Common Insects in New Zealand| last1=Miller| first1=David |date=1984 |first2=Annette| last2=Walker |edition=Rev. |location=Wellington [NZ] |publisher=Reed |isbn=0589014803 |oclc=12748887}}{{Cite web |title=Huhu beetle (Prionoplus reticularis) or tunga rere |url= https://collections.tepapa.govt.nz/topic/985 |website=Te Papa |date=1998 |access-date=14 May 2025}}{{Cite journal|last=Edwards|first=John S.|date=1961 |title=Observations on the biology of the immature stages of Prionoplus reticularis White (Col. Ceramb.) |url= https://paperspast.natlib.govt.nz/periodicals/TPRSNZ1960-88.2.10.10 |journal=Transactions of the Royal Society of New Zealand|volume=88|pages=727–731|via=Papers Past}} Eggs are laid in cryptic sites or in cracks in the bark of fallen wood. In laboratory conditions of 20°C ± 2°C and a relative humidity of c. 75%, eggs hatched in 23 ± 2 days.

Before hatching, the larva can be seen to move inside the egg and will break free from the egg using its mandibles to pierce the chorion of the egg and then enlarging the opening by chewing, although the chorion itself is not ingested. Setae that are found on abdominal segments 1-6 assist in providing support as the larva leaves the egg and excavates the initial gallery.

The whitish-coloured larvae measure up to {{convert|70|mm}} long and normally feed on dead wood of gymnosperms (mainly native and introduced conifers) associated with lowland podocarp forest.{{cite journal |last=Edwards|first=John S. |year=1959|title=Host range in Prionoplus reticularis White |url= https://www.cerambycoidea.com/titles/edwars1959.pdf |journal=Transactions of the Royal Society of New Zealand|volume=87|issue=Parts 3 and 4 |pages=315–318}} Larval duration of P. reticularis is two to three years in the wild. Under laboratory conditions, larval duration has been reduced to c. 250 days using an artificial diet and maintaining a temperature of 20°C.{{Cite journal |last1=Rogers |first1=David J.|last2=Lewthwaite|first2=Sonya E.|last3=Dentener|first3=Peter R. |date=2002 |title=Rearing huhu beetle larvae, Prionoplus reticularis (Coleoptera: Cerambycidae) on artificial diet|journal=New Zealand Journal of Zoology |volume=29|issue=4 |pages=303–310 |doi=10.1080/03014223.2002.9518314|s2cid=84043980|issn=0301-4223}} In its final instar the larva moves to within 7.5–10cm of the surface of the wood before constructing the pupal chamber. The pupal chamber is constructed by enlarging the diameter of the normal gallery over a period of one to three days. This process creates fragments of wood similar to wood shavings about 3cm by 1cm in size which are then packed into the larval gallery to form a plug. Once the plug is completed the larva lines the walls of the pupal chamber with the last frass voided from its gut. The larva then undergoes a resting period of around ten to fifteen days where the abdominal segments contract and the body darkens slightly whereupon it moults into a pupa.

The pupal phase lasts around 25 days with gametogenesis being completed during this stage.{{Cite journal |last=Edwards|first=John S.|date=1961-12-01|title=On the reproduction of Prionoplus reticularis (Coleoptera, Cerambycidae), with general remarks on reproduction in the Cerambycidae|url=http://jcs.biologists.org/content/s3-102/60/519.short|journal=Journal of Cell Science |language=en|volume=s3-102|issue=60|pages=519–529 |doi=10.1242/jcs.s3-102.60.519 |issn=0021-9533}} Eclosion occurs with a rupture along the frontal suture followed by a longitudinal rupture to the posterior border of the mesothorax. The head, feet and wings are freed during arching movements of the body through the ruptured cuticle. The emerged adult may then enter an inactive period of three to five days prior to creating an exit tunnel out of the pupal cavity.

Following pupation and emergence, the adult beetle does not eat and lives for approximately two weeks.

File:HuhuFemaleCatlinsDorsal1.jpg|Female huhu beetle

File:Huhu beetle 08.jpg|Huhu beetle (wire mesh 8mm spacing)

File:Prionoplus reticularis.jpg|Huhu beetle (front)

File:Prionoplus reticularis 2.jpg|Huhu beetle

File:Female Prionoplus reticularis (huhu beetle).png|The head and prothorax of a female P. reticularis

File:Eggs of Prionoplus reticularis (huhu beetle). 01.png|Eggs of P. reticularis

File:Huhu grubs.jpg|Huhu larvae in wood

File:HuhuGrubParty50mmBG.png|Larvae of P. reticularis

File:Huhu pupae Foods 2023, 12(2).png|Pupae

The beetles are nocturnal and are attracted by the lights of dwellings as noted by Hudson in 1892 "it is greatly attracted to light, and this propensity frequently leads it on summer evenings to invade ladies' drawing-rooms, when its sudden and noisy arrival is apt to cause much needless consternation amongst the inmates".{{cite encyclopedia| title=Huia | encyclopedia=The Official World Wildlife Fund Guide to Extinct Species of Modern Times| volume =1| pages =63–65| publisher =Beacham Publishing | year =1997}}{{Cite book|url=https://archive.org/details/elementarymanual00huds|title=An elementary manual of New Zealand entomology; being an introduction to the study of our native insects|last=Hudson|first=G. V. (George Vernon)|date=1892|publisher=London, West, Newman & Co.|others=Smithsonian Libraries}} They have powerful mandibles, which can produce a painful bite.

Adult females of P. reticularis produce an olfactory cue which attract adult males to the female.{{Cite web|url=http://rsnz.natlib.govt.nz/volume/rsnz_88/rsnz_88_04_008450.html|title=Observations on the ecology and behaviour of the huhu beetle, Prionoplus reticularis White.(Col. Ceramb.)|last=Edwards|first=John S.|website=rsnz.natlib.govt.nz|publisher=Transactions and Proceedings of the Royal Society of New Zealand|pages=733–741|date=1961|access-date=2018-07-11}} Adult individuals of both sexes will show a display behaviour if disturbed with the head jutting forward, mandibles opening to their full extent, antennae flailing and the head being raised and lowered. High intensity displays between individuals may lead to combat with preliminary grappling occurring with fore legs which usually results in an individual being thrown onto its back. Any object coming into contact with the mandibles is seized frequently resulting in the loss of appendages.

File:Wildfoods 2021 MRD 02.jpg 2021]]

The larvae of P. reticularis are edible to humans, with a long history of indigenous consumption, and their flavour has been described as like buttery chicken{{cite web |url=http://www.weird-food.com/weird-food-bugs.html |title=Weird Food from around the World |year=2008 |accessdate=18 July 2008 |archive-date=18 July 2008 |archive-url=https://web.archive.org/web/20080718171353/http://www.weird-food.com/weird-food-bugs.html |url-status=dead }} or peanut butter.{{cite web |url=https://teara.govt.nz/en/photograph/10076/eating-huhu-grubs |first=George |last=Gibbs |title=Insects – overview - In the bush |website=Te Ara - the Encyclopedia of New Zealand |year=2007|accessdate=12 February 2019}} There are different names in Māori for grubs at different stages of development, for example young larvae still actively feeding on timber are called tunga haere or tunga rākau, while full grown grubs which have ceased to feed and are preparing to pupate are called tataka and are the most prized (because there is no undigested wood pulp inside of them at this point). Huhu grubs may be consumed either raw or traditionally cooked in a hāngī, and are an especially rich source of fat in the New Zealand wilderness.{{cite web |url=http://tpo.tepapa.govt.nz/ViewTopicExhibitDetail.asp?TopicFileID=0x000a49be|archive-url=https://web.archive.org/web/20170413070425/http://tpo.tepapa.govt.nz/ViewTopicExhibitDetail.asp?TopicFileID=0x000a49be|url-status=dead|archive-date=13 April 2017 |title=Huhu on the menu |website=Te Papa-Tai Awatea/Knowledge Net |date=22 January 2016|accessdate=12 February 2019}}

P. reticularis contains substantial amounts of nutrients. The larvae and pupae are relatively high in fat (up to 45% and 58% dry weight in large larvae and pupae respectively).{{Cite journal |last1=Kavle |first1=Ruchita Rao |last2=Carne |first2=Alan |last3=Bekhit |first3=Alaa El-Din Ahmed |last4=Kebede |first4=Biniam |last5=Agyei |first5=Dominic |date=2022-07-01 |title=Proximate composition and lipid nutritional indices of larvae and pupae of the edible Huhu beetle (Prionoplus reticularis) endemic to New Zealand |url=https://www.sciencedirect.com/science/article/pii/S088915752200196X |journal=Journal of Food Composition and Analysis |language=en |volume=110 |pages=104578 |doi=10.1016/j.jfca.2022.104578 |s2cid=248209931 |issn=0889-1575}} The fat in huhu grubs is mostly oleic acid and palmitic acid. The second most abundant nutrient is protein, which is present at 30% dry weight in the large larvae, and close to 28% dry weight in the pupae. Protein extracts from huhu larvae and pupae are high in essential amino acids such as isoleucine, lysine, leucine, and valine.{{Cite journal |last1=Kavle |first1=Ruchita Rao |last2=Nolan |first2=Patrick James |last3=Bekhit |first3=Alaa El-Din Ahmed |last4=Carne |first4=Alan |last5=Morton |first5=James David |last6=Agyei |first6=Dominic |date=2023 |title=Physicochemical Characteristics, Techno-Functionalities, and Amino Acid Profile of Prionoplus reticularis (Huhu) Larvae and Pupae Protein Extracts |journal=Foods |language=en |volume=12 |issue=2 |pages=417 |doi=10.3390/foods12020417 |issn=2304-8158 |pmc=9857897 |pmid=36673509 |doi-access=free }} The total essential amino acid content of huhu grubs meets the WHO essential amino acid requirements for human nutrition. The essential amino acid content of huhu is significantly higher than that of mealworms, and is comparable to beef and chickpeas. When reconstituted in water, the protein powders of huhu larvae and pupae are able to form stable foams and emulsions. The ash content (representing minerals) of huhu grubs is 1.8% dry weight in large larvae, and 2.2% in pupae. The minerals include manganese, magnesium, phosphorus, iron, copper, and zinc.{{Cite journal |last1=Kavle |first1=Ruchita Rao |last2=Carne |first2=Alan |last3=Bekhit |first3=Alaa El-Din Ahmed |last4=Kebede |first4=Biniam |last5=Agyei |first5=Dominic |date=2022 |title=Macronutrients and mineral composition of wild harvested Prionoplus reticularis edible insect at various development stages: nutritional and mineral safety implications |url=https://onlinelibrary.wiley.com/doi/10.1111/ijfs.15545 |journal=International Journal of Food Science & Technology |language=en |volume=57 |issue=10 |pages=6270–6278 |doi=10.1111/ijfs.15545 |issn=0950-5423}}

• Witchetty grub

{{Reflist|2}}

{{Wikispecies|Prionoplus reticularis|Huhu beetle}}

{{Commons|Prionoplus reticularis|Huhu beetle}}

• [http://www.landcareresearch.co.nz/research/biodiversity/invertebratesprog/invertid/bug_details.asp?Bu_Id=199 Landcare Research] {{Webarchive|url=https://web.archive.org/web/20050310060752/http://www.landcareresearch.co.nz/research/biodiversity/invertebratesprog/invertid/bug_details.asp?Bu_Id=199 |date=10 March 2005 }} - data
• Huhu beetle discussed on RNZ Critter of the Week, [https://www.rnz.co.nz/national/programmes/afternoons/audio/2018724704/critter-of-the-week-huhu-beetle-huhu-grub 29 November 2019]

{{Taxonbar|from=Q1941645}}

Category:Prioninae

Category:Edible insects

Category:Māori cuisine

Category:Beetles and humans

Category:Beetles described in 1843

Category:Endemic beetles of New Zealand

Category:Taxa named by Adam White (zoologist)