Stethaspis
{{Short description|Genus of beetles}}
{{Automatic taxobox
| image = Stethaspis longicornis by Peter de Lange.jpg
| image_caption = Stethaspis longicornis
| taxon = Stethaspis
| authority = Hope, 1837
}}
Stethaspis is a genus of beetles in the family Scarabaeidae, subfamily Melolonthinae.{{Cite web |title=Stethaspis Hope, 1837 |url=https://www.gbif.org/en/species/4993582 |access-date=2023-02-14 |website=www.gbif.org |language=en}}
Description
Like other Melolonthinae, adult Stethaspis are oval and robust in shape. The antennae are relatively short and have the last few segments flattened and finger-like. The elytra leave the end of the abdomen exposed. Stethaspis are green in colour and range from 13 to 24 mm in length.{{Cite web |title=NZ Farm Forestry - Melolonthine beetles in forests - grass grub and other chafers |url=https://www.nzffa.org.nz/farm-forestry-model/the-essentials/forest-health-pests-and-diseases/Pests/Melolonthine/melolonthine-beetles-in-forests---grass-grub-and-other-chafers/ |access-date=2023-02-14 |website=www.nzffa.org.nz}}
Larvae are creamy white with a prominent head, relatively large legs and a darkened posterior end (this darkening is due to the gut contents showing through the body wall). The body is curled up into a C-shape. When mature, Stethaspis larvae can be up to 45 mm long.
Ecology
Similar to other melolonthines, Stethaspis beetles feed on plant foliage as adults and plant roots as larvae. Adults are known to damage Douglas fir.
Larvae of S. longicornis are eaten by Polynesian rats.{{Cite journal |last=CAMPBELL |first=D. J. |last2=MOLLER |first2=H. |last3=RAMSAY |first3=G. W. |last4=WATT |first4=J. C. |date=1984 |title=OBSERVATIONS ON FOODS OF KIORE (RATTUS EXULANS) FOUND IN HUSKING STATIONS ON NORTHERN OFFSHORE ISLANDS OF NEW ZEALAND |url=https://www.jstor.org/stable/24052709 |journal=New Zealand Journal of Ecology |volume=7 |pages=131–138 |issn=0110-6465}} Additionally, Stethaspis larvae are potential hosts for the introduced scoliid wasp Radumeris tasmaniensis, an ectoparasitoid of scarab larvae.{{Cite journal |last=Barratt |first=B.I.P. |last2=Willoughby |first2=B.E. |last3=Wilson |first3=D. |last4=Booth |first4=A.M. |date=2002-08-01 |title=The yellow flower wasp Radumeris tasmaniensis Saussure (Hymenoptera Scoliidae) potential threat to New Zealand native fauna |url=https://nzpps.org/_journal/index.php/nzpp/article/view/3908 |journal=New Zealand Plant Protection |volume=55 |pages=25–29 |doi=10.30843/nzpp.2002.55.3908 |issn=1179-352X|doi-access=free |url-access=subscription }}
Life cycle
Stethaspis follow the usual beetle life cycle of egg, larva, pupa and adult. The life cycle takes two years. Adults emerge en masse in summer.{{Cite news |last=Taonga |first=New Zealand Ministry for Culture and Heritage Te Manatu |title=Habitats |language=en |url=https://teara.govt.nz/en/beetles/page-4 |access-date=2023-02-14}}
Species
Gallery
File:Stethaspis suturalis 111940868.jpg|Stethaspis suturalis
File:Stethaspis suturalis 109318726.jpg|Underside of a different S. suturalis