Rhynchodes ursus

Rhynchodes ursus, also known as the elephant weevil, is a weevil in the Curculionidae family.^[2] It is endemic to New Zealand. It is a wood-boring weevil found throughout New Zealand.

Rhynchodes ursus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Coleoptera
Suborder:	Polyphaga
Infraorder:	Cucujiformia
Family:	Curculionidae
Genus:	Rhynchodes
Species:	R. ursus
Binomial name
Rhynchodes ursus White, 1846[1]

Taxonomy

This species was first described by Adam White in 1846.^[3]

Description

R. ursus illustration

The adults of this species were originally described by White as follows:

Deep brown; the thorax with two longitudinal bands of a lighter colour near the side; elytra above with five rows of hairs, on each side of which is a row of very deep punctures, between every two of which is a smoothish ridge; across the elytra are two obscure, dark brown bands; legs black, femora above at the end with a spot of yellowish brown hairs; abdomen beneath with the last segment having two tufts of hair.
Length, 101⁄2 lines.^[3]

This large weevil has a deep brown colour with two lighter bands near the side of its thorax. It has black legs with a spot of yellowish-brown hairs on each femur.^[3] It has dense scales on its body, which can be hair-like. In female specimens the antennae are inserted halfway along the rostrum and nearer the front in males.^[1] This species varies greatly in size, colour, and in the amount and nature of its hair-like scales. Male specimens are covered with short scale-like hairs, whilst females have longer, deep brown, or grey, longer more shaggy scale-like hairs. Old individuals are occasionally met with quite black and shining, and almost destitute of any scales whatsoever.^[4]

The larvae of R. ursus can be distinguished from other weevil larvae as it is large in size and has broad rounded ends to its premedial plates on its exoskeleton.^[5]

Distribution

This species is endemic to New Zealand and is found throughout the country.^[2][4]

Behaviour

R. ursus at night

This species is active at night and is able to fly.^[6]

Hosts

Adult weevils are found on trees, where they gather to feed on sap. Larvae tunnel into dead trunks and branches of southern beeches, rimu and Dracophyllum traversii.^[1]

Parasites

The larvae of R. ursus are the host of New Zealand's largest parasitic wasp, Certonotus fractinervis. Female wasps use a long ovipositor to lay eggs inside the larvae whilst those larvae develop inside trees.^[4]