Gonipterus gibberus is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of weevil

Weevil

A weevil is any beetle from the Curculionoidea superfamily. They are usually small, less than , and herbivorous. There are over 60,000 species in several families, mostly in the family Curculionidae...

 in the Curculionidae

Curculionidae

Curculionidae is the family of the "true" weevils . It was formerly recognized in 1998 as the largest of any animal family, with over 40,000 species described worldwide at that time...

 family. It is commonly known as the eucalyptus snout beetle, the eucalyptus weevil or the gum tree weevil. It feeds and breeds on Eucalyptus

Eucalyptus

Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...

trees and is endemic to Australia.

Description

This weevil is greyish-brown with a light coloured transverse band. It is about thirteen millimetres long and not readily distinguishable from the closely related weevil, Gonipterus scutellatus

Gonipterus scutellatus

Gonipterus scutellatus is a species of weevil in the Curculionidae family. It is commonly known as the eucalyptus snout beetle, the eucalyptus weevil or the gum tree weevil. It feeds and breeds on Eucalyptus trees and is endemic to Australia.-Description:This weevil is greyish-brown with a light...

, which shares the same common names. The larvae are yellowish-green with dark markings and no green stripes on the underside, which distinguishes them from larvae of G. scutellatus.

Host plants

Eucalyptus trees are the only hosts for the gum tree weevil. The species most susceptible to attack include Eucalyptus camaldulensis, Eucalyptus globulus

Eucalyptus globulus

The Tasmanian Blue Gum, Southern Blue Gum or Blue Gum, is an evergreen tree, one of the most widely cultivated trees native to Australia. They typically grow from 30 to 55 m tall. The tallest currently known specimen in Tasmania is 90.7 m tall...

, Eucalyptus maidenii

Eucalyptus maidenii

Eucalyptus maidenii, commonly known as Maiden's Gum, is a Eucalypt species native to eastern Victoria and southeastern New South Wales, Australia. It grows in wet forest on fertile soils in valleys in subcoastal ranges....

, Eucalyptus punctata, Eucalyptus robusta

Eucalyptus robusta

Eucalyptus robusta, commonly known as Swamp Mahogany, Swamp Messmate or Swamp Stringybark, is a tree native to eastern Australia.-Description:...

, Eucalyptus smithii

Eucalyptus smithii

Eucalyptus smithii, or gully gum, is a native tree of northern Victoria and southern New South Wales, Australia. In its natural situation it occurs on the lower slopes, gullies, and swamps - where soils do not dry out....

and Eucalyptus viminalis.

Distribution

The gum tree weevil is endemic to Australia where Eucalyptus trees are native. The weevil has spread to South America, either as eggs and larvae on imported planting material or in soil, and is found in Argentina, Uruguay and the states of Paraná, Rio Grande do Sul and Santa Catarina in Brazil.

Life history

Over a period of about three months, adult female gum tree weevils lay about two hundred eggs in batches of about ten contained in grey coloured capsules attached to leaves. These hatch after about a week and the larvae begin to feed on leaves and young shoots. After moulting three times, the larvae crawl or fall to the ground where they pupate a few centimetres beneath the surface. The weevil's life cycle takes seven to eleven weeks from egg laying to maturity, depending on the temperature. In Mauritius

Mauritius

Mauritius , officially the Republic of Mauritius is an island nation off the southeast coast of the African continent in the southwest Indian Ocean, about east of Madagascar...

 there are about four generations annually and the weevils breed throughout the year. In South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

 there are two generations and they overwinter as adults.

Significance

The gum tree weevil is of little economic significance in Australia where it has natural enemies. In other countries where Eucalyptus has been introduced, that is not the case. Adult gum tree weevils feed mostly on leaves and the soft bark of twigs while the larvae feed mostly on leaves. Heavy infestations cause die back of shoots which may result in the development of epicormic shoot

Epicormic shoot

An epicormic shoot is a shoot growing from an epicormic bud which lies underneath the bark of a trunk, stem, or branch of a plant.-Epicormic buds:...

s. Repeated defoliations may cause the splitting and death of branches or even whole trees.