Ophelimus

Haliday, 1844

Eucalyptus gall wasps

Species Guides

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Ophelimus is a of minute in the Eulophidae. in this genus are gall inducers, causing the formation of leaf galls on Eucalyptus plants. Several species, including O. maskelli and O. eucalypti, have become pests in Eucalyptus plantations outside their native Australian range. The genus is subject to efforts using such as Closterocerus chamaeleon.

Ophelimus by (c) Dave Richardson, some rights reserved (CC BY), uploaded by Dave Richardson. Used under a CC-BY license.Ophelimus maskelli by (c) Michele Jones, some rights reserved (CC BY), uploaded by Michele Jones. Used under a CC-BY license.Ophelimus maskelli galls on Eucalyptus by Giancarlo Dessì. Used under a CC BY-SA 3.0 license.

Pronunciation

How to pronounce Ophelimus: //oʊˈfɛlɪməs//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Members of this are small chalcid wasps, typically under 2 mm in length. -level identification requires examination of microscopic morphological characters; O. mediterraneus and O. maskelli can be distinguished using multivariate ratio analysis and molecular markers ( oxidase I, 28S).

Images

Habitat

Eucalyptus forests and plantations; associated with leaves of Eucalyptus .

Distribution

Native to Australia (Queensland, Western Australia, New South Wales). Introduced and established in New Zealand, Europe (France, Italy, Portugal, Spain, UK, Greece), Asia (Israel, Turkey), Africa (Algeria, Morocco, Tunisia), Indonesia (Sumatra), and Colombia.

Seasonality

Multivoltine; continuous breeding in suitable climates. Maximum of O. eucalypti observed in August and December in New Zealand.

Host Associations

  • Eucalyptus - gall induction on leavesPrimary plant for all Ophelimus
  • Eucalyptus globulus - gall induction for O. maskelli, O. eucalypti, O. migdanorum, and O. near migdanorum
  • Eucalyptus saligna - gall induction for O. eucalypti
  • Eucalyptus botryoides - gall induction for O. eucalypti
  • Eucalyptus camaldulensis - gall induction for O. maskelli
  • Eucalyptus grandis - gall induction for O. eucalypti
  • Eucalyptus deanei - gall induction for O. eucalypti
  • Closterocerus chamaeleon - Eulophid with greater longevity and survival than its Ophelimus ; used in biocontrol
  • Aprostocetus causalis - Eulophid of O. eucalypti in Indonesia
  • Chrysonotomyia spp. - Prevalent of O. eucalypti in North Sumatra
  • Mikeius hartigi - that lays in galls induced by Ophelimus spp.

Life Cycle

Complete (, larva, pupa, ). Gall development progresses through six color-differentiated stages. Larvae grow to fill the entire gall cavity prior to gall . Gall mass peaks when larvae are at one-third of maximum mass. Adults live approximately 10 days; females produce up to 350 eggs. Lifespan of O. eucalypti averages 44 days in greenhouse conditions.

Behavior

Induces formation of leaf galls on Eucalyptus. Gall and development rate influenced by microclimate; drier conditions favor larger gall size, faster development, and higher densities.

Ecological Role

Herbivore and gall inducer on Eucalyptus. Acts as for multiple , supporting local parasitoid in invaded regions.

Human Relevance

Several are significant pests of commercial Eucalyptus plantations, causing foliar damage and reduced growth. Subject to classical and programs using . O. maskelli and O. eucalypti are particularly problematic in Mediterranean Europe, Indonesia, and New Zealand.

Similar Taxa

  • Ophelimus maskelliClosely related to O. mediterraneus; distinguished by molecular and morphological analysis
  • Ophelimus mediterraneusSympatric with O. maskelli in introduced Mediterranean areas; previously confused with O. maskelli
  • Ophelimus eucalyptiSimilar and range; distinguished by gall characteristics and microscopic
  • Ophelimus migdanorumSimilar leaf-gall induction on E. globulus; specific diagnostic characters not detailed in available sources

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Sources and further reading