Leptocybe invasa

Leptocybe invasa Fisher and La Salle.

Taxonomic placing: Insecta, Holometabola, Hymenoptera, Eulophidae.

Common name: Blue gum chalcid, Eucalyptus gall wasp.

Geographical distribution: Africa, India, Iran, Mediterranean countries, South-East Asia, and the USA.

Host plants: Eucalyptus spp.

Morphology: The body of the adult is brownish with a blue to green metallic hue, the legs are pale and the antennae are mostly brown. The larvae are whitish.

Life history: This wasp has a strong female-biased sex ratio, and males are rare. The females oviposit their eggs (about 25/female) in young leaves and twigs. The hatching larvae feed in a cavity within the plant, inducing the formation of the typical pink, bump-shaped galls. Their development may last several months. The adults then emerge via typical round exit holes. The adult pest lives only for about one week, and is active only when average temperatures are above 20°C. In different parts of the world it may complete 3-4 annual, overlapping generations.

Economic importance: Severely affected young eucalypt trees show leaf abscission, loss of vigor and stunted growth. Elder trees are less damaged. This wasp is a serious problem in Eucalyptus plantations and nurseries in many parts of the world.


Monitoring: Periodic examinations of infestations in nurseries and young plantations and the setting of yellow sticky traps to attract the adults.

Horticultural control: The removal and burning of infested plant parts, and the avoidance of susceptible Eucalyptus species or clones.

Plant resistance: Several resistant Eucalyptus species or clones are available for planting.

Chemical control: Applications of systemic or botanic insecticides on the foliage at fortnightly intervals were effective. However, as the developing stages are within the gall, and the pest has overlapping generations, it is difficult to determine the optimum period for pesticide applications in order to obtain effective chemical control.

Biological control: Two Australian eulophids, Quadrastichus mendeli Kim and La Salle and Selitrichodes kryceri Kim and La Salle, were introduced and became established in Israel. Other eulophids include Selitrichodes neseri Kelly and La Salle, which was released in South Africa, and Aprostocetus causalis La Salle and Wu, from China and Thailand. Several Torymidae also attack the pest.


Almatni, W. and Mayhoob, M. 2004. Eucalyptus gall-wasp Leptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae), a new insect in the Mediterranean region and Syria. Arab and Near East Plant Protection Newsletter 40: 38.

Dittrich-Schröder, G., Wingfield, M.J., Hurley, B.P. and Slippers, B. 2012. Diversity in Eucalyptus susceptibility to the gall-forming wasp Leptocybe invasa. Agricultural and Forest Entomology 14: 419-427.

Doğanlar, M. and Hassan, E. 2010 Review of Australian species of Megastigmus (Hymenoptera: Torymidae) associated with Eucalyptus, with descriptions of new species. Australian Journal of Basic and Applied Science 4: 5059–5120.

Javaregowda, P.S.T. and Patil, R.S. 2010. Evaluation of botanicals and synthetic insecticides against eucalyptus gall wasp, Leptocybe invasa (Hymenoptera: Eulophidae). Karnataka Journal of Agricultural Sciences 23: 200–202.

Kelly, J., La Salle, J., Harney, M., Dittrich-Schröder, G. and Hurley, B. 2012. Selitrichodes neseri, a new parasitoid of the eucalyptus gall wasp Leptocybe invasa Fischer & La Salle (Hymenoptera: Eulophidae: Tetrastichinae). Zootaxa 3333: 50–57.

Mendel, Z., Protasov, A., Fisher, N. and La Salle, J. 2004. Taxonomy and biology of Leptocybe invasa gen. & sp. n. (Hymenoptera: Eulophidae), an invasive gall inducer on Eucalyptus. Australian Journal of Entomology 43: 101–113. Protasov, A., Doĝanlar, M., La Salle, J. and Mendel, Z. 2008. Occurrence of two local Megastigmus species parasitic on the eucalyptus gall wasp Leptocybe invasa in Israel and Turkey. Phytoparasitica 36: 449–459.

Ramadan, H.M., 2004. Morphological characteristics and distribution of Aprostocetus sp. (Hymenoptera: Eulophidae: Tetrastichinae) a gall wasp of eucalyptus new for Egypt. Alexandria Journal Agricultural Research 49: 59-63.

Thu, P.Q., Dell, B. and Burgess, T.I. 2009. Susceptibility of 18 eucalypt species to the gall wasp Leptocybe invasa in the nursery and young plantations in Vietnam. ScienceAsia 35 113–117.

Yang, M.-M. (and 8 co-authors) 2014). Aprostocetus causalis La Salle & Wu is a parasitoid of Leptocybe invasa Fisher & La Salle on Eucalyptus spp. (Myrtaceae) in China and Thailand. Zootaxa 3846: 261–272.

Zheng, X.L. (and 7 co-authors) 2014. Review of invasive biology, prevalence and management of Leptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae: Tetrastichinae). African Entomology 22: 68-79.

Website: https://www.google.co.il/search?q=leptocybe+invasa&biw=1536&bih=836&tbm=isch&tbo=u&source=univ&sa=X&ved=0CBoQsARqFQoTCNaA-8H918gCFQHXGgodipAI0g