Distribution and impact of the Asian seed beetle, Megabruchidius tonkineus (Pic, 1904) (Coleoptera: Chrysomelidae: Bruchinae) on Gleditsia triacanthos L. seeds in South Africa


  • Sara Salgado Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa
  • Grant Martin Centre for Biological Control, Department of Zoology and Entomology, Rhodes University, Makhanda, South Africa https://orcid.org/0000-0001-9302-1369




Honey Locust, Alien insect, biological control, seed predator


Honey locust, Gleditsia triacanthos (Fabaceae) is a fast-growing deciduous tree native to North America. The tree has been introduced worldwide and has become invasive in South Africa. In 2017, it was listed as one of the nine fastest-spreading weeds in South Africa. Once established, it competes with and displaces indigenous species and dense stands can significantly reduce stream flow. The Asian seed-feeding bruchid, Megabruchidius tonkineus (Coleoptera: Chrysomelidae: Bruchinae) was introduced into South Africa and has subsequently taken honey locust as a host plant. The beetle damages honey locust seeds and is therefore considered a biological control agent, despite no host-specificity or impact studies having been conducted. This study shows that M. tonkineus has established across the entire G. triacanthos population range in South Africa, damaging approximately 9% of seeds. Laboratory studies show that M. tonkineus completes its larval development in the seeds of G. triacanthos in about 66.80 ± 0.69 SE days before emerging. This study is the first to describe the distribution and impact of this alien insect in South Africa.


Download data is not yet available.


Metrics Loading ...


Atlas of Living Australia. nd. ‘Gleditsia triacanthos L.’ Database. https://bie.ala.org.au/species/https://id.biodiversity.org.au/node/apni/2895256 [accessed 13 January 2021].

CABI. 2021. Gleditsia triacanthos (honey locust). In: Invasive species compendium. Wallingford, United Kingdom. https://www.cabidigitallibrary.org/doi/10.1079/cabicompendium.25272 [accessed 13 January 2021].

Department of Environmental Affairs. 2014. The National Environmental Management: Biodiversity Act (10/2004): draft alien and invasive species list. Government Gazette.

Di Iorio OR. 2015. A new previously predicted larval host for the Asian seed beetle Megabruchidius tonkineus (Pic, 1904), and the incorporation of M. dorsalis (Fåhraeus, 1839) to the Argentinian fauna of Bruchinae (Coleoptera: Chrysomelidae). Boletin de la Sociedad Entomologica Aragonesa.56: 327–334.

Eow L, Rako L, Selleck C, Valenzuela I. 2023. First record of Megabruchidius tonkineus (Pic, 1904) (Coleoptera: Chrysomelidae, Bruchinae) in Australia. BioInvasions Record. 12(2):581-592.


Fernández RD, Ceballos SJ, Malizia A, Aragón R. 2017. Gleditsia triacanthos Fabaceae in Argentina: A review of its invasion. Australian Journal of Botany. 65(3):203–213. https://doi.org/10.1071/BT16147

Gavrilović B, Savić D. 2013. Invasive bruchid species Bruchidius siliquastri Delobel, 2007 and Megabruchidius tonkineus (Pic, 1904) (Insecta: Coleoptera: Chrysomelidae: Bruchinae) new in the fauna of Serbia: Review of the distribution, biology and host plants. Acta Entomologica Serbica. 18(1–2):129–136.

GBIF. 2021. Gleditsia triacanthos L. Checklist Dataset. GBIF, viewed on 16 January 2021, https://www.gbif.org/species/2959443

György Z. 2007. To the biology of the honey locust seed beetle, Megabruchidius tonkineus (Pic, 1904) (Coleoptera: Chrysomelidae: Bruchinae). Folia Entomologica Hungarica. 68: 89–96.

György Z, Germann C. 2012. First record of the invasive Megabruchidius tonkineus (Pic, 1904) for Switzerland (Coleoptera, Chrysomelidae: Bruchinae). Bulletin de la Société Entomologique Suisse. 85:243–249.

Henderson L. 2016. SAPIA News No. 41. Newsletter of the Southern African Plant Invaders Atlas, Weeds Programme of Plant Protection Research, Agricultural Research Council (ARC). https://invasives.org.za/wp-content/uploads/SAPIA_News_41_Jul2016.pdf [accessed 17 January 2020].

Henderson L, Wilson JRU. 2017. Changes in the composition and distribution of alien plants in South Africa: An update from the Southern African Plant Invaders Atlas. Bothalia. 47(2):a2172. https://doi.org/10.4102/abc.v47i2.2172

Hoffmann JH, Moran VC. 1991. Biological control of Sesbania punicea (Fabaceae) in South Africa. Agriculture, Ecosystems and Environment. 37(1–3):157–173. https://doi.org/10.1016/0167-8809(91)90144-M.

Isely D. 1975. Legumes of the United States. New York Botanic Gardens. 25: 1–228.

Klein H. 2011. A catalogue of the insects, mites and pathogens that have been used or rejected, or are under consideration, for the biological control of invasive alien plants in South Africa. African Entomology. 19(2):515–549. https://doi.org/10.4001/003.019.0214

Kleinjan CA, Hoffmann JH, Heystek F, Ivey P, Kistensamy Y. 2021. Developments and prospects for biological control of Prosopis (Leguminosae) in South Africa. African Entomology. 29(3):859–874. https://doi.org/10.4001/003.029.0859

Korotyaev BA. 2011. On invasion of an East Asian seed beetle, Megabruchidius tonkineus (Pic) (Coleoptera, Bruchidae), developing in Gleditsia seeds, in the Northwest Caucasus. Entomological Review. 91:1167–1169.

Korotyaev BA. 2016. First records of an East Asian seed beetle Megabruchidius dorsalis Fåhraeus (Coleoptera, Bruchidae) from Germany and the Black Sea Coast of Crimea and Caucasus. Entomological Review. 96(4):460–461. https://doi.org/10.1134/S0013873811090089.

Kurtek I, Zahirović Ž, Turić N, Vrućina I, Vignjević G, Merdić E, Sudarić Bogojević M. 2017. First record of the invasive seed beetle Megabruchidius tonkineus (Coleoptera, Chrysomelidae, Bruchinae) in Croatia. Natura Croatica. 26(1):109–115. https://doi.org/10.20302/NC.2017.26.9

Martin GD. 2021. Prospects for the biological control of Northern Temperate Weeds in South Africa. African Entomology. 29(3):791-808. https://doi.org/10.4001/003.029.0791

Mucina L, Rutherford MC. 2006. The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African Biodiversity Institute, Pretoria.

Pintilioaie AM, Manci CO, Fusu L, Mitroiu MD, Rădac AI. 2018. New invasive bruchine species (Chrysomelidae: Bruchinae) in the fauna of Romania, with a review on their distribution and biology. Annales de la Societe Entomologique de France. 54:401–409. https://doi.org/10.1080/00379271.2018.1506265

Salgado Astudillo SE. 2021. Post release evaluation of Megabruchidius tonkineus (Coleoptera: Chrysomelidae: Bruchinae) a biological control agent for Gleditsia triacanthos L. (Fabaceae) in South Africa. MSc thesis, Rhodes University, Makhanda, South Africa.

Schulze RE. 1997. South African Atlas of Agrohydrology and Climatology. University of Natal, Pietermaritzburg.

Syrett P, Fowler SV, Emberson RM. 1996. Are chrysomelid beetles effective agents for biological control of weeds. In: Proceedings of the IX International Symposium on biological control of weeds. University of Cape Town Stellenbosch, South Africa. pp 399–407.

Yus-Ramos R, Ventura D, Bensusan K, Coello-García P, György Z, Stojanova A. 2014. Alien seed beetles (Coleoptera: Chrysomelidae: Bruchinae) in Europe. Zootaxa. 3826:401–448. https://doi.org/10.11646/zootaxa.3826.3.1.

Yus-Ramos R, Ventura D, García P, Stojanova A. 2011. Bruchidius terrenus Sharp, 1886. Coleoptera: Bruchidae.: primera cita para la Península Ibérica y para Iitalia, caracterización del imago y primeros datos biológicos. Boletín de la Sociedad Entomológica Aragonesa. 48:253–260.

Zachariades C. 2021. A catalogue of natural enemies of invasive alien plants in South Africa: classical biological control agents considered, released and established, exotic natural enemies present in the field, and bioherbicides. African Entomology. 29(3):1077–1142. https://doi.org/10.4001/003.029.1077




How to Cite

Salgado S, Martin G. Distribution and impact of the Asian seed beetle, Megabruchidius tonkineus (Pic, 1904) (Coleoptera: Chrysomelidae: Bruchinae) on Gleditsia triacanthos L. seeds in South Africa. Afr. Entomol. [Internet]. 2023 Nov. 9 [cited 2023 Dec. 1];31. Available from: https://www.africanentomology.com/article/view/13386