Megymenum


Megymenum is a genus of Asian and Australian shield bugs in the family Dinidoridae and typical of the subfamily Megymeninae. It was erected by Félix Édouard Guérin-Méneville in 1831 and species have been recorded from India through to Japan, Indochina, Malesia, New Guinea and Australia.

Description

Species in genus Megymenum have extended or greatly expanded pronotal margins with a rounded scutellum: characteristic of the Dinidoridae. In most species the second valvifers are reduced, lightly sclerotised, and fused in the middle. Some species have reduced hemelytra and are flightless. Female Megymenum gracilicorne has distinctive sexual dimorphism in the hind legs, and females have a broadened part on the inner hind tibia which was thought to be a tympanal organ, but in 2025 it was discovered that this organ has a layer of secretory cells and the cavity contains special fungi. These fungi, mostly in the family Cordycipitaceae, are transferred to eggs at the time of oviposition and the fungus is thought to provide protection to the eggs against parasitic wasps.

Species

The following species are currently accepted in the genus:
  1. Megymenum affine
  2. Megymenum anacanthum
  3. Megymenum aruense
  4. Megymenum basale
  5. Megymenum brevicorne
  6. Megymenum confusum
  7. Megymenum dentatumtype species
  8. Megymenum distanti
  9. Megymenum dohrni
  10. Megymenum gracilicorne
  11. Megymenum lisi
  12. Megymenum megaspinosum
  13. Megymenum mekongum
  14. Megymenum obliquum
  15. Megymenum parallelum
  16. Megymenum pratti
  17. Megymenum quadratum
  18. Megymenum rectangulatum
  19. Megymenum salebrosum
  20. Megymenum semivestitum
  21. Megymenum severini
  22. Megymenum spinosum
  23. Megymenum sumatranum
  24. ''Megymenum tuberculatum''