Allard, D., Ito, F., Aikawa, Y., Gotoh, A. and Billen, J. 2011. Testes degeneration in ants: a histological study of Gnamptogenys bicolor.-Acta Zoologica (Stockholm) 92: 372-376.
Sperm synthesis in the males of social Hymenoptera is not continuous, as the testes degenerate before the males become sexually active. This article presents the first histological study focusing on the degeneration of testes tissue, using adult males of the ant Gnamptogenys bicolor. At eclosion, spermatogenesis is still in process in the apical part of the testes, while the basal spermatocysts are all packed with mature sperm. During the second week after eclosion, the first signs of degeneration appear as small clear vacuoles inside the spermatocysts, interspersed between maturing sperm cells. Sperm starts migrating into the vasa deferentia shortly after. As spermatocysts void their contents into the vasa deferentia, the follicles start shrinking and losing their shape and the fibrillar capsule tissue gets looser. Cellular breakdown yields dark vacuoles of various density and large granular, multi-layered bodies.