Sperm morphology of the leafhopper Diaphorina citri Kuwayama (Hemiptera: Sternorrhyncha: Psylloidea: Liviidae)

Abstract

In this study, by using light and electron microscopy, we describe the sperm morphology of the leafhopper Diaphorina citri, a serious pest of citrus throughout the world. In this species the sperm measures 538.49 ± 8.75 μm in length, and as observed in psylloids, the sperm, when manipulated, opens into two filaments, one of which is attached to the nuclear base and the other becomes free. Along the flagellum, and only of it, there are lateral projections, about 2 μm in length. Furthermore, at the end of the flagellum three appendages, with approximately 7 μm in length, are observed. The head region is formed by the nucleus with compact chromatin, and, parallel to it, a structure of median electron density that extends about 25 μm in length ahead of the nuclear tip. The flagellum consists of an axoneme with a 9 + 9 + 2 microtubule arrangement, two mitochondrial derivatives, and two accessory bodies each with two regions of different electron density. The presence of lateral projections is a characteristic observed in other Sternorrhyncha. As seen previously, the sperm opening in two filaments, when manipulated, was observed only in Psylloidea, and the presence of the three appendices at the end of the flagellum distinguishes D. citri from the other Psylloidea species studied.