Anatomy of the male reproductive system and sperm morphology in the caterpillar‐hunting wasp Ancistrocerus antilope (Hymenoptera, Vespidae)

Abstract

Abstract. The male reproductive system of the caterpillar‐hunting wasp Ancistrocerus antilope was composed of the testes, seminal vesicles, accessory glands, the penis, and the connecting ducts. The testes, which were paired structures lined with a thin layer of squamous epithelium, were composed of several lobes that contain developing spermatozoa. These spermatozoa began as spermatocytes in the distal portion of the testicular lobe and, as they matured, they moved proximally toward the seminal vesicles. Upon maturation, the spermatozoa were long, thin structures with a nucleus of ∼10–15 μm in length and 1–2 μm in width. Their tails, which were not morphologically distinct from their heads at the gross level, averaged 388±25 μm in length. Once the spermatozoa had fully developed, they traveled from the testes to the seminal vesicles, where they were stored. The walls of the seminal vesicles were composed of a ciliated, pseudostratified, columnar epithelium. A layer of fibrous connective tissue termed the testicular capsule encapsulated both the testes and the seminal vesicles. Upon ejaculation, the spermatozoa moved through the deferent ducts, where they combined with granular fluid from the accessory glands. From here, they traveled via the ejaculatory duct to the penis, where they were expelled. In this study, these anatomical descriptions are discussed in reference to other species of the Hymenoptera.

Morphology of male reproductive system of two solitary bee species (Hymenoptera: Apidae)

“…The epithelium found in the spermatic ducts along the reproductive tract of bees is similar to that described for social bees (Snodgrass 1956, Cruz-Landim & Cruz-Hofl ing 1969a, b, Dallacqua & Cruz-Landim 2003, Araújo et al 2005, Lima et al 2006, ants (Ball & Vison 1984, Wheeler & Krutzsch 1992, and wasps (Dirks & Sternburg 1972, Bushrow et al 2006, Moreira et al 2008. However, some differences are evident, such as the large amount of inclusions in the epithelium of the seminal vesicle and the differences in the epithelium type in the accessory glands found in the two bee species studied.…”

“…The ejaculatory duct is a single, median structure and presents a cuticle that shows its ectodermic origin, as in most insects (Bushrow et al 2006, Moreira et al 2008. The epithelium found in the spermatic ducts along the reproductive tract of bees is similar to that described for social bees (Snodgrass 1956, Cruz-Landim & Cruz-Hofl ing 1969a, b, Dallacqua & Cruz-Landim 2003, Araújo et al 2005, Lima et al 2006, ants (Ball & Vison 1984, Wheeler & Krutzsch 1992, and wasps (Dirks & Sternburg 1972, Bushrow et al 2006, Moreira et al 2008.…”

Structural and ultrastructural characteristics of male reproductive tract and spermatozoa in two Cryptinae species (Hymenoptera: Ichneumonidae)

“…Morphological aspects of the male reproductive system of parasitoids analyzed are similar to those described for most Hymenoptera (Dallacqua and Cruz-Landim, 2003;Ferreira et al, 2004;Damiens and Boivin, 2005;Araú jo et al, 2005a;Brito et al, 2005;Bushrow et al, 2006;Fiorillo et al, 2008Fiorillo et al, , 2009). However, the number of follicles per testis varies considerably between the different groups.…”

Morphology of male reproductive system in three species of Trypoxylon (Trypargilum) Richards (Hymenoptera: Crabronidae)

“…Bushrow et al (2006) ejaculatory ducts in Ancistrocerus antilope Panzer (Vespidae) that began at the base of the anterior accessory glands and joined later forming the common ejaculatory duct later.…”