Abstract: Here we present an ultrastructural study of the male and female reproductive systems of Zorotypus hubbardi and compare the findings to those presented in an earlier study. The male reproductive system consists of small testes and thin and short deferent ducts opening into a huge seminal vesicle. At the end of the deferent duct a wiredrawer structure is present which initiates the spermatophore formation. A long ejaculatory duct, originating from the seminal vesicle, receives the secretions of three accessory glands. The copulatory organ is a relatively stout structure consisting of two cuticular claspers connected to a ventral sclerite. The testes contain very large and few germ cells (32 sperm in each cyst) which give rise to large sperm characterized by two giant mitochondrial derivatives, two large accessory bodies, and an axoneme with accessory tubules with 17 protofilaments in their tubular wall. In the seminal vesicle the sperm are joined by a secretion to form an elongate spermatophore. The female system consists of panoistic ovarioles, two lateral oviducts, and a common oviduct which receives the spermathecal duct of a huge spermathecal sac in the terminal part of the vagina. The duct is an anterior prolongation of the sac. Its distal part turns back twisting around its proximal portion. At this level a conspicuous muscle layer gives rise to a valve. The bent spermatophore is hosted in the spermathecal sac, with the sperm heads placed in the proximal part of the spermathecal duct. The opening of the duct is close to the female genital opening. The reproductive systems of Zorotypuscaudelli and Z. hubbardi, apart from a distinctly different general organization, also have a different sperm structure: those of the former species are free long-moving cells, while the sperm of Z. hubbardi are giant cells joined in a spermatophore. This allows to hypothesize and discuss a different reproductive behaviour in the two species: monandric in Z. hubbardi and polyandric in Z. caudelli. Apparently different forms of selection have resulted in a very uniform general morphology in Zoraptera, and in highly divergent features related to the reproductive system. The presence of 17 protofilaments in the accessory microtubules of the flagellar axoneme is a potential synapomorphy of Zoraptera and Phasmatodea.
Abstract: The general structure of the female genital system of Zorotypus caudelli is described. The ovarioles are of the panoistic type. Due to the reduction of the envelope (tunica externa) the ovarioles are in direct contact with the hemolymph like in some other insect groups, Plecoptera included. The calices are much larger in Z. caudelli then in Zorotypushubbardi and their epithelial cells produce large amounts of secretions, probably protecting the surface of the eggs deposited on the substrate. Eggs taken from the calyx bear a series of long fringes, which are missing in the eggs found in the ovariole, and in other zorapteran species. The long sperm of Z. caudelli and the long spermathecal duct are likely related to a sexual isolating mechanism (cryptic female choice), impeding female re-mating. The apical receptacle and the spermathecal duct - both of ectodermal origin - consist of three cell types. In addition to the cells beneath the cuticle lining the lumen, two other cell types are visible: secretory and canal cells. The cytoplasm of the former is rich in rough endoplasmic reticulum cisterns and Golgi complexes, which produce numerous discrete dense secretory bodies. These products are released into the receiving canal crossing the extracellular cavity of secretory cells, extending over a series of long microvilli. The secretion is transported towards the lumen of the apical receptacle of the spermatheca or to that of the spermathecal duct by a connecting canal formed by the canal cells. It is enriched by material produced by the slender canal cells. Before mating, the sperm cells are enveloped by a thick glycocalyx produced at the level of the male accessory glands, but it is absent when they have reached the apical receptacle, and also in the spermathecal duct lumen. It is likely removed by secretions of the spermatheca. The eggs are fertilized at the level of the common oviduct where the spermathecal duct opens. Two micropyles at the dorsal side of the equator level possibly facilitate fertilization. The presence of these two micropyles is a presumably derived feature shared with Phasmatodea. The fine structure of the female reproductive system of Z. caudelli does not allow to assess the phylogenetic position at the present stage of knowledge. The enlarged calyx and the temporary presence of long fringes on the eggs are potential autapomorphies of Z. caudelli or may indicate relationships with other Zorotypus species.
Abstract: The ultrastructure of spermatogenesis and spermatozoa was studied in Timema poppensis Vickery & Sandoval, 1999, a putative basal taxon of Phasmatodea. The apical portion of testis follicles consists of spermatogonial cells with polymorphic nuclei. Primary spermatocytes display very short primary cilia originating from the peripheral centrosomes. Early spermatids develop a conspicuous "nebenkern" consisting of fused mitochondria. They have a single peripheral centriole with microtubular triplets, which expresses a 3.6 µm long cilium featuring a 9 + 2 axonemal pattern. In a later stage, the centriole and the ciliary shaft displace towards the inner part of the cytoplasm by an infolding of the plasma membrane. Mature spermatids exhibit a derived centriole with microtubule doublets devoid of dynein arms, which is equipped with a dense arc-like outer structure. Ciliary degeneration was not observed during spermiogenesis. Spermatozoa are short flagellate cells about 55-60 µm in length. They are characterized by a three-layered acrosomal complex. The distinctive bell-shaped morphology of the acrosome vesicle is likely an autapomorphic trait of Timema. The flagellum has a 9 + 9 + 2 axoneme, two accessory bodies, two membranous sacs, and two elongated mitochondrial derivatives. Results support the hypothesis that Phasmatodea, comprising Timema + Euphasmatodea, form a monophyletic group. The presence of 17 protofilaments in the wall of accessory microtubules, and the flattened configuration of the flagellum are potential apomorphic groundplan features of the order. Within Phasmatodea, a key evolutionary divergence was from the conventional insect spermiogenesis and sperm structure of Timema, to the unusual spermiogenetic process and peculiar sperm structure of Euphasmatodea. As a result, Timema retains more sperm chatacter states found in the polyneopteran ground pattern, whilst Euphasmatodea have evolved outstanding sperm autapomorphies, like the loss of mitochondria and flattened cisterns, and the presence of strongly expanded accessory bodies.
Abstract: A distinctive new species of the phasmatodean genus Ophicrania Kaup, 1871 (Phasmatidae: Platycraninae) is described and ï¬gured from the Philippines. Ophicrania conlei n. sp. (from Mount Madja-as, on Panay island) is characterized by the bicoloured anal region of the male hind wing, divided into an inner whitish patch, and an outer brownish area. The species is also distinguished from its most similar congeners on the basis of integumental coloration, features of the antennae, thoracic nota, wings, legs, and terminalia. The present study also provides an emended diagnosis of Ophicrania, and an updated checklist of the taxa of Platycraninae recorded from the Philippine archipelago.
Abstract: Based on characters of both sexes, a new genus and species of the basal euphasmatodean lineage Aschiphasmatidae is described and figured from the Philippines. Dallaiphasma eximius gen. et sp. n. displays interesting features for the group, including: a cone-shaped vertex, which is notably raised above the pronotum; the tibial area apicalis represented by a depressed membranous posterior lateral region, and a strongly sclerotized central apical region; the euplantulae consisting of smooth-type attachment pads; the pretarsal claws pectination reduced to minute denticulations; and the well-differentiated boundary between the metanotum and the first abdominal tergum. The phylogenetic information content of the new findings is discussed. Furthermore, as a result of this study, the Aschiphasmatidae are newly recorded from Mindoro island, and now include five genera and six species of the Philippines.
Abstract: Considering the overall uniformity of the morphology of Zoraptera, the structural diversity of the male genital system is remarkable. Structures related to the male reproductive system of Zorotypus caudelli differ profoundly from those of Zorotypushubbardi. The testes are elongated rather than spherical, the seminal vesicle is apparently absent, and the deferent ducts are very long. A feature shared by these two species and other zorapterans examined is that the two accessory glands are closely adherent to each other and form a single large structure, from which the ejaculatory duct originates. This is a potential zorapteran autapomorphy. Another feature possibly present in the groundplan of the order is the strong elongation of the sperm cells. This may be connected with a reproductive strategy of males trying to avoid re-mating of females with other males after the first copulation. The extremely long and coiled spermathecal duct of Z. caudelli and other zorapteran species is possibly correlated with the sperm elongation, and both features combined may result in a sexual isolating mechanism. The short duration of mating of Zorotypusbarberi and Zorotypusgurneyi suggests that the male introduces sperm into the female tract up to the opening of the spermathecal duct using their long coiled aedeagus. A thick glycocalyx around the sperm in the distal part of the deferent ducts probably protects the sperm cells during their forward progression towards the long spermathecal duct, and is removed when they reach the apical receptacle. The spermatogenesis of Z. caudelli follows a pattern commonly found in insects, but differs distinctly from that of Z. hubbardi in the number of spermatids in each sperm cyst. An unusual and possibly autapomorphic feature of Z. caudelli is a disconnection of sub-tubules A and B at the level of microtubule doublets 1 and 6 of the mature sperm cells. It is conceivable that this results in a shorter period of sperm motility. The character combination found in different zorapteran species supports the view that the sperm, a very compact functional unit, does not evolve as a unit, but like in other more complex body regions, sperm components can also be modified independently from each other. This results in different mosaic patterns of plesiomorphic and derived features in a very compact entity in different species of the very small and otherwise uniform order Zoraptera. In Z. caudelli, for instance, the bi-layered acrosome and small accessory bodies are plesiomorphic states among several others, whereas the mitochondrial derivatives and the elongate nucleus are apparently derived conditions. Other combinations likely occur in other zorapteran species. Only few but noteworthy sperm characters indicate possible phylogenetic affinities of Zoraptera. A possible synapomorphic feature, the presence of dense laminae radiating in a cartwheel array between neighbouring centriolar triplets, is shared with Phasmatodea and Embioptera. Another potential synapomorphy shared with Phasmatodea is the presence of 17 protofilaments in the tubular wall of the outer accessory microtubules.
Abstract: The structural features of eggs of Zorotypus caudelli Karny are described in detail. The egg is elliptic with long and short diameters of 0.6 and 0.3 mm respectively, and creamy white. The egg shows a honeycomb pattern on its surface, without any specialized structures for hatching such as an operculum or a hatching line. The fringe formed by a fibrillar substance secreted after the completion of the chorion encircles the lateral surface. The egg layer is composed of an exochorion, an endochorion, and a vitelline envelope. The exochorion and endochorion are electron-dense and homogeneous in structure. The exochorion shows a perforation of numerous branching aeropyles. The exo- and endochorion are connected by numerous small columnar structures derived from the latter. The vitelline envelope is very thin and more electron-dense than the chorion. A pair of micropyles is present at the equator on the dorsal side of the egg. Originating at the micropyle, the micropylar canal runs through the chorion obliquely. The structural features of the eggs of Zoraptera were compared with those of other polyneopteran and paraneopteran orders.
Notes: This article is featured on the cover of the issue in which it appeared.
Abstract: Endosymbionts of the Cardinium-like genus are described in the testes and other tissues of the proturan Acerella muscorum (Ionescu). Few endosymbionts are present in the large apical cells of functional testes, but they become numerous at the end of the reproductive cycle. They are also found within sperm cells where induce their degeneration. The Gram-negative endosymbionts are characterized by the presence of microtubule-like structures (MLC) in their cytoplasm. It is suggested a possible role of the endosymbionts in the elimination of degenerating sperm cells when the testes activity is ended, thus somewhat playing a role in the timing of the reproductive cycle of the proturan species.
Abstract: Phyllium westwoodii is a phasmid insect (Order Phasmatodea) belonging to the Family Phylliidae (leaf insects). These rather large and ornate creatures are known for their morphological resemblance to plant leaves for camouflage. Pyrazines are a common class of compounds used or produced by a wide variety of organisms, even humans. When an individual of P. westwoodii is disturbed, it sprays an opaque liquid from a pair of prothoracic glands, which are utilized by other phasmid species for defense. The current study has found that this liquid contains glucose and a mixture of 3-isobutyl-2,5-dimethylpyrazine, 2,5-dimethyl-3-(2-methylbutyl)pyrazine, and 2,5-dimethyl-3-(3-methylbutyl)pyrazine. This is the first report of pyrazines found in the defensive gland spray of phasmid insects, and the first chemical analysis of glandular material from family Phylliidae.
Notes: This article is featured on the cover of the issue in which it appeared.
Abstract: The Philippine endemic phasmid Hermarchus leytensis Zompro, 1997 is newly recorded from Mindanao island (Mount Apo). Furthermore, egg, nymphal and adult stages are briefly described along with some notes on the life history of the species in laboratory conditions. The female has an 9-instar developmental cycle, and a high total egg production (2375 eggs). The male is still unknown.
