Morphology of eggs and spermatheca of <Emphasis Type="Italic">Odontotarsus purpureolineatus</Emphasis> (Heteroptera,Scutelleridae)

The morphology of the spermatheca and eggs of Odontotarsus purpureolineatus were studied by optical microscopy and scanning electron microscopy. The spherical eggs were about 1.35 mm long and 1.09 mm wide. The egg batches generally consist of 13–14 eggs. The egg surface is covered by polygonal (hexagonal and pentagonal shapes prevail) ridges and tiny chorionic tubercles. There were 8–10 aero-micropylar processes between the polygons. The spermatheca of O. purpureolineatus is characterized by a spherical spermathecal bulb, a pumping region, a flange of pump and dilation of spermathecal duct. Spermathecal processes and a median spermathecal dilation with sclerotized rod are missing. The spermathecal bulb and the pumping region possess many pores.     

A new tropiduchid planthopper genus and species from China with descriptions of in copula genitalic structures (Hemiptera: Fulgoromorpha)

Abstract The new planthopper taxon, Garumnella bella gen.n. , sp.n. , from Xizang, China, is described and illustrated, including external morphology of adult and eggs and structures of the male and female genitalia. The new genus is compared with Garumna Melichar and Paragarumna Muir, resulting in Paragarumna ( syn.n. ) being placed as a junior synonym of Garumna, with two new combinations, i.e. Garumna pseudolepida (Muir) comb.n. and Garumna melichari Baker comb.rev. New locality records for Garumna species are given. The morphology of the genitalia and egg of a copulating pair of the new genus is investigated. The female has a ventrally sclerotized posterior vagina forming a torsion groove, an unusual long membranous anterior vagina and an enlarged common oviduct. During copulation both the aedeagus and the torsion groove appear tightly interlocked, which may help to maintain the copulatory position. The aedeagus is observed in the bursa copulatrix.     

Female genitalia of goblin spiders (Arachnida: Araneae: Oonopidae): a morphological study with functional implications

Abstract. Fine morphological details of the genitalia have large potential consequences for the understanding of the reproductive biology of a particular species, especially when mating behavioral studies are difficult to conduct. Oonopidae are a highly diverse spider family comprising a variety of species with complex female reproductive systems, which may have evolved under sexual selection by cryptic female choice. The present study describes the female genitalia of five oonopid species belonging to both conventionally recognized subfamilies by means of semi‐thin sections and scanning electron microscopy. In addition, the male palps are briefly described. The organization of the female genitalia in Scaphiella hespera and Scaphiella sp. resembles the entelegyne type. A chitinized canal connects the receptaculum, where sperm are stored, with the uterus. Sperm are also present in the uterus and the canal is suggested to function as fertilization duct. The genitalia of the parthenogenetic species Triaeris stenaspis are surprisingly complex. A large sac with glands is proposed to represent the equivalent of a receptaculum in sexually reproducing females. In females of Opopaea recondita, sperm are stored in a bulge derivating from the uterus. Contractions of muscles attached to the bulge may lead to sperm dumping. The uterus can be closed by a sclerite in its anterior wall. The receptacula of females of Stenoonops reductus are joined together and contain masses of spermatozoa. Additional sperm were found in the receptacula connection suggesting that fertilization takes place there. The male palps of all the investigated species, except for S. hespera, seem to lack a distincly sclerotized sperm duct. Spermatozoa and secretions are stored in a large reservoir inside the genital bulb surrounded by glandular epithelium.     

Description of a new species of Nesotriatoma Usinger, 1944 from Cuba and revalidation of synonymy between Nesotriatoma bruneri (Usinger, 1944) and N. flavida (Neiva, 1911) (Hemiptera,Reduviidae, Triatominae)

Nesotriatoma confusa sp. nov. (Hemiptera, Reduviidae, Triatominae) is described based on specimens from Cuba. From one male, one female, and eleven nymphs of a then‐undescribed species of Nesotriatoma collected in Cuba, a colony was formed and its specimens were used to describe N. confusa sp. nov. Characters were observed on the head, thorax, abdomen, female external genitalia, and male genitalia with optical microscopy and scanning electron microscopy. We concluded that N. bruneri (Usinger, 1944 ) was indeed a synonym of N. flavida (Neiva, 1911 ) as previously proposed.     

Ovulation in Diplosoma (Tunicata, Ascidiacea, Didemnidae): a light microscopical study

Serial sections of non-ovulated and ovulated eggs of Diplosoma migrans (Tunicata, Ascidiacea, Didemnidae) were compared in order to study the process of ovulation on the level of light microscopy. Fully grown eggs are surrounded by an outer follicular epithelium consisting of cubic cells, and an inner follicular epithelium consisting of flat cells. Egg release is initiated by a fusion of the epidermis with the outer follicular epithelium at the distal pole of the egg. A contraction of the outer follicular epithelium leads to an opening of both epidermis and outer follicular epithelium, and their removal from the egg. The envelope of ovulated eggs corresponds to the former inner follicular epithelium. Mainly due to a contraction of the epidermis, the outer follicular epithelium is shifted into the abdomen and separates from the epidermis. It transforms into a vestigial body (corpus luteum) and finally atrophies. The epidermis flattens and resumes its typical appearance. On the basis of these observations, the results of studies on the closely related Diplosoma listerianum are discussed and questioned. Electronic Publication     

The cortical contraction related to the ooplasmic segregation inCiona intestinalis eggs

Summary The egg cytoplasm of ascidian,Ciona intestinalis, segregates towards both the animal and vegetal poles within a few minutes of fertilization or parthenogetic activation with ionophore A23187. A constriction appears first on the egg surface near the animal pole and then moves to the vegetal pole. Carmine granules and spermatozoa attached to the egg surface move towards the vegetal pole with the movement of the constriction. Microvilli, which are distributed uniformly in unfertilized egg, disappear on the animal side of the constriction and became more dense on the vegetal side of the constriction. Transmission electron microscopy revealed that sub-cortical cytoplasm, containing numerous mitochondria and sub-cortical granules, moves towards the vegetal pole with the movement of the constriction and then concentrates into a cytoplasmic cap at the vegetal pole. An electron-dense layer appears in the cortex of the cap. The ooplasmic segregation and the cortical contraction were inhibited by cytochalasin B and induced by ionophore A23187. These observations suggest that ooplasmic segregation is caused by the cortical contraction which is characterised by a surface constriction and by the formation of an electron-dense layer.     

Ooplasmic segregation in theTubifex egg: Mode of pole plasm accumulation and possible involvement of microfilaments

Summary Ooplasmic segregation, i.e. the accumulation of pole plasm in theTubifex egg, consists of two steps: (1) Cytoplasm devoid of yolk granules and lipid droplets migrates toward the egg periphery and forms a continuous subcortical layer around the whole egg; (2) the subcortical cytoplasm moves along the surface toward the animal pole in the animal hemisphere and toward the vegetal pole in the vegetal hemisphere, and finally accumulates at both poles of the egg to form the animal and vegetal pole plasms. Whereas the subcortical layer increases in volume during the first step, it decreases during the second step. This is ascribed to the compact rearrangement in the subcortical layer of membraneous organelles such as endoplasmic reticulum and mitochondria. The number of membraneous organelles associated with the cortical layer increases during the second step. Electron microscopy reveals the presence of microfilaments not only in the cortical layer but also in the subcortical layer. Subcortical microfilaments link membraneous organelles to form networks; some are associated with bundles of cortical microfilaments. The thickness of the cortical layer differs regionally. The pattern of this difference does not change during the second step. On the other hand, the subcortical cytoplasm moves ahead of the stationary cortical layer. The accumulation of pole plasm is blocked by cytochalasin B but not by colchicine. The first step of this process is less sensitive to cytochalasin B than the second step, suggesting that these two steps are controlled by differnt mechanisms. The mechanical aspects of ooplasmic segregation in theTubifex egg are discussed in the light of the present observations.     

A comparison of wheat bulb fly (Delia coarctata) egg numbers in ridge and furrow soil samples from potato crops

In soil samples taken with a shovel from 97 potato maincrops in east Scotland during 1978 to 1981, wheat bulb fly (Delia coarctata) eggs were more numerous on ridges than in furrows. The ratio of the number of eggs on the ridge to the number of eggs in the furrow was higher in Lothian Region (3·25) than in Fife Region (1·59) but differed significantly (P < 0·05) from 1·0 in both Regions. To obtain maximum precision of the estimate of the total wheat bulb fly egg population in a potato field, more samples should be taken from the ridge than from the furrow, in approximate proportion to the egg numbers.     

Female genital system of the folding-trapdoor spider Antrodiaetus unicolor (Hentz, 1842) (Antrodiaetidae, Araneae): ultrastructural study of form and function with notes on reproductive biology of spiders

The genitalia of the female folding-trapdoor spider Antrodiaetus unicolor are characterized by two pairs of spermathecae that are arranged in a single row and connected to the roof of the bursa copulatrix. Each single spermatheca is divided into three main parts: stalk, bowl, and bulb, which are surrounded by the spermathecal gland. The epithelium of the spermathecal gland is underlain by a muscle meshwork and consists of different types of cells partly belonging to glandular cell units (Class 3 gland cells) that extend into pores in the cuticle of the stalk and bowl. Interestingly, the bulb lacks glandular pores and is characterized by a weakly sclerotized cuticle. This peculiarly structured bulb probably plays an important role in the discharge of the sperm mass. It is suggested that by contraction of the muscle layer the sperm mass may be squeezed out, when the bulb invaginates and expands into the spermathecal lumen, pushing the sperm to the uterus lumen. Each glandular unit consists of usually one or two central secretory cells that are for the most part surrounded by a connecting cell that again is surrounded by a canal cell. The canal cell, finally, is separated from the other epithelial cells (intercalary cells) located between the glandular units by several thin sheath cells that form the outer enveloping layer of the unit. The secretions are released through a cuticular duct that originates proximally between the apical part of the connecting cell and the apical microvilli of the secretory cells and runs into a pore of the spermathecal cuticle. The glandular products of the Class 3 gland cells likely contribute to the conditions allowing long-term storage of the spermatozoa in this species. Details regarding the ovary, the uterus internus, and the uterus externus are reported. Most of the secretion that composes the chorion of the egg is produced in the ovary. Glandular cell units observed in the uterus externus differ structurally from those in the spermathecae and likely play a different role. Finally, we briefly discuss our results on the female genitalia of A. unicolor in the light of knowledge about the reproductive biology of spiders.