Origin and rearing season of honeybee queens affect some of their physiological and reproductive characteristics

Queen honeybees of Apis mellifera ligustica and Apis mellifera syriaca were raised to investigate physiological and reproductive characteristics and to determine the most suitable time for queen rearing under semi‐arid conditions in Jordan. The queen rearing season as well as the origin of the queens affected the queens’ weight, acceptance, preoviposition period, volume of the spermatheca, and quantity and quality of sperm in the spermatheca. Italian bees were heavier than Syrian bees at emergence. The introduced queen acceptance rate appeared to be a genetic influence of the queen: A. m. ligustica virgin queens were accepted at a higher rate than were A. m. syriaca queens. There were large seasonal variations in the acceptance rate. Experimental bee colonies accepted their virgin queens during spring with good honey flows at a higher rate compared to the other rearing periods. The greatest mating success was achieved in May and the smallest was during July and August. The preoviposition period was shorter in the Syrian than in the Italian queens, and was longer during summer for both honeybee subspecies. The volume of the spermatheca was smaller in Syrian bees and the spermatheca had lower numbers of spermatozoa compared with Italian bees. Thus, under semi‐arid Mediterranean region conditions, it is highly recommended to raise virgin queens in the spring months only to obtain their highest quality.     

Morphology of the female reproductive system of three dorippid crabs (Crustacea: Decapoda: Brachyura: Dorippidae) and the role of accessory cuticle structures associated with seminal receptacles

The reproductive systems of crabs reveal characters of considerable importance for the understanding of brachyuran phylogeny and evolution. The Dorippoidea show several plesiomorphic characters within Eubrachyura and similarities to podotreme crabs. Hence, they are often considered as an early diverging lineage, sometimes even as the sister group to all remaining eubrachyurans. Due to their role as prime candidates for putative plesiomorphic characters of the reproductive system of the Eubrachyura, we compared the morphology of the vaginae, seminal receptacles, and ovaries of three dorippid species using histological methods, micro‐computed tomography, and 3‐D reconstructions. Despite the putative phylogenetic position of dorippids, the female reproductive system shows features that are regarded as derived characters in eubrachyurans, including a concave vagina and a ventral‐type seminal receptacle. In contrast to other eubrachyurans, the oviduct does not enter the seminal receptacle directly but through specific cuticular valves. The female reproductive systems of Dorippe sinica and Dorippe quadridens are remarkable in further aspects. The seminal receptacles of both species are completely cuticle‐lined and have accessory sperm storage structures, the bursae. Our findings on the morphology of the female reproductive system of dorippids with its unique combination of basal, derived, and new characters challenges the prevailing hypothesis on the evolution of sperm storage organs in Eubrachyura.     

Oviducal glands throughout the gonad development stages: a case study of Octopus mimus (Cephalopoda)

The oviducal glands (ODG) play a crucial role in octopus reproduction. Herein, structural changes of each section of the ODG of Octopus mimus are described histologically throughout the gonad development stages (GDS). To do this, the epithelial height, stereociliated or non-stereociliated epithelium, nucleus type (pycnotic or non-pycnotic), epithelial secretions and the value range of the macroscopic maturity index (MaMI), which directly involves ODG status, were measured. The ODG are internally constituted of two glandular units (central and peripheral glands) and one set of receptacles (the spermathecae). High epithelia (40 to 80?μm) were observed in both gland units during periods with low MaMI values (< 0.1) corresponding to III-mature and IV-pre-spawning. The stereociliated epithelium was only apparent in II-maturing and III-mature in both gland units. The nuclei were noticeably pycnotic in the central gland during III-mature, IV-pre-spawning and V-spawning, but pycnotic in the peripheral gland only during VI-depletion. The epithelium was disorganised during VI-depletion, while sulphated acid mucin was only present during III-mature in the central gland. The epithelium transformations during the GDS are related to the functions of the gland units and to their multiple secretions. The ODG histology complements the GDS and provides better reproductive status assessment.     

Sperm aggregations in the spermatheca of female desmognathine salamanders (Amphibia: Urodela: Plethodontidae)

The alignment of sperm in a cloacal sperm storage gland, the spermatheca, was studied in female desmognathine salamanders by scanning and transmission electron microscopy. Females representing nine species and collected in spring, late summer, and fall in the southern Appalachian Mountains contained abundant sperm in their spermathecae. The spermatheca is a compound tubuloalveolar gland connected by a single common tube to the middorsal wall of the cloaca. Sperm enter the common tube in small groups aligned in parallel along their axes, and continue in a straight course until encountering divisions of the common tube (neck tubules) or luminal borders of distal bulbs, which can act as barriers. Sperm may form tangles, in which small clusters retain their mutual alignment, at the branches of the neck tubules from the common tube, or in the lumen of the distal bulbs, where subsequent waves of sperm collide with sperm already present. The nuclei of some sperm from the initial group to encounter the walls of the distal bulbs appear to become embedded in secretory material on the luminal border or in the apical cytoplasm of the spermathecal epithelial cells. We propose that these sperm become trapped in the spermatheca and are ultimately degraded. J. Morphol. 238:143–155, 1998. © 1998 Wiley-Liss, Inc.     

Sperm storage by spermatodoses in the spermatheca of Trioza alacris (Flor, 1861) hemiptera,psylloidea, triozidae: A structural and ultrastructural study

Female insects generally store sperm received during mating in specific organs of their reproductive tract, i.e., the spermathecae, which keep the sperm alive for a long time until fertilization occurs. We investigated spermatheca morphology and ultrastructure in the psylloidean insect Trioza alacris (Flor, 1861 ) in which spheroidal sperm packets that we refer to as ‘spermatodoses’ are found after mating. The ectoderm‐derived epithelium of the sac‐shaped spermatheca that has a proximal neck, consists of large secretory and flat cuticle‐forming cells. Secretory cells are characterized by a wide extracellular cavity, bordered by microvilli, in which electron‐dense secretion accumulates before discharge into the spermathecal lumen. The cuticle‐forming cells produce the cuticular intima of the organ and a peculiar specialized apical structure, through which secretion flows into the lumen. At mating, the male transfers bundles of sperm cells embedded in seminal fluid into the spermathecal neck. Sperm cells proceed towards the spermathecal sac lumen, where they are progressively compacted and surrounded with an envelope that also encloses secretions of both male and female origin. We describe the formation of these sperm containing structures and document the contribution of the female secretion to spermatodose or female‐determined spermatophore construction. We also discuss the choice of the term ‘spermatodose’ for T. alacris and suggest it be used to refer to sperm masses constructed in the female reproductive organs, at least when they involve the contribution of female secretion. © 2011 Wiley Periodicals, Inc.     

Age at sexual maturity of male and female banana weevils,Cosmopolites sordidus Germar (Coleoptera: Curculionidae)

This study was to determine the age at sexual maturity and the relationships between age and internal reproductive organs of Cosmopolites sordidus. Male banana weevils become sexually mature 18 days after emergence (DAE), that is after 2 weeks of adult eclosion, in spite of the fact that spermatogenesis is completed at emergence. A positive correlation exists between age and male internal organs, for example for mean testis diameter (r = .849, p ≤ .001), mean seminal vesicle diameter (r = .679, p ≤ .001), mean accessory gland length (r = .561, p ≤ .01) and mean accessory gland diameter (r = .498, p ≤ .05), respectively. Significant differences were recorded between sexually mature and immature weevils with respect to mean testis diameter (T = 4.471, p ≤ .001) and mean seminal vesicle diameter (T = 3.939, p ≤ .001), but not with mean accessory gland length and mean accessory gland diameter (T = 1.899 and 1.661). Male internal organs were visibly underdeveloped at emergence but became significantly enlarged and developed on attainment of sexual maturity. Female C. sordidus, on the other hand, are sexually mature at 5 DAE. There was also a strong, positive correlation between age of females and mean ovariole length (r = .656, p ≤ .001), and significant differences existed between mean ovariole lengths of sexually mature and immature females (T = 4.306, p ≤ .001). Increasing age of females witnessed progressive increases in ovariole lengths and developmental changes within female ovarioles and calyces. The findings made here may be helpful in Musa germplasm screening works, as weevils bred on susceptible cultivars may reveal similar results, while those bred on resistant ones may experience possible delays in their reproductive developments.     

Functional morphology of the copulatory organs of a reed beetle and a shining leaf beetle (Coleoptera: Chrysomelidae: Donaciinae,Criocerinae) using X-ray micro-computed tomography

For more than 100 years it has been known that the sclerotised median lobe of beetles harbours a membranous structure (the "internal sac" or "endophallus") which is everted during copula inside the female genital tract. In order to explore the functional role of this structure and those associated with it, we cryofixed copulating pairs of Donacia semicuprea and Lilioceris lilii and studied the relative position of the elements of the copulatory apparatus of males and females by micro-computer-tomography.We found that the everted endophallus fills the lumen of the bursa copulatrix completely. Our data suggest that in Lilioceris lilii the tip of the sclerotised distal part of the ejaculatory duct, the flagellum, is positioned exactly over the opening of the spermathecal duct inside the bursa copulatrix. The mouth of the bursa copulatrix in Donacia semicuprea is armed with a strong muscle ring, and the whole wall of the bursa is covered externally with a layer of muscle fibres. These morphological differences correspond with differences in mating behaviour: In reed beetles (Donaciinae), females seemingly can control mating to a higher degree than in lily beetles (Lilioceris spp.).     

Morphology and function of the reproductive system of representatives of the genus Uca

The morphology of the reproductive organs of three species of fiddler crabs, Uca ecuadoriensis, Uca c.f. forcipata, and Uca tangeri were investigated to subsequently produce a model of their mode of operation. Vulva, vagina, and spermatheca in females, and the first and second gonopods in males were examined by applying histological techniques and electron microscopy. In all three species, vulva and vagina conform to the concave type, and the spermatheca complies with the ventral type. The tissue of the oviduct orifice is enlarged and bulges into the lumen of the spermatheca. Differences between the three species are apparent in the organization of the spermatheca, especially in the distribution and structure of glandular epithelium: In U. ecuadoriensis and U. c.f. forcipata the largest proportion of the spermathecal wall is lined with cuticle and only a small area consists of glandular epithelium, while in U. tangeri almost all of the lining is glandular. Furthermore, the glandular epithelia of the species differ in their histology and ultrastructure: In U. ecuadoriensis it is tubular and multilayered, while in U. c.f. forcipata it is mono‐layered. U. tangeri finally has both forms of this tissue. In the males, the terminal segments of the first gonopod exhibit a tight fit to female organs and narrow, tightly sealed sperm channels. These features suggest a tendency towards minimizing loss of fluids, which can be interpreted as an adaptation to mating on land. The tight fit of male gonopod and female opening seem to be protection from interbreeding, which points toward a strong sexual selection. In the terrestrial environment, these originally aquatic organisms experience serious competition for resources; therefore there is pressure on successful reproduction. According to the current results a model of the process of fertilization and egg‐laying involving the investigated organs was generated. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.     

Effects of sublethal doses of chlorfluazuron on insemination and number of inseminated sperm in the common cutworm, Spodoptera litura (F.) (Lepidoptera: Noctuidae)

Sublethal doses (LD₁₀: 1.00 ng larva^?1; or LD₃₀: 3.75 ng larva^?1) of chlorfluazuron were applied topically to the cuticles of newly moulted fifth instars of the common cutworm, Spodoptera litura (F.) (Lepidoptera, Noctuidae). During mating, the treated males transferred spermatophores of a significantly lower weight into females. The weight of spermatophores transferred by LD₃₀‐treated males was significantly lower than the weight of spermatophores transferred by LD₁₀‐treated males, which was in turn significantly lower than the weight of spermatophores transferred by untreated males. The transfer of spermatophores was delayed by 5–15 min in LD₁₀‐ and LD₃₀‐treated males. However, mating duration was not affected by chlorfluazuron treatment. The transfer of spermatozoa was also delayed by 5–10 min in LD₁₀‐ and LD₃₀‐treated females. Polygynous male adults mated an average of ten times during their lifespan of 11–13 days when paired every day with a new virgin female of the same age. The number of matings per polygynous male was not affected by chlorfluazuron treatment, but the first mating was delayed by 1 day. The number of inseminated sperm found in the spermatophore averaged 10.3 (± 2.1) × 10⁵ over the lifespan of a male, in which the number of eupyrene sperm was 5.4 (± 1.1) × 10⁵. The number of inseminated eupyrene sperm decreased by 66% and 88%, respectively, in LD₁₀‐ and LD₃₀‐treated males. No significant reduction in the number of inseminated eupyrene sperm was observed when females were treated with LD₁₀ or LD₃₀ doses, nor was there a significant reduction when both sexes were treated with the LD₁₀ or LD₃₀ doses relative to treatment of males with the same doses. The ratio of inseminated eupyrene to apyrene sperm was not affected by chlorfluazuron treatment.