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2. Effects of the juvenile hormone mimic NC-184 on the development of the reproductive organs and mating behaviour of nymphs of the desert locust, Schistocerca gregaria (Orthoptera: Acrididae)
- Creator:
- Hiroyoshi, Satoshi, Kokwaro, Elizabeth , Mettupalli, Sai , Mitsunaga, Takayuki , Yagi, Shigemi , and Reddy, Gadi V. P.
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- Orthoptera, Acrididae, Schistocerca gregaria, juvenile hormone mimic, moulting, reproductive organs, oogenesis, and spermatheca
- Language:
- English
- Description:
- The insect growth regulator NC-184, a juvenile hormone mimic, prevents moulting to the adult stage in the desert locust, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae). Male nymphs treated in the penultimate or final nymphal instar with NC-184 exhibit precocious mating behaviour in the final instar. We examined whether this chemical affects the development of the internal reproductive organs of crowded nymphs. In treated males, both accessory glands and seminal vesicles were underdeveloped, and no sperm was found in the seminal vesicle, whereas these organs in control individuals had greatly increased in size 10 days after treatment, when all the insects had moulted to adults. Testis size in treated males was similar to that in controls, regardless of their smaller body size due to the inhibition of moulting. Oogenesis and development of spermatheca in females treated with NC-184 continued to some degree, but no eggs matured, unlike what occurred in the control. In conclusion, treatment of S. gregaria nymphs with NC-184 resulted in changes in the reproductive organs in both sexes.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
3. Functional anatomy of the spermatheca and its duct in the seed bug Lygaeus simulans (Heteroptera: Lygaeidae)
- Creator:
- Gschwentner, Robert and Tadler, Andreas
- Type:
- article, model:article, and TEXT
- Subject:
- Lygaeidae, Lygaeus simulans, insemination, genitalia, spermatheca, spermathecal muscle, and speramthecal duct
- Language:
- English
- Description:
- Female genitalia of lygaeid bugs are characterized by a tube-shaped ductus receptaculi (spermathecal duct) connecting the bursa copulatrix with the highly coiled receptaculum seminis (spermatheca). In this study the morphology and functional anatomy of these structures in Lygaeus simulans were examined by light-, fluorescence- and electron microscopy. In addition, copulating animals were freeze fixed and their interconnected genital structures observed using light microscopy. The ductus receptaculi is separated from the receptaculum seminis by a complicated valve. The valve is nearly surrounded by the spermathecal muscle, which controls its opening. The ductus receptaculi leads into the proximal convoluted tube of the receptaculum seminis. Both the ductus receptaculi and the convoluted tube are composed of a single layer of epithelial cells lined by a thick electron dense apical cuticle. The distal part of the receptaculum seminis is a brownish, irregularly coiled, blind ending canal made of small epithelial cells covered with cuticle. Big glands are present in the epidermal layer. The cuticle of this distal part is much thinner and features concentric lamellae. The lumen of the receptaculum seminis cannot be expanded. For transfering sperm into the receptaculum the male aedeagus is equipped with a long, tube-like, sclerotized appendix (processus gonopori), which enlarges the ductus receptaculi considerably during copulation. For successful insemination the tip of the processus gonopori has to pass the valve. The convoluted tube, the valve and the surrounding spermathecal muscle may enable females to control insemination and egg fertilization.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
4. Insemination and fertilization in the seed bug Lygaeus simulans (Heteroptera: Lygaeidae)
- Creator:
- Micholitsch, Thomas, Krügel, Peter, and Pass, Günther
- Format:
- print, text, and regular print
- Type:
- article, model:article, and TEXT
- Subject:
- Lygaeidae, kopulace, entomologie, hmyz, ploštice, Lygaeus simulans, kopulační orgány, morfologie, inseminace, fertilizace, Heteroptera, genitalia, copulation, cryptic female choice, sperm utilization, spermatheca, aedeagus, processus gonophori, insemination, fertilization, 595.2/.7, and 591.4
- Language:
- English
- Description:
- In the laboratory, not all females of the seed bug Lygaeus simulans Deckert, 1985, produced fertilized eggs after copulation: 26.7% of the females were not inseminated and 5% were inseminated but did not lay fertilized eggs; only in 40% of the couples did copulation result in fertile eggs. The remaining 28.3% of couples refrained from mating. Duration of copulation was associated with insemination and fertilization: (i) fertile eggs were produced by only one couple that copulated for less than 60 min and all those that copulated for more than 360 min, (ii) probability of fertilization increased steadily with duration of copulation between 60 and 360 min, and (iii) duration of copulation was significantly different for couples that showed different insemination status. A possible morphological explanation for this rime dependency was revealed by examining the genitalia of 69 couples freeze-fixed in copula after different periods in copulation. Because of the intricate structure of the genitalia in L. simulans, a male takes a long time to manoeuver its intromittent organ into the narrow insemination duct of the female. Only if completely inserted is the tip of the intromittent organ close enough for successful ejaculation of sperm into the spermatheca. The freeze-fixing experiment revealed that it usually took the male more than 30 min to locate the entrance to the insemination duct and another 30 min for full penetration. This explains why copulations that lasted less than 60 min failed, since insemination began only after intromission was complete. The experiments, therefore, indicated that there is a relationship between the complex morphology of the genitalia and the low rates of insemination and fertilization in L. simulans., Thomas Micholitsch, Peter Krügel, Günther Pass, 7 obrázků, 1 tab., and Lit.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
5. Morphology of the spermatheca in the Cydnidae (Hemiptera: Heteroptera): Bearing of its diversity on classification and phylogeny
- Creator:
- Pluot-Sigwalt, Dominique and Lis, Jerzy A.
- Type:
- article, model:article, and TEXT
- Subject:
- Heteroptera, Pentatomomorpha, Pentatomoidea, Cydnidae, Amaurocorinae stat. n., vaginal structures, spermatheca, parietovaginal gland, ring sclerite, fecundation canal, morphology, classification, and phylogeny
- Language:
- English
- Description:
- Cuticular parts of the spermatheca and associated vaginal structures (chiefly the ring sclerites of the parietovaginal glands) have been examined and compared in 190 cydnid species representing 65 genera and all five subfamilies currently recognized in the family (Amnestinae, Cephalocteinae, Cydninae, Garsauriinae, Sehirinae). Four species belonging to genera formerly included within the Cydnidae (Dismegistus, Parastrachia, Thaumastella, Thyreocoris) were also examined. Morphology of the three main parts of the spermatheca [seminal receptacle (distal bulb), intermediate part (pump apparatus), spermathecal duct] is described. Four main types of spermathecae can be recognized from the distal receptacle and the intermediate part: the amaurocorine type (in Sehirinae: Amaurocorini), amnestine type (in Amnestinae), garsauriine type (in Garsauriinae), and "cydnoid" type (in Cephalocteinae + Cydninae: Cydnini, Geotomini + Sehirinae: Sehirini). No synapomorphy of these types was found which suggests that the currently conceived Cydnidae are not monophyletic. Moreover, out of these four types only the "cydnoid" is typically pentatomoidean due to the presence of an intermediate part usually well delimited by two flanges and having always an unsclerotized flexible zone as well as two internal cuticular structures (septum and fretum) partly obstructing the lumen. The simple tubular amaurocorine type is unusual and aberrant within all Pentatomoidea. The amnestine and garsauriine types display some similarities with taxa outside the Pentatomoidea, especially with some lygaeoid or coreoid spermathecae, mainly in the structure of the intermediate part not delimited proximally (absence of flanges) and devoid of the flexible zone. Within the "cydnoid" type, six spermathecal facies can be characterized principally according to the shape of both the apical reservoir along with the intermediate part, and the differentiations of the spermathecal duct. It has been impossible to find any synapomorphy for all species and for the six facies belonging to the "cydnoid" type of spermatheca. We suggest that the Cydnidae as defined presently are probably a polyphyletic group; moreover its main "cydnoid" branch, called by us Cydnidae sensu stricto (Cephalocteinae + Cydninae + Sehirinae: Sehirini) seems to be relatively recent among the Pentatomoidea. Nishadana and Nishocoris are transferred from Garsauriinae back to Cydninae: Cydnini and the tribe Amaurocorini (Sehirinae) is upgraded to a separate subfamily Amaurocorinae stat. nov. Moreover, we regard the Geotomini and the Sehirini both as non-monophyletic and we indicate that by appending them sensu lato (Geotomini "s. l.", Sehirini "s. l.")
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
6. Sexual activity in Coccinellidae (Coleoptera): a review
- Creator:
- Hodek, Ivo and Ceryngier, Piotr
- Type:
- article, model:article, and TEXT
- Subject:
- mating, preferential mating, sperm competition, dormancy, spermatheca, testes, Coccinellidae, Coccinella septempunctata, Ceratomegilla (syn. Semiadalia) undecimnotata, Adalia bipunctata, Harmonia axyridis, Cryptolaemus montrouzieri, and Epilachninae
- Language:
- English
- Description:
- Although there are few studies of the sexual life of coccinellids these phenomena have attracted the interest of isolated groups of coccinellidologists. Probably the most important finding is that at least some coccinellid species (Adalia bipunctata and Harmonia axyridis) do not mate at random with the females prefering certain males. This phenomenon was first observed in Adalia bipunctata by Lusis and then studied in detail by Majerus, O'Donald, de Jong and others. In Japan, Harmonia axyridis was similarly studied by Osawa and Ueno. While the former author found that in this species (as in A. bipunctata) the colour of the elytra is most important in mate choice by females, the latter stresses that size and activity are important. Sperm competition is another interesting phenomenon, most often the sperm of the last male fertilizes the eggs (Ueno, Katakura). Obata and Hidaka have contributed in an important way to elucidating the function of the spermatophore in mating. The studies by Hodek and Ceryngier recorded the maturation and regression of testicular follicles and the relation of mating activity to diapause in four coccinellid species. In contrast to females, where induction of diapause prevents maturation of ovaries, in diapausing males the tissue of testicular follicles remains active until the temperatures decrease in late autumn. Dissection of spermathecae revealed principal difference in autumn mating activity between Coccinella septempunctata, in which 40-60% of the beetles mated before hibernation and Ceratomegilla (syn. Semiadalia) undecimnotata, which does not mate in autumn.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
7. Sperm viability in the male accessory testes and female spermathecae of the bumblebee Bombus terrestris (Hymenoptera: Apidae)
- Creator:
- Freeff, Michael and Schmid-Hempel, Paul
- Type:
- article, model:article, and TEXT
- Subject:
- Apidae, sperm storage, sperm viability, sperm competition, accessory testes, spermatheca, Bombus terrestris, bumblebees, and colony cycle end
- Language:
- English
- Description:
- In many species sperm competition selects for large ejaculates while females eliminate or disable a high percentage of the spermatozoa in their storage organs in order to control paternity. Therefore, sperm viability is an excellent measure of the reproductive success of both males and females. Here we assess the viability of spermatozoa in males, freshly mated queens and old queens at the end of a colony cycle of the monandrous bumblebee Bombus terrestris. We found that the accessory testes of males contained a significantly lower percentage of dead sperm (i.e. higher average viability) than the spermathecae of both freshly mated and old queens. In each case, however, the percentage of dead spermatozoa was very small. No differences could be detected between sperm viability in freshly mated and old queens. To test for the possible incompatibility of the sperm and the environment provided by female spermathecae males and females either from different geographic regions (north and south of the Alps) or the same region were mated. We did not find any differences between matings of individuals from within or between regions. The mechanism that causes the lower sperm viability in females remains unknown.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public