Manganese and zinc in the ovipositors and mandibles of hymenopterous insects

X-ray microanalysis of the ovipositor and mandibles of various hymenopterous insects has revealed the presence in many species of up to 10% wt/wt of either zinc or manganese in the cuticle. These metals appear to be involved in cuticular hardening, so helping to reduce abrasive wear. Zinc is found in the ovipositors of most Siricidae, Stephanoidea, and Chalcidoidea. In Ichneumonoidea and Cynipoidea, the metal involved is manganese. Megalyroidea are unique in the Hymenoptera in having both zinc and manganese in their ovipositors, though in different locations. Except for Bethylidae, no metals were detected in the ovipositors or stings of species that penetrate soft substrates or do not make holes at all. The cutting edge of the mandibles of many insects that chew their way through hard substrates during egress from their pupation sites almost invariably contain high concentrations of zinc, and this is present in many that lack metals in their ovipositor. The phylogenetic and ecological implications of metal occurrence are discussed.     

Arhopalus ferus (Coleoptera: Cerambycidae): structure and function of the female reproductive system

Abstract

Arhopalus ferus (Mulsant) female pupae and adults were dissected, and both internal and external genitalia are described. The external genitalia involve segments 8 and 9. Segment 9 and its appendages are modified into a long ovipositor which telescopes with segment 8 into segment 7 when retracted. The internal genitalia include ovaries, bursa copulatrix, spermatheca, spermathecal gland, vagina, and accessory glands. The terminology applied to coleopteran genital anatomy is critically discussed.     

Venom gland and reservoir morphology in cynipoid wasps

The venom apparatus morphology was examined in 25 species of Cynipoidea, representing 11 parasitoid taxa; 12 gall inducers and two inquilines. Typically the venom apparatus consists of an oval or bilobed reservoir connected to the ovipositor apparatus by a very short venom duct at the anterior end and to a single elongate unbranched venom gland at or near its posterior end. The Dufour's gland was not found in any of the examined species. The elongate unbranched venom gland and the absence of the Dufour's gland are putative cynipoid synapomorphies. The shape and size of especially the venom reservoir were found to vary considerably within the Cynipoidea. It is typically less prominent in the parasitoid taxa than in the gall inducers. Exceptions include the poppy gallers Barbotinia and Aylax, in which the venom reservoirs were remarkably small and in the rose galler Diplolepis, where only a rudimentary venom apparatus was found. Possible functional and phylogenetic implications of cynipoid venom apparatus features are discussed.     

Differences in genitalia structure and function between subfamilies of longhorn beetles (Coleoptera: Cerambycidae)

Beetle genitalia are usually described only for taxonomic purposes without considering the possible function of structures. Exceptions are sporadic detailed studies on single species. We studied genital structures in the subfamilies of Cerambycidae and outlined assumptions on the function of these structures and the implications for the phylogeny of the Cerambycidae. We found that male genitalia in particular are taxon-specific on a higher taxonomic level; e.g., the parameres are widely variable in Cerambycinae, while in most Lamiinae species they appear relatively uniform and differ from those of the Cerambycinae. Internal sac structures are very different among the various subfamilies. Small backwards-pointing spines are the most common armature of the internal sac. The female genitalia are less variable, although ovipositor morphology may differ among subfamilies. In most species, the connection between the mates during copulation is achieved by the long internal sac and the ovipositor only, whereas the median lobe and parameres are in contact with the female abdomen only at the beginning of copulation. Cerambycinae and Lepturinae have a basal swelling of the endophallus to prevent it from sliding back into the male abdomen during copulation. The long internal sac functions in connecting the mates and guaranteeing the sperm transfer.     

PHYLOGENETIC RELATIONSHIPS OF SCOTUSSA AND LEIOTETTIX (ORTHOPTERA: ACRIDIDAE)

Abstract— A cladistic analysis of the South American grasshopper genera Scotussa and Leiotettix was performed in order to test the monophyly of these genera. Eurotettix, Chlorus and the Dichroplus bergi species group were included as terminal taxa. The genus Atrachelacris was used to root the tree. Twenty-nine characters from external morphology, male genitalia and female ovipositor were used in the analysis. In order to test for association between the structural change that occurred in the ovipositor valves of Scotussa and the functional change of the oviposition habits, the data matrix was partitioned and two analyses were performed. Characters from the female ovipositor were excluded from the data set used in the first analysis and another analysis was performed where all the characters were included in the analysis. Information on oviposition habits was then mapped on the cladogram, to determine the transformation for performance. Both analyses yielded only one most parsimonious tree and produced congruent results, confirming the monophyly of Leiotettix and Scotussa and corroborating their close relationship. Characters from the female ovipositor valves were informative not only at the species level but also at higher levels in the cladogram. The results also support the hypothesis of association between the structural change that occurred in the ovipositor valves of Scotussa with the functional change in the oviposition habits. However, this association did not seem to be correlated with the adaptive radiation in the genus.     

Genitalic heterogeneity in Cornutiplusia circumflexa (Lepidoptera: Noctuidae: Plusiinae)

Abstract. Remarkable morphological variation in the male and female genitalia of the plusiine noctuid moth Cornutiplusia circumflexa L. is described. The geographical distribution of this variation is discussed and it is concluded that, given the gaps in the known distribution of the species, it would be unwise to recognize the five forms as formal subspecies.     

Dimorphism of right–left asymmetry in the female genitalia of the brachypterous grasshopper Parapodisma mikado (Orthoptera: Acrididae)

Several insects exhibit morphological asymmetry in the mouthparts or genitalia. In a part of species with asymmetric genitalia, two mirror‐image forms of the genitalia are reported to occur in a population. This dimorphism, called chiral dimorphism, is usually observed in male genitalia, but its examples in female genitalia are very limited. Here, we report that the females of the brachypterous grasshopper Parapodisma mikado are equipped with an asymmetric sclerite in the copulatory bursa, and that two mirror‐image forms of the sclerite occur in local populations. This dimorphism was detected in all of seven populations examined, and the ratio of the two forms was approximately 2:1 for the right : left forms. In one population, the ratio of the two forms did not vary among three consecutive years. Thus, chiral dimorphism in the female genitalia is kept almost constant spatiotemporally. Mating experiments indicated that the direction of female genitalia did not affect the direction to which the males twist their abdomen (right or left side) during mating or the duration of mating. We propose two hypotheses, a neutral developmental mechanism and sexual conflict, for the maintenance of chiral dimorphism in the genitalia of P. mikado females.     

The structure of the female reproductive system in the Eurytomidae (Chalcidoidea: Hymenoptera)

An account is given of the structure of the gaster and mechanism of the ovipositor in the females of the Eurytomidae. The histology and the possible functions of the components of the reproductive systems are described and its bearing on their phylogenetic relationships of the group discussed.  

Summary:

The female gastral sclerites and ovipositor mechanism in the Eurytomidae have a number of distinctive characters. Within the family there is a progressive evolution of a coiling of the ovipositor associated with accommodating a longer shaft within the abdomen. Each ovary has three ovarioles and the shape of the egg is constant. There are two pairs of colleteral glands, a well developed "venom" system and a distinctive spermatheca.
The family has affinities with the Torymidae and may be close to the ancestral chalcid stock.     

Spider silk felting—functional morphology of the ovipositor tip of Clistopyga sp. (Ichneumonidae) reveals a novel use of the hymenopteran ovipositor

Apical serrations of the hymenopteran ovipositor have been widely postulated to originally constitute adaptations for cutting through hard substrates. Simplifications of the ovipositor tip have occurred in several ichneumonid wasp genera associated with spiders. Despite such reduction in Clistopyga (Hymenoptera, Ichneumonidae), the ovipositor still possesses some apical serrations. Through the first detailed study, we believe, on the behaviour of an ovipositing Clistopyga species, we show that it can alter its ovipositor for different purposes and that the primary function of the apical serrations is clinging to its spider host as the spider attempts to escape. Intriguingly, we also discover a hitherto undocumented adaptation for the hymenopteran ovipositor. The female wasp seals openings in the silken spider nest by using its ovipositor on the silk in a highly sophisticated way that is comparable to how humans entangle wool by needle felting. By studying the ovipositor morphology through a scanning electron microscope, we elucidate how this works, and we hypothesize that by closing the nest the female wasp protects its developing kin.     

The gonangulum: A reassessment of its morphology,homology, and phylogenetic significance

The gonangulum is a sclerite in the female genitalic region of insects. Its presence or full development has long been considered an apomorphy supporting Zygentoma + Pterygota. Recent studies of female genitalia in several insect orders (K.-D. Klass and co-workers) revealed many new data on the gonangulum and homologous sclerotisations (laterocoxa LC9). Herein the gonangulum area is described (including articulations, muscle attachments, sulci) and compared among Archaeognatha, Zygentoma, Odonata, Dermaptera, Dictyoptera, and Notoptera. A wider perspective is provided to the topic by addressing some novel issues: identification of LC9 sclerotisations in non-insect taxa and in insects that secondarily lack an ovipositor; occurrence of homonomous sclerotisations in other abdominal segments of both sexes; morphological interpretation of LC9; and the role of paedomorphosis in LC9 evolution. As a result, there is currently no support for any insect lineage from this character system. For gonangulum-related characters both a significant intra-ordinal variation and frequent homoplasy are demonstrated using various Odonata, Dermaptera, and Dictyoptera as examples. Divergent fates of LC9 in simplified genitalia are shown using a dermapteran and an odonatan. We view all this as a showcase of how a renewed and more detailed examination of a character system can dramatically change the phylogenetic evidence drawn from it.     

The evolutionary role and fate of the primary ovipositor in insects

The development of a piercing-sawing ovipositor for introducing eggs into living plant tissues has made its owners independent of the soil characteristics and increased egg protection. This was the most important prerequisite for the appearance of wings and flight which provided the winged insects with tremendous opportunities for finding new niches and led to unparalleled adaptive radiation. The ovipositor has passed several stages of improvement and differentiation. The four principal types of the primary ovipositor are considered: those of Odonata, Diaphanopteroidea (only extinct forms), Cicadina (including Paraneoptera and Hymenoptera), and Orthoptera. A new hypothesis of the gonangulum homologies is put forward, interpreting it as half of sternite IX lateral of the midline plus the paratergite of the same segment. The constructions of the valvae and different homologies of the third valvae in Polyneoptera and Eumetabola are discussed. The primary ovipositor has been repeatedly (i.e., in many lineages) reduced in the evolution of Pterygota. The main circumstances of these reductions are: (1) subterranean (fossorial) life in narrow cavities; (2) aquatic life of the larvae, mostly linked with submerged oviposition; (3) development and perfection of flight to which the heavy and protruding ovipositor was a hindrance. All the holometabolous insects except Hymenoptera lack the primary ovipositor.     

Significance of constraints on genital coevolution: Why do female Drosophila appear to cooperate with males by accepting harmful matings?

The mechanisms driving the coevolution of male and female genital morphologies are still debated. Female genitalia in Drosophila species bear membranous “pouches” or hardened “shields,” which the male genital armature contact during copulation. Although shield‐like structures likely serve to mitigate the effects of harmful mating, some authors have suggested that soft pouches, which do not prevent male genitalia from inflicting wounds, represent a congruent sensory organ. To elucidate the evolutionary forces responsible for the development of such organs, I examined the effects of artificial damage to various genital parts of female Drosophila erecta on reproductive success. Despite a high survival rate among females, damage to the ovipositor plate resulted in frequent failure of insemination and in the embedment of eggs into the substrate. Damage to the vaginal shield resulted in increased mortality and frequent failure of egg embedment, with an egg blocking the vagina under the damaged shield in some females. Wounding of the pouch had less of an effect on both mating and oviposition success, suggesting that the structure “lures” the male trauma‐causing organs to areas where the resultant wounds do not interfere with insemination or oviposition. These data show that the dual functions of female genitalia (mating and oviposition) mediate genital coevolution.     

The structure of the female reproductiiye system in the Agaonidae (Chalcidoidea,Hymenoptera)

An account is given of the gaster, ovipositor mechanism and reproductive system in female Agaonidae. The structure and possible functions are compared with that of other chalcid families and the phylogenetic relationships of the group are discussed.     

Sexual mosaics induced by tetracycline treatment in the Wolbachia-infected adzuki bean borer, Ostrinia scapulalis.

Wolbachia-infected Ostrinia scapulalis (Lepidoptera: Crambidae) females generate all-female or nearly all-female broods. Curing the infection by tetracycline treatment during larval stages results in the generation of all-male broods in the next generation. Here we show that sexually mosaic offspring are produced by Wolbachia-infected females treated with tetracycline at the adult stage. The sexual mosaics had wings that were composed of distinctive female and male sectors. Besides wings, the sexually dimorphic mid tibiae displayed an intermediate morphology in some of the mosaics. Many of the mosaic individuals had an abnormal structure of the external genitalia as well, a combination of the male uncus and the female ovipositor. We assume that Wolbachia has a feminizing effect on O. scapulalis genetic males and, hence, incomplete curing of the Wolbachia infection results in the generation of sexually mosaic individuals.     

Localized epidermolytic hyperkeratosis of the female genitalia: a case report and review of an underappreciated disorder of women

Epidermolytic hyperkeratosis (EHK) is a distinct pathologic entity that may present as a generalized congenital disorder. A localized form occurring only upon the female genitalia may not be well appreciated by clinicians dealing with women. EHK of the female genitalia is a rare diagnosis, with just 6 cases reported within the indexed literature. Clinically, it may resemble condyloma, although involvement of human papillomavirus has never been demonstrated. Providers unfamiliar with this entity may be further confused by reports of the histopathologic features. Herein, we describe a case and review the literature with respect to EHK of the female genitalia. Familiarity with this condition is desirable, as confusion with condyloma is likely, yet the prognosis is decidedly different.     

Climatic adaptation and species status in the lawn ground cricket

Summary The cricket tentatively identified as Pteronemobius taprobanensis shows a stepwise pattern of latitudinal variation in ovipositor length. Abrupt elongation of ovipositor at about 28° N marks the replacement of the subtropical form by the temperate form. The latter maintains almost a constant ovipositor length up to about 35° N within the bivoltine area. Further north in the univoltine area, an ascending cline extends to about 39° N, beyond which no further increase occurs. The ovipositor length adjusted for body size shows a northeastward increase in each of the univoltine and bivoltine areas, though this tendency is less clear in the latter. The optimum length of ovipositor would vary with the relative amounts of gain (due to the protection of eggs in the soil) and loss (due to the metabolic cost and the difficulty to emerge from the soil) in fitness. If so, it may be predicted that a longer ovipositor would be selected for, when the metabolic cost and the risk at hatching are smaller, the environmental pressure in the egg stage is stronger, and the egg stage lasts longer. The last parameter seems to be mainly responsible for the observed association of the type of life cycle with the geographic pattern of variation in ovipositor length.Contribution No. 76 from the Laboratory of Entomology, Hirosaki University     

黑肩绿盲蝽外生殖器及其感器的超微结构

黑肩绿盲蝽Cyrtorhinus lividipennis Reuter是稻飞虱重要天敌之一.为分析黑肩绿盲蝽成虫生殖器上与生殖有关的感器类型,本文通过扫描电镜对黑肩绿盲蝽雌成虫交配孔和产卵器,雄成虫交配器感器分布进行了观察.结果表明,黑肩绿盲蝽雌成虫交配孔有毛形感器Ⅱ(TSⅡ)和锥形感器Ⅱ(BSⅡ)2种感器;产卵器上有毛形感器Ⅰ(TS Ⅰ)、刺形感器(CHS)、凹状感器(DS)、锥形感器Ⅰ(BS Ⅰ)等4种感器;雄成虫交配器上有毛形感器Ⅰ(TS Ⅰ)、二叉状感器(DIS)、刺形感器(CHS)、凹状感器(DS)、钟形感器(CAS)、栓锥形感器Ⅰ(SS Ⅰ)、栓锥形感器Ⅱ(SSⅡ)和腔形感器(CS)等8种感器.研究结果为揭示黑肩绿盲蝽外生殖器上感器在其交配和产卵过程中的作用奠定了基础.     

Histological structure of the female gonads and ovipositor of the European bitterling,Rhodeus amarus (Bloch, 1782) (Cyprinidae: Acheilognathinae)

We investigated the histological structure of the female gonads and ovipositor of the European bitterling, Rhodeus amarus. The base of the ovipositor was formed by the conical organ or ‘eminence’. Based on the structure of the conical organ, including a special distribution of collagenous and muscular fibrils, a well‐developed vascular system and numerous scyphoid mucous cells in the internal epithelium, this organ was used for temporary storage of oocytes during the spawning period and for their movement along the ovipositor. An extensive network of blood vessels, muscular fibrils and numerous collagenous fibrils in the connective tissue of the ovipositor may make a functional contribution to the ovipositor by making it firmer during egg laying. Mucous cells were detected in the medial and distal regions of the ovipositor, which may play a role in facilitating insertion of the ovipositor into the exhalant siphon of a mussel during oviposition. European bitterling are batch spawners, and the female spawns eggs in clutches at intervals during the breeding season, which were visible as three distinct cohorts of oocytes in the ovary.