Morphology Of Genitalia Research Articles

Morphological observations of the eggs, spermatophores, and male/female genitalia of Leptotrombidium fletcheri (Acari: Trombiculidae) by light and scanning electron microscopy.

Scanning electron micrographs elucidated the anatomical relationships of specialized male genitalia to spermatophore production, morphology and dimensions of spermatophores, surface structures of eggs, and morphology of the female genitalia of Leptotrombidium fletcheri. Paired spermathecae were also demonstrated for the first time in trombiculid mites.

Electrophysiologic Studies of the Cutaneous Innervation of the External Genitalia of the Female Dog

SummaryThe cutaneous innervation of the external genitalia of the female dog was studied using electrophysiologic recording of evoked afferent activity in peripheral branches of the caudal cutaneous femoral, superficial perineal, and genitofemoral nerves, and the dorsal nerve of the clitoris. The observed cutaneous distribution was comparable to that of the male dog, with expected but relatively minor variation due to differences in morphology of the external genitalia. A speculative developmental sequence for the cutaneous innervation of the external genitalia was presented incorporating the distribution of the nerves studied to homologous structures between the sexes.

A genitália externa dos machos em quatro espécies do gênero Sirthenea Spinola, 1837 (Hemiptera, Reduviidae, Peiratinae)

Com o intuito de acrescentar parâmetros à taxonomia do gênero Sirthenea Spinola, 1837, realizamos uma análise morfológica comparativa da genitália externa dos machos de quatro espécies: S. carinata (Fabricius, 1798), S. stria (Fabricius, 1794), S. flavipes (Stal, 1855) e S. amazona Stal, 1866. Foram evidenciadas 10 estruturas (8º esternito, processo do pigóforo, parâmeros, falosoma e seus quatro processos e os dois processos do endosoma) que permitem diferenciar as quatro espécies. Uma descrição resumida da morfologia geral de cada espécie é adicionada.

Morphology and Taxonomic Importance of the Female Genitalia of the Genus Nacaduba MOORE (Lepidoptera, Lycaenidae)

Morphology and Taxonomic Importance of the Female Genitalia of the Genus Nacaduba MOORE (Lepidoptera, Lycaenidae)

雄生殖器の比較形態に基づいた東洋区産ニクバエ亜科(双翅目, ニクバエ科)の系統分類

雄生殖器の比較形態に基づいた東洋区産ニクバエ亜科(双翅目, ニクバエ科)の系統分類

Morphology of male sex organs and insemination in the grasshopper Taeniopoda eques (Burmeister).

The functional morphology of the male genitalia and the insemination process of Taeniopoda eques were examined using scanning electron microscopy and dissections of mating pairs. Male accessory glands consist of 17 separate tubules belonging to eight categories. Males attach to females via a genital locking mechanism, with special motions of the four aedeagal valves aiding in insertion of the aedeagus. The male passes a series of spermatophores. Each is emptied of its spermatodesm contents, then extracted from the male and female genital tracts through motions of the aedeagal valves, while the pair remain in copulo. This allows the male to keep a strong hold on the female, presumably preventing usurpation by other males, while filling the spermatheca with sperm.

The comparative morphology of the thelycum in the Euphausia gibba species group

Because adult females of the closely related species Euphausia hemigibba, E. pseudogibba, E. paragibba and E. gibba are difficult to distinguish, the external morphology of the femal external genitalia in these species is described. In the four species, together composing the ‘gibba’ group, the thelyca are shown to be sufficiently different for positive identifications to be made. A distinction is made between the terms thelycum and spermatheca. The morphological similarity of the thelyca of the four species, particularly the presence of structures on the seventh segment and the fact that unlike other members of the genus, impregnated females retain the sperm mass but not complete spermatophores in the spermatheca, together with similarities in the petasma on the first abdominal pleopod of the male strongly support the view that the four species make up a natural group. The degree of complexity of the external genitalia together with the geographical distribution of the four species suggest that E. hemigibba is the least specialised, and it is thought that it may be closely related to the ‘gibba’ precursor. In E. pseudogibba, E. paragibba and E. gibba, it is believed that the spermatophores are held by the male and transferred briefly to structures on the seventh thoracic segment in the female where they are positioned to discharge a sperm mass into the spermatheca. In E. hemigibba where the structures on the seventh segment are less complex, the spermatophore is possibly held briefly by the male on or close to the spermatheca during the discharge of sperm.

Differentiating the Saw-Toothed Grain Beetle, Oryzaephilus surinamensis (L.), and the Merchant Grain Beetle, O. mercator (Fauv.), by Morphology of the Male Genitalia

Male saw-toothed grain beetles (Oryzaephilus surinamensis) and merchant grain beetles (O. mercator) were dissected, and the major differences in their genitalia were reviewed. Differences in the morphology of the internal sac, setae of the lateral lobes, chitinous rods of the median lobe, and setae on the eighth sternite are illustrated with photomicrographs. The only other difference between the 2 species is the outline of the adult head. The dissection procedure is described briefly.

Anatomical relations during sperm transfer in Glossina austeni Newstead (Glossinidae, Diptera)

SYNOPSISAn account is given of the uterine anatomy of virgin Glossina austeni Newstead and this is compared with the anatomy of the female tract both during mating and after the mating act has been completed. Notes on the functional morphology of the male genitalia are included.

Progestin-induced pseudohermaphroditism in the female hamster.

The effect of the neonatally administered synthetic progestins norethynodrel norethindrone progesterone and dydrogesterone on sexual behavior and the morphology of genitalia was studied in female golden hamsters. Measures of effect were sexual receptivity a female characteristic; mounting a male characteristic; and morphological characteristics of anogenital distance clitoral bone and cartilage length and ovarian histology. Norethynodrel and norethindrone caused masculinization of genitalia increased masculine sexual behavior in adults and reduced spontaneous and hormone-induced female sexual behavior. Progesterone did not masculinize female hamsters but did diminish hormone-induced feminine behavior. Dydrogesterone had no effect on any of these characteristics.

Internal genitalia of the female house fly, Musca domestica L. (Diptera: Muscidae): Analysis of copulation and oviposition

The morphology of the internal genitalia of the adult female Musca domestica L. was examined to determine the role of these structures during copulation and oviposition. Three major structures, the dorsal, ventral, and posterior valves, project into the lumina of the posterior common oviduct and anterior vagina in the region of the vaginal pouches. The dorsal valve is composed of 2 folds of epithelial tissue suspended from the dorsal vaginal wall, and houses the posterior openings of the spermathecal and accessory gland ducts. During copulation, the dorsal valve receives the aedeagus and is the site of sperm deposition. The ventral valve lies directly anterior to the dorsal valve and consists of a large, transverse muscle band and a posteriorly directed epithelial projection. Immediately beneath the epithelial projection, the vagina forms a blind, conical pocket, the anterior chamber. Fertilization is accomplished within this structure during oviposition. The posterior valve consists of 2 widely separated folds (or arms) of epithelial tissue arising from the ventral floor of the vagina. These arms, along with those of the dorsal valve, hold the egg in position while sperm penetration occurs.

Species rank for Anopheles franciscanus based on failure of hybridization with Anopheles pseudopunctipennis pseudopunctipennis.

The taxonomic position of Anopheles Franciscanus as either a species or a subspecies of Anopheles pseudopunctipennis has been disputed by earlier authors for many years. Induced copulation resulted in failure of hybridization through sperm inactivation in the spermatheca of the female. These data and a cytogenetic comparison of the 2 species confirm their separate specific status. A reconsideration of the literature relative to the vector potential, distribution, male genitalia and egg morphology of the 2 species further supports the specific status of franciscanus.

A Revision of the Nearctic Representatives of Hygrotus (Coleoptera: Dytiscidae)1

This paper is the 1st section of a revision of the genus Hygrotus Stephens. Justification for using the name Hygrotus and an explanation of the morphological characters used in delineating species, with emphasis on the external male genitalia, is given. A key to the 6 species-groups proposed for this genus, as well as the 6 species placed in the 1st group, is provided. The synonymy, diagnosis, description, and distribution are presented for Hygrotus acaroides (LeConte), H. marginipennis (Blatchley), H. farctus (LeConte), H. sayi J. Balfour-Browne, H. hydropicus (LeConte), and H. intermedius (Fall). As considerable emphasis is placed on the morphology of the external male genitalia, each is figured and its distinctions are discussed.

Hétérogénéité de la Croissance Larvaire Chez Pyrgomorpha Conica [Orth. Acrididae

SUMMARYR. Abou-Elela: Heterogenity of nymphal growth in Pyrgomorpha conica [Orth. Acrididae]The species studied (from Salins d'Hyères, Var, France) shows variation in the instar number: the males pass through six or seven, the females pass through six, seven or eight instars.This result has been obtained by studying the growth of the female external genitalia, that of the wing rudiments and after measuring the length of the hind femur. This study was facilitated by the existence of eye stripes. We should mention here that the number of these stripes is related to the instar numbers, i. e. the total number of stripes in the adult indicates the total number of instars.The morphology of the female genitalia is important for distinguishing the instars and their changes during the development are shown.The growth of the antenna occurs by successive divisions: the number of segments added at each moult varies from nil to six.The instar in which the reversal of the wing rudiments occurs, varies according to the modality of growth: during the moult from the IVth to Vth instar, Vth to VIth or from VIth to VIIth in the females passing through six, seven or eight instars respectively. In the male it occurs during the IVth to Vth instars or Vth to VIth for individuals passing through six or seven instars respectively.The length of the hind femur is used as an indication for the total body length. According to this size, hatchings obtained can be allocated to five distributions, each being associated with a different modality of growth. The growth showing an extra instar, associated with a slower rate of growth, is originally derived from the distribution of small hind femur. The rate of growth of the femur shows a rang from 1.136 to 1.415 in the females and from 1.181 to 1.319 in the males; it appears that the extra instar is associated with a low rate of femur increase.The mean rate of femur increase in both sexes is not far from 1.26. This increase is higher in the females than in the males, and higher for individuals with lower number of instars than for others.The larvae which are initially smaller than the average give rise to adults which are significantly larger than the average.

Comparative Morphology of Insect Genitalia

Comparative Morphology of Insect Genitalia

Evolutionary Morphology of External Insect Genitalia. 1. Origin and Relationships to Other Appendages

Components of external genitalia in both sexes of ectognathous insects are homologous in all orders, item by item. They consist of presumed telopodites (gonostyli: female ovipositor sheaths, male claspers) and possible endiles (gonapophyses: female ovipositor, male aedeagus) (in (gono) coxites of abdominal segments VIII and IX. One or both pairs of gonapophyses and usually a pair of gonostyli are present in at least 1 sex of all insect orders, and these gonopods are homodynamous with api:eiu‗ages or derivatives on other body segments. Gonopods are annulated or segmented, and primitively identical in both sexes. Gonapophyses IX are rotated 180° laterally on their long axes, fused with each other along their new dorsal margins to form a bridge (notum), and either gonapophysis IX interlocked on its new ventral margin with a gonapophysis VIII. The interlock provides a track (olistheter) along which the gonapophyses can be moved. Rotation of IX had inverted rami and internal structure. The notum formed through fusion of the dorsal (euventral) rami of gonapophyses IX is a landmark in both sexes of nearly all insects. Articulation of gonocoxite VIII has shifted from tergite VIII to tergite IX immediately proximal to the insertion of gonocoxite IX to provide coordination between interlocked gonapophyses. Types of coordinated gonopod movement possible if gonapophyses IX are fused dorsally and interlocked ventrally with gonapophyses VIII include: (1) gonapophyses IX provide a stationary track for alternate thrusts of VIII (most common condition); (2) gonapophyses IX move synchronously in 1 direction as both gonapophyses VIII either move together in the other (some female Microcoryphia, hemipteroids), or remain stationary (some female Microcoryphia, Odonata); or (3) all gonapophyses move together in the same direction (some female Diptera, Coleoptera). Many female insects and all nnlcs have disengaged gonopods, and different mechanisms have evolved. Female insects retaining both sets of gonapophyses have faced 2 restrictions: (1) the distance VIII can be thrust in relation to IX is relatively small, and (2) little vertical leverage (as opposed to back-and-forth motion) is possible. The first has been ameliorated in the only Holometabola retaining the entire primitive ovipositor (Hymenoptera) by a change in articulation: gonocoxite IX has shifted from tergite IX to gonocoxite VIII. The 2nd restriction has been reduced in orthopteroids through articulation of the independently movable gonostyli IX with the independently movable gonapophyses VIII. Gonapophyses IX are reduced in higher orthopteroids and many Holometabola. Gonopods of somite VIII have been lost in male Pterygota (gonapophyses VIII are retained but disengaged from IX in Machilidae), and gonapophyses IX have been reduced to 1 segment (radix). Gonapophyses IX often are detached from gonocoxites IX, and the gonocoxites may be disarticulated from tergite IX. Olistheter components of either gonapophysis IX (rhachis) have fused mesally in many Pterygota to make a ventral floor and form an intromittent tube from the appendages. This cylinder may redivide between the fused rhachies and the ventral rami to either side, and the 2 rhachies left as a separate mesal sclerite. Upon reconstitution of this tube a 2nd time in some Holometabola through overgrowth of the ventral rami, the rhachies became internal within the gonapophyses. Gonostyli usually retain their musculature and typically have been modified into clasping organs. External genitalia of males may be augmented by coxosternal or tergal derivatives, fragmenta of gonapophyseal rami or gonocoxites, or by cerci. Gonodal gonoducts of both sexes appear to have opened originally through paired papillae on somite VIII, and accessory gonoducts, on IX. Papillae are outgrowths of muscles and membranes between the gonocoxites and coxosternites, and homologues of coelomoducal ampullae of other arthropods. Gonoducts have coalesced and migrated in various directions due to development of articulating gonopods. Papillae may remain as separate labia in females or phalli in males; in the latter, they are fused usually into a median penis. Both may supplant appendicular genitalia.

The unique morphology of the male genitalia of the genus Diplorhoptrum Mayr (Hymenoptera Formicidae) with consequent taxonomic suggestions

The conformation of the laminae volsellares of the european populations of Solenopsis seems to be unique among Formicidae. On the basis of this character they are separated from the genus Solenopsis s. str. (neotropical) to form another genus bearing the name Diplorhoptrum Mayr.

The Morphology and Higher Systematics of the Idiostolinae (Hemiptera: Lygaeidae)

Both sexes of Idiostolus insularis Berg were dissected. Some details of genitalic morphology are advanced, other details of the morphology of the female genitalia, wings, and pregenital abdomen are primitive in the Pentatomomorpha. The adult arrangement of trichobothria is very primitive. These primitive morphological features probably resemble those found in the pentatomomorphan group ancestral to the Trichophora. Idiostolus and the genus Trisecus Bergroth are best regarded as comprising a separate family Idiostolidae, in the Lygaeoidea.

Four New Species of Crickets from the Caribbean Region (Orthoptera: Gryllidae)

AbstractThe genus Gryllita Hebard is redefined on the basis of the internal genitalia and external morphology. Three additional species from Haiti are described: G. bondi, G. arndti and G. uhleri. A description is given of the external morphology of Hispanogryllodes rehni.

Two gynandromorphs of Schistocerca gregaria Forskål (Orthoptera: Acridoidea): morphology and behaviour

SYNOPSISTwo instances of gynandromorphism, one in a common and the other in an albino strain of S. gregaria are reported. The external morphology of the fifth (last) instar nymph as well as the external morphology, internal genital organs and sexual behaviour of the adult of the common strain are described. The external morphology, internal genital organs and sexual behaviour of the adult of the albino strain are also described. The bearing of the results on the comparative morphology of the external genitalia in Acridoidea, and the sexual behaviour of the gynandromorphs in the light of the anatomical findings, are discussed.