Search results for "Cercus"

Revision of the Afrotropical genus Leiodontocercus (Orthoptera, Tettigoniidae, Phaneropterinae) with a description of four new species

2020

Specimens belonging to the genus Leiodontocercus are rare or even absent in natural history museum collections; this is likely due to at least two reasons, notably, their relatively small size, and, the sheer difficulty in finding them in dense Afrotropical forests. Until recently, three species from less than fifteen specimens were known from this genus, whose identification relied on a singular diagnostic character, that is, the shape of the male cerci. The present contribution is based on the examination of thirty specimens collected from various countries, ranging from central to west Africa; apart from the male cerci, a second diagnostic character – the stridulatory file – is used to d…

Isolation and identification of 4,6,8-trimethyl-7,9-undecadien-5-ol, a female-specific compound, in tergal gland secretion ofCryptocercus punctulatus…

1991

International audience; The secretion of the tergal glands of Cryptocercus punctulatus consists of a complex mixture of 27 compounds. Of this mixture, only one compound (compound B) is specific for females. By dissecting 200 tergal glands, 50 µg of pure compound B was collected by preparative GC; it was identified as (Z, E-4,6,8-trimethyl-7,9-undecadien-5-oI. Its functions as well as its absolute configuration still have to be determined.

Tergal glands of male and femaleCryptocercus punctulatus scudder (Dictyoptera: Cryptocercidae): Composition, sexual dimorphism, and geographic variat…

1991

International audience; Males and females of Cryptocercus punctulatus possess tergal glands, but they differ in position, size, morphology, and secretion chemistry. Compound A (linalyl acetate) is the most abundant of the 21 compounds found only in the secretion of these glands. Compound B, 4,6,8-trimethyl-7,9-undecadien-5-ol, is specific to the tergal secretion of females.C. punctulatus lives only in the United States; its distribution is disjunct. Compound A is found in samples from the eastern population but is absent in samples from the western population. The amount of compound B per gland in samples from the western population is at least twice as high as in the samples from the easte…

Taeniasis vs cysticercosis infection routes

2016

Although cysticercosis caused by Taenia solium ( T. soliu ) is considered a neglected disease, its life cycle has been well known for more than two centuries. T. solium not only causes cysticercosis but also taeniasis in humans. These two diseases have totally different infection routes. To acquire taeniasis (the presence of the adult stage of T. solium in the intestine), humans have to ingest the larval stage (cysticercus) that infects a variety of organs and viscera in pigs, its intermediate hosts. Therefore, taeniasis is acquired when eating raw or undercooked infected pork. The adult stage in the human intestine release eggs that contain a hexacanth embryo, the oncosphere. If humans acc…

The Cryptocercus punctulatus species complex (Dictyoptera: Cryptocercidae) in the eastern United States: comparison of cuticular hydrocarbons, chromo…

2008

1055-7903; The goal of the current study was to determine if cuticular hydrocarbons could be used to empirically delimit taxa within the Cryptocercus punctulatus species complex in the eastern United States. Cockroaches were collected from rotting logs in 22 locations across four states. Hydrocarbon phenotypes and two mitochondrial (16S and COII) genes and one nuclear (ITS2) gene were independently analyzed to determine their relationship with chromosome number. Five distinct hydrocarbon phenotypes were found, but these were only partly congruent with chromosome number and thus with purported species descriptions. Molecular and cuticular hydrocarbon data each indicate that Cryptocercus with…

The ultrastructure of the thread-hairs on the cerci of the cockroach Periplaneta americana L.: The intermoult phase

1976

The structure of the thread-hairs on the cerci of the cockroach Periplaneta american during the intermoult phase has been investigated by scanning and transmission electron microscopy. The present study demonstrates that to each thread-hair belong one sensory cell, two glial cells, and three enveloping cells. The data indicate that: (a) the inner glial cells, which may have a trophic function, sends fingerlike processes into the cytoplasm of the senory cell body; (b) the internal enveloping cell forms the dendritic sheath; (c) the middle enveloping cell corresponds to the trichogen cell and the external enveloping cell to the tormogen cell; (d) the outer dendritic segment terminates in a ca…

What does Cryptocercus kyebangensis, n.sp. (Dictyoptera: Blattaria: Polyphagidae) from Korea reveal about Cryptocercus evolution? A study in morpholo…

2001

doi: 10.1635/0097-3157(2001)151[0061:WDCKNS]2.0.CO;2 0097-3157 doi: 10.1635/0097-3157(2001)151[0061:WDCKNS]2.0.CO;2; The description of a new species of the woodroach Cryptocercus kyebangensis Grandcolas from South Korea offers the opportunity to bring comparative information within the genus. This species, though morphologically very similar to other East Asian and North American species, presents conspicuous differentiation of both ribosomal genes (sequenced fragments of 12S and 16S) and chemical blends from tergal glands (proportions of linalyl acetate and the alcohol 4, 6, 8-trimethyl-7, 9-undecadien-5-ol, compounds previously identified in females originating from North America). A phy…

2015

Songs in passerine birds are important for territory defense and mating. Speciation rates in oscine passerines are so high, due to cultural evolution, that this bird lineage makes up half of the extant bird species. Leaf warblers are a speciose Old-World passerine family of limited morphological differentiation, so that songs are even more important for species delimitation. We took 16 sonographic traits from song recordings of 80 leaf warbler taxa and correlated them with 15 potentially explanatory variables, pairwise, and in linear models. Based on a well-resolved molecular phylogeny of the same taxa, all pairwise correlations were corrected for relatedness with phylogenetically independe…

Morphology of the male and female tergal glands of the woodroach Cryptocercus punctulatus (Insecta, Dictyoptera)

1989

Males and females of Cryptocercus punctulatus possess tergal glands which differ in position, size, morphology, and chemical composition of their secretions. Ultrastructural studies reveal the presence of class 1 and class 3 glandular units interspersed throughout the glands; class 3 glandular units are 30 times as numerous as in the female, but no cytological difference was found between the sexes. The morphology of the tergal glands is characterized by the occurrence of a subcuticular space reservoir, a dense tracheal system, and a thick collagenous layer instead of the typical basement membrane. Comparison with the termite abdominal gland system indicates a great similarity in the fine s…

Cricket combined mechanoreceptors and kicking response

1977

1. Only those filiform hairs on the cerci ofGryllus, which are coupled with campaniform sensilla, show a) a thickening of the hair shaft at the height of the upper ring lamella of their sockets and b) a thin cuticular membrane, which surrounds their sockets. While thefiliform hairs themselves are deflected either parallel to the long axis of the cerci or perpendicular to it, thesockets of the filiform hairs may be deflected preferentially in the proximal and distal direction. 2. Spike potentials can be recorded from the sensory cells of the filiform hairs as long as these are deflected in a weak air current, but not during permanent deflection in strong air streams when they touch the inner…