Number of results to display per page
Search Results
222. Morphological variation and sex-biased frequency of wing dimorphism in the pygmy grasshopper Tetrix subulata (Orthoptera: Tetrigidae)
- Creator:
- Steenman, Anja, Lehmann, Arne W., and Lehmann, Gerlind U.C.
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Orthoptera, Caelifera, Tetrigidae, Tetrix subulata, pygmy grasshopper, polymorphism, polyphenism, wing-dimorphism, sex-biased frequency, 2, and 59
- Language:
- English
- Description:
- Dimorphism in wing length is well known in many insect species. It is generally believed that a trade-off between dispersal and reproduction exists, with the long-winged (LW) morph being a better disperser due to its superior flight capability. The short-winged (SW) morph is less mobile and it is hypothesised that females of this morph invest more of their energy reserves in producing offspring. We determined the variation in body and wing size in the pygmy grasshopper Tetrix subulata (Orthoptera: Tetrigidae). The results of the morphological study support the occurrence of two clearly distinct wing morphs in both sexes. SW individuals, especially males, were smaller and in accord with proposed developmental instability showed greater variability in body size than LW individuals. Using data for 700 wild-caught individuals from 10 populations, we demonstrate a variable frequency in the percentage of LW individuals, ranging from all-LW to all-SW populations, even if the LW morph is by far the most common morph in an area. The male-biased percentage of LW individuals recorded in intermediate populations supports a difference in the dispersal reproduction trade-off between the sexes., Anja Steenman, Arne W. Lehmann, Gerlind U. Lehmann., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
223. Morphometric indicators for quality assessment in the aphid parasitoid, Lysiphlebus fabarum (Braconidae: Aphidiinae)
- Creator:
- Ameri, Mohammad, Rasekh, Arash, Michaud, J.P., and Allahyari, Hossein
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Braconidae, Aphidiinae, Lysiphlebus fabarum, Aphis fabae, body size, egg load, mass rearing, quality control, 2, and 59
- Language:
- English
- Description:
- Body size is a standard criterion of quality control in insect rearing and often assumed to correlate with fitness in parasitoid wasps, but various metrics of body size can be used. The purpose of this study was to determine which morphological feature provides the best correlation with body size and egg load in a thelytokous population of the parasitoid wasp, Lysiphlebus fabarum (Marshall), when reared on Aphis fabae Scopoli under standardized conditions in a growth chamber (21 ± 1°C, 60–70% RH, and 16L : 8D). Candidate metrics included head width, length and width of the pronotum, length and width of the right forewing, and length of the right hind tibia. In the first experiment, correlations were determined between these measurements and overall wasp body length. As head width and hind tibia length emerged as the most suitable proxies for total body length, the next experiment these two variables as proxies for egg load in females reared from different nymphal instars of the host aphid. There was a non-linear relationship between body size and egg load of wasps emerging from hosts parasitized in different nymphal instars. Egg load increased linearly with body size across all host growth stages, but the second nymphal instar was the most suitable stage for parasitism when speed of development was factored in. The results suggest that head width is a suitable morphometric for monitoring quality control in mass-reared cultures of this wasp., Mohammad Ameri ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
224. Muga silkworm, Antheraea assamensis (Lepidoptera: Saturniidae) – an overview of distribution, biology and breeding
- Creator:
- Tikader, Amelendu, Vijaydan, Kunjupillai, and Saratchandra, Beera
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Lepidoptera, Saturniidae, muga silkworm, Antheraea assamensis, rearing, improvement, disease, grainage, 2, and 59
- Language:
- English
- Description:
- Muga silkworm (Antheraea assamensis Helfer) is endemic to Assam and adjoining areas in North-Eastern India, and naturally produces golden silk. From time immemorial, many ethnic and tribal groups have produced muga silk. Muga silkworms are mostly wild unlike the mulberry silkworm, which is completely domesticated. The muga silkworm is a single species with little genetic variation among populations, survives harsh climatic conditions and is subject to various diseases, pests and predators. Due to the high incidence of disease and natural enemies, and variations in climatic conditions, the production of muga silk has recently declined dramatically. In order to improve the productivity of this silkworm it is important to have a better knowledge of both its host plants and biology. Lack of knowledge of its genetics and host plants is a major bottleneck. This paper reviews various aspects of muga silkworm culture, including the availability of different populations, and methods used to select for improvement in survival, cocoon yield, disease resistance, conservation and egg production., Amelendu Tikader, Kunjupillai Vijayan, Beera Saratchandra., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
225. Multicoloniality in the highly polygynous ant Crematogaster pygmaea (Formicidae: Myrmicinae)
- Creator:
- Hamidi, Rachid, Debout, Gabriel, Heredia, Ana, Fournier, Denis, Quinet, Yves, and De Biseau, Jean-Christophe
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Formicidae, Myrmicinae, multicoloniality, polygyny, polydomy, Crematogaster pygmaea, context-dependent nestmate discrimination, 2, and 59
- Language:
- English
- Description:
- In social insects, the high variability in the number of queens per colony raises fundamental questions about the evolution of altruism. It is hypothesized, for instance, that nestmate recognition should be less efficient in polygynous than in monogynous colonies because the presence of several breeders increases the diversity of genetically determined recognition cues, leading to a less specific colonial signature. Recent studies, however, have shown that the link between the number of queens in a colony and the recognition abilities of its members is more complex than previously suggested. Here, we studied intraspecific aggression, diversity of potential recognition cues and genetic structure of colonies in the highly polygynous ant Crematogaster pygmaea. Our results reveal that workers of this species are clearly aggressive towards non-nestmates in field experiments but not in more artificial bioassays conducted in Petri dishes, underscoring the importance of context-dependent aspects of the assessment of nestmate recognition. Behavioural, genetic and chemical data show that C. pygmaea is a multicolonial species, forming spatially restricted and well-defined entities. Therefore, the postulated negative correlation between recognition ability of workers and queen number in a colony is not supported by the results of this study., Rachid Hamidi ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
226. Musí být výuka systematické zoologie popisná?
- Creator:
- Roman Fuchs
- Format:
- bez média and svazek
- Type:
- article, text, články, journal articles, model:article, and TEXT
- Subject:
- Biologické vědy, biologie, zoologie, studium a výuka, systematická zoologie, předmětová didaktika, terénní vyučování, biology, zoology, animal classification, study and teaching, teaching school subjects, practical teaching, popisnost, 2, and 57/59
- Language:
- Czech
- Description:
- Roman Fuchs.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
227. Myotropic neuropeptides from the retrocerebral complex of the stick insect, Carausius morosus (Phasmatodea: Lonchodidae)
- Creator:
- Predel, Reinhard, Kellner, Roland, and Gäde, Gerd
- Format:
- print, text, and regular print
- Type:
- article, bibliography, model:article, and TEXT
- Subject:
- zoologie, hmyz, Phasmatodea, Lonchodidae, Carausius morosus, neuropeptidy, myotropin, myotropické neuropeptidy, izolace, bioaktivita, 595.2/.7, and 591.1
- Language:
- English
- Description:
- Myotropic neuropeptides were isolated from the retrocerebral complex of the stick insect, Carausius morosus, by using three HPLC steps. Bioactivity during purification was measured by heterologous bioassays monitoring the contractions of the hyperneural muscle and hindgut of the American cockroach. Additionally, fractions not active in these bioassays were tested in a homologous bioassay evoking contractions of the hindgut of C. morosus. Peptide sequence analysis and mass spectrometry yielded the following structures: Pro-Phe-Cys-Asn-Ala-Phe-Thr-Gly-Cys-NH2 (CCAP), pGlu-Thr-Phe-Gln-Tyr-Ser-His-Gly-Trp-Thr-Asn-NH2 (His7-corazonin) and Asp-Glu-Gly-Gly-Thr-Gln-Tyr-Thr-Pro-Arg-Leu-NH2 (Cam-PK-1). These neuropeptides are the first myotropins isolated from C. morosus. The most bioactive compound in the homologous bioassay, the C. morosus-hindgut assay, was CCAP., Reinhard Predel, Roland Kellner, Gerd Gäde, and Lit
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
228. Mytologická jména Kákos a Pégasos ve středověkých odborných pramenech /
- Creator:
- Šedinová, Hana
- Type:
- text and studie
- Subject:
- Lingvistika. Jazyky, latina středověká, slovníky jazykové, hesla slovníková, lexikografie, terminologie, zoologie, mytologie řecká, živočichové bájní, and jazykové slovníky
- Language:
- Czech
- Description:
- Mythological Names Cacus and Pegasus in Medieval Treatise.
- Rights:
- unknown
229. Nejmenší kopytníci světa - kančilové
- Creator:
- Pluháček, Jan
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, zoologie, savci, mammals, 2, and 59
- Language:
- Czech
- Description:
- Kančilové (Tragulidae) jsou málo známí obyvatelé tropických lesů západní Afriky, jižní a jihovýchodní Asie. Cílem tohoto článku je proto shrnutí všech nových informací, a to jak o jejich taxonomickém postavení mezi ostatními kopytníky, tak i o jejich vnitřním členění včetně základních charakteristik jednotlivých druhů. Následuje shrnutí jejich základní ekologie a etologie. Závěrečná část článku je pak věnována problematice jejich ochrany a přehledu jejich chovu v českých zoologických zahradách., Chevrotains or mouse deer (Tragulidae) are rarely studied inhabitants of the rainforests of Africa, south and south-east Asia. This article summarizes the latest knowledge about their taxonomy including the basic features of individual species, and describes their ecology and ethology. It also deals with conservation issues and provides a detailed survey of keeping and breeding chevrotains in Czech zoos., Jan Pluháček., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
230. Nepůvodní savci a jejich vliv na ekosystémy ostrova Sokotra
- Creator:
- Josef Suchomel
- Format:
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, zoologie, savci, ekosystémy, zoology, mammals, ecosystems, Sokotra (Jemen : souostroví), Socotra Archipelago (Yemen), 2, and 59
- Language:
- Czech
- Description:
- Příspěvek přináší informace o nepůvodních savcích ostrova Sokotra a jejich vlivu na místní ekosystémy. Nejvýraznějším problémem je nadměrná pastva dobytka. Nadměrné spásání je výsledkem rostoucí početnosti populací domácích zvířat, zejména koz v důsledku zvýšené poptávky po mase, změny způsobu chovu a vymizením tradičního kočovného pastevectví. Důsledkem je pak nárůst půdní eroze, změna a destrukce původních rostlinných společenstev i úbytek populací endemických druhů živočichů. Snížení počtu koz na ostrově i změna způsobu jejich chovu jsou nutnými kroky zdejší ochrany přírody., This article presents information about the alien mammal species of Socotra Island and their impact on local ecosystems. The most important problem is overgrazing by livestock. It is a result of rising numbers of domestic animals, mainly goat populations, as a consequence of higher demand for meat, change of breeding style and the disappearance of traditional nomadic pasturage. This situation leads to increasing soil erosion, change and destruction of native plant populations and decreasing endemic animal species populations., and Josef Suchomel.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public