Number of results to display per page
Search Results
122. Feeding strategies and competition between terrestrial Haemadipsa leeches (Euhirudinea: Arhynchobdellida) in Danum Valley rainforest (Borneo, Sabah)
- Creator:
- Gąsiorek, Piotr and Różycka, Hanna
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- parazitismus, parasitism, ectoparasites, foraging behaviour, Haemadipsidae, haematophagy, 2, and 59
- Language:
- English
- Description:
- Haemadipsid leeches are among the most successful terrestrial invertebrates in Bornean rainforests. They are very common ectoparasites of vertebrates, and their abundance has facilitated the conduction of numerous projects in the fields of ecology, zoogeography and taxonomy. We undertook research on two species inhabiting lowland dipterocarp forest, Haemadipsa picta Moore, 1929 and Haemadipsa subagilis (Moore, 1929), in order to address the following questions: (a) is there a difference in leech abundance between trails and off-trails?; (b) is ambush location dependent on specimen size or is species-specific?; (c) is intra- and interspecific competition limited by differences in foraging behaviours or vertical niche partitioning? Our results clearly show that H. picta is more abundant on trails than on off-trails and is vertically dispersed within the understory; the size of a specimen is strongly correlated with plant height. Haemadipsa subagilis was found not to exhibit such patterns. We suggest a possible lowering of interspecific competition between these species as a result of: (i) size-dependent dispersion of H. picta (together with reduction of intraspecific competition); and (ii) habitat specialisation of H. subagilis. Moreover, we provide new observations on their foraging behaviour., Piotr Gąsiorek, Hanna Różycka., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
123. Females of the parasitoid wasp, Dendrocerus carpenteri (Hymenoptera: Megaspilidae), adjust offspring sex allocation when competing for hosts
- Creator:
- Mackauer, Manfred and Chow, Andrew
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, konkurence, poměr pohlaví, competition, sex ratio, Megaspilidae, Dendrocerus carpenteri, hyperparasitoid, larval mortality, intensity of parasitism, offspring sex allocation, superparasitism, 2, and 59
- Language:
- English
- Description:
- Parasitoid females may adjust offspring sex allocation according to the number and quality of hosts available. Because in solitary species only one offspring survives per host, already parasitized hosts are of low quality and generally rejected. Superparasitism (i.e., sequential oviposition by the same or different females) results in aggressive interactions and competition for nutritional resources among larvae. We examined variations in the offspring sex ratio of Dendrocerus carpenteri (Curtis) (Hymenoptera: Megaspilidae), a solitary ectoparasitoid developing as a hyperparasitoid on the prepupae and pupae of primary aphid parasitoids inside mummified aphids. Mated females produced a female-biased sex ratio of 0.433 (proportion of sons) when caged singly and provided with 12 mummies for 2 h; they parasitized an average of four mummies/h and rarely superparasitized. Superparasitism increased when two females were caged together and provided with 12 mummies, from 1.18 to 1.24 and 1.38 eggs/host parasitized in 1, 2 and 3 h, respectively. The offspring sex ratio became increasingly more female-biased with increase in superparasitism; however, sex ratio variations were not correlated with cohort size. One mated and one unmated female provided with 12 mummies and caged together for 1 h produced a mean cohort sex ratio of 0.645, which differed from the one predicted (0.717) by an algebraic model incorporating the assumptions that both females contribute equal numbers of offspring and that the mated female does not change her offspring-sex allocation strategy. The observed shift in the cohort sex ratio to an increased female-bias indicates that mated females of D. carpenteri change their behaviour when encountering parasitized mummies or a conspecific competitor in the same patch. By depositing fertilized rather than unfertilized eggs, a female can increase the proportion of her daughters among parasitoids competing for a diminishing host supply., Manfred Mackauer, Andrew Chow., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
124. Field and laboratory studies on drought tolerance and water balance in adult Pergalumna nervosa (Acari: Oribatida: Galumnidae)
- Creator:
- Slotsbo, Stine, Sørensen, Jesper G., Josef Starý, and Holmstrup, Martin
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, pancířníci, ztráty vody, propustnost materiálů, přežití, Oribatida, water losses, permeability, survival, Galumnidae, oribatid mites, drought, soil water potential, osmolality, desiccation tolerance, 2, and 59
- Language:
- English
- Description:
- We studied the water balance, body fluid osmolality and survival of the oribatid mite, Pergalumna nervosa, when exposed to drought in field and laboratory experiments. In a replicated field experiment we artificially lowered the soil water content by putting roofs over selected plots, which reduced soil water potential to levels well below the permanent wilting percentage for plants (i.e. below -1.5 MPa). Even though a slight decrease in the abundance of P. nervosa (only found in the 0-5 cm soil layer) was recorded during the most severe drought stress (ca. -3.5 MPa), the majority of adult mites clearly survived these conditions for 3 weeks in the field without migrating to deeper soil layers. Exposing field collected adults in laboratory experiments simulating even more severe drought conditions revealed that P. nervosa can survive several weeks of gradually increasing drought stress (down to -7 MPa) with moderate water loss. The osmolality of body fluids increased as dehydration progressed, but apparently as a result of simple up-concentration of solutes and not the de novo synthesis of protective osmolytes. We compare and discuss these results in the light of what is known about other arthropods., Stine Slotsbo, Jesper G. Sørensen, Josef Stary, Martin Holmstrup., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
125. Fine fluorescent powder marking study of dispersal in the spruce bark beetle, Ips typographus (Coleoptera: Scolytidae)
- Creator:
- Petr Doležal, Okrouhlík, Jan, and Davídková, Markéta
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, kůrovcovití, lýkožrout smrkový, Scolytidae, Ips typographus, Coleoptera, bark beetle, dispersal, fluorescent powder, chráněná území, 2, and 59
- Language:
- English
- Description:
- A novel method was used to study dispersal in the spruce bark beetle, Ips typographus (L.), under epidemic conditions (rapidly increasing population density) in the Šumava National Park. Infested spruce logs were coated with a fine fluorescent powder and the passively marked emerging beetles were captured in pheromone baited traps located at various distances from these logs. The number of marked beetles captured decreased exponentially with increasing distance from the release point. The sex ratio of the bark beetles was more female biased the further they were recaptured from the logs, being 57% and 60% at distances of up to 50 and 100 m, respectively. The maximum distance flown by a marked beetle recorded in this experiment was 1094 m. A model fitted to the data on dispersal indicates that 10% of the spruce bark beetles dispersed over distances of 55 m and 4 m in spring (overwintered parental generation) and summer (first filial generation), respectively. Differences between spring and summer swarming are briefly discussed., Petr Doležal, Jan Okrouhlík, Markéta Davídková., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
126. Fine structure of the external sheaths of the ovipositor of Aphidius ervi (Hymenoptera: Braconidae)
- Creator:
- Ruschioni, Sara, Riolo, Paola, Romani, Roberto, Battaglia, Donatella, and Isidoro, Nunzio
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- blanokřídlí, lumčíkovití, Hymenoptera, Braconidae, Aphidius ervi, ultrastructure, ovipositor valve, parasitoid, gland, marking pheromone, 2, and 59
- Language:
- English
- Description:
- The function and structure of the ovipositor in Hymenoptera have been studied intensively, although there is a lack of information on the external sheaths. We provide here a contribution on the structure of the external sheaths of the ovipositor of the parasitic wasp Aphidius ervi, in particular the secretory structure is described for the first time. These glands are made up of a large epithelial structure that consists a single layer of large secretory cells that occupy most of the lumen of the valve and belong to gland cell class 1. Based on the different features of the glands, a lubricating and/or host marking function is hypothesized and discussed., Sara Ruschioni, Paola Riolo, Roberto Romani, Donatella Battaglia, Nunzio Isidoro., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
127. First evidence of serotoninergic components in the nervous system of the monogenean Chimaericola leptogaster (Chimaericolidae, Polyopisthocotylea), a gill parasite of the relict holocephalan fish
- Creator:
- Mochalova, Natalya V, Terenina, Nadezhda B, Poddubnaya, Larisa G, Yashin, Valery A, Kuchin, Andrei V, and Kreshchenko, Natalya D
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- ploštěnci, Platyhelminthes, serotonin, reproductive system, muscle system, haptor, 2, and 59
- Language:
- English
- Description:
- The localisation and distribution of the serotoninergic nerve elements was studied for the first time in the flatworm Chimaericola leptogaster (Leuckart, 1830) using immunocytochemical methodology and confocal laser scanning microscopy. The musculature was investigated by histochemical staining of actin filaments; scanning electron microscopy was used to identify the sensory structures on the worm's surface. Uniciliated, bi-ciliated and multiciliated sensory endings have been described on the worm's surface. The morphological data demonstrate the presence of circular, longitudinal and diagonal muscles that comprise the musculature of C. leptogaster in the anterior, median and posterior body regions. Well-developed radial and circular muscle fibres were also observed surrounding the genital pore, two vaginae and in clumps of the haptor. The study revealed the presence of biogenic amine, serotonin, in the central and peripheral nervous systems of C. leptogaster: in the neurons and fibres of the cephalic ganglia and ventral nerve cord, in the innervation of reproductive system compartments. The localised sites of the serotoninergic elements point to important roles of serotonin in monogenean reproductive processes and, possibly, in the regulation of muscle function., Natalya V. Mochalova, Nadezhda B. Terenina, Larisa G. Poddubnaya, Valery A. Yashin, Andrei V. Kuchin, Natalya D. Kreshchenko., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
128. First mitogenome for the subfamily Miltogramminae (Diptera: Sarcophagidae) and its phylogenetic implications
- Creator:
- Yan, Liping, Zhang, Ming, Gao, Yunyun, Thomas Pape, and Zhang, Dong
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, dvoukřídlí, fylogeneze, Diptera, phylogeny, Calyptratae, Sarcophagidae, Miltogramminae, mitogenome, flesh fly, 2, and 59
- Language:
- English
- Description:
- The mitochondrial genome of Mesomelena mesomelaena (Loew, 1848) is the first to be sequenced in the flesh fly subfamily Miltogramminae (Diptera: Sarcophagidae). The 14,559 bp mitogenome contains 37 typical metazoan mitochondrial genes: 13 protein-coding genes, two ribosomal RNA genes and 22 transfer RNA genes, with the same locations as in the insect ground plan. All the protein-coding genes have the start codon ATN, except for cox1 (TCG). Eight protein-coding genes have the stop codon TAA, while the remaining five have the stop codon T (cox1, cox2, nad5, and nad4) or TAG (cytb). Synonymous and non-synonymous substitution rates (Ks and Ka) for each protein-coding gene indicate that these genes evolved primarily under negative (or purifying) selection (Ka < Ks). Phylogeny of Sarcophagidae is proposed based on all the sarcophagid mitogenomes in GenBank, and the subfamily topology is reconstructed as (Sarcophaginae (Paramacronychiinae, Miltogramminae))., Liping Yan, Ming Zhang, Yunyun Gao, Thomas Pape, Dong Zhang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
129. First mitogenome for the tribe Saccharosydnini (Hemiptera: Delphacidae: Delphacinae) and the phylogeny of three predominant rice planthoppers
- Creator:
- Huang, Yi-Xin and Qin, Dao-Zheng
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- polokřídlí, ostruhovníkovití, fylogeneze, rýže, Hemiptera, Delphacidae, phylogeny, rice, Delphacinae, Saccharosydne procerus, mitochondrial genome, planthopper, 2, and 59
- Language:
- English
- Description:
- The mitochondrial genome of Saccharosydne procerus (Matsumura) is the first sequenced in the tribe Saccharosydnini (Hemiptera: Delphacidae: Delphacinae). In addition, the mitogenome sequence of Sogatella vibix (Haupt) (in Delphacini) is also sequenced. The Sa. procerus mitochondrial genome is 16,031 bp (GenBank accession no. MG515237) in length, and So. vibix is 16,554 bp (GenBank accession no. MG515238). The existence of purifying selection was indicated by the rate of nonsynonymous and synonymous substitutions. Three species of Delphacini, Laodelphax striatellus (Fallén), Sogatella furcifera (Horváth) and Nilaparvata lugens (Stål), are important pests of rice. The phylogeny of these three rice planthoppers based on the mitochondrial genome sequence was (L. striatellus + (So. vibix + So. furcifera)) + (N. muiri + N. lugens)., Yi-Xin Huang, Dao-Zheng Qin., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
130. First molecular assessment of the interrelationships of cladorchiid digeneans (Digenea: Paramphistomoidea), parasites of Neotropical fishes, including descriptions of three new species and new host and geographical records
- Creator:
- Pantoja, Camila, Tomáš Scholz, Luque, José Luis, and Arlene Jones
- Format:
- print, počítač, and online zdroj
- Type:
- model:article and TEXT
- Subject:
- motolice, vrubozubcovití, Trematoda, Cichlidae, Jižní Amerika, South America, diversity, taxonomy, new species, SEM, 28S rDNA, ITS2, cox1, Characiformes, Siluriformes, 2, and 59
- Language:
- English
- Description:
- a1_The first molecular assessment of phylogenetic relationships of cladorchiid digeneans (superfamily Paramphistomoidea Fischoeder, 1901) from freshwater fishes based on 28S rDNA, ITS2 and cox1 sequences reveals the subfamilies Dadayiinae Fukui, 1929 and Kalitrematinae Travassos, 1933 as non-monophyletic, whereas Dadaytrema Travassos, 1931 represented by three species is monophyletic. Fourteen species of cladorchiids were found in characiform, perciform and siluriform fishes in the Neotropical Region (Brazil and Peru), with numerous new host and geographical records. The first scanning electron micrographs of seven species are presented. Two new species of dadayiine and one new species of kalitrematine paramphistomes are described. Microrchis macrovarium sp. n. from Pimelodella cristata (Müller et Troschel) (type host), Tetranematichthys quadrifilis (Kner) and Pterodoras granulosus (Valenciennes) in Brazil and Peru differs from all three congeners in that the testes are directly tandem, not oblique, and that the ovary, between the caecal ends, is widely separated from the testes. Pronamphistoma philippei sp. n. from Heros sp. in Brazil is distinguished from the type and only species, Pronamphistoma cichlasomae Thatcher, 1992, by the absence of the anterior collar-like expansion present in the type species, the presence of extramural rather than intramural pharyngeal sacs, and the unusual development of the dorsal and ventral exterior circular muscle fibre series in the acetabulum., a2_Pseudocladorchis romani sp. n. from P. granulosus (type host), Brachyplatystoma vaillantii (Valenciennes), Calophysus macropterus (Lichtenstein), Megalodoras uranoscopus (Eigenmann et Eigenmann) and Oxydoras niger (Valenciennes) in Brazil and Peru, is most similar to Pseudocladorchis nephrodorchis Daday, 1907 but differs in the shape of the testes (irregular, versus reniform in the latter species) and the size of the ovary (as large as, or larger than, the testes in the new species). The generic diagnosis of Pronamphistoma Thatcher, 1992 is amended. Dadaytremoides parauchenipteri Lunaschi, 1989 is transferred to Doradamphistoma Thatcher, 1979 as D. parauchenipteri (Lunaschi, 1989) comb. n. based on morphological and molecular evidence., Camila Pantoja, Tomáš Scholz, José Luis Luque, Arlene Jones., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public