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52. 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
53. 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
54. 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
55. 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
56. Fitness traits of Drosophila melanogaster (Diptera: Drosophilidae) after long-term laboratory rearing on different diets
- Creator:
- Trajković, Jelena, Vujić, Vukica, Miličić, Dragana, Gojgić-Cvijović, Gordana, Pavković-Lučić, Sofija, and Savić, Tatjana
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, dvoukřídlí, octomilkovití, Diptera, Drosophilidae, Drosophila melanogaster, nutrition, fitness components, protein content, C/N ratio, 2, and 59
- Language:
- English
- Description:
- Nutrition is one of the most important environmental factors that influence the development and growth in Drosophila. The food composition strongly affects their reproduction, welfare and survival, so it is necessary for flies to search for a mixture of macronutrients that maximizes their fitness. We have five D. melanogaster strains, which were reared for 13 years on five different substrates: standard cornmeal-agar-sugar-yeast medium and four substrates modified by adding tomato, banana, carrot and apple. This study was aimed at determining how such long-term rearing of flies on substrates with different protein content affects fitness traits (dynamics of eclosion, developmental time and egg-to-adult survival). Further, we determined how transferring flies reared on fruit/vegetable substrates to a standard laboratory diet affected their fitness. Results indicate that strains reared on the diet with the lowest content of protein and the highest C/N ratio had the slowest eclosion and developmental time, and lowest egg-to-adult survival (apple diet). The flies reared on the diet with the highest protein content and the lowest C/N ratio had the highest survival (tomato diet). Flies reared on the carrot diet, which is quite similar in protein content and C/N ratio to the standard cornmeal diet, had the fastest development. Transferring flies to the standard cornmeal diet accelerate eclosion and developmental time, but did not affect survival., Jelena Trajković, Vukica Vujić, Dragana Miličić, Gordana Gojgić-Cvijović, Sofija Pavković-Lučić, Tatjana Savić., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
57. Fungi associated with Ips acuminatus (Coleoptera: Curculionidae) in Ukraine with a special emphasis on pathogenicity of ophiostomatoid species
- Creator:
- Davydenko, Kateryna, Vasaitis, Rimvydas, and Menkis, Audrius
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, borovice lesní, Scots pine, Coleoptera, Curculionidae, pine engraver beetle, Ips acuminatus, pathogens, Ophiostoma, Diplodia pinea, insect-fungus interaction, 2, and 59
- Language:
- English
- Description:
- Conifer bark beetles are well known to be associated with fungal complexes, which consist of pathogenic ophiostomatoid fungi as well as obligate saprotroph species. However, there is little information on fungi associated with Ips acuminatus in central and eastern Europe. The aim of the study was to investigate the composition of the fungal communities associated with the pine engraver beetle, I. acuminatus, in the forest-steppe zone in Ukraine and to evaluate the pathogenicity of six associated ophiostomatoid species by inoculating three-year-old Scots pine seedlings with these fungi. In total, 384 adult beetles were collected from under the bark of declining and dead Scots pine trees at two different sites. Fungal culturing from 192 beetles resulted in 447 cultures and direct sequencing of ITS rRNA from 192 beetles in 496 high-quality sequences. Identification of the above revealed that the overall fungal community was composed of 60 species. Among these, the most common were Entomocorticium sp. (24.5%), Diplodia pinea (24.0%), Ophiostoma ips (16.7%), Sydowia polyspora (15.1%), Graphilbum cf rectangulosporium (15.1%), Ophiostoma minus (13.8%) and Cladosporium pini-ponderosae (13.0%). Pathogenicity tests were done using six species of ophiostomatoid fungi, which were inoculated into Scots pine seedlings. All ophiostomatoid fungi tested successfully infected seedlings of Scots pine with varying degrees of virulence. Ophiostoma minus was the only fungus that caused dieback in inoculated seedlings. It is concluded that I. acuminatus vectors a species-rich fungal community including pathogens such as D. pinea and O. minus. The fungal community reported in the present study is different from that reported in other regions of Europe. Pathogenicity tests showed that O. minus was the most virulent causing dieback in seedlings of Scots pine, while other fungi tested appeared to be only slightly pathogenic or completely non-pathogenic., Kateryna Davydenko, Rimvydas Vasaitis, Audrius Menkis., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
58. Genetic identification of a non-native species introgression into wild population of the field cricket Gryllus campestris (Orthoptera: Gryllidae) in Central Europe
- Creator:
- Panagiotopoulou, Hanna, Baca, Mateusz, Baca, Katarzyna, Sienkiewicz, Paweł, Ślipiński, Piotr, and Żmihorski, Michał
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, rovnokřídlí, cvrčkovití, konzervátorství, Orthoptera, Gryllidae, conservation, Gryllus campestris, Gryllus bimaculatus, mtDNA, microsatellite loci, X-chromosome-linked markers, 2, and 59
- Language:
- English
- Description:
- Two species of the genus Gryllus occur in Europe: G. campestris and G. bimaculatus. The first is widely distributed in the north-western Palaearctic, while the second, G. bimaculatus, occurs predominantly in the Mediterranean area. There is a visible pattern in the distribution of G. campestris, the insect being rare and threatened in the western part of its range, whereas it is still abundant in the east. Despite the fact that this species is commonly used in laboratory experiments, its natural populations are poorly characterised. In the present study, we analysed cricket populations from the lower Oder and Vistula River valleys in Poland. Based on the phylogeny of the mtDNA cytochrome b fragment, we found that 17% of the individuals studied had a G. bimaculatus-like mtDNA haplotype. Analyses of 11 autosomal microsatellite loci failed to reveal any clear genetic differentiation between individuals assigned to these two clades. This suggests, along with the spatial distribution of G. bimaculatus-like haplotypes, successful interbreeding of G. bimaculatus with native populations of G. campestris. However, both the nuclear data and additional analyses of two X-chromosome-linked microsatellite loci revealed incomplete introgression. Human-mediated introgression seems to be the most plausible explanation of the observed genotypic pattern such that caution needs to be taken in conservation efforts carried out in the western part of the species' range., Hanna Panagiotopoulou, Mateusz Baca, Katarzyna Baca, Paweł Sienkiewicz, Piotr Ślipiński, Michał Żmihorski., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
59. Gut microbiota influences female choice and fecundity in the nuptial gift-giving species, Drosophila subobscura (Diptera: Drosophilidae)
- Creator:
- Walsh, Benjamin S., Heys, Chloe, and Lewis, Zenobia
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, dvoukřídlí, octomilkovití, Diptera, Drosophilidae, Drosophila subobscura, microbiota, gut bacteria, mate preference, reproductive success, 2, and 59
- Language:
- English
- Description:
- Recently, there has been rapidly growing interest in the effects of the microbiota on host physiology and behaviour. Due to the nutritional value of bacteria, gut microflora may be particularly important in species that present nuptial gifts during courtship. Here, we explore whether the presence or absence of gut microbiota in males and females of the nuptial gift-giving species Drosophila subobscura (Collin, 1936) alters mating behaviour in terms of female preference, male investment, and female fecundity. We found that females that had been fed antibiotics, compared to females with intact gut bacteria, were more willing to mate with a male that had been fed normally. However female fecundity was higher when both males and females lacked gut bacteria compared to both individuals having a full complement of gut bacteria. This implies that the presence of the microbiota acts to reduce female fecundity in this species, and that male gut bacterial content influences female fecundity. Our results provide further evidence to the growing consensus that the microbiota of an individual may have important effects on both reproductive behaviour and physiology, and suggest that it may also contribute to the nutritional value of the nuptial gift in this system., Benjamin S. Walsh, Chloe Heys, Zenobia Lewis., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
60. Harmonia axyridis (Coleoptera: Coccinellidae): Smelling the rat in native ladybird declines
- Creator:
- John J. Sloggett
- Format:
- print, počítač, and online zdroj
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Zoologie, brouci, slunéčkovití, slunéčko východní, urbanizace, beetles, Coccinellidae, Harmonia axyridis, urbanization, Coleoptera, Adalia bipunctata, alien invasive, habitat compression, native species decline, 2, and 59
- Language:
- English
- Description:
- In the last two decades a huge amount of research has focused on the invasive harlequin ladybird, Harmonia axyridis, particularly on potential or actual deleterious effects that have arisen after it has colonised new regions. A focus of this work has been real or anticipated declines in native ladybird abundance since the introduction of H. axyridis, for which it is deemed responsible. Scientists have generally painted a very bleak picture of the effects of H. axyridis on native species: in this paper I argue that the picture painted is often too bleak. I use the case of the 2-spot ladybird, Adalia bipunctata, the species most often invoked as threatened by H. axyridis, to illustrate my point. While there is little question that H. axyridis has led to a decline in A. bipunctata populations in Europe, it seems likely that prior to the invasive ladybird's arrival A. bipunctata occurred in artificially high numbers in the urban environments in which it was typically studied. Pollution in towns and cities led to enhanced numbers of prey aphids on plants there which initially favoured A. bipunctata, and later H. axyridis. Thus one species, A. bipunctata, that has benefitted from an association with humans has been replaced by another, H. axyridis, just as brown rats replaced black rats in Europe and North America. Viewed with a longer perspective, A. bipunctata has more likely declined back to pre-industrial levels: the artificially high level from which it has declined recently was not a 'natural' one, and thus its decline from this level does not imply that it is now threatened or endangered. More broadly, we need a wider perspective, encompassing other ladybirds, longer timeframes and better comparisons with other (non-ladybird) invasive species to more clearly assess whether H. axyridis really poses as much of a threat as is often proposed., John J. Sloggett., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public