A new species of tetraphyllidean cestode in the genus Trilocularia is described from an undescribed shark species, Squalus cf. mitsukurii, off the coast of South Africa. Trilocularia eberti sp. n. is the second known member of its genus, and like its congener, T. gracilis (Olsson, 1866-1867) Olsson, 1869, is extremely hyperapolytic, dropping proglottids from its strobila while they are still very immature. Characteristic of the genus, it possesses a distinctive scolex with triloculated bothridia, but differs conspicuously from its congener in its possession of an anterior loculus that is much larger in width relative to the paired posterior loculi, and also in its possession of an anterior, enlarged region of its free proglottids that is triangular with a slit-like ventral aperture, rather than rounded and cup-like. This anterior region of the free proglottid is used in attachment, and its development is described. For assessment of fecundity, an attempt was made to record all free proglottids of all ages found in both host individuals, and yielded an average estimate of 362 free proglottids being produced per individual worm of T. eberti sp. n. Both Trilocularia species parasitize sharks of the genus Squalus, and given the host specificity typically exhibited by tetraphyllideans and preliminary examinations of other members of this shark genus, it is likely that other Squalus species will be found to host additional new Trilocularia species.
Alien flora of the Czech Republic is presented. In Appendix 1, 1378 alien taxa (33.4% of the total flora) are listed with information on the taxonomic position, origin, invasive status (casual, naturalized, invasive; a new category post-invasive is introduced), time of immigration (archaeophytes vs. neophytes), habitat type invaded (natural, seminatural, human-made), vegetation invaded (expressed as occurence in phytosociological alliances), mode of introduction into the country (accidental, deliberate), and date of the first record. Number of phytogeographical as well as biological and ecological attributes were compiled for each species in the database; its structure is presented in Appendix 2 as a suggestion for similar work elsewhere. Czech alien flora consists of 24.1% of taxa which arrived before 1500 (archaeophytes) and 75.9% neophytes. There are 891 casuals, 397 naturalized and 90 invasive species. Of introduced neophytes, 21.9% became naturalized, and 6.6% invasive. Hybrids contribute with 13.3% to the total number of aliens, and the hybridization is more frequent in archaeophytes (18.7%) than in neophytes (11.7%). If the 184 hybrids are excluded from the total number of aliens, there are 270 archaeophytes and 924 neophytes in the Czech flora, i.e. total of 1195 taxa. Accidental arrivals account for 53.4% of all taxa and deliberate introduction for 46.6%; the ratio is reversed for neophytes considered separately (45.5 vs. 54.5%). Majority of aliens (62.8%) are confined to human- made habitats, 11.0% were recorded exclusively in natural or seminatural habitats, and 26.2% occur in both types of habitat. Archaeophytes and neophytes occur in 66 and 83 alliances, respectively, of the phytosociological system. Flora is further analysed with respect to origin, life histories, life forms and strategies. Only 310 species (22.4% of the total number of all alien taxa) are common or locally abundant; others are rare, based on a single locality or no longer present. The following 19 taxa are reported as new for the Czech alien flora: Agrostis scabra, Alhagi pseudalhagi, Allium atropurpureum, Bromus hordeaceus subsp. pseudothominii, Carduus tenuiflorus, Centaurea ×gerstlaueri, Centaurea nigra ×phrygia, Cerastium ×maureri, Gilia capitata, Helianthus strumosus, Hieracium pannosum, Hordeum leporinum, Oenothera coronifera, Papaver atlanticum subsp. mesatlanticum, Parietaria pennsylvanica, Polypogon fugax, Rodgersia aesculifolia, Sedum pallidum var. bithynicum, Sedum stoloniferum; these represent results of our own field research as well as of herbaria search, and unpublished data from colleagues. Other 44 taxa are reported as escaping from cultivation for the first time. Twenty two archaeophytes are listed in the Red List of the Czech flora.
A complete list of all alien taxa ever recorded in the flora of the Czech Republic is presented as an update of the original checklist published in 2002. New data accumulated in the last decade are incorporated and the listing and status of some taxa are reassessed based on improved knowledge. Alien flora of the Czech Republic consists of 1454 taxa listed with information on their taxonomic position, life history, geographic origin (or mode of origin, distinguishing anecophyte and hybrid), invasive status (casual; naturalized but not invasive; invasive), residence time status (archaeophyte vs neophyte), mode of introduction into the country (accidental, deliberate), and date of the first record. Additional information on species performance that was not part of the previous catalogue, i.e. on the width of species’ habitat niches, their dominance in invaded communities, and impact, is provided. The Czech alien flora consists of 350 (24.1%) archaeophytes and 1104 (75.9%) neophytes. The increase in the total number of taxa compared to the previous catalogue (1378) is due to addition of 151 taxa and removal of 75 (39 archaeophytes and 36 neophytes), important part of the latter being the reclassification of 41 taxa as native, mostly based on archaeobotanical evidence. The additions represent taxa newly recorded since 2002 and reported in the national literature; taxa resulting from investigation of sources omitted while preparing the previous catalogue; redetermination of previously reported taxa; reassessment of some taxa traditionally considered native for which the evidence suggests the opposite; and inclusion of intraspecific taxa previously not recognized in the flora. There are 44 taxa on the list that are reported in the present study for the first time as aliens introduced to the Czech Republic or escaped from cultivation: Abies concolor, A. grandis, A. nordmanniana, Avena sterilis subsp. ludoviciana, A. ×vilis, Berberis julianae, B. thunbergii, Bidens ferulifolius, Buddleja alternifolia, Buglossoides incrassata subsp. splitgerberi, Buxus sempervirens, Corispermum declinatum, Cotoneaster dielsianus, C. divaricatus, Euphorbia myrsinites, Gleditsia triacanthos, Helleborus orientalis, Hieracium heldreichii, Koelreuteria paniculata, Lonicera periclymenum, Lotus ornithopodioides, Malus baccata, M. pumila, Miscanthus sacchariflorus, Morus alba, Muscari armeniacum, Paeonia lactiflora, Pennisetum alopecuroides, Pinguicula crystallina subsp. hirtiflora, P. grandiflora subsp. rosea, Podophyllum hexandrum, Pyracantha coccinea, Rhodotypos scandens, Rumex patientia × R. tianschanicus ‘Uteuša’, Salix cordata, Sarracenia purpurea, Sasa palmata ‘Nebulosa’, Scolymus maculatus, Spiraea japonica, Tagetes tenuifolia, Thuja occidentalis, Trifolium badium, Vaccinium corymbosum and Viburnum rhytidophyllum. All added and deleted taxa are commented on. Of the total number of taxa, 985 are classified as casuals, 408 as naturalized but not invasive, and 61 as invasive. The reduction in the number of invasive taxa compared to the previous catalogue is due to a more conservative approach adopted here; only taxa that currently spread are considered invasive. Casual taxa are strongly overrepresented among neophytes compared to archaeophytes (76.7% vs 39.4%), while naturalized but non-invasive taxa follow the reversed pattern (18.8% vs 57.4). However, these two groups do not significantly differ in the proportion of invasive taxa. Of introduced neophytes, 250 taxa (22.6%) are considered vanished, i.e. no longer present in the flora, while 23.3% became naturalized, and 4.5% invasive. In addition to the traditional classification based on introduction–naturalization–invasion continuum, taxa were classified into 18 population groups based on their long-term trends in metapopulation dynamics in the country, current state of their populations, and link to the propagule pressure from cultivation. Mapping these population groups onto the unified framework for biological invasions introduced by Blackburn et al. in 2011 made it possible to quantify invasion failures, and boom-and-busts, in the Czech alien flora. Depending on inclusion criteria (whether or not extinct/vanished taxa and hybrids are considered), alien taxa ever recorded in the Czech Republic contribute 29.7–33.1% to the total country’s plant diversity; taking into account only naturalized taxa, a permanent element of the country’s flora, the figure is 14.4–17.5%. Analysis of the dates of the first record, known for 771 neophytes, indicates that alien taxa in the flora have been increasing at a steady pace without any distinct deceleration trend; by extrapolating this data to all 1104 neophytes recorded it is predicted that the projected number would reach 1264 in 2050. Deliberate introduction was involved in 747 cases (51.4%), the remaining 48.6% of taxa are assumed to have arrived by unintentional pathways. Archaeophytes are more abundant in landscapes, occupy on average a wider range of habitat types than neophytes, but reach a lower cover in plant communities. The alien flora is further analysed with respect to representation of genera and families, origin and life history. and Nevejdou se dvě poslední jména autorů
The size and fecundity of Hemiberlesia lataniae (Signoret) (Hemiptera: Diaspididae) on partially resistant and susceptible kiwifruit (Actinidia spp.) varieties was measured. The size ratio of mature H. lataniae grown on a partially resistant genotype, compared with those on a susceptible genotype, was 0.67-0.51 for 2nd instar exuviae area, 0.32 for adult body area and 0.18 for estimated body volume. The fertility ratio was 0.1, but the pre-oviposition period and the size of the crawlers were the same. Diaspidid scale insects' unusual ability to continue growing after the final moult appears to be a key feature allowing these insects to show extreme size plasticity while retaining the ability to reproduce even when very small. These observations challenge current theories of insect development that postulate the need to achieve a critical weight threshold before the final moult. We suggest that this strategy may have assisted the evolution of polyphagy within the Diaspididae. and M. Garry HILL, Rosa C. HENDERSON, Nicola A. MAUCHLINE.
The expansion of urban areas is one of the most significant anthropogenic impacts on the natural landscape. Due to their sensitivity to stressors in both aquatic and terrestrial habitats, dragonflies and damselflies (the Odonata) may provide insights into the effects of urbanisation on biodiversity. However, while knowledge about the impacts of urbanisation on odonates is growing, there has not been a comprehensive review of this body of literature until now. This is the first systematic literature review conducted to evaluate both the quantity and topics of research conducted on odonates in urban ecosystems. From this research, 79 peer-reviewed papers were identified, the vast majority (89.87%) of which related to studies of changing patterns of biodiversity in urban odonate communities. From the papers regarding biodiversity changes, 31 were performed in an urban-rural gradient and 21 of these reported lower diversity towards built up city cores. Twelve of the cases of biodiversity loss were directly related to the concentrations of pollutants in the water. Other studies found higher concentrations of pollutants in odonates from built-up catchments and suggested that odonates such as Aeshna juncea and Platycnemis pennipes may be candidate indicators for particular contaminants. We conclude by identifying current research needs, which include the need for more studies regarding behavioural ecology and life-history traits in response to urbanisation, and a need to investigate the mechanisms behind diversity trends beyond pollution., Giovanna Villalobos-Jiménez, Alison M. Dunn, Christopher Hassall., and Obsahuje bibliografii
Velia currens (Fabricius, 1794) and V. gridellii Tamanini, 1947 are two South European species of Veliidae, whose ecology and behaviour are poorly known. The aims of this study were to investigate their life histories, quantify occurrence of wing polymorphism and gather information on their degree of co-occurrence. Nine different populations were regularly surveyed from April to November 2010. Furthermore, a dataset containing information on the occurrence of the two species and the presence of winged morphs at 294 sites was compiled from museum collections, private collections and published literature. No evidence for multivoltinism was detected in either species. However, oviposition and and/or hatching were protracted in time so that early-instar nymphs and adults co-occurred up to midsummer. Although their distributional ranges completely overlap at a large spatial scale, the two species co-occurred only rarely at the same sites and the degree of co-occurrence was lower than expected by chance. Winged specimens were rarely recorded. At least in V. gridellii, the numbers of winged individuals were inversely related to the altitudes of the sites. During the summer, when some of the streams surveyed dried up, several specimens were found in an apparent state of lethargy, under stones. It is hypothesized that the ability to aestivate, coupled with the ability to walk from one site to another may reduce the advantage associated with producing winged forms and account for the low rate of occurrence of macropterism in these species., Fabio Cianferoni and Giacomo Santini., and Obsahuje seznam literatury
Encarsia bimaculata (Heraty & Polaszek) is an abundant parasitoid of Bemisia tabaci in southern China. The effects of constant temperatures on a range of life history traits, including development, survival of immatures, longevity and reproduction of adults, were studied in the laboratory. The developmental period from egg to adult ranged from 34.3 ± 0.4 d at 20°C to 8.7 ± 0.6 d at 32°C, A total of 181.4 ± 2.4 degree-days were required to complete development with a lower developmental threshold of 11.6 ± 0.3°C. The survivorship of E. bimaculata from 2nd instar to adult varied from 81.3 ± 1.7% at 20°C to 91.0 ± 1.8% at 26°C. Average adult female longevity was 8.4 ± 0.7 d at 20°C and 5.4 ± 0.4 d at 32°C, and daily production of offspring peaked at 29°C with 4.5 offspring per female. The maximum oviposition occurred three days after adult emergence at 23, 26, 29 and 32°C, and four days at 20°C. Total number of offspring produced per female varied from 24.3 ± 2.0 at 32°C to 29.3 ± 2.9 at 20°C. The maximum intrinsic rate of increase (rm) was 0.2163 ± 0.013 at 29°C, followed by 0.2062 ± 0.022 at 32°C. Results indicate that E. bimaculata reaches its maximum biological potential at temperatures ranging from 26°C to 32°C with 29°C being the optimal temperature.
Interactions between syrphid predators and their prey are poorly known. The adaptations of syrphids to aphid defences and the consequences for the evolution of life history traits in these predators especially are mostly unstudied. This is the first of two papers investigating the evolution of prey specialization in aphidophagous hoverflies. The study focuses on two questions: (1) Are differences in the body size of syrphid predators reflected in differences in the size of their prey? (2) Are differences in body size, body mass and development time of the syrphid predators correlated with the defence strategies of their aphid prey (e.g. mobility, toxicity)? Platycheirus clypeatus (Meigen, 1822), Platycheirus fulviventris (Macquart, 1829), Melanostoma mellinum (Linnaeus, 1758), and Melanostoma scalare (Fabricius, 1794), which differ considerably in their prey specialization, but are closely related, were chosen as model species. Life history data for these syrphids came from a laboratory study, and that for the aphids from a literature survey. These syrphid species can be arranged on a gradient of increasing prey specialization, from 32 prey species for the generalist M. mellinum and only 3 for the specialist P. fulviventris. Differences in prey specialization were even more evident when the defence ability of the various species of aphid prey was considered. For instance, the specialization on ant-attended aphids in M. scalare. Larvae exhibited a one or two weeks diapause which made the determination of developmental time imprecise. Body size of the predators was not reflected in that of their aphid prey. The postulated relationship between body size of the predator and the defence strategies of their prey was not supported by our data. A comparison of a wider range of syrphid species from different taxonomic groupings together with a phylogenetic correction procedure might reveal clearer trends. The second part of this paper (Dziock, in prep.) will investigate the correlation between prey specialization and reproductive strategies (i.e. clutch size, egg size and number) and will put the results into a broader framework.
Flight is important for insects but also incurs costs in terms of reduced reproductive reserves. Recent studies on butterflies have shown that thorax mass and nitrogen content decrease over the adult lifespan, suggesting that flight muscle breakdown may also occur in butterflies. However, unlike other insects known to resorb flight muscles, butterflies will continue to fly throughout the reproductive period. Nonetheless, use of nutrients from flight muscles for reproduction has the potential to improve the reproductive output considerably. In this study we have tested to what extent female Pieris napi L. (Pieridae) butterflies actually do breakdown flight muscles. By comparing muscle mass in recently emerged and older free-flying females we show that mass and nitrogen content of the two most important groups of flight muscles each decrease by more than 50% over the adult lifespan. The significance of this finding is discussed in relation to reproduction and flight in butterflies.
Five flightless species of Micromus are known from the Hawaiian Archipelago; only one, the rare Micromus usingeri, is reported from the Island of Hawai'i. Herein, we report the natural occurrence of intermediates between this brachypterous species and its near relative, the macropterous Micromus longispinosus. We compare some morphological and life-history characteristics of the two species and the intermediates. Our study shows that: (1) The two closely related species are broadly distributed on Hawai'i, but they appear to be allopatric altitudinally. (2) M. usingeri is associated with a cool, misty, high-altitude environment, M. longispinosus with warmer, rainy conditions at lower elevations. The intermediates occur in both types of situations and generally at intermediate elevations. (3) The macropterous M. longispinosus has large, oblong, flexible, membranous forewings and hind wings. In contrast, the brachypterous M. usingeri has convex, shortened, elytra-like forewings with reticulate venation, and very small, thick, triangular, stub-like hind wings with greatly reduced venation. The wings of intermediate specimens exhibit a broad range of variation between the two species. (4) Several characteristics of wing venation are highly correlated with reduced wing size; others are not. (5) Aside from the wings, adults of M. usingeri and M. longispinosus differ in relatively few morphological features, most notably the antennal and metatibial length, prothoracic length, mesothoracic length and width, and the length of the spine-covered process on the posteroventral margin of the male T9+ectoproct. The intermediate specimens are variable in adult characteristics, but they generally fall between the two species. (6) Egg size and larval characteristics (except the body length of the fully-fed first and third instars) do not differ between the two species. (7) The evolution of the wing variation is discussed.