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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Mimeze pestřenkovitých (Diptera: Syrphidae) v kontextu selekčních tlaků ze strany predátorů, termoregulace a pohlavního výběru / Mimicry of hoverflies (Diptera: Syrphidae) in the context of selection pressures from predators, thermoregulation and sexual selection

Daňková, Klára January 2019 (has links)
Thermoregulation plays an important role in organisms' lives during foraging, escaping from predators, sexual selection or overwintering. Moreover, pressure on efficient thermoregulation could affect species on an evolutionary level and was recently hypothesized to maintain imperfect mimicry in hoverflies (Diptera, Syrphidae). We set these two aims: 1) to study relationships between thermoregulation, mimicry accuracy and resembled model, 2) to closely study effect of developmental temperature in an intermediately accurate honeybee mimic, Eristalis tenax. In the first part of the project, we examined temperature excess of 566 specimens in 47 species of hoverflies in the field. We did not find significant effect of mimicry accuracy on temperature excess in our data. However, we found a strong sexual dimorphism. Females had lower temperature excess, which was very resilient to internal and external factors, whereas males had higher temperature excess, influenced by activity at time of capture (flying > sitting) and resembled model (bumblebee-mimics > honeybee- mimics > wasp-mimics > solitary bee-mimics). We suggest, that males are pushed to higher temperature excess by sexual selection within lekking. In the second part of the project, we reared E. tenax in three different temperatures in laboratory...
22

Examining the Link between Temperature and Flight Phenology in Hoverflies (Diptera: Syrphidae) Using Swedish Citizen Science Data

Magnusson Rundqvist, Malin January 2021 (has links)
Global warming is causing a general trend of rising temperatures worldwide. Simultaneously there is also a decline in populations of pollinators all over the world. Therefore, it is important to examine the effect warming temperatures might have on different pollinator species. The focus of this study was to look at how flight phenology of hoverflies in southern Sweden is affected by rising summer temperatures using two regions differing in temperature, and 11 years of citizen science data on hoverfly observations. Summer temperature and observations of 13 species were used. Although four species had a significantly earlier first flight in years with warmer weather, there were overall no apparent trends toward earlier or longer flight periods due to temperature deviation. However, geographical location had a strong impact on flight behaviour of hoverflies in Sweden with hoverflies in Götaland having an earlier first flight compared to Svealand (located further north). This might be the result of an earlier onset of spring and summer in Götaland than in Svealand. The results of this study indicate that more factors than temperature affect flight phenology in hoverflies.
23

Distribucija i diverzitet rodova Merodon Meigen i Cheilosia Meigen (Diptera: Syrphidae) u jugoistočnoj Evropi: predeono - ekološka analiza / Distribution and diversity of genera Merodon Meigen and Cheilosia Meigen in Southeast Europe: landscape ecological analysis

Popov( rođ.Jovičić) Snežana 26 October 2017 (has links)
<p>Istraživanje je urađeno u cilju utvrđivanja obrazaca distribucije rodova <em>Merodon</em><br />Meigen, 1802 i <em>Cheilosia</em> Meigen, 1822 na području jugoistočne Evrope. Rodovi<br /><em>Cheilosia</em> i<em> Merodon </em>su najbrojniji fitofagni rodovi osolikih muva, a jugoistočna<br />Evropa je izabrana kao posebno interesantno područje analiziranja distribucije vrsta<br />zbog specifične kombinacije istorijskih, abiotičkih i biotičkih faktora koji određuju<br />distribuciju. Na području jugoistočne Evrope registrovano je ukupno 202 vrste<br />istraživanih rodova; 121 vrsta pripada rodu <em>Merodon</em>, a 81 vrsta pripada rodu<br /><em>Cheilosia</em>. Broj od preko 200 vrsta pokazuje da je jugoistočna Evropa područje od<br />izuzetnog bogatstva vrsta rodova <em>Merodon</em> i <em>Cheilosia</em>. Ovakav zaključak dopunjen je<br />postojanjem čak 79 (39%) endemskih vrsta za područje jugoistočne Evrope. Prema<br />gradijentu geografske &scaron;irine, rodovi <em>Merodon</em> i <em>Cheilosia</em> pokazuju različit distributivni<br />obrazac; uočava se da broj vrsta roda <em>Merodon</em> opada od juga ka severu, dok je<br />distributivni obrazac obrnut za rod <em>Cheilosia</em>.<br />U cilju analiziranja uticaja koje predeona struktura i promene u načinu kori&scaron;ćenja<br />zemlji&scaron;ta imaju na vrste rodova <em>Merodon </em>i <em>Cheilosia</em>, sprovedena je predeono -<br />ekolo&scaron;ka analiza, uz pomoć GIS i odgovarajućih ekolo&scaron;kih softvera. Istraživanje<br />pokazuje da postoji specifičan odnos između predeonih parametara i kompozicije vrsta<br />istraživanih rodova - sa različitom osetljivo&scaron;ću rodova <em>Merodon</em> i <em>Cheilosia</em> na<br />povezanost stani&scaron;ta i promene u načinu kori&scaron;ćenja zemlji&scaron;ta. Vrste roda <em>Cheilosia</em> su<br />pozitivno korelisane sa povezno&scaron;ću stani&scaron;ta a negativno korelisane sa svim ostalim<br />predeonim parametrima, dok najveći broj vrsta roda <em>Merodon</em> pokazuje veću otpornost<br />pri antropogenim promenama u ekosistemima. Ovakvi rezultati upućuju na<br />diferenciraniji pristup pri upravljanju područjima, fokusiran na intenzitet kori&scaron;ćenja<br />zemlji&scaron;ta (ispa&scaron;e) i povezanost stani&scaron;ta.<br />Istraživanje je obuhvatilo i evaluaciju stani&scaron;ta u okviru predela različitih karakteristika<br />(prostorno i vremenski), primenom analize SyrphTheNet bazom podataka, koja<br />uključuje vrste rodova <em>Merodon </em>i <em>Cheilosia</em> kao bioindikatore. Vrste rodova <em>Merodon</em> i<br /><em>Cheilosia</em> su se pokazale kao veoma dobri indikatori koji mogu da ukažu na trenutni<br />kvalitet istraživanog područja, kao i promene tokom dužeg vremenskog perioda.<br />Analizom korelacije utvrđeno je da postoji povezanost između promena predeonih<br />parametra u periodu od 25 godina i gubitka vrsta i kvaliteta makrostani&scaron;ta na 17<br />istraživanih lokaliteta.</p> / <p>The research has been carried out with the main aim to determine distributional patterns of two genera, <em>Merodon</em> Meigen 1802, and <em>Cheilosia</em> Meigen, 1822, in Southeast Europe region. <em>Cheilosia</em> and <em>Merodon</em> are the most numerous phytophagous hoverflies genera.</p><p>Southeast Europe has been chosen as the specific region of interest to analyze species distribution due to its specific combinations of historical, abiotic and biotic factors that determine the species distribution.</p><p>In the area of Southeast Europe, a total of 202 species of <em>Merodon</em> and <em>Cheilosia</em> have been recorded; 121 species belonging to the genus <em>Merodon</em>, and 81 species belonging to the genus <em>Cheilosia</em>, being a region exceptionally rich in species of the two genera. This conclusion has been supported by the fact that 79 (39%) endemic species has been found in the region. With regard to the gradient latitude, species of <em>Merodon </em>and <em>Cheilosia</em> genera show a different distribution pattern. More precisely, it has been shown that the number of <em>Merodon</em> species decreases from the south to the north, while the opposite pattern is true for the species of <em>Cheilosia</em> genus.</p><p>In order to analyze the responses of hoverfly species to landscape structure, land cover analyses were performed using GIS tools and related ecological software. <em>Merodon </em>and <em>Cheilosia </em>species differ in their responses to land-use change and connectivity, with the latter genus being positively correlated with connectivity and negatively correlated with all other variables. Connectivity is the primary factor affecting <em>Cheilosia</em>, while most <em>Merodon</em> species demonstrated greater resistance to changes in human-modified ecosystems. These results suggest that different management efforts, focused on land-use intensity (grazing) or connectivity, seem to be appropriate when trying to conserve these taxa.</p><p>In addition, the study examined the quality of habitats in landscapes of different characteristics (spatial and temporal), using SyrphTheNet database, in which species of the <em>Merodon</em> and <em>Cheilosia</em> genera were&nbsp;&nbsp; used as bioindicators. Species of the two genera proved to be very good indicators of the current quality of the study area, as well as changes over a longer period of time. Correlation analysis has found a significant relationship between the changes of landscape parameters for a period of 25 years and the loss of species and quality macrohabitats on 17 investigated study sites.</p>
24

Funkcionalni karakteri i modelovanje distribucije vrsta osolikih muva (Diptera: Syrphidae) jugoistočne Evrope u proceni rizika od izumiranja / Functional traits and species distribution modelling of hoverflies (Diptera:Syrphidae) in Southeast Europe in assessment of extinction risk

Miličić Marija 27 December 2017 (has links)
<p>U radu je izvr&scaron;ena podela 572 registrovane vrste osolikih muva sa područja jugoistočne Evrope na funkcionalne grupe, na osnovu registrovanih funkcionalnih karaktera. Za<br />odabrane 44 endemske i nativne ne-endemske vrste koje su svojim klimatskim ni&scaron;ama ograničene na istraživani prostor, kreirane su mape sada&scaron;nje i buduće potencijalne distribucije (za dva perioda, 2041 -2060 i 2061-2080) upotrebom MAXENT algoritma. Na osnovu dobijenih mapa, izračunata je potenijalna promena areala za odabrane vrste, čime je procenjen efekat klimatskih promena na distribuciju vrsta sirfida. Detektovane su vrste koje će najvi&scaron;e biti pogođene klimatskim promenama, kao i prostori sa najvećim potencijalnim bogatstvom vrsta u budućnosti i područja predviđena da će izgubiti deo diverziteta sirfida. Pokazano je da vrste sa ograničenim arealom neće u budućnosti iskusiti veće smanjenje areala u odnosu na &scaron;iroko rasprostranjene vrste. Takođe, na osnovu mapa potenicijalne sada&scaron;nje distribucije i procenjene retkosti vrsta, izvr&scaron;ena je prioretizacija područja značajnih za opstanak osolikih muva u jugoistočnoj Evropi. Primenom linearnih regresionih i linearnih modela sa me&scaron;ovitim efektom ispitana je međuzavisnost&nbsp; funkcionalnih karaktera vrsta i procenjene promene veličine areala. Definisani su&nbsp; funkcionalni karakteri koji utiču na promenu veličine areala osolikih muva. Ustanovljeni koncept može biti upotrebljen za detekciju vrsta koje se jo&scaron; uvek ne smatraju ugroženim, ali zbog svojih biolo&scaron;ko-ekolo&scaron;kih karakteristika imaju potencijal da to postanu, te stoga zaslužuju pažnju konzervacionista. Dobijeni rezultati mogu u velikoj meri poslužiti za kreiranje sistematskog konzervacionog plana za očuvanje osolikih muva na teritoriji jugoistočne Evrope.</p> / <p>In this paper, the division of 572 species of hoverflies registered in Southeast Europe into functional groups was conducted, based on their functional traits. For 44 selected&nbsp; endemic and native non-endemic species that have their climatic niches limited in the study area, maps of current and future potential distributions were created (for the periods, 2041-2060 and 2061-2080) using MAXENT algorithm. Based on the obtained &nbsp; maps, changes in potential area of occupancy were calculated, in order to estimate the &nbsp; effect of climate change on the distribution of hoverfly species. Species that will be most affected by climate change were detected, as well as the areas with the greatest potential species richness in the future and areas predicted to lose part of the diversity of hoverflies. It is shown that species with limited distribution in the future will not experience a greater reduction of its area in relation to the widespread species. Also, based on the current maps of potential distribution and assessed rarity of species,priority areas important for the survival of hoverflies in Southeast Europe were established. By using linear regression and linear mixed effect models, the interdependence between functional traits and the estimated changes in the range size was tested. Traits affecting the changes in range size of hoverflies were determined. The established concept can be used for the detection of species that are not yet considered endangered, but because of their biological and ecological traits have the potential to become threatened, and therefore deserve the attention of conservationists.&nbsp; This results can largely be used to create a systematic conservation plan for the preservation of hoverflies in Southeast Europe.</p>
25

Estudio del ciclo de vida de sírfidos eristalinos (Diptera, Syrphidae) y bases para su cría artificial

Hurtado Asencio, Pilar 01 March 2013 (has links)
Esta tesis doctoral aborda el estudio del ciclo de vida de varias especies de sírfidos saprófagos de la tribu de los Eristalini: Eristalis tenax (Linneo, 1758), Eristalinus aeneus (Scopile, 1763) y Eristalinus taeniops (Wiedemann, 1818). Se ha incidido especialmente en múltiples aspectos de su biología larvaria así como en parámetros básicos de la biología imaginal implicados en su cría artificial y el establecimiento de colonias permanentes. A continuación se exponen brevemente los objetivos planteados y los resultados en cada uno de los capítulos, organizados en dos grandes bloques referentes al estudio de la biología larvaria y de la biología de los imagos. Bloque I. Estudio de la biología preimaginal de Eristalis tenax, Eristalinus taeniops y Eristalinus aeneus. Capítulo 1: Influencia del tipo de medio de desarrollo larvario en el ciclo de vida. En este capítulo se analiza el efecto de diferentes medios de desarrollo larvario sobre varios parámetros biológicos relacionados con el ciclo biológico de cada especie. En concreto se comparan tres medios de tipos artificial basados en cereal en grano (avena, arroz y cebada) frente a un medio natural elaborado con purín procedente de explotaciones porcinas. Capítulo 2: Influencia de la competencia intraespecífica durante el desarrollo preimaginal. En este capítulo se planteó el estudio de la influencia de la densidad larvaria sobre desarrollo larvario mediante el análisis de parámetros biológicos de relevada importancia como la supervivencia, la duración del periodo preimaginal, y el tamaño/peso seco de los imagos. Los resultados indican que, para todas las especies, el incremento de la densidad larvaria en medios artificiales de desarrollo (cereales) provoca un aumento en los periodos de desarrollo, una disminución en la supervivencia y una reducción en el tamaño final de los imagos. Este efecto fue también observado en Eristalis tenax utilizando un medio de desarrollo con purines porcinos. Capítulo 3: Estudios mediante microscopía electrónica de barrido (SEM) de los estados inmaduros de sírfidos eristalinos Eristalis similis (Fallen, 1817) y Eristalis tenax (Linnaeus, 1758). Este capítulo presenta la primera descripción de la larva y el pupario de E. similis, incluyendo un estudio morfológico comparativo de los estados preimaginales de la especie sinatrópica y cosmopolita E. tenax. Las descripciones de ambas especies se han llevado a cabo utilizando por vez primera microscopía electrónica de barrido (SEM). La morfología preimaginal de E. similis fue comparada con todas las descripciones larvarias conocidas del género Eristalis. Capítulo 4: Biología de Rhembobius quadrispinus (Gravenhörst) (Hymenoptera: Ichneumonidae) y su efecto como parasitoide de pupas de especies de sírfidos saprófagos. En este capítulo se presenta la biología e importantes detalles del ciclo de vida del parasitoide de pupas R. quadrispinus, tanto en condiciones naturales como en experimentos controlados en laboratorio. El comportamiento de cópula y de ovoposición fue filmado en video para su posterior análisis. La idoneidad del hospedador y la influencia tanto de la edad de la pupa como de la edad de la hembra de parasitoide en el desarrollo de su progenie fue evaluada mediante experimentos en condiciones controladas. Bloque II. Estudio de la biología imaginal de Eristalis tenax, Eristalinus taeniops y Eristalinus aeneus. Capítulo 5: Análisis de los principales parámetros biológicos relacionados con la cría artificial de sírfidos eristalinos. En este capítulo se presentan resultados preliminares sobre varios parámetros relacionados con la cría artificial de sírfidos eristalinos. En el caso de Eristalis tenax, se evaluaron diferentes tipos de polen resultando como el más óptimo el polen fresco de abeja sin ser sometido a procesamientos por deshidratación. Respecto a la disponibilidad de polen en la colonia, una mayor frecuencia en el aporte de polen fresco proporciona a las hembras de E. tenax una longevidad mayor, llegando a superar los 30 días si se alimentan cada 3 días frente a los 18 días de media si se oferta cada 10 días. Capítulo 6: Análisis de los principales parámetros biológicos relacionados con la fertilidad y la maduración de los imagos. En este capítulo se describe el desarrollo ovárico de las hembras de Eristalis tenax, Eristalinus taeniops y Eristalinus aeneus, evaluándose la idoneidad de diversos tipos de alimentación y su repercusión en la fertilidad. También se analizó la influencia de la densidad larvaria en el proceso de maduración sexual de las hembras. En las colonias de E. tenax, las hembras no lograron una maduración completa de sus ovarios hasta una edad media de unos 20 días. El número medio de huevos en la primera puesta fue de unos 200 huevos y las hembras alcanzaron longevidades próximas a los 3 meses. En el caso de E. aeneus se han obtenido unos resultados muy positivos en todos los parámetros estudiados con relación a su fertilidad. La longevidad media de las hembras fue de 60 días en media, alcanzando frecuentemente los cuatro meses. Es la especie con un periodo de preovoposición más corto. El número medio de huevos por puesta fue de unos 135 huevos. En el caso de E. taeniops, se ha detectado una reducida longevidad de las hembras en condiciones artificiales, con un periodo de vida de poco más de un mes y con un prolongado periodo de maduración de las hembras. / European LIFE project ECODIPTERA (LIFE05-ENV/E/000302)
26

The ecology and conservation of endangered saproxylic hoverflies (Diptera, Syrphidae) in Scotland

Rotheray, Ellen L. January 2012 (has links)
Hoverflies are important for their roles in ecological and environmental services, and are also charismatic species of conservation interest in their own right. Almost half of all hoverflies are saprophages, which are organisms that feed on dead or decaying organic matter, and these include saproxylic species that depend on deadwood. Deadwood and its associated community are a rich source of forest biodiversity and are fundamental to forest function, but due to poor management, many saproxylics are threatened or endangered, and techniques for conserving saproxylic species are poorly developed. In this thesis I study the ecology and conservation management of an endangered UK saproxylic fly, the Pine hoverfly, Blera fallax (Linnaeus) (Diptera, Syrphidae) and the dispersal ability of the similarly endangered Aspen hoverfly, Hammerschmidtia ferruginea (Fallén) (Diptera, Syrphidae). My main goals were to clarify methods to support their recovery in active programmes of species conservation in Scotland, UK. For B. fallax, this included experimenting with habitat creation techniques, investigating the best conditions for larval growth and assessing competition effects. In addition, I evaluated the genetic variability of the remaining population in Scotland by comparing it with one in Europe to determine whether genetic constraints may limit recovery. For H. ferruginea, I determined dispersal ability with field experiments involving mark and recapture techniques. By cutting holes at the surface of stumps of Pinus sylvestris, breeding habitat was created artificially for B. fallax at the remaining known locality for this species in the UK. Over 4 years, 81 % of holes were colonized by B. fallax, and by up to six other saproxylic syrphid species. The most successful holes were those cut into the heartwood, seeded with pine chips and sawdust and partially covered, as indicated by a combination of field occupancy monitoring and lab growth experiments. Observations of larval morphology and behaviour within rot holes revealed specializations that largely segregate the species in both time and space, and may mitigate interspecific competition between B. fallax and three more common syrphid species. I further demonstrated that B. fallax has a life history that features facultative semivoltine development, which may be a bet-hedging strategy to cope with fluctuating levels of larval food. Fifty B. fallax larvae were successfully reared and bred in captivity and from these, 430 descendent laboratory reared larvae and adults were released across three relocation sites. After initial success at the first re-location site when a new generation of larvae appeared in holes in 2010, a population crash at all sites occurred in the following year, possibly caused by adverse weather conditions. This disappointing result highlights the vulnerability of small populations to stochastic events, and means that survival of B. fallax may now depend on those larvae that are semivoltine, supplemented by animals currently being reared in captivity. My genetic analyses revealed similarly troubling information that highlights the precarious existence of B. fallax in Scotland: compared with a population in Sweden, Scottish B. fallax had significant less neutral genetic variation, and showed signs of a recent and severe bottleneck that reduced the effective population size to just 12 (CI: 0 - 266) individuals at some point in the last 200 years. Mindful of these challenges, I exploit my new data on the ecology and life history of B. fallax and combine it with techniques for captive rearing and for monitoring the genetic health of B. fallax into specific protocols and general prescriptions for the on-going recovery and management of this species. In order to assess the dispersal ability of H. ferruginea (and therefore its potential for recolonizing newly created habitat), in May to July over two years, adults were marked and released from a central point and subsequently monitored at the breeding site, decaying aspen wood Populus tremula, where adults tend to assemble for mating and oviposition. Adults were resighted visiting logs of decaying aspen set out at 1 km intervals along transects up to 7 km away. Up to 10 % of released individuals were resighted up to 5 km from the central release point. Most dispersing individuals (68 %) were resighted at 1 km, which I propose as the optimal distance for managing aspen for this species. Both of these hoverflies are case studies of techniques for recovering endangered saproxylic flies. Overall, my findings greatly increase fundamental knowledge of the ecology and natural history of these flies, and clarify some of the practical approaches that will be required in their conservation.
27

Redes de Interacción Formadas por Coleópteros y Dípteros (Syrphidae) Saproxílicos en Oquedades Arbóreas del Bosque Mediterráneo Ibérico

Sánchez Galván, Ingrid R. 27 September 2017 (has links)
En la presente tesis doctoral se presenta un estudio profundo de los ensambles formados por insectos saproxílicos (Coleópteros y Dípteros Syrphidae) ligados a las cavidades arbóreas de quercínas ibéricas (Quercus spp). Las especies saproxílicas (coleópteros y dípteros sírfidos) conforman complejas redes ecológicas conectadas a través de diferentes interacciones de especies insecto-insecto. Nuestros hallazgos recalcan la importancia para la conservación de la comunidad entomológica saproxílica, centrar la atención en el estudio de especies clave que cumplen un papel fundamental en la organización de los ensambles al condicionar la presencia o la ausencia de otras especies o gremios de especies que se desarrollan dentro de cada oquedad (ej. especies “ingenieros del ecosistema”). Ponemos de manifiesto también la importancia que tiene la microbiota dentro la oquedad como recurso trófico de las fases larvarias acuáticas de especies de sírfidos que como adultos, son visitantes florales asiduos de las flores de nuestros bosques mediterráneos.
28

Mejora de la cría artificial de dípteros (Diptera: Syrphidae, Stratiomyidae) con potencial para su utilización en servicios ecosistémicos. Bases para su aplicación en Argentina

Lillo, María Inés 19 November 2020 (has links)
En la tesis doctoral se aborda la mejora de la cría artificial de 4 especies de dípteros pertenecientes a las familias Syrphidae y Stratiomyidae que se han seleccionado como modelos de los distintos servicios ecosistémicos que pueden desempeñar estas familias de dípteros. La tesis cuenta con un total de siete capítulos divididos en tres bloques, en función de tres tipos de servicios ecosistémicos. En el primer bloque están reunidos tres capítulos relacionados con la biología, reproducción y morfología de dos especies de sírfidos (Diptera: Syrphidae) depredadores con potencial en el control biológico de plagas: Eupeodes corollae (F) y Austroscaeva occidentalis (S). En el capítulo 1 se evaluó la supervivencia y reproducción de Eupeodes corollae así como su capacidad depredadora sobre Myzus persicae (S) utilizando las metodologías de tablas de vida de dos sexos y de tasa de depredación diaria concluyéndose, en base a los datos obtenidos, que E. corollae es una especie de interés para el manejo de M. persicae en diferentes cultivos. En el capítulo 2 se estudió el desarrollo ovárico y el proceso de maduración de oocitos de las hembras de E. corollae y se estimó su fecundidad potencial. El seguimiento de la oogenesis se realizó según los criterios establecidos por Bier (1963) mientas que la evolución del desarrollo ovárico se siguieron las etapas de maduración propuestas por Branquart y Hemptinnne (2000). La fecundidad potencial se estimó realizando el recuento de las ovariolas presentes en los ovarios. Entre los resultados obtenidos, podemos destacar que, el proceso de maduración de oocitos no se produce de forma simultánea en todas las ovariolas dentro de un ovario. En el capítulo 3 Se describe por primera vez la morfología de la larva de tercer estadio y pupa de Austroscaeva occidentalis (Shannon, 1927) y se actualiza la morfología de larvas de tercer estadio y pupas de Eupeodes utilizando técnicas de microscopía óptica, crio-escaneo y microscopía electrónica de barrido. También se compararon entre si y con las de otros taxones pertenecientes al linaje evolutivo de Eupeodes-Scaeva. Además, se proporciona información preliminar del ciclo biológico y nuevos códigos de barras de ADN para A. occidentalis. En el segundo bloque estan reunidos dos capítulos relacionados con la cría en cautividad de Eristalinus taeniops (W.) (Diptera, Syrphidae), especie de díptero con importancia como polinizador con presencia en Argentina. En el capítulo 4 Se comparó la influencia de tres medios de desarrollo larvario en el ciclo de vida, fecundidad y fertilidad de E. taeniops utilizando el método de tablas de vida de dos sexos. De los tres medios, el suplementado con estiércol fue el más eficiente para la cría de E. taeniops. Sin embargo, es necesaria una mayor investigación para incrementar la supervivencia de la etapa larvaria y la longevidad del adulto con el objetivo de llevar a cabo una cría artificial eficiente. En el capítulo 5 se evaluó la influencia de tres fuentes de hidratos de carbono sobre la fecundidad y longevidad de hembras de E. taeniops. Los datos obtenidos se analizaron con la técnica anteriormente mencionada. Como resultado se observó que los mejores valores en los parámetros de fecundidad se obtuvieron en las hembras alimentadas con azúcar sin que se encontraran diferencias en la longevidad de las hembras de los tres tratamientos. Finalmente, en el tercer bloque están reunidos dos capítulos en los que se trabajó con Hermetia illucens (L) ( Diptera: Stratiomyidae), especie de gran valor en la prestación de servicios ecosistémicos, siendo los considerados de soporte (degradación de materia orgánica en la cadena trófica) y de provisión o abastecimiento (obtención de materia prima para alimentación animal y otros compuestos de interés industrial) los más destacables. En el capítulo 6 se realizaron dos ensayos con el objetivo de determinar la densidad óptima de larvas en el sustrato de alimentación necesaria para garantizar la producción de hembras con una fecundidad potencial óptima. Teniendo en cuanta los datos obtenidos se considera que, bajo las condiciones evaluadas, la densidad óptima para maximizar la fecundidad potencial de las hembras es de 1500 larvas neonatas/kg de medio de desarrollo. Por último, en el capítulo 7 se evaluó la influencia de tres proporciones de sexos distintas en las jaulas de adultos sobre longevidad de los adultos y la fecundidad real y efectiva de las hembras. Como resultado se observó que no existieron diferencias significativas ni la longevidad de los adultos ni en el período de preovoposición de las hembras en los tres tratamientos evaluados. Como resultado se ha obtenido que, para optimizar la producción de neonatos de la mosca soldado negra en explotaciones masivas, sería recomendable trabajar con jaulas en las que la proporción de sexos sea lo más cercana posible a 1 (♀/♂).
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Faune pollinisatrice, paysage et échelle spatiale des flux de pollen chez brassica napus l. (brassicaceae) / Pollinator fauna, landscape and spacial scale of pollen flow of brassica napus l. (brassicaceae)

Chifflet, Rémy 16 December 2010 (has links)
L’intérêt pour la dispersion des gènes via le pollen a augmenté avec les cultures de plantes génétiquement modifiées. A ce jour, les données expérimentales ainsi que la modélisation portant sur les mouvements du pollen de colza, Brassica napus L., à l’échelle du paysage ne différencie pas clairement la part du vent et des insectes dans cette dispersion. Cependant, l’estimation de la dispersion des gènes par le pollen reste une condition nécessaire pour la gestion des risques d’échappement des (trans-)gènes vers l’environnement et les cultures conventionnelles. A travers cette thèse, nous avons pu mettre en évidence qu’une grande diversité d’insectes pollinisateurs pouvait transporter du pollen viable entre différentes plantes de colza sur des distances importantes (>1.1 km). La diversité d’insectes varie d’une région à l’autre et d’une année sur l’autre. Cependant, bien que la majorité des insectes sur une zone de grande production de colza ait du pollen de cette culture sur leur corps, seulement 39,4 % des insectes capturés sur des plantes mâle-stériles transportent du pollen de colza viable. Bien que nous n’ayons pas pu déterminer avec précision la part du vent et des insectes dans le pollinisation du colza, il semblerait que les insectes participent de façon plus importante à la pollinisation de plantes présentes en bordures de champs, augmentant ainsi le taux de pollinisation croisée. Nos résultats fournissent des données fiables pour améliorer les modèles de dispersion pollinique pour des cultures entomophiles à l’échelle du paysage. Ces modèles sont essentiels pour l’aide à la gestion afin de réduire la dispersion des gènes par le pollen des cultures génétiquement modifiées vers les plantes sauvages ou les cultures conventionnelles / Interest in pollen-borne gene dispersal has grown with the cultivation of genetically modified plants. To date both experimental data and models of oilseed rape (OSR) Brassica napus pollen movement at the landscape scale do not clearly differentiate between wind- and insect-mediated dispersal. Estimations of pollen-borne gene dispersal would be valuable for managing potential escapes of transgenes. Our study provides clear evidence that a large variety of insect species can transfer viable pollen between oilseed rape plants over considerable distances (>1.1 km). Insect’s diversity according to geographical site and years. However, the majority of pollinator have OSR pollen in their body hairs, only 39.4% of the insects caught on male-sterile flowers carried OSR pollen. Although we could not determine with precision the role of the wind and the insects in the OSR pollination, it would seem that insects take part in a more important way in pollination of plants present in edges of fields, thus increasing cross pollination rate. Our results provide valuable data to improve models of pollen dispersal for entomophilous crops at the landscape scale. These models are essential to help land-managers reduce pollen-borne gene dispersal from genetically modified plants to wild relative and field planted with non-GM crops
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Taksonomija i distribucija vrsta roda Merodon (Meigen, 1803) (Diptera: Syrphidae) u Palearktiku / Taxonomy and Distribution of the genus Merodon (Meigen, 1803) (Diptera: Syrphidae) in Palaeartic

Ačanski Jelena 24 May 2017 (has links)
<p>Predmet ovog istraživanja su vrste iz<em>&nbsp; Merodon&nbsp; aureus,&nbsp; M.&nbsp; nanus&nbsp; i&nbsp; M. ruficornis&nbsp; </em>grupe i&nbsp;<em> M.&nbsp; avidus&nbsp; </em>kompleksa sa područja Palearktika. Usled izuzetne morfolo&scaron;ke sličnosti pomenutih vrsta, kori&scaron;ćene su tri različite metode u cilju utvrđivanja&nbsp; prisustva skrivenih taksona i definisanja granica vrsta. Komparativnom geometerijsko-morfometrijskom analizom su obuhvaćene vrste iz&nbsp;<em> M.&nbsp; aureus&nbsp; i&nbsp; M.&nbsp;</em> <em>nanus&nbsp; </em>grupe i&nbsp;<em> M.&nbsp; avidus</em>&nbsp; kompleksa. Interspecijska varijabilnost&nbsp;<em> M.&nbsp; aureus</em>&nbsp; grupe i&nbsp;<em> M.&nbsp; avidus&nbsp;</em> kompleksa je analizirana sa dva geometrijsko-morfometrijska pristupa: analiza oblika krila -&nbsp; zasnovana na specifičnim tačkama (<em>landmarks</em>) i analiza oblika genitalnog aparata mužjaka&nbsp; -&nbsp; zasnovana na pomoćnim tačkama (<em>semilandmarks</em>).<br />Sredinske ni&scaron;e su kvantifikovane i poređene &ldquo;<em>Point base</em>&rdquo; metodom i njome su obuhvaćene sve istraživane vrste. Uslovljenost razlika u obliku krila i surstila analiziranih vrsta geografskom distribucijom i klimatskim faktorima je testirana upotrebom Mantel testa. Dobijeni rezultati analize oblika krila i genitalnog aparata mužjaka ukazuju na veliki potencijal geometrijske morfometrije u detekovanju morfolo&scaron;ke&nbsp; varijabilnosti, odnosno kriptičnih vrsta kod sirfida. Na osnovu oblika krila i genitalnog aparata mužjaka, unutar svih istraţivanih grupa vrsta prepoznato je 45 nezavisnih evolucionih jedinica (<em>M.</em>&nbsp;<em>aureus</em>&nbsp;grupa - 36;&nbsp; <em>M.</em> <em>nanus</em>&nbsp;grupa - 5,&nbsp; <em>M. avidus&nbsp;</em> kompleks&nbsp; -&nbsp; 4). Sve kriptične vrste iz 12 analiziranih kompleksa vrsta su uspe&scaron;no razdvojene, sa visokim procentom korektne klasifikacije jedinki. Rezultati ukazuju na veću moć diskriminacije oblika genitalnog aparata mužjaka u odnosu na krila. Razlike u obliku krila se odnose prvenstveno na promene u apikalnom delu<br />krila &scaron;to utiče na promene u dužini i &scaron;irini ovog dela, dok su razlike u obliku genitalnog aparata mužjaka najvećim delom koncentrisane u posteriornom delu posteriornog lobusa surstila, delu genitalnog aparata mužjaka koja igra ključnu ulogu u pridržavanju ženki tokom kopulacije. Razlike u obliku krila nisu posledica geografske udaljenosti, kao ni razlika u ekolo&scaron;kim ni&scaron;ama vrsta. Uticaj abiotičkih parametara na razlike u obliku genitalnog aparata mužjaka nije zabeležen ni kod jedne od analiziranih vrsta, dok je uticaj geografske distribucije na razlike u obliku surstila zabeležen samo u jednom slučaju, kod&nbsp; <em>M. luteomaculatus</em>&nbsp;kompleksa vrsta. Ovi rezultati ukazuju da je<br />izolacija putem distance imala glavnu&nbsp; ulogu u diverzifikaciji oblika genitalnog aparata mužjaka kod vrsta ovog kompleksa.</p><p>Rezultati su pokazali da se klimatski profili svih analiziranih parova vrsta razlikuju u makar jednoj sredinskoj ni&scaron;i (PC osi), osim para vrsta&nbsp; <em>M. rojoi - M. puniceus&nbsp;</em> i&nbsp; <em>M.&nbsp; loewi&nbsp; -&nbsp; M. ovaloides</em>. Faktori koji najvi&scaron;e doprinose&nbsp;divergenciji klimatskih profila analiziranih vrsta predstavljaju esktreme tj. limitirajuće faktore poput niskih vrednosti padavina i temperature i fluktuacija temperaure tokom godine. Za razliku od &scaron;iroko rasprostranjenih vrsta, endemske vrste imaju uzak opseg nadmorskih visina na kojima se javljaju i uglavnom su vezane za planinska stani&scaron;ta. Takođe, imaju niske vrednosti standardne devijacije za većinu izdvojenih PC osa &scaron;to ukazuje na njihovu striktnu klimatsku adaptibilnost. Prema rezultatima analize distribucije i specijskog diverziteta, Balkansko poluostrvo odlikuje najveći&nbsp;divezitet analiziranih vrsta. On predstavlja centar biodiverziteta za&nbsp;<em>M. aureus</em> grupu, a zajedno sa severnim delom Apeninskog poluostrva za <em>M. ruficornis</em> grupu, dok je najveći diverzitet vrsta <em>M. nanus</em>&nbsp;grupe zabeležen na jugozapadu i severoistoku Anadolije. Analize klimatskih profila i specijskog diverziteta zajedno sa rezultatima geometrijske morfometrije ukazuju da je geolo&scaron;ka istorija, tj. kontrakcije areala tokom glacijacija i interglacijacija, značajno uticala na diverzifikaciju istraživanih grupa u refugijumima zapadnog Palearktika.</p> / <p>The objects of this study are species from <em>Merodon aureus</em>, <em>M. nanus</em>&nbsp;and <em>M.&nbsp; ruficornis</em> groups, and <em>M. avidus</em> complex in Palaearctic. These species are characterised by great morphological&nbsp; similarity, and three different approaches were used to detect cryptic species and establish species boundaries. Species from <em>M. aureus</em>&nbsp;and <em>M.&nbsp; nanus</em>&nbsp;groups, and <em>M. avidus</em> complex were analysed using geometric morphometry. Interspecific variability of <em>M. aureus</em> group and <em>M. avidus</em> complex were studied using two approaches: landmark based wing shape analysis and semilandmark analysis of male genitalia.&nbsp; Ecological niche analysis were conducted for all analyzed species.&nbsp; Correlation between Squared Mahalanobis&nbsp; distances of both wing and surstylus, and geographic and environmental distances were addressed using&nbsp; the two tailed Mantel test. Geometric morphometric results indicate that wing and especially surstylus shape, have meaningful interspecific discriminatory power. Based&nbsp; on these characters 45 evolutionary independent units are recognized (<em>M. aureus</em>&nbsp;group - 36; <em>M. nanus</em>&nbsp;group - 5, <em>M. avidus</em> complex - 4). All cryptic species from 12 analysed species complexes were successfully distinguished with high overall&nbsp; classification success. Results showed that geometric morphometry of surstylus had a higher classification rate than wing geometric morphometry. The main wing shape differences are connected with apical part of the wing which influences his length and width. The main differences in surstylus shape are connected to the posterior margin of the posterior part of the surstylus lobe, involved in gripping the female during copulation. Mantel tests revealed that geographic and environmental distances exhibited no association with wing and&nbsp; surstylus shape distance among investigated species, except in <em>M. luteomaculatus</em>&nbsp; complex. In this complex, Mantel test results suggested that isolation by distance had a major role in the diversification of male genitalia.</p><p>Ecological niche analysis contributed to the species delimitation. These results demonstrated that among all related species, with the exception of species pairs <em>M. rojoi - M. puniceus</em> and <em>M. loewi - M. ovaloides</em>, overall or partial divergence in environmental&nbsp; space is present. Distribution patterns of all analyzed species are mainly affected by the limiting effects such as low temperature and precipitation values,&nbsp; as well as the temperature fluctuation during the year.</p><p>Endemics and species with a narrow range had smaller altitudinal ranges and were mainly connected with mountainous areas. Additionally, low standard deviation values for endemic species reflect their narrow geographic distribution and very strict climatic adaptations, whereas large values for widely distributed species reflect their broad adaptability.</p><p>According to the results of distribution and species diversity analysis, the Balkan Peninsula is characterized with highest diversity. It is a centre of biodiversity for&nbsp;<em>M. aureus</em> group, together with the northern part of the Apennine peninsula for <em>M. ruficorn</em>&nbsp;is group, while the largest species diversity of <em>M. nanus</em>&nbsp;group is recorded in the southwest and northeast Anadolia.</p><p>Distribution and species diversity analyses, together with&nbsp; the results of geometric morphometry indicate that geological history, i.e. range contraction during glaciations and interglaciations had a significant impact on the diversification of the studied groups in refuges in the Western Palaearctic.</p>

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