The greenbottle blowflies, Lucilia sericata (Meigen, 1826) and Lucilia cuprina (Wiedemann, 1830) (Diptera: Calliphoridae) are very difficult to distinguish on the basis of their external morphology. The literature suggests that these two species may be interbreeding. Sequencing two nuclear (28S rRNA and Period) and one mitochondrial (COI) gene indicated that there has been an ancient hybridization event and that mtDNA of L. sericata has become fixed in a lineage of L. cuprina through mtDNA introgression, possibly involving Wolbachia infection. This has implications for identifications of these species based on mtDNA alone. No study has shown explicitly that hybrids of L. sericata and L. cuprina can be identified morphologically. Morphological characters used to identify L. sericata and L. cuprina were scored and tested using specimens of both species and known hybrids. Discriminant function analysis of the characters successfully separated the specimens into three unambiguous groups – L. sericata, L. cuprina and hybrids. This is the first evidence that hybrids of these two species can be identified from physical characteristics.Lucilia sericata and L. cuprina have medical, veterinary and forensic importance. Knowing their distribution in South Africa would allow more effective management and utilisation of these flies. Their predicted geographic distributions in South Africa were modelled using maximum entropy analysis of selected climatic variables. The most important environmental variables in modelling their distributions were magnitude of monthly rainfall and the magnitude of the monthly maximum temperature for L. sericata, and the seasonal variation in monthly mean humidity and magnitude of monthly rainfall for L. cuprina. Both species have a widespread distribution in South Africa and one therefore cannot identify specimens of these flies by locality of capture alone.Luciliinae is a diverse and geographically widespread subfamily containing four genera - Hemipyrellia, Lucilia, Dyscritomyia and Hypopygiopsis – that all contain parasitic species ranging from saprophages to obligate parasites. The phylogenetic relationships between these genera are unclear. The 28S rRNA, COI and Period genes of 14 species of Lucilia and Hemipyrellia were partially sequenced and analysed together with 11sequences from GenBank and the Barcode of Life Database (BOLD). Lucilia sericata and L. cuprina were shown to be sister-species. Three cases of paraphylly were identified within Lucilia that affects identification of these species using mtDNA alone. Hemipyrellia consistently caused Lucilia to be paraphyletic when it was included in analyses, so Hemipyrellia should be synonymized with Lucilia. The relationships of Dyscritomyia and Hypopygiopsis to Lucilia are unclear and further studies are required. No geographic pattern was found within the different forms of parasitism within this group, but the different degrees of parasitism were phylogenetically clustered.

Blowflies (Diptera: Calliphoridae) are main colonizers of decomposing remains and any information on the influences of their lifecycle of growth and development are important to forensic entomologists when estimating postmortem interval during a medicolegal death investigation. Pupal survival of blowfly species, Lucilia sericata were studied at different developmental stages following pupation, white (0-12 hrs), young (24 hrs), medium (5 days), old (9 days) were submerged at various immersion intervals ranging from 1 hr to 120 hr (5 days) in different water types (fresh, salt, polluted, and drinking water). Control group (N= 100) were white pupae that were not submerged were also observed in order to compare the survival and eclosion rate. Two trials of the submergence process were conducted to observe the pupae survival. Data were analyzed using multiple logistic regressions in a 3-way interaction to determine if significant differences were seen between the water, time in water, and pupal stage. Dissolved inorganic nitrogen (DIN) of NH4+, NO2-, NO3-, and oP or DIP were analyzed to examine to determine if a correlation between the water types could be seen. DIN analyses exhibited similar NO2- + NO3- and NO3- in polluted and fresh water. The results show that as the pupae developmental age progressed, the pupae generally survived longer immersion intervals. The survival of white pupae decreased with the increase of submergence for all four water types, exhibiting a 100%mortality rate with pupae submerged longer than 24-36 hours. While pupae immersed in polluted water had similar survival rates in the white stage, the survival rate declined as the developmental age increased for pupae immersed in polluted water. Pupae immersed in salt and polluted water had earlier eclosion times when compared to other water groups, emerging at 36 hours from when the control group first emerged at day 12. Understanding the survival rate of submerged Lucilia sericata (Diperta: Calliphoridae) pupae will be potentially useful for criminal investigations by providing a better understanding of the survival of pupae submerged in different aquatic environments.

Made available in DSpace on 2014-08-20T14:31:32Z (GMT). No. of bitstreams: 1 dissertacao_sabrina_pires_capa.pdf: 403567 bytes, checksum: 5752dd89517a54f40cd0632e1db1c1c6 (MD5) Previous issue date: 2007-03-30 / The blowflies are the first insects to compose the faunistic succession of human cadavers, thus helping to determine the postmortem interval (PMI). However, failing to consider larval post-feeding dispersal can compromise medical-criminal inquiries. In order to investigate the relationship between post- feeding Lucilia sericata larvae and their weight, radial dispersion and depth, an artificial arena was built simulating the natural environment. We observed a difference in mean pupal weight between males (30.28mg) and females (32.35mg). We also observed that the majority of pupae were recovered a distance of 33 to 45cm from the center of the arena, and at a depth of 6 to 8cm from the surface. However, we observed no differences in radial dispersion and depth of pupation between males, females or unviable individuals. Correlation analysis between weight and distance (r = 0.246) and between weight and depth (r = 0.321) was directly proportional, suggesting that heavier pupae dispersed farther and deeper than lighter pupae. The experiment also allowed us to conclude that a circular arena permitted larval dispersion all directions. / Os dípteros califorídeos são os primeiros indivíduos a compor a sucessão faunística dos cadáveres humanos auxiliando assim na estimativa do intervalo pós- morte. Porém, a não consideração da dispersão pós-alimentar de larvas pode comprometer as investigações médico-criminais. Diante disto uma arena circular, simulando o ambiente natural, foi montada em laboratório a fim de verificar-se a dispersão larval radial pós-alimentar de Lucilia sericata, tentando assim estabelecer relações entre as variáveis peso, distância e profundidade de enterramento na arena. Os resultados demonstraram que a maioria das pupas foram recuperadas a uma profundidade compreendida entre 6cm e 8cm e a uma distância entre 33cm e 45cm do centro da arena. Não houve diferenças significativas quanto a propagação e profundidade de enterramento de machos, fêmeas e indivíduos inviáveis. Com relação ao peso, verificou-se que a média das fêmeas (x = 32,35mg) foi superior a dos machos (x = 30,28mg). A análise de correlação entre peso e distância percorrida (r = 0,246) e entre peso e profundidade (r = 0,321) foi diretamente proporcional, ou seja pupas mais pesadas propagaram e se aprofundaram mais. O experimento permitiu ainda concluir que uma arena circular possibilita o deslocamento das larvas em todas as direções.

<p>This thesis attempts to improve our understanding of the role of population size for the process of speciation. First, the effect of population size on speciation is studied using several meta-analyses of published laboratory experiments. Second, the effect of population size on behaviour is studied using a laboratory population of the blowfly <i>Lucilia sericata</i>. Third, the effect of population size on morphological and genetic variation is studied using wings and microsatellites from wild populations of <i>L. illustris</i> as well as experimentally bottlenecked populations of <i>L. sericata</i>. The meta-analyses showed that the result of many previous laboratory experiments on sympatric and parapatric speciation may have been biased by too small population sizes. Reduced interbreeding was less likely to develop in small populations where the selection against hybridisation often seemed to have been opposed by inbreeding depression or loss of genetic variation. In allopatric speciation experiments, no general consistent effect of population size was observed. There was no support for speciation through founder events. In fact, significant assortative mating was only found in vicariance experiments where derived populations was tested against each other. Population size influenced reproductive behaviour in <i>L. sericata</i>. There was a positive effect of increasing number of males on egg-laying but only as long as the female was in the company of at least one other female. Female mate choice and a positive effect of number of eggs on larval survival are suggested to be the underlying factors. No historic bottlenecks could be detected in the fly populations, but strong genetic indications suggest a fine grained genetic population structure of wild <i>Lucilia</i> flies. Bottlenecks had unpredictable effects on wing morphology as well as on genetic variation and fitness in a laboratory stock of <i>L. sericata</i>. Thus a bottlenecked population will not necessarily have a higher chance of evolving morphological novelties than one which has not undergone a bottleneck. However, among many bottlenecked populations there is a good chance that in at least one of them the conditions will be conducive to morphological change and evolution. In this statistical sense, thus, strong population fluctuations may enhance the probability of speciation events.</p>

This thesis attempts to improve our understanding of the role of population size for the process of speciation. First, the effect of population size on speciation is studied using several meta-analyses of published laboratory experiments. Second, the effect of population size on behaviour is studied using a laboratory population of the blowfly Lucilia sericata. Third, the effect of population size on morphological and genetic variation is studied using wings and microsatellites from wild populations of L. illustris as well as experimentally bottlenecked populations of L. sericata. The meta-analyses showed that the result of many previous laboratory experiments on sympatric and parapatric speciation may have been biased by too small population sizes. Reduced interbreeding was less likely to develop in small populations where the selection against hybridisation often seemed to have been opposed by inbreeding depression or loss of genetic variation. In allopatric speciation experiments, no general consistent effect of population size was observed. There was no support for speciation through founder events. In fact, significant assortative mating was only found in vicariance experiments where derived populations was tested against each other. Population size influenced reproductive behaviour in L. sericata. There was a positive effect of increasing number of males on egg-laying but only as long as the female was in the company of at least one other female. Female mate choice and a positive effect of number of eggs on larval survival are suggested to be the underlying factors. No historic bottlenecks could be detected in the fly populations, but strong genetic indications suggest a fine grained genetic population structure of wild Lucilia flies. Bottlenecks had unpredictable effects on wing morphology as well as on genetic variation and fitness in a laboratory stock of L. sericata. Thus a bottlenecked population will not necessarily have a higher chance of evolving morphological novelties than one which has not undergone a bottleneck. However, among many bottlenecked populations there is a good chance that in at least one of them the conditions will be conducive to morphological change and evolution. In this statistical sense, thus, strong population fluctuations may enhance the probability of speciation events.

Le comportement d’agrégation est considéré comme le premier pas vers des niveaux de socialité supérieurs. La compréhension des facteurs clés permettant l’émergence des décisions collectives chez les groupes composés d’individus simples (ayant une connaissance limitée de leur environnement) est donc fondamentale pour étudier l’évolution de la socialité. A l’heure actuelle, la majorité des études se sont focalisées sur les espèces les plus sociales, et notamment celles formant des groupes monospécifiques. A contrario, les larves nécrophages de Diptères (asticots) forment sur un même cadavre des agrégats hétérospécifiques pouvant contenir des milliers d’individus, leur offrant divers bénéfices(production de chaleur, d’enzymes). De part ces observations in natura, ces insectes apparaissent être un bon modèle biologique dans un contexte évolutif d’étude des comportements collectifs. Ce travail de thèse s’attache à mettre en évidence et quantifier les phénomènes d’agrégations des larves de Lucilia sericata (Diptera :Calliphoridae) et les mécanismes qui sous-tendent ces regroupements. Après une description introductive des groupes hétérospécifiques chez les arthropodes, nous présentons pour la première fois la démonstration expérimentale d’un comportement d’agrégation actif des larves. Nous avons également démontré l’effet d’attraction/rétention sur les larves d’un composé cuticulaire déposé au sol par les individus et reconnu par leurs congénères. Cette reconnaissance se fait probablement via l’utilisation d’un comportement exploratoire caractéristique que nous avons décrit et quantifié :le scanning. Puis, nous avons mis en évidence la capacité des larves de deux espèces proches phylogénétiquement et écologiquement, L. sericata et Calliphora vomitoria, à faire un choix collectif en groupe monospécifique comme en hétérospécifique. Ces résultats suggèrent l’existence d’une reconnaissance interspécifique de vecteurs d’agrégation (e.g. le signal larvaire). Enfin, nous avons mis en évidence l’existence de préférendums thermiques chez ces espèces, et la capacité des larves à sélectionner collectivement cette température préférentielle. Dans son ensemble, ce travail offre des connaissances inédites sur la vie de ces groupes. Il ouvre des perspectives d’étude prometteuses sur les comportements collectifs interspécifiques et les bénéfices évolutifs liés à l’agrégation. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

no / Larval biotherapy is a debridement tool used in wound management. The mechanism of action involves degradation of eschar by serine proteases including chymotrypsin within the alimentary fluids of first instar Lucilia sericata. With the rationale of obviating some limitations of biotherapy, including cost, complexity of use, and patient reticence, the present study describes a mobile hydrogel formulation containing freeze-dried recombinant L. sericata chymotrypsin designed for topical application. Neither freeze-drying nor formulation into the hydrogel significantly attenuated the measured activity of released enzyme compared to fresh-frozen enzyme in aqueous solution. Gel electrophoresis confirmed qualitatively that the chymotrypsin/hydrogel formulation both with and without supplementary urea at 10% w/v degraded human chronic wound eschar ex vivo. Mindful that the hallmark of intractability of chronic wounds is aberrant biochemistry, the pH activity profile for the enzyme/hydrogel formulation was compared with exudate pH in chronic wounds of mixed aetiology in a cohort of 48 hospital in-patients. Five patients' wounds were acidic, however, the remainder were predominantly alkaline and coincided with the pH optimum for the insect enzyme. Thus, a recombinant L. sericata chymotrypsin and hydrogel formulation could represent a pragmatic alternative to larval therapy for the management of chronic wounds.

El previsible aumento de la población mundial, estimado para el año 2050 en 9.500-10.000 millones de personas, supondrá uno de los principales retos a los que se enfrente el siglo XXI. Además de los recursos e insumos necesarios (espacio, agua, residuos etc.), la seguridad alimentaria del planeta conllevará una elevada demanda de proteínas tanto para la alimentación animal como para la nutrición humana. Nuestras principales fuentes de proteína provienen de la agricultura, la ganadería (incluyendo la acuicultura) y la pesca. Es por ello por lo que la producción y rendimiento de las plantas y animales domesticados, ha aumentado exponencialmente a lo largo de las últimas décadas, estando en la actualidad muy cerca de sus límites biológicos. Sin embargo, esta elevada eficiencia esta inversamente relacionada con la sostenibilidad ambiental de estos sistemas de producción. Entre las consecuencias, la producción de piensos compuestos altamente nutritivos también ha aumentado. Para su elaboración son necesarias grandes cantidades de harina y aceite de pescado, así como de soja, entre otros componentes. El cultivo intensivo de soja conlleva graves problemas medioambientales. Por otro lado, el medio marino está cada vez más deteriorado como consecuencia de la contaminación derivada de la actividad humana y la sobreexplotación pesquera. Todo ello ha provocado una inestabilidad económica a largo plazo y un aumento continuado de los precios de estas materias primas. Pero ¿es técnicamente posible maximizar la sostenibilidad de estos sistemas de producción, optimizando simultáneamente la imprescindible eficiencia económica? Con este objetivo, se hace necesaria la búsqueda de nuevas fuentes de proteínas que puedan utilizarse como ingredientes en la elaboración de piensos compuestos destinados a la alimentación animal e indirectamente a la nutrición humana. Una de las más prometedoras, es la obtención de proteína animal a partir de la biomasa de ciertas especies de insectos domesticados. En particular, la utilización de proteínas y grasas de insectos a escala industrial, mejorará significativamente la sostenibilidad y eficiencia de la ganadería terrestre y la acuicultura. Indirectamente, permitirá mantener los niveles de pesca a unos niveles racionales y los subproductos derivados tienen un gran valor agronómico como fertilizantes de origen natural. Entre los candidatos más plausibles, los dípteros (Insecta: Diptera) presentan características biológicas y nutricionales que los hacen buenos candidatos para su producción a escala industrial. Una de las especies más prometedoras es la mosca soldado negra Hermetia illucens (Linnaeus, 1758) que junto con el coleóptero Tenebrio molitor Linnaeus, 1758 constituyen actualmente los principales integrantes de este nuevo sector de producción. La Unión Europea, también ha aprobado el uso de otras cinco especies de insectos como ingredientes de la alimentación animal, destacando entre estas la mosca común Musca domestica Linnaeus, 1758. Otras especies de dípteros no están todavía aprobadas con este fin, pero también resultan muy interesantes por su gran potencial para la cría artificial, como las especies de Calliphoridae Lucilia sericata (Meigen, 1826) o Chrysomya megacephala (Fabricius, 1794). Entre los componentes que forman parte de los piensos compuestos en la alimentación animal, los minerales suponen un importante grupo limitante desde un punto de vista nutritivo. Mediante un aporte óptimo de minerales, se puede aumentar considerablemente el rendimiento de la producción ganadera a un bajo coste. No obstante, los niveles de estos compuestos deben mantenerse dentro de unos niveles determinados por la legislación para evitar problemas nutricionales o provocar efectos nocivos en la salud animal y humana. En este sentido, existen muy pocos estudios sobre los perfiles minerales de la biomasa de insecto en general y en particular de la mosca soldado negro y otras especies de dípteros. Son especialmente escasos los datos sobre la influencia que pueda ejercer la composición del sustrato de desarrollo de las larvas, así como su importancia en las diferentes etapas de desarrollo del ciclo de vida. Por otro lado, existe la posibilidad de que se produzca bioacumulación de metales pesados en la biomasa del insecto a través de la ingesta. Así, debido a su alta toxicidad, existen diversos trabajos sobre las concentraciones de Cd y Pb en larvas maduras de mosca soldado negra, pero hay muy poca información sobre bioacumulación en el resto de etapas y estadios de desarrollo, así como de la posible influencia del medio de cría larvario. En este proyecto de tesis se analiza la posible influencia del sustrato de cría en las concentraciones de distintos minerales y metales pesados a lo largo de las etapas del ciclo de vida de Hermetia illucens y otras especies de dípteros. Para ello se usaron tres sustratos larvarios con diferentes orígenes: a) pienso comercial de gallina ponedora, b) bagazo derivado de la producción de cerveza y c) una mezcla de carne de origen porcino. En el caso de H. illucens se tomaron muestras de larvas prepupales, pupas, puparios, exuvias prepupales y adultos desarrollados en los tres medios de desarrollo. En todos los casos, tras su secado y digestión en horno microondas, se analizaron mediante espectrometría de emisión óptica de plasma acoplado por inducción (ICP-OES) para obtener las concentraciones de Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Ni y Zn, y en espectrometría de masas con fuente de ionización de plasma (ICP-MS) para obtener las concentraciones de Ti, Co, Sr, Mo, Cd, Sn y Pb. Pocos insectos tienen la capacidad para desarrollarse en medios de tan diferente composición orgánica, por ello a modo comparativo se utilizó M. domestica con pienso comercial de gallina y el bagazo de cerveza, mientras que Lucilia sericata y Chrysomya megacephala se desarrollaron exclusivamente en el medio de origen cárnico. De esta manera no solamente se pudieron comparar diferentes tipos de medio procesados por diferentes tipos de insectos sino que también pudieron compararse los resultados obtenidos por diferentes especies de mosca con el mismo tipo de medio. En cuanto a relaciones entre patrones de acumulación (Factor de Bioacumulación) y concentraciones de los minerales, con la especie de díptero y el sustrato utilizado, en larvas prepupales y adultos no se observa ninguna relación entre resultados y la especie o el sustrato, en cambio, los resultados en pupas y puparios sí están influenciadas por la especie de estudio y el sustrato de alimentación usado. Por otro lado, Ca y Na se comportan de manera distinta en las especies estudiadas en esta investigación. La mosca soldado negra presenta un buen perfil mineral para su uso en alimentación animal, comparable con los de harina de pescado y soja. Los resultados con mosca doméstica son también comparables a las harinas de pescado y soja, en los dos medios estudiados. Los dos califóridos presentan un perfil mineral de menor calidad, pero comparable a la harina de soja y también aptos para su uso en la elaboración de piensos.

No description available.

Diss. (sammafattning) Uppsala : Univ., 2001. / Härtill 6 uppsatser.