Papers by Isabel Arnaldos
Annales de la Société entomologique de France (N.S.)
Parasitology Research, 2015
Sarcophagids are a large family of Diptera, with a worldwide distribution. They are related to de... more Sarcophagids are a large family of Diptera, with a worldwide distribution. They are related to decomposing organic matter and are very interesting for health science and in forensic cases since many species produce myiasis and occur in human corpses. This family is considered difficult to study, particularly with regard to their immature stages, to which little attention has been paid. Genus Sarcophaga Meigen, 1826 is composed of species of very similar morphology, making very difficult to distinguish. Knowledge of the immature stages of this genus is important because such stages occupy the greater part of the life cycle, so that establishing a basis for their identification will increase their usefulness in systematic and applied sciences. This contribution presents a detailed study of the morphological features, both external and internal, of the preimaginal stages of Sarcophaga (Liosarcophaga) tibialis Macquart, 1851, providing a taxonomical context for the correct identification of Liosarcophaga species of forensic interest in the Iberian Peninsula. Both light and scanning electron microscopy were applied. Complete descriptions of every stage are provided and illustrated, and their usefulness for species comparison, taking into account our uneven knowledge of morphologically immature stages of this subgenus, is indicated. Features of the cephalopharyngeal skeleton, such as the shape of the mouth hook and the intermediate and basal sclerites, and external morphology, such as the pattern of spinose band and anterior and posterior spiracles, proved useful for separating species. Finally, tentative identification keys based on light microscopy observation to distinguish S. (L.) tibialis from other species of forensic interest belonging to Liosarcophaga subgenus are proposed for every immature stage.
Faunistic information is presented for 10 species of Calliphoridae flies from Portugal: Calliphor... more Faunistic information is presented for 10 species of Calliphoridae flies from Portugal: Calliphora vicina Robineau-Desvoidy, 1830; Calliphora vomitoria (Linnaeus, 1758); Chrysomya albiceps (Wiedemann, 1819); Lucilia ampullacea Villeneuve, 1922; Lucilia caesar (Linnaeus, 1758); Lucilia illustris (Meigen, 1826); Lucilia sericata (Meigen, 1826); Lucilia silvarum (Meigen, 1826); Melinda viridicyanea (Robineau-Desvoidy, 1830) and Protophormia terraenovae (Robineau-Desvoidy, 1830). Six of these species are reported for the first time for Portugal and it is the first record of the 10 species for Portuguese mainland. The material studied was collected from rabbit and piglet cadavers, in experiments related to forensic entomology, in Coimbra and Lisbon.
Entomología aplicada a las Ciencias Forenses Código 0443 Tipo Optativa Créditos ECTS 5 Estimación... more Entomología aplicada a las Ciencias Forenses Código 0443 Tipo Optativa Créditos ECTS 5 Estimación del volumen de trabajo del alumno (ECTS)* 50 h presenciales+ 75 h trabajo personal Duración Cuatrimestral (1º) Idiomas en que se imparte Español B.-PROFESORADO La docencia en esta asignatura se encuentra adscrita al Área
Código 09B1 Curso / Grupos Primer curso Tipo Troncal Créditos LRU 9,5 (6T + 3,5P) Estimación del ... more Código 09B1 Curso / Grupos Primer curso Tipo Troncal Créditos LRU 9,5 (6T + 3,5P) Estimación del volumen de trabajo del alumno (ECTS) 218,25 Duración Anual Idioma en que se imparte Castellano B.-PROFESORADO La docencia en esta asignatura se encuentra adscrita al Área
Forensic Entomology is a speciality contributing more frequently to Forensic Sciences. It can be ... more Forensic Entomology is a speciality contributing more frequently to Forensic Sciences. It can be critical for solving forensic cases such as criminal cases through estimation of the postmortem interval, whether the corpse has been moved... or civil cases such as infestation of food or structures, urban pests... In any case, a clear identification of evidence is necessary since a proper expert report depends on the precise knowledge of the species that were involved in each case. It is known that the specific identification of the insects is a complex task, even if they are large, since certain parts of the body, usually of small size, are used. Therefore, from the beginning of Entomology it has been necessary to use microscopical techniques. Most of the studies use optical microscopy, although lately scanning electron microscopy (SEM) is becoming a very popular technique. One of the main goals of Forensic Entomology, the estimation of postmortem interval, deals with the larval stage...
Microscopy Research and Technique, 2014
The Sarcophagidae are one of the most numerous groups of Diptera in the world, consisting of many... more The Sarcophagidae are one of the most numerous groups of Diptera in the world, consisting of many species of forensic interest, whose immature stages are useful in the estimation of postmortem interval. The immature stages of some species of forensic importance still remain unknown or undescribed, like in the case of Sarcophaga (Liopygia) cultellata Pandellé, 1986, a species restricted to the Iberian Peninsula, south of France and north of Italy, which shares a ecological niche with species of the same subgenus, e.g., Sarcophaga (Liopygia) argyrostoma (Robineau-Desvoidy, 1830) and Sarcophaga (Liopygia) crassipalpis Macquart, 1839, making it necessary to lay the groundwork for a proper specific differentiation before it can be successfully applied in forensic practice. This study provides the first micromorphological description of all preimaginal stages of S. (L.) cultellata using light microscopy and scanning electron microscopy (SEM), the results of which allow the morphology of the main features to be followed during the immature life cycle. We propose a combination of features for distinguishing Liopygia from other sarcophagid subgenera, based on the current level of morphological knowledge of immature stages. S. (L.) cultellata can be differentiated from S. (L.) argyrostoma and S. (L.) crassipalpis in every immature stage by both light microscopy and SEM. The presence of tegumental warts and a fan-shaped anterior spiracle with a single row of 15-18 respiratory papillae allow distinguishing the third instar larvae of S. (L.) cultellata from other Sarcophaga species described hitherto by SEM. Identification keys based on light microscopy observations are provided, covering all the immature stages of Liopygia subgenus occurring in the Iberian Peninsula.
Forensic science international, 2014
This paper presents a forensic investigation that took place in the city of Murcia (SE Spain) and... more This paper presents a forensic investigation that took place in the city of Murcia (SE Spain) and shows how the entomological specimens collected at the scene were extremely helpful for estimating the minimum post-mortem interval (PMImin). The occurrence of Telomerina flavipes (Meigen, 1830) (Diptera: Sphaeroceridae) is reported here for the first time in a forensic case. Additionally, the importance of other entomological evidence in this case is discussed. The first known images of the puparium are provided, as well as its redescription and that of the cephalopharyngeal skeleton recovered from the puparium.
Resumen: La Entomología es una ciencia de uso potencial en múltiples aspectos de interés humano. ... more Resumen: La Entomología es una ciencia de uso potencial en múltiples aspectos de interés humano. Uno de los aspectos aplicados es la Entomo- logía Forense, de creciente interés en su aplicabilidad a procesos de índo- le judicial. Al igual que en las demás investigaciones forenses, el procedi- miento riguroso resulta fundamental en la práctica de esta disciplina. En este caso,
Annales de la Société Entomologique de France, 2011
The fi rst forensic entomological study performed in Portugal is presented. Two piglet (Sus scrof... more The fi rst forensic entomological study performed in Portugal is presented. Two piglet (Sus scrofa L.) carcasses were used to determine adult Calliphoridae activity on carrion over a period of 121 days, all along the end of spring and the summer, both in a shaded and a sunny site. Five decomposition stages were observed and a total of 10723 adult Calliphoridae, belonging to 11 species, were collected. Calliphora vicina, Calliphora vomitoria, Chrysomya albiceps and Lucilia caesar were the dominant species in this study. Decomposition was faster on the carcass exposed to the sun and the number of Calliphoridae specimens was higher there than in the shaded site. It was found a signifi cant effect of the decomposition stage in the number of specimens attracted to the carcass, as well as a signifi cant effect of the interaction between the decomposition stage and insolation regime. Calliphora and Lucilia species did not show preference for sunny or shaded areas. Important differences in the Calliphoridae community structure were found compared to other regions of the Iberian Peninsula, reinforcing the need of further studies in different environments and regions of this geographical area in order to collect information about the local necrophagous fauna used in forensic practice.
Technology Education and Development, 2009
Parasitology Research, 2013
Piophila Fallén, 1810 is a genus of small flies composed of two species: Piophila casei (P. casei... more Piophila Fallén, 1810 is a genus of small flies composed of two species: Piophila casei (P. casei ) (Linnaeus, 1758), worldwide distributed, and Piophila megastigmata (P. megastigmata ) McAlpine, 1978, recently referred in the Palaearctic Region, from the Iberian Peninsula. Both species share ecological niche and are very interesting for forensic purposes, since they are present in carrion in advance stages of decay and have been found to be related to human corpses. The immature stages of P. megastigmata have ever been described, so this paper gives the ultrastructural morphologies of all preimaginal stages of P. megastigmata studied by light microscopy and scanning electron microscopy (SEM). Particular attention is given to pseudocephalon features—antenna, maxillary palps, facial mask, etc.—cephalopharyngeal skeleton, anterior and posterior spiracles, tegumentary sculpturing, and anal division among others. A comparative analysis of the main distinguishing features is made in order to understand how those features evolve along the developmental process, while larvae II and III are morphologically similar to each other, the larva I shows particular features. Larvae of all stages and pupae are easily distinguishable from other Diptera of forensic importance just based on the presence of trichoid sensilla associated to respiratory slits, instead of peristigmatig tufts, as well as on thewell-known disposition of anal papillae. The shapes of both dorsal edge at the basal part of mouthhook and dorsal bridge of cephalopharyngeal skeleton, and the tegumental ornamentationmay be considered as good features to distinguish the Piophila species, especially for P. megastigmata and P. casei . At the SEM level, shape, number, and arrangement of oral combs, oral ridges, sensilla of maxillary palpus, papillae of anterior spiracle, scales of spiracular field, and posterior spiracles represent good features to distinguish P. megastigmata from P. casei, but further studies will be necessary in West-Paleartic specimens of latter species. The key for identifying third instar larvae of forensically important Piophilidae in the Iberian Peninsula has been updated to include P. megastigmata.
Micron, 2014
In forensic practice, the use of arthropod evidences to estimate the postmortem interval is a ver... more In forensic practice, the use of arthropod evidences to estimate the postmortem interval is a very good approach when the elapsed time from death is long, but it requires the correct identification of the specimens. This is a crucial step, not always easy to achieve, in particular when dealing with immature specimens. In this case, scanning electronic microscopy (SEM) can be useful, but the techniques used to preserve specimens in forensic practice are usually different from those used to prepare specimens for SEM studies. To determine whether forensic evidences preserving techniques are also compatible with SEM analysis, we have compared specimens of all the immature stages of Calliphora vicina Robineau-Desvoidy, 1830 (Diptera, Calliphoridae) preserved in 70% ethanol, with others prepared with aldehydic fixative techniques that are more appropriate for SEM studies. At the same time, two drying techniques have also been compared with both fixative techniques, the critical point drying and air-drying following with hexamethyldisilizane treatment (HMDS). Our results indicate that there are not basis against recommending the use of ethanol to preserve forensic entomological evidences and that both drying methods appear to offer good results for second and third instar larvae, although HMDS behaves better with eggs and pupae.
Uploads
Papers by Isabel Arnaldos