الفهرس 
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Abstract
The aim of this thesis was to assess the utility of insect DNA in two main areas insect identification and determination time of death using traditional and molecular techniques.
For identification of Sarcophaga fly species, five species of different Sarcophagaid were collected from 2 countries Egypt: (Sarcophaga ruficornis (Qena), Sarcophaga argyrostoma (Benha) and Wohlfahrtia magnifica (Qena & Benha)) and USA: (Blaesoxipha plinthopyga and Sarcophaga bullata) during 2016 and 2017 and were identified using morphology-based keys. This traditional method was very difficult due to the similarity and simplicity in external morphology among the Sarcophaga flies. To overcome this problem, cytochrome oxidase I was used. MtDNA phylogeny of Sarcophagaid fly species strongly resulted in support separation of the species included in this study into two clades (Sarcophaga and Wohlfahrtia). The separation of these two groups is further supported morphologically based on the morphological character of the abdomen for each one. The deeper analysis showed a strong support for inter-specific relationships between the Sarcophaga species according to the location for each one collected. However, it failed to differentiate between Wohlfahrtia magnifica collected from two different regions in Egypt (Benha and Qena).
Because of the poor data obtained from the COI to differentiate between the same species from different regions, we tested an Inter-simple sequence repeat (ISSR) microsatellite technique as a genotyping technique for characterization of genetic relatedness among populations using seven fluorescently labeled primers to target the region between identical microsatellites. Our results demonstrated that ISSR markers are promising for the molecular identification of the Sarcophagid flies. With the advantages of high accuracy, rapid and convenient, (six of seven) ISSR markers were able to differentiate between the same species collected from 2 different regions in Egypt (Benha and Qena).
Regarding to genome size, there were differences in genome size both within and between species of Egyptian Sarcophagidae when immature samples are analyzed. Genome sizes of Wohlfahrtia magnifica ranged from 1040.56 in Edfo to 1229 Mbp in Aswan, the Sarcophaga argyrostoma genome was 863 Mbp in Benha to 1045.87 Mbp in Edfo and finally the genome size of Sarcophaga dux was 1552.17 Mbp as estimated for one individual. These estimates are useful not only as preliminary information for some molecular and genomic studies, but also for determination of the species through immatures providing faster identification method than sequencing. However, the genome size was efficient to differentiate between the sexes of B. plinthopyga during their larval stage.
For determination the time of death by estimation the age of the larvae found on the corpse, Blaesoxipha plinthopyga (Wiedemann) (Diptera: Sarcophagidae) was reared at the same conditions (at 25 0C, 50% relative humidity and 14:10 light:dark cycle) on different substrates that are likely to be encountered at indoor and outdoor scenes Wet Sand, Dry Sand, Clothes and Carpet to estimate the minimum post-mortem interval (mPMI), through information about progression of larval size, developmental stadia on different substrates and miRNA variations among different ages of larvae of B. plinthopyga.
Larval growth of B. plinthopyga showed a pattern of rapid increase in length and area, followed by shrinking prior to pupariation. The first instar was relatively small 4.83 ± 0.46 mm in length and 3.51 ± 0.73 mm2 in area, with the developmental transition from this stage to then next observe within 12 h. The second instar was measuring 7.99 ± 0.64 mm in length and 12.81 ± 2.11 mm2 in area, with 16.8 ± 6.2 h duration at this stage. The size of the feeding third instar was 15.02 ± 1.69 mm in length and 41.38 ± 7.53 mm2 in area with 54 ± 13.7 h duration at this stage. The size of the post-feeding third instar was the largest, measuring 15.51 ± 1.65 mm in length and 52.46 ± 5.62 mm2 in area, with 60 ± 18.97 h duration at this stage.
Moreover, the results revealed that substrate and humidity/moisture significantly affected minimum development times of B. plinthopyga during their larval and intra-puparial stages without affecting the sexes differently; though a female bias in sex ratio was observed consistently. Average minimum larval developmental times were 160 to 179 h with a significantly faster development in Carpet than in Clothes. Similarly, average minimum intra-puparial developmental times were 331 to 352 h; fastest on Carpet and the slowest in Dry Sand. In addition, the largest difference observed between female and male was recorded in Carpet (58.84 : 41.16) compared to the lowest in the Clothes with a proportion (54.27 : 45.73).
While the age determination of B. plinthopyga larvae by the morphological changes and variation of length and width was not completely accurate, miRNA was applied using quantitative real-time polymerase chain reaction (qRT-PCR) as a potential method for age estimation of 3rd larval stage. The 2 loci studied herein resulted in a relatively variation in age overestimation had the potential to improve the precision of sarcophagid fly age estimates, and thus PMI estimates.