ABSTRACT
In forensic entomology practice, it is more common to use raw animal tissue to breed dipteran larvae and it often brings unpleasant odour in the laboratory. Few studies suggested the use of synthetic diets, mainly agar-based media, as alternatives to animal tissue but it is rarely being practiced in forensic entomology laboratory. The present study observed the growth of a forensically important fly, Megaselia scalaris (Loew) on raw cow’s liver, nutrient agar, casein agar and cow’s liver agar. A total of 100 M. scalaris eggs were transferred each into the different media and placed in an incubator at 30°C in a continuous dark condition. Data on length and developmental period were collected by randomly sampling three of the largest larvae from each rearing media, twice a day at 0900 and 1500 hours until pupariation. M. scalaris larvae reared on raw cow’s liver recorded the highest mean length (4.23 ± 1.96 mm) followed by cow’s liver agar (3.79 ± 1.62 mm), casein agar (3.14 ± 1.16 mm) and nutrient agar (3.09 ± 1.11 mm). Larval length in raw liver and liver agar were significantly different from those in nutrient and casein agar (p < 0.05). Larvae bred in liver agar and raw liver recorded the shortest larval duration before entering the post-feeding stage (89 hours), followed by nutrient agar (119 hours) and casein agar (184 hours). Total developmental time from oviposition until adult emergence for M. scalaris in liver agar and raw liver was approximately 163 hours. All puparia in nutrient agar and casein agar failed to hatch. This research highlighted the potential use of cow’s liver agar as an alternative diet of raw liver to culture M. scalaris in laboratory.
ABSTRACT
Determination of races in the analysis of hair on scalp is one of the challenges faced in forensic analysis to identify victims, suspects and crime scene. This study aimed to determine the differences among the two main races in Malaysia which included Malay and Chinese, through the examination of the characteristics of hair. These includes general features of the hair, patterns of cuticle, colors, cortex pigment distribution and characteristics of medulla - types, thickness and medulla index. This study was carried out by using a light microscope and consisted of five steps, which were sample preparation, examination of common features of hair, preparation and examination of cuticle scales matrix, cortex and medulla. Result showed that most of the Malay have dark brown pigments while Chinese have pigments of light brown color. We also noted that thickness of medulla can also be used to differentiate between Malay and Chinese where average values for Malay and Chinese are 7.59 ± 1.45 μm and 9.12 ± 1.85 μm, respectively. The average values of medulla index for Malay and Chinese were noticeably different at 0.17 ± 0.02 μm and 0.18 ± 0.02 μm, respectively. However, textures, thickness of hair, patterns of cuticle scales, and types of medulla do not show any significant difference between Malay and Chinese. In conclusion, this study has shown that pigment colors, thickness of medulla and medulla index are important characteristics that can be used to determine race