ABSTRACT
In addition to the scarcity of forensic entomology baseline data on oviposition of necrophagous insects and completion of their life cycles in the Borneo region, similar data derived from caves remain unreported. Since entomological baseline data can differ from one biogeoclimatic region to another, the lack of such data would limit the practical values of applying entomological evidence in estimating minimum postmortem interval (mPMI). Therefore, this present research that investigated oviposition and completion of life cycles of necrophagous flies infesting rabbit carcasses decomposing in Mount Kapur Cave and its surrounding forest habitat in Kuching, Sarawak merits forensic consideration. In general, 13 taxa of necrophagous flies were identified viz. Hypopygiopsis violacea, Hypopygiopsis fumipennis, Hemipyrellia ligurriens, Hemipyrellia tagaliana, Chrysomya megacephala, Chrysomya villeneuvi, Chrysomya rufifacies, Chrysomya chani, Chrysomya pinguis, Chrysomya nigripes, Ophyra spinigera and Ophyra chalcogaster, as well as unidentified Sarcophagidae. In addition, Hyp. violacea and Hyp. fumipennis were the two earlier necrophagous flies that oviposited in all rabbit carcasses decomposing in both habitats. While all these necrophagous flies were observed infesting carcasses in Mount Kapur Cave, Hem. ligurriens and Hem. tagaliana were not found infesting carcasses in the surrounding forest habitat. Complete life cycles for six and five different necrophagous fly species were successfully observed in Mount Kapur Cave and its surrounding forest habitat, respectively. Significant delay in oviposition, as well as longer durations for completing the life cycles in several necrophagous fly species were observed in Mount Kapur Cave when compared with those of surrounding forest habitat (p < 0.05). These findings deserve consideration as the first ever forensic empirical baseline data on oviposition and completion of life cycles for necrophagous flies in Sarawak as well as in a cave habitat, in view of its practical values for estimating mPMI for forensic practical caseworks.
Subject(s)
Caves , Diptera/classification , Forensic Entomology , Animals , Cadaver , Female , Larva , Malaysia , Oviposition , RabbitsABSTRACT
@#In addition to the scarcity of forensic entomology baseline data on oviposition of necrophagous insects and completion of their life cycles in the Borneo region, similar data derived from caves remain unreported. Since entomological baseline data can differ from one biogeoclimatic region to another, the lack of such data would limit the practical values of applying entomological evidence in estimating minimum postmortem interval (mPMI). Therefore, this present research that investigated oviposition and completion of life cycles of necrophagous flies infesting rabbit carcasses decomposing in Mount Kapur Cave and its surrounding forest habitat in Kuching, Sarawak merits forensic consideration. In general, 13 taxa of necrophagous flies were identified viz. Hypopygiopsis violacea, Hypopygiopsis fumipennis, Hemipyrellia ligurriens, Hemipyrellia tagaliana, Chrysomya megacephala, Chrysomya villeneuvi, Chrysomya rufifacies, Chrysomya chani, Chrysomya pinguis, Chrysomya nigripes, Ophyra spinigera and Ophyra chalcogaster, as well as unidentified Sarcophagidae. In addition, Hyp. violacea and Hyp. fumipennis were the two earlier necrophagous flies that oviposited in all rabbit carcasses decomposing in both habitats. While all these necrophagous flies were observed infesting carcasses in Mount Kapur Cave, Hem. ligurriens and Hem. tagaliana were not found infesting carcasses in the surrounding forest habitat. Complete life cycles for six and five different necrophagous fly species were successfully observed in Mount Kapur Cave and its surrounding forest habitat, respectively. Significant delay in oviposition, as well as longer durations for completing the life cycles in several necrophagous fly species were observed in Mount Kapur Cave when compared with those of surrounding forest habitat (p < 0.05). These findings deserve consideration as the first ever forensic empirical baseline data on oviposition and completion of life cycles for necrophagous flies in Sarawak as well as in a cave habitat, in view of its practical values for estimating mPMI for forensic practical caseworks.
ABSTRACT
Influence of citronella and chlorpyrifos on oviposition and duration for completing life cycles for Chrysomya megacephala and Chrysomya rufifacies infesting decomposing rabbit carcasses was studied. Male rabbit carcasses (n = 12) were equally divided into control, citronella- and chlorpyrifos-treated groups, and left to decompose for 14 consecutive days. C. megacephala was the first necrophagous fly oviposited in all control and citronellatreated carcasses followed by C. rufifacies. Although initial oviposition of C. megacephala was delayed (4-6 hours) in citronella-treated carcasses (P andlt; 0.05), prolongation in completing its life cycle was not observed. Neither delayed initial oviposition nor prolonged life cycle for C. rufifacies in citronella-treated carcasses was observed. Oviposition was delayed for chlorpyrifos-treated carcasses (0.42 g/L), and eclosion of eggs remained unsuccessful. The findings deserve consideration because these chemicals are easily accessible and can be used by cunning criminals to confuse forensic entomologists while estimating minimum postmortem interval.
ABSTRACT
@#Influence of citronella and chlorpyrifos on oviposition and duration for completing life cycles for Chrysomya megacephala and Chrysomya rufifacies infesting decomposing rabbit carcasses was studied. Male rabbit carcasses (n = 12) were equally divided into control, citronella- and chlorpyrifos–treated groups, and left to decompose for 14 consecutive days. C. megacephala was the first necrophagous fly oviposited in all control and citronellatreated carcasses followed by C. rufifacies. Although initial oviposition of C. megacephala was delayed (4-6 hours) in citronella-treated carcasses (P < 0.05), prolongation in completing its life cycle was not observed. Neither delayed initial oviposition nor prolonged life cycle for C. rufifacies in citronella-treated carcasses was observed. Oviposition was delayed for chlorpyrifos-treated carcasses (0.42 g/L), and eclosion of eggs remained unsuccessful. The findings deserve consideration because these chemicals are easily accessible and can be used by cunning criminals to confuse forensic entomologists while estimating minimum postmortem interval.
ABSTRACT
Considering that crimes against animals such as illegal killing and cruelty have been alarmingly increasing and since burning is one of the common ways for disposing cadavers, ability to estimate minimum postmortem interval (PMI) using entomological data merits consideration. Chrysomya megacephala and Chrysomya rufifacies are common necrophagous species recovered from cadavers in many countries including Malaysia. Specific studies focusing on the oviposition and developmental patterns of both species on cadavers manifesting different levels of burn as described by the Crow-Glassman Scale (CGS) remain scarce. In four replicates, rabbit carcasses were burned to CGS levels #1, #2 and #3 by varying the amount of petrol used and duration of burning. Oviposition by C. megacephala and C. rufifacies was delayed by one day in the case of carcasses burned to the CGS level #3 (p<0.05) when compared with that of controls. Such delay in oviposition was not observed in the CGS level #1 and #2 carcasses. No significant differences (p>0.05) in the duration of development were found between control and burned carcasses. These findings deserve consideration while estimating minimum PMI since burning as a mean for disposing animal and human cadavers is gaining popularity.
