Tang Rui, Wan Lihua, Lü Zhou, et al. Time of invading and colonizing of necrophagous flies in Chongqing and its significance in forensic application. [J]. Journal of Chongqing Medical University 41(10):1060-1064(2016)
Tang Rui, Wan Lihua, Lü Zhou, et al. Time of invading and colonizing of necrophagous flies in Chongqing and its significance in forensic application. [J]. Journal of Chongqing Medical University 41(10):1060-1064(2016) DOI: 10.13406/j.cnki.cyxb.000680.
Time of invading and colonizing of necrophagous flies in Chongqing and its significance in forensic application
Objective:To study the time of invading and colonizing of necrophagous flies on mouse carcasses in Chongqing and to explore its application and significance in death related cases. Methods:Eggs oviposited by blowflies in natural environment were reared for 3 generations. Mice were killed and placed in research field. At the same time
two stock colonies of blowflies were released at the different distances from carcasses and marked in different colors. The effects of different distances from original habitats to carcasses were compared. Effects of different seasons and different time points on invading and colonizing of flies were also observed. This study was replicated in same season. Results:The invasion interval of flies released 100 m away from the carcasses was 152.50(117.50
555.75)min showed by median M(Q
1
Q
3
)
and the colonization interval was 253.00(186.75
720.50)min. The colony released 1 000 m away did not invade the carcasses. The comparison about the invasion interval and colonization interval in different time points showed significant differences among some groups. The invasion intervals of 9:00
14:00
21:00 were T
ii9
(100.67±61.59)min
T
ii1
4(133.00±32.39)min
T
ii21
(683.83±119.38)min;the colonization intervals of 9:00
14:00
21:00 were T
ci9
(267.50±201.97)min
T
ci14
(198.00±39.41)min
T
ci21
(842.83±163.63)min. The comparison between 3 time points(T
ii9
vs. T
ii14
vs. T
ii21
H=11.942
P=0.003;T
ci9
vs. T
ci14
vs. T
ci21
H=11.380
P=0.003)and the comparison between 9:00 with 21:00(T
ii9
vs. T
ii21
H=8.308
P=0.004
Tci9 vs. Tci21
H=8.308
P=0.004)and the comparison between 14:00with 21:00(T
ii14
vs. T
ii21
H=8.308
P=0.004
T
ii14
vs. T
ii21
H=8.308
P=0.004)were significantly different. The invasion interval and colonization intervals of 21:00 were delayed compared with those of 9:00 and 14:00. The invasion interval and the colonization intervals of spring and summer and autumn were(293.83±314.74)min
(289.00±206.30)min
(334.67±365.76)min;(339.83±331.48)min
(489.17±214.07)min
(479.33±444.22)min. The comparison about the invasion interval and colonization intervals in different seasons showed no difference in comparison of 3 seasons(Tiisprvs. Tiisumvs. Tiiaut
H=0.573
P=0.751;Tcisprvs. Tcisumvs. Tciaut
H=1.556
P=0.459). The seasons did not impact on invasion interval and colonization interval. Conclusion:The invasion interval and colonization interval are affected by different distances from original habitats of flies to carcasses. Flies will not invade carcasses when the original habitats of flies are too far away from carcasses. The change of season will not impact on invasion interval and colonization interval in Chongqing;the main different is day and night;the night could delay invasion interval and colonization interval. This research is important for determining postmortem interval accurately according to actual circumstance in the crime scene.
关键词
法医昆虫学死亡时间推断侵袭尸体蝇类建群
Keywords
forensic entomologyestimation of postmortem intervalinvading carcassescolonization of flies