Studies On Development Of Diplonevra Peregrina(Wiedemann) Under Constant Temperature And Natural Condition Indoors

Diplonevra peregrina(Wiedemann)belongs to Diplonevra Lioy Genus in the family Phoroidea and distributes widely in our country.It is the first phorid species recorded by binomial nomenclature in China.Their larvae are saprophagous or necrophagous.The species is a common and important fly in forensic science and plays an important role on estimaion of postmortem interval.Under constant temprature and humidity and indoor natural conditions.The immature developmental periods of D.peregrina were observed,larval body length was measured by the Olympus 3D reconstruction image processing system,pupal development was observed by vivisecting,the threshold temperature and effective accumulated temperature of immatures were also measureed in this study which aims at accumulating developmental biology information of D.peregrina and laying the foundation for estimation of postmortem interval using necrophagous phorid in our country.The main results are as follows:1.Developmental period of D.peregrina of eggs,larvae and pupae are shortened with the increase of temperature.At 24?,27 ?and 30?,the average minimum developmental time of eggs are 17.86 ± 0.44 h,15.13 ± 0.39 h,12.28 ± 0.48 h,respectively;the average minimum developmental time of larvae are 158.88 ± 16.50 h,127.03 ± 4.72 h,107.53 ± 3.80 h,respectively;the average minimum developmental time of female pupae are 376.37 ± 13.64 h,311.56 ± 8.53 h,264.56 ± 9.46 h,respectively;while they are 367.66 ± 19.19 h,308.74 ± 6.45 h,255.04 ± 4.37 h for male pupae,respectively.At 33?,eggs can not develop.2.At 24?,27 ?and 30?,the fitted equations about the larval body length and developmental durations of D.peregrina are Y=?0.299?0.208X?0.001X2(R2=0.929),Y=?0.053?0.224X?0.001X2(R2=0.934)and Y=0.614?0.19X?0.001X2(R2=0.951),respectively.3.Under indoor natural conditions,two equations of linear regression(Y1=0.862?0.848X1,Y2=27.604?1.46X2)were established between the total effective temperature and the body length of larvae.4.According to visible external morphological characteristics of naked pupae of D.peregrina,pupal ages could be devided into 8 stages: prepupa,protruding of respiratory horns,segmentation of thorax and abdomen,differentiation of dorsal muscle of thorax and segment of abdomen,yellow eyes,colorable dorsum of thorax,colorable tergum of abdomen,black eyes.5.At conditions of constant temperature and indoor temperature,the threshold temperature and effective accumulated temperature about eggs,larvae and pupae of D.peregrina were measured.The results show that D.peregrina develops much faster at indoor natural conditions than at constant temperature.At constant temperature,the threshold temperature about eggs,larvae and pupae of D.peregrina are 11.22 ± 2.52?,11.40 ± 0.46 and 11.34 ± 1.35? ?,respectively;the effective accumulated temperature are 232.54 ± 36.83h·?,1994.56 ± 57.68h·? and 4808.67 ± 410.17h·?,respectively.Under indoor temperature,the threshold temperature about eggs,larvae and pupae are 14.78 ± 1.25?,15.88 ± 0.9 ?and 16.04 ± 0.2?,respectively;the effective accumulated temperature are 176.24 ± 19.52h·?,1571.95 ± 158.07h·? and 3516.41 ± 100.46h·?,respectively.