Constant Temperature Of Diazepam On The Larvae Of Parasa-rcophaga Crassipalpi And Its Forensic Significance

Objective: To study the growth and development of Parasarcophagacrassipalpi changes in diazepam, experimental index to explore the regularityof change with time, so as to infer that the time interval between death andforensic toxicology insects provide a reference.Methods: Adult Parasarcophaga crassipalpi were collected from theoutdoors. The experiment was done with offspings of the third generation.Four domestic rabbits were prepared. The first one was used as a control andthe other three were given diazepam via ear vein according to the differentdosages. All the rabbits were sacrificed by hitting the head quickly30minterslater. The muscles from the four rabbits were take down and stored. They weremarked with M0,M1,M2and M3.They were reared successively in biochemicalculture boxes under the temperature of28℃. The humidity, photoperiod andfood supply were kept unchanged during the entire study. From then on, eggswere placed onto each group of test muscle tissues to initiate the test colonies.When larvae were laid,10of them were randomly sampled from eachgroup at12h intervals until the beginning of the prepuparial stage. The10larvae were fixed in boiling water and then preserved in70﹪alcohol mixedwith glycerine.Preparation and observation of experimental specimenThe samples were taken out from the preserved solution and liquid ofsurface was blotted up by the filter paper.Stick some holes on the abdomensof specimen with a pin, then fill them with10%KOH to corrod their innards.24hours later, press the larvae gently until they excreted the corroded tissues.Washed several times in clean water, it was taken apart that the section ofscolex subsequent the2nd section thoracic part under the stereomicroscopewith anatomical scissors and scalpel. The specimens were dehydrated with alcohol from30%to100%gradudlly. After being transparent withdimethlbenzene, the specimens were observed and photographed. Finally theindexes including areas of different parts of cephalopharyngeal skeleton hadbeen given by digital image processing equipment.Use analysis of variance when made statistical analysis different indexeof cephalopharyngeal skeleton. Finally the data were statistically curved withExcel.Results:1Morphological characteristics of cephalopharyngeal skeleton1.1Under the same temperature condition, the color of each part ofcephalopharyngeal skeleton becomed deeper than ever during the growth oflarvae. The degree and range of chitinazation in cephalopharyngeal skeletonincreased in accordance with the development. Parasarcophaga crassipalpilarvae mouth bone without attached.1.2In the same temperature, the area of mouth hook increased periodically. InM0, M1, M2and M3group, the mouth hook area in phased growth whenreplacement mouth hook area changing significant. Each larva after maximummouth hook area with the extension of time, the basic remain unchanged.When12h, the larvae for minimal, mouth hook area between groups minimummouth hook area exist significant difference (P<0.05). M1, M2, and M3grouplarvae36h reaches maximum mouth hook area; M0group larvae48h reachesmaximum. The larvae for minimal, mouth hook area between groupsmaximum mouth hook area has no obvious difference (P>0.05).1.3In the same temperature, the sclerotized area and the average opticaldensity of mouth hook increased periodically. In M0, M1, M2, and M3group,the sclerotized area and the average optical density of mouth hook in phasedgrowth when replacement the sclerotized area and the average optical densityof mouth hook changing significant. Each larva after maximum the sclerotizedarea and the average optical density of mouth hook with the extension of time,the basic remain unchanged. When12h, the larvae for minimal the sclerotizedarea and the average optical density of mouth hook between groups minimum mouth hook area exist significant difference (P<0.05). M0group larvae96hreaches maximum; M1group larvae84h reaches maximum; M2and M3grouplarvae72h reaches maximum the sclerotized area and the average opticaldensity of mouth hook. The larvae for minimal, mouth hook area betweengroups maximum the sclerotized area and the average optical density of mouthhook has no obvious difference (P>0.05).1.4In the same temperature, the area of pharyngeal sclerite increasedperiodically. In M0, M1, M2and M3group, the pharyngeal sclerite area inphased growth when replacement pharyngeal sclerite area changing significant.Each larva after maximum pharyngeal sclerite area with the extension of time,the basic remain unchanged. When12h, the larvae for minimal, pharyngealsclerite area between groups minimum pharyngeal sclerite area existsignificant difference (P<0.05). M1, M2and M3group larvae36h reachesmaximum pharyngeal sclerite area; M0group larvae48h reaches maximum.The larvae for minimal, pharyngeal sclerite area between groups maximumpharyngeal sclerite area has no obvious difference (P>0.05).1.5In the same temperature, the sclerotized area and the average opticaldensity of pharyngeal sclerite increased periodically. In M0, M1, M2and M3group, the sclerotized area and the average optical density of pharyngealsclerite in phased growth when replacement the sclerotized area and theaverage optical density of pharyngeal sclerite changing significant. Each larvaafter maximum the sclerotized area and the average optical density ofpharyngeal sclerite with the extension of time,the basic remain unchanged.When12h, the larvae for minimal the sclerotized area and the average opticaldensity of pharyngeal sclerite between groups minimum pharyngeal scleritearea exist significant differefce (P<0.05). M0group larvae96h reachesmaximum; M1group larvae84h reaches maximum; M2andM3group larvae72hreaches maximum the sclerotized area and the average optical density ofpharyngeal sclerite. The larvae for minimal, pharyngeal sclerite area betweengroups maximum the sclerotized area and the average optical density ofpharyngeal sclerite has no obvious difference (P>0.05). 2The change of larvea’s weight and length2.1The change of larvae’s weightIn the same temperature, the change of larvae’s weight at three agesincreased gradually. When36h, the larvae’s weight between groups existsignificant difference (P<0.05). M0group larvae96h reaches maximumweight; M1group larvae84h reaches maximum; M2, M3group larvae72hreaches maximum. The larvae’s weight between groups maximum has obviousdifference (P<0.05), M3>M2>M1>M0.2.2The change of larvae’s weightThe change of larvae’s weight has the same trends with the larvae’slength.Conclusions:1Diazepam increased the larvea’s weight and length.2Larvea’s mouth hook area, sclerotized area and the average optical densityincreased periodically. Diazepam has no obvious effect to the maximum ofmouth hook area, sclerotized area and the average optical density.3Larvae pharynx bone area and mouth hook area trend is same. The averageoptical density and the sclerotized area of pharyngeal scleritr grew graduallyall the time and almost at the speed to the third instars.