Darkness as factor influencing the oviposition delay in Calliphora vicina (Diptera: Calliphoridae) (original) (raw)
Related papers
Further observations on the nocturnal oviposition behaviour of blow flies (Diptera: Calliphoridae
Forensic Science International, 2001
Calculating the age of immature stages of blow flies showing the longest period of association with a dead body often gives a fairly accurate estimate of the post-mortem interval (PMI). Determination of the exact time of oviposition by these flies had generally been made in the light of the conventional belief that blow flies are neither active nor do they lay eggs during night. This method of estimating the time of oviposition was modified when Greenberg [J. Med. Entomol. 27 (1990) 807] reported nocturnal oviposition by three calliphorid species that are occasionally used as forensic indicators. However, a technical problem with his experiment, having long term consequences, was placement of the bait on the ground among bushes. This could have made it possible for the flies already resting near the bait to climb over the piece of meat and lay eggs. Though Greenberg’s experiment proves beyond any doubt that blow flies do lay eggs at night as well as by day, active attraction of these flies at night towards the oviposition medium had yet to be proved and the present experiment has been designed for this purpose.
Journal of Medical Entomology, 2007
The use of the postmortem interval (PMI) in practical applications of forensic entomology is based upon developmental data of blow flies (Diptera: Calliphoridae) generated under controlled environmental conditions. Careful review of the published forensic entomology data sets showed that experimental (environmental) parameters differed between studies. Despite the differences in study design, there are no empirical data on the effect of photoperiod on blow fly development; yet, photoperiod has been shown to alter some insect development and behavior among noncalliphorids. Consequently, will differences in photoperiod alter the developmental times of calliphorids, and thereby alter PMI estimates? To answer this question, we used a replicated design with precise temperature measurement to examine the effects of photoperiod on the forensically important blow fly Phormia regina (Meigen). We concluded that inaccurate temperature recordings by using set-chamber temperatures over rearing-container temperatures would have overshadowed any affect light had on development. Second, constant light increased variation in overall adult developmental time and significantly delayed development compared with cyclic light. Finally, not accounting for delayed development induced by photoperiod underestimated the initial empirical estimate of the PMI. These sources of variation need to be included in forensic estimates because this variation can compromise predictions of PMI based upon current data sets. Without pinpointing optimal photoperiods with which to test development, we must assume that potentially large sources of variability exist within current estimates of the PMI.
Applied Sciences
Necrophagous insects are indicators of corpse decay. Analyses of their development stages give us indications on the degree of decay of corpses and contribute to the determination of the post-mortem interval. The differences in structure, biochemical composition and nutritive capacity of the cadaveric substratum can impair the duration of the developmental stages and dimensions of the organisms that metamorphose. This work tackles the study of the development, in laboratory conditions, of Calliphora vicina in correlation with different nutritive substrates (from areas of the corpse strongly affected by the incipient attack of Diptera) in order to obtain preliminary data, aiming to determine the post-mortem interval.
Forensic science, medicine, and pathology, 2017
Published research has offered contradictory evidence of the occurrence of nocturnal oviposition by carrion-breeding blowflies, a behavior that can affect the interpretation of forensic estimates of a minimum post mortem interval (minPMI) by up to 12 hours, depending on latitude and season. The majority of published studies are from the northern hemisphere. Field experiments were conducted in South Africa and Australia that extend observations to species of the southern hemisphere. Various vertebrate carrion was exposed at night in summer under different lunar phases and/or artificial lighting, and in woodland and pasture areas. Three laboratory experiments were also conducted. No nocturnal oviposition occurred outdoors in Berry, Australia, but Lucilia cuprina, Lucilia sericata and Chrysomya megacephala laid eggs outdoors at night in Grahamstown and Durban, South Africa. In laboratory experiments L. sericata, L. cuprina, Chrysomya chloropyga and Chrysomya putoria laid eggs and Calli...
Revista Brasileira De Entomologia, 2006
Blowflies use discrete, ephemeral breeding sites for larval nutrition. After exhaustion of the food supply, the larvae disperse in search of sites to pupate or to seek other sources of food in a process known as post-feeding larval dispersal. In this study, some of the most important aspects of this process were investigated in larvae of the blowflies Chrysomya megacephala exposed to a variety of light: dark (LD) cycles (0:0 h, 12:12 h and 24:0 h) and incubated in tubes covered with vermiculite. For each pupa, the body weight and depth of burrowing were determined. Statistical tests were used to examine the relationship of depth of burrowing and body weight to photoperiod at which burrowing occurred. The study of burial behavior in post-feeding larval dispersing can be useful for estimating the postmortem interval (PMI) of human corpses in forensic medicine.