Post-feeding larval behaviour in the blowfly, Calliphora vicina: effects on post-mortem interval estimates.
Using the rate of development of blowflies colonising a corpse, accumulated degree hours (ADH), or days (ADD), is an established method used by forensic entomologists to estimate the post-mortem interval (PMI). Derived from laboratory experiments, their application to field situations needs care. This study examines the effect of the post-feeding larval dispersal time on the ADH and therefore the PMI estimate. Post-feeding dispersal in blowfly larvae is typically very short in the laboratory but may extend for hours or days in the field, whilst the larvae try to find a suitable pupariation site. Increases in total ADH (to adult eclosion), due to time spent dispersing, are not simply equal to the dispersal time. The pupal period is increased by approximately 2 times the length of the dispersal period. In practice, this can introduce over-estimation errors in the PMI estimate of between 1 and 2 days if the total ADH calculations do not consider the possibility of an extended larval dispersal period.
Arnott
Sophie
S
Department of Forensic Science and Drug Monitoring, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, United Kingdom.
Turner
Bryan
B
D000818:Animals; D004175:Diptera; D004772:Entomology; D005247:Feeding Behavior; D018732:Forensic Anthropology; D006801:Humans; D007814:Larva; D023421:Models, Animal; D011180:Postmortem Changes; D013552:Swine