Annual blowfly attraction and colonisation patterns of liver-baited traps and rabbit carcasses in Southern England

Despite numerous carrion decomposition and insect succession studies, fewer than ten have been published for the UK and none have been published in the past nine years that describe necrophagous insect communities. The aim of this research was to document the current colonisation and succession patterns in Southern England, to aid distribution datasets and forensic investigations (estimation of time since death). Liver-baited traps and rabbit carcasses were placed outside monthly from April 2015 for a year. Weather data, observations and primary colonising calliphorid flies were collected daily, the latter using sticky traps placed near the rabbit and using a vial to catch flies on the rabbit itself. In summer, peak insect activity occurred within two days and decomposition was completed within 7-9 days. In January to March, this peak was extended to >11 days and the carcasses had not dried out within a month. Calliphora vicina Robineau-Desvoidy, 1830 always dominated both carrion and liver-baited traps, however differences between species collected from traps and carcasses were observed. Lucilia illustris (Meigen, 1826) and Lucilia caesar (Linnaeus, 1758) were more often identified than Lucilia sericata (Meigen, 1826), particularly in spring, however only L. sericata oviposited on carcasses. The potential impact of changes in calliphorid diversity for forensic investigations using insect succession and development indicate the need for continued monitoring of local population dynamics, using suitable model carcasses, to ensure we have a robust, current datasets. The British Entomology and Natural History Society