Estimating the pre-appearance interval from temperature in Necrodes littoralis L. (Coleoptera: Silphidae)

While estimating post-mortem interval from entomological evidence it is useful to divide it into two separate intervals: the pre-appearance interval (PAI) and the development interval in the case of immature insects and PAI and the presence interval in the case of adult insects. An accurate estimate of PAI is critically important particularly in the case of those insects which appear on remains late in decomposition. In this paper the possibilities of PAI estimation from temperature are evaluated in late-arriving, forensically important carrion beetle Necrodes littoralis. The relationship between PAI of adult and larval N. littoralis and temperature was modelled by using results of succession experiments in forests of Central Europe. In both stages PAI was found to be strongly, inversely dependent on mean daily ground level temperatures averaged for the duration of PAI. Several methods of PAI estimation were proposed and their accuracy was initially evaluated with external successional data.