Survival and development of the forensically important blow fly, Calliphora varifrons (Diptera: Calliphoridae) at constant temperatures.
The influence of temperature on the development of the forensically important blow fly, Calliphora varifrons Malloch 1932 (Diptera: Calliphoridae), was investigated at seven constant temperatures ranging from 12 to 30 °C. C. varifrons completed development between 12 and 27 °C. At 30 °C larvae formed pupae but did not successfully emerge. Temperature significantly influenced development time, mortality, maximum larval length, and adult body size. Development time (larviposition to adult emergence) ranged from 16.65 ± 0.17 days at 27 °C to 49.93 ± 0.26 days at 12 °C. Development rate was essentially linear throughout the 12-27 °C temperature range. Linear estimates of lower developmental threshold and thermal requirement (K) for development of C. varifrons were 4.20 °C and 368.46 ± 26.38 K. At 30 °C, a slight inhibitory effect of high temperature on third instar development rate was observed followed by a rapid decline when subsequent development and survival ceased. Nonlinear estimates of lower developmental threshold for third instar development were comparatively higher (6.29 °C). Nonlinear estimates of optimal developmental temperature and upper lethal developmental threshold were 25.94 and 32.13 °C respectively. Mortality was high at both temperature extremes (12 and 27 °C) and lowest between 18 and 24 °C. Maximum larval length was inversely related to temperature. Adult body size was significantly smaller at 12 °C, peaked at 18 °C, and declined as temperatures increased. The species-specific development data presented are the first available for C. varifrons for use by forensic practitioners for estimation of minimum time since death.
Centre for Forensic Science M420, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia, sasha.voss@uwa.edu.au.
Sasha C
SC
Voss
David F
DF
Cook
Wei-Feng
WF
Hung
Ian R
IR
Dadour
D000818:Animals; D049628:Body Size; D004175:Diptera / Q000196:embryology / Q000254:growth & development*; D004772:Entomology; D044707:Forensic Sciences / Q000379:methods*; D007814:Larva / Q000254:growth & development; D016014:Linear Models; D008954:Models, Biological; D017711:Nonlinear Dynamics; D013696:Temperature; D013997:Time Factors