Thermal attributes of Chrysomya species

Abstract

The correct identification of forensically important arthropods for post‐mortem interval estimation is crucial, as the rate of larval development can vary substantially between species. The identification of forensically important blowflies of the genus Chrysomya (Diptera: Calliphoridae) may be hampered by their close morphological similarities, especially as immatures. The aim of this study was to establish whether genetically closely related blowfly species would share similar developmental profiles. This could permit the application of developmental data to a number of closely related species, including those for which thermodevelopmental studies are lacking. If Australian Chrysomya were found to share developmental profiles, identification of the blowfly specimen to a level beyond genus may not be necessary, or at least it may not be necessary to distinguish morphologically similar sister species. The three Chrysomya species studied were collected from the same geographical location (Cairns, Australia), reducing the effects of acclimation and population‐level genetic variation. The experimental conditions in this study were virtually identical, which enabled direct comparisons to be made among the species. Blowfly larval lengths were obtained for 24‐hourly intervals at constant temperatures of 25, 30, and 35 °C. The thermal preferences of newly‐hatched feeding larvae were determined by their positions on a temperature gradient apparatus. This study established that all three species investigated differed significantly in their developmental profiles, despite the genetic closeness of the sister species Chrysomya megacephala (Fabricius) and Chrysomya saffranea (Bigot). Because of this, genetic distance was not considered to be a useful factor for predicting thermodevelopment profiles of closely related species within a genus, and highlights the necessity for correct species identification.

Nocturnal Colonization Behavior of Blowflies (Diptera: Calliphoridae) in Southeastern Australia

“…C. vicina and Chrysomya rufifacies that colonized baits in their study are both common in Victoria during at least some of the months over which the study ran, although neither was encountered during this current project. There is certainly widespread evidence for differences in larval growth rates among blowfly species , and the same may apply to propensity for nocturnal activity.…”

Tracking Movement and Temperature Selection of Larvae of Two Forensically Important Blow Fly Species Within a “Maggot Mass”

“…rufifacies throughout their development, a temperature gradient apparatus, as utilized previously by Johnson and Nelson et al. , was used to generate a range of temperatures between 23 and 54 (±1)°C. The apparatus featured a sheet of copper fashioned into a tray designed to hold meat on which larvae can feed.…”

The uses of Chrysomya megacephala (Fabricius, 1794) (Diptera: Calliphoridae) in forensic entomology

“…Chrysomya megacephala has been observed in all months of the year in its native range [ 6 ], in a wide range of natural and modified habitats, in a variety of climates [ 74 ], at altitudes from sea level to 2 667 meters above sea level [ 75 ]. The range of body temperatures that C. megacephala prefers is quite broad, even compared to eight other species of blow fly [ 76 , 77 ]. Such catholic preferences further explain why this species has spread around the world so successfully ( Figure 2 ).…”