Temperature-dependent development of the parasitoid Tachinaephagus zealandicus on five forensically important carrion fly species

Abstract

The influences of temperature and host species on the development of the forensically important parasitoid Tachinaephagus zealandicus Ashmead (Hymenoptera: Encyrtidae) were studied at six constant temperatures in the range of 15-30 degrees C. T. zealandicus completed development successfully between 15 degrees C and 27 degrees C on five species of Calliphoridae, Calliphora albifrontalis Malloch, Calliphora dubia Macquart, Lucilia sericata Meigen, Chrysomya rufifacies Macquart and Chrysomya megacephala Fabricius. No adult parasitoids emerged from any of the host species reared at 30 degrees C. Temperature and host species significantly influenced development time, emergence success and progeny size. Development was significantly longer on Ch. megacephala and Ch. rufifacies at 18-24 degrees C and significantly longer on Ch. rufifacies and C. albifrontalis at 15 degrees C and 27 degrees C. Parasitoid emergence success was greatest at 21 degrees C, declined at the temperature extremes (15 degrees C and 27 degrees C) and was significantly lower on Ch. megacephala and Ch. rufifacies than on the three other host species. Progeny numbers per host pupa were highest at 21-24 degrees C, declined on either side of this temperature range and were significantly lower on L. sericata, Ch. rufifacies and Ch. megacephala than on either C. dubia or C. albifrontalis. An effect of host species on sex ratio was only observed at 27 degrees C, at which a higher proportion of T. zealandicus females emerged from Ch. megacephala and Ch. rufifacies than from the other host species. The thermal requirements for development (developmental thresholds, thermal constant, optimum temperature) of T. zealandicus in each host species were estimated using linear and non-linear models. Upper and lower developmental thresholds ranged between 29.90 degrees C and 31.73 degrees C, and 9.73 degrees C and 10.08 degrees C, respectively. The optimum temperature for development was estimated at between 25.81 degrees C and 27.05 degrees C. Given the significant effect of host species on development time, the use of parasitoid-host-specific developmental data in forensic application is recommended.

Development of the gregarious ectoparasitoid Nasonia vitripennis using five species of necrophagous flies as hosts and at various developmental temperatures

“…Rather, such data are needed from all hosts of relevance to the case conditions. This is readily apparent when comparing the development times for N. vitripennis when reared on the five species of flies used as hosts in this study, and when the data are compared to previous developmental studies using this wasp with a range of fly hosts (Grassberger & Frank, 2003;Voss et al, 2010). Host species can also magnify differences associated with multi-and superparasitism involving this parasitoid.…”

“…Wasp development rates from egg to adult emergence at any given temperature show low variation among siblings (Whiting, ; Rivers & Denlinger, 1995a), and because little outbreeding occurs with N. vitripennis in patchy environments like carrion (Werren, ), developing wasp progeny in multiple puparia collected at a crime scene are likely related. Recent investigations (Grassberger & Frank, ; Mello & Coelho, ; Mello et al., ; Voss et al., ) have attempted to examine several key features of wasp development, providing estimates of developmental rates (from egg to adult) and developmental thresholds using an array of fly hosts at different temperatures, and at varying host to parasitoid ratios. Each of these studies provides diligent analyses of the collected data but each also suffers from similar experimental design flaws: none controlled for the length of exposure of parasitoids to hosts based on the biology of N. vitripennis , and most did not use a 1:1 host to parasitoid ratio.…”

The Community of Hymenoptera Parasitizing Necrophagous Diptera in an Urban Biotope

“…These five species colonized a broad spectrum of Diptera hosts associated with decomposing carcasses, including Calliphoridae, Muscidae, Fanniidae, and Sarcophagidae (Laing 1937; Whiting 1967; Rueda and Axtell 1985; Blanchot 1992; Goulet and Huber 1993; Ferreira De Almeida et al 2002; Voss et al 2010). …”

“…Encyrtidae is one of the most important chalcidoid families for biological control (Goulet and Huber 1993; Voss et al 2010). Species are gregarious endoparasitoids of eggs, third instar larvae, and postfeeding or prepupae of several forensically important Diptera (Fanniidae, Muscidae, Calliphoridae) (Goulet and Huber 1993; Ferreira De Almeida et al 2002; Voss et al 2010).…”

“…Species are gregarious endoparasitoids of eggs, third instar larvae, and postfeeding or prepupae of several forensically important Diptera (Fanniidae, Muscidae, Calliphoridae) (Goulet and Huber 1993; Ferreira De Almeida et al 2002; Voss et al 2010). In 2003, the presence of T. zealandicus was detected in northern Italy during September (Turchetto et al 2003; Turchetto and Vanin 2004).…”