Developmental rates of immatures of three Chrysomya species (Diptera: Calliphoridae) under the effect of methylphenidate hydrochloride, phenobarbital, and methylphenidate hydrochloride associated with phenobarbital

Abstract

Entomotoxicology is focused on obtaining data on necrophagous entomofauna, for criminal investigations purposes. This study aimed to evaluate the effect of different concentrations of methylphenidate hydrochloride, phenobarbital, and their association on the developmental rate, larval and pupal survivorship, and the interval of emergence of adults of Chrysomya albiceps (Wiedemann), Chrysomya megacephala (Fabricius), and Chrysomya putoria (Wiedemann) (Diptera: Calliphoridae). Considering the therapeutic dose (TD) of methylphenidate hydrochloride (0.29 mg/Kg), the concentrations tested were 10× TD, 50× TD, and 100× TD. For phenobarbital, the concentrations used were 1× TD (=150 mg/Kg), 3.3× TD, and 6.7× TD. For the association of the drugs, the combinations used were 10× TD-methylphenidate hydrochloride plus 1× TD-phenobarbital, 50× TD-methylphenidate hydrochloride plus 3.3× TD-phenobarbital, and 100× TD-methylphenidate hydrochloride plus 6.7× TD-phenobarbital. The control group, without addition of drug, was maintained under the same conditions of temperature (25 ± 1 °C), humidity (70 ± 10%), and photoperiod (12 h). Specimens of each group were weighed every 12 h until pupariation. The developmental rate of the three Chrysomya species immatures was monitored. For C. albiceps the developmental time was delayed in 24 h for methylphenidate hydrochloride group and in 12 h for the phenobarbital and the drugs association groups. The effect was observed only at specific ages for C. megacephala, without altering the developmental time. For C. putoria, the developmental time was delayed in 12 h for methylphenidate hydrochloride group and in 24 h for the phenobarbital and the drugs association groups. The emergence interval was similar among all experimental groups, but larval and pupal viabilities were affected in different ways.

Developmental Times of Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) at Constant Temperatures and Applications in Forensic Entomology

“…The developmental rate of C . megacephala at constant temperatures has been reported previously , but the developmental data were documented at a single constant temperature, which makes it difficult to estimate the PMI min under ambient conditions. Richards et al studied the developmental time of C .…”

Intraguild predation influences oviposition behavior of blow flies (Diptera: Calliphoridae)

“…The oviposition preference of female blow flies affects the estimates of the minimum postmortem interval, by delaying or hastening egg laying (Yang and Shiao 2012). Ecological interactions, such as competition and predation, which may affect the development of insects and their populations (Hanski 1987;Rezende et al 2014), may result in misinterpretations of a crime scene, by causing the exclusion of a given species from a corpse, for example. These interactions should therefore be considered when assessing the minimum postmortem interval since a given species, belonging to the group of first colonizers of carrion, may have been predated by Ch.…”

“…Interspecific interactions in blow flies result from complex biological processes, which involve specific behaviors that influence the abundance and the diversity of insects in decomposing organic substrates (Faria et al 1999;Rosa et al 2006;Rezende et al 2014). The presence of species with strong interactive attributes (i.e., predators, competitors, and parasitoids) may substantially affect the composition of insects inhabiting vertebrate carrion (Grassberger et al 2003).…”

Effect of Psychoactive Drugs on Demographic Parameters of the Blow Fly Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae)

“…The PMI min is often determined by calculating the age of the oldest of the insect life stages collected from a corpse and/or crime scene, which are usually immature stages of blow flies (Diptera: Calliphoridae) [2]. However, errors in these estimates may occur if the larvae are desiccated, frozen [3], evaluated with inaccurate temperature models [4], or have absorbed chemical substances [5,6]. Other factors such as intra-or interspecific interactions and trophic interactions should also be considered, since they may also affect the development time, weight, size, and co-occurrence of related species [7][8][9].…”