Syritta pipiens (Diptera: Syrphidae), a new species associated with human cadavers

The analyses of necrophagous insects feeding on a corpse can be successfully used to estimate the minimum time since death. A minimum time frame is sometimes an underestimate, but it is actually the only method that can provide such information when decomposed remains are found at a crime scene. Many insects are known to be colonisers of a corpse, but because there is an endless spectrum of crime scene environments, the development data bases for necrophagous insects is incomplete. The two cases detailed in this paper show different entomological patterns due to the different environments (well and burial) and locations (south and central Italy) where the two cadavers were found. Common to both of these cases' was the discovery of the corpse in the same period of the year (January) and the presence of Syritta pipiens (Diptera: Syrphidae), a species that has never been associated with deceased humans. The ecological information concerning this insect was used in combination with the more typical entomofauna found on the corpse to provide a minimum post mortem interval.

Predatory behavior of Synthesiomyia nudiseta larvae (Diptera: Muscidae) on several necrophagous blowfly species (Diptera: Calliphoridae)

Intraguild interactions play a prominent role in sarcosaprophagous communities, so intraspecific and interspecific competition phenomena between fly larvae take place. Synthesiomyia nudiseta is a species that has recently been recorded on human corpses in Europe, and it has been cited in forensic cases in Spain and Italy. The mature larvae are known to be facultative predators on necrophagous fly larvae, but their role as predators is unknown. The aim of this paper is to investigate the predatory behavior of S. nudiseta on the most abundant blowfly larvae in sarcosaprophagous communities in southwestern Europe (i.e., Chrysomya albiceps, Lucilia sericata, and Calliphora vicina). Intraspecific and interspecific competition experiments were carried out to study the effect of this species in the necrophagous diptera community. First-instar larvae were placed in plastic cups with the same amount of pig liver (15 g) at different densities (50, 100, 150, and 300 individuals/cup). Mortality in blowflies increased when S. nudiseta larvae were present: up to 98.40% in Ch. albiceps, 89.60% in L. sericata, and 84.93% in C. vicina. Pre-imaginal developmental time and adult wing size were analyzed and compared under each of the intraspecific and interspecific conditions; both variables were affected by competition in all cases. The implications of the presence of S. nudiseta for sarcosaprophagous community dynamics and its effect on the estimation of postmortem interval (PMI) are discussed.

Thermal requirements of immature stages of Chrysomya albiceps (Diptera: Calliphoridae) as a common forensically important fly

Entomological material may be used to estimate the time since death occurred (postmortem interval, PMI) in forensically obscure cases. The method that is commonly used to calculate minimum post-mortem interval (mPMI, i.e., the least amount of time since one can be confident death occurred) is based on the relationship between insect development and ambient temerature. Isomegalen and isomorphen diagrams are among methods allowing to calculate the age of necorphagous insects, yet thermal summation models provide the most precise and acurate estimations. The digrams are prepared based on the length or the developmental stages of the larvae as a function of time and mean ambient temperature. A knowledge of thermal requirements, in particular lower temperature threshold (D_z) at which development of a species terminates, is of essential importance to calculate ADD (Accumulated Degree Days). In this study different temperature regimes were used to construct the isomorphen diagram, examinate changes in larval body length at different ambient temperatures and to estimate the thermal requirements for developemnt of Chrysomya albiceps, the most common dipteran species reported on human and animal cadavers in Iran. Six development events including hatching, 1st ecdysis, 2nd ecdysis, wandering, pupariation and eclosion were studied under eleven constant temperature regims (17-37 ⁰C). The development rate of Ch. albiceps increased as temperature increased. The larval length peaked at the end of third stage and then decreased at wandering stage. The maximum larval length occurred at 72 h post oviposition at either 31, 33, or 35 °C. At 17 °C, larvae did not hatch from eggs and at 37 °C wandering larvae did not proceed to pupariation, and thus larval development were analysed at the nine left over temperatures. The development stages required at least (D_z ± SE) 13.04 ± 0.37, 14.29 ± 0.45, 15.69 ± 0.56, 15.18 ± 0.56, 14.94 ± 0.48, and 11.23 ± 0.41 °C to reach one of the successive developmentl events, respectively. The estimated thermal summation constant (k) for those the six events were 10.43 ± 0.27, 19.31 ± 0.32, 27.87 ± 1.3, 55.94 ± 1.82, 66.69 ± 3.5, and 143.52 ± 5.61 ADD accordingly.

First record of Chrysomya albiceps Wiedemann, 1819 (Diptera: Calliphoridae) maggots from a sambar deer (Rusa unicolor) in Kerala, South India

Fully grown third stage larvae (LIII) of Chrysomya albiceps were recovered from aberrant sites viz. trachea and rumen during necropsy of a free-range sambar deer that had been observed to bear an inflamed tongue infested with maggots and subsequently died due to starvation. Five dead maggots of C. bezziana were also recovered from rumen. The aberrant locations of the recovery of the maggots indicated that they might have reached these sites accidentally. This is the first report of LIII of C. albiceps from a sambar deer from Kerala, South India.

Coexistence and intraguild competition of Chrysomya albiceps and Lucilia sericata larvae: case reports and experimental studies applied to forensic entomology

The larval development of Chrysomya albiceps and Lucilia sericata is a well-known and valuable tool for estimating the postmortem interval (PMI). The third instar larvae of Ch. albiceps are facultative predators of the larvae of other necrophagous dipterans, and this behaviour is undoubtedly an important factor to consider. Both species are found together during human autopsies in Spain and other parts of Europe, where they cohabit, so a precise knowledge of their larval coexistence data is essential. The aim of this study is to investigate their coexistence and the intraguild predation of Ch. albiceps on L. sericata under experimental conditions and in real case reports. To analyse intra- and interspecific competition, four densities were used under controlled abiotic conditions [25ºC, 60-70% RH and 12:12 (D:N)]. The experimental data were compared with data corresponding to their coexistence in natural conditions, so annual activity and forensic case reports for both species were studied. The results indicate that the mortality of immature specimens in both species, the preimaginal developmental time, and adult size were affected by competition. In natural conditions, adult coexistence during the spring-summer period was confirmed. The simultaneity of the two species colonising human corpses is frequent in the studied area, with Ch. albiceps being the dominant species, and L. sericata the relevant species for estimating the minimum postmortem interval.

An examination of the intrapuparial development of Chrysomya albiceps (Wiedemann, 1819) (Calliphoridae: Diptera) at three different temperatures

The determination of intrapuparial development periods and development times of insects with holometabolous metamorphosis is necessary both in terms of developmental biology and for minimum Post-mortem interval (PMImin) calculations in forensic entomology. In this study, Chrysomya albiceps (Wiedemann, 1819), which is a cosmopolitan species and one of the most rapidly attracted to carrion, was studied. The focus was the intrapuparial development periods of this species at varying temperatures (20, 25, and 30 °C), knowledge which is used in forensic entomology for the estimation of Post-mortem interval (PMI) and is a type of black box. At the specified temperatures, pupae were collected and puparia were dissected hourly; thus, developmental periods were determined, and minimum and maximum starting times of these periods were calculated. With this research, a total of 20 periods, nine of which are new, were determined. The hourly determination of intrapuparial development periods at three different temperatures is the first in the world for this species.

Insect Fauna of Human Cadavers in Tehran District

BACKGROUND

Entomological data can provide valuable information for crime scene investigations especially in post-mortem interval (PMI) estimation. This study performed to determine insect fauna of human corpses in Tehran district.

METHODS

Insect specimens were collected from 12 human cadavers during spring and summer 2014 and were identified using morphological characteristics.

RESULTS

Four fly species including two blowflies Chrysomya albiceps and Lucilia sericata (Calliphoridae), one flesh fly Sarcophaga argyrostoma (Sarcophagidae), and one phorid fly Megaselia scalaris (Phoridae) and a beetle Dermestes maculatus (Dermestidae) was observed on the human cadavers. Chrysomya albiceps was the most dominant species on the corpses temporally and spatially.

CONCLUSION

Chrysomya albiceps was the most dominant insect species on human cadavers in the area study spatio-temporally. The data make C. albiceps as a valuable entomological indicator for PMI estimation in Tehran and other parts of the country. However, further biological and ecological data such as its behavior, life tables, and consistent developmental time should be investigated when establishing a PMI in the region.

Oviposition Deterrent Activity of Some Wild Plants for Adult Females of Chrysomya albiceps with Medical and Veterinary Importance

<b>Background and Objective:</b> <i>Chrysomya albiceps</i> is widely spread worldwide, causing myiasis in both humans and animals and playing a mechanical role in the spreading of helminths, viruses and bacteria. Searching for new and safe alternative control methods is very important to eliminate the transmission of pathogens. This study aims to determine the oviposition-deterrent activity of <i>Juniperus procera</i>, <i>Artemisia absinthium</i>, <i>Rosmarinus officinalis</i> and <i>Hypoestes forskaolii</i> wild plants against adult <i>Chrysomya albiceps</i>. <b>Materials and Methods:</b> The effect of plant extracts from <i>Juniperus procera</i>, <i>Artemisia absinthium</i>, <i>Rosmarinus officinalis</i> and <i>Hypoestes forskaolii</i> plants were tested against adult females of <i>Chrysomya albiceps</i> for oviposition deterrent or repellency. These extracts resulted in oviposition deterrent efficacy for adult females of <i>C. albiceps</i> based on the plant type, plant part (leaves or stems), extract type (methanol, acetone and petroleum ether) and tested dose. <b>Results:</b> The highest anti-oviposition activity against <i>C. albiceps</i> females presented from <i>A. absinthium</i> stems acetone extract at a dose of 1 mg cm² by 100 %, while at 0.5 mg cm² recorded remarkable repellency by 86.7% as compared with the control treatment. According to the dose-response relationship, <i>A. absinthium</i> methanol and acetone extracts were ED₅₀ values of 0.85, 0.319 mg cm² (leaves) and 1.88, 0.576 mg cm² (stems), followed by <i>J. procera</i> methanol extract by 0.983 mg cm² (leaves) and 0.98 mg cm² (stems), respectively achieved highest oviposition deterrent efficiency as compared with other extracts. <b>Conclusion:</b> The high repellency activities of these extracts can be utilized to stop <i>C. albiceps</i> flies from laying eggs on wounds and transmitting myiasis diseases to humans and animals and could potentially replace pesticides used in the future control programs of flies.

Impact Fed Larvae on Residues (Tramadol, Sildenafil Citrate and Diazepam) Chrysomya albiceps on Enzymes

&lt;b&gt;Background and Objective:&lt;/b&gt; &lt;i&gt;Chrysomya albiceps&lt;/i&gt; are the insects most commonly associated with corpses, they are of medical and forensic value and thus their immature stages are used to estimate the post mortem interval (PMI) and may provide medicolegal experts essential information regardless of the time, place and cause of death. The current study's goal was to determine the impacts of these pharmaceuticals compounds in some of the biochemical parameters enzymes of the &lt;i&gt;C. albiceps&lt;/i&gt; third instar larvae. &lt;b&gt;Materials and Methods:&lt;/b&gt; The experiment was performed from April to June, 2018. &lt;i&gt;C. albiceps&lt;/i&gt; was fed rabbit tissues during its development for three generations tramadol is administered an overdose of (30.8 mg kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt;), sildenafil citrate an overdose of (10.26 mg kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt;) and diazepam an overdose of dissolved in distilled water (4.06 mg kg&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt;), by intra-injection into the abdominal cavity twice daily for one week and rabbits injected with distilled water were also used to raise the control group. &lt;i&gt;Chrysomya albiceps&lt;/i&gt; larvae in their third instars measured enzymes by using a spectrophotometer. &lt;b&gt;Results:&lt;/b&gt; The results indicated to significantly increase of antioxidant enzymes activity of control group of TP, TAC, SOD, GST and CAT and decrease of MDA and significantly decreased of TP, TAC, SOD, GST and CAT and increase of MDA for the tramadol, sildenafil and diazepam groups for the three generations of larvae, respectively. &lt;b&gt;Conclusion:&lt;/b&gt; In conclusion, the evidence suggested that decreased antioxidant enzyme activity and increase of MDA might be involved in the production of free radicals in &lt;i&gt;C. albiceps&lt;/i&gt; oxidative stress is caused by these pharmaceuticals compounds.

Canine Myiasis and Its Causal Agents in Northeastern Iran

BACKGROUND

Myiasis is defined as the infestation of live human and vertebrate animals with dipterous larvae for a certain period. There are reports indicating that dogs are the most common species affected by myiasis. This study was conducted to identify myiasis-causing flies in owned and stray dogs in Mashhad (Northeastern Iran).

METHODS

A total of 435 owned dogs and 800 stray dogs were examined for myiasis. Myiasis cases were cured and fly larvae were identified by microscopy using the relevant standard identification keys.

RESULTS

Ten out of 435 owned dogs (2.29 %) and 18 out of 800 stray dogs (2.25 %) had myiasis. The causative agents of myiasis in dogs based on their frequencies were as follows: Wohlfahrtia magnifica (50%), Lucilia sericata (28.57%) and Chrysomya albiceps (21.42%).

CONCLUSION

W. magnifica was the most important myiasis-causing fly among the dogs sampled here, sometimes causing very serious damages. However, when treatment was given early enough, the larvae removed and the wound disinfected, the animals usually made a full recovery.