Larvae of the Synthesiomyia nudiseta (Wulp) were collected from a decomposed human corpse at the Department of Forensic Medicine, Penang Hospital. A colony of this species was established and the eggs were collected for rearing. The developmental times, rearing temperatures, and relative humidity were recorded twice daily from the time the eggs collected until adult emergence. An average of 5 larvae were randomly collected from the rearings twice daily, warm-water killed and preserved in Kahle's solution. The larval instar stages were determined by observing the number of posterior spiracular slits and the length of the preserved larvae were measured. When the larval life cycle was completed, the accumulated developmental times were calculated. A total of 8 replicates were carried out. The temperature of the rearing room was 28.5+/-1.5 degrees Celcius while the relative humidity was within 67-85%. The total developmental time for S. nudiseta was 322+/-19 hours (13.4+/-0.8 days).
Synthesiomyia nudiseta (van der Wulp, 1883) is a synanthropic muscid found in tropical and subtropical zones around the world. The larvae of this species are a secondary agent of myiasis with necrophagous habits and play an important role in forensic entomology, as they are used as an indicator of post-mortem interval. Adults can be considered vectors of etiological agents such as Escherichia coli and Shigella dysenteriae. Due to its ability to adapt to different environmental conditions, its high dispersal capacity (shown by its introduction to Europe), its predatory habits in the last larval stage and the difficulty of identifying it, a very important goal is to update our knowledge about this species. Therefore, the main objective of this paper is to review the identification, geographical distribution and biology of this species in order to provide better support to investigations involving this fly.
To better understand the population dynamics and dispersal ability of insect species, it is often helpful to derive a life table containing fundamental demographic data. The aim of this study was to determine a life table for the predatory necrophagous species Synthesiomyia nudiseta (van der Wulp, 1883) on a pig liver diet and under controlled laboratory conditions (29.5 ± 2. 5°C, RH 50 ± 15%, and a photoperiod of 12:12). This species has medical and veterinary importance and its distribution extends in tropical and subtropical areas and now it has been established in the southwestern of Europe. The mean adult longevity was 36. 18 ± 2. 06 d and the net reproduction rate, R, was 27.65 offspring/female, the mean generation time, T, was 22. 09 d, the finite rate of increase, λ, was 1. 16 d-1, and the intrinsic rate of increase, r, was 0. 15 d-1. These results indicate that S. nudiseta cannot be considered an r-strategist as the most common synanthropic necrophagous blowflies due to its predatory behavior; however, its invasive and colonist abilities are discussed. This is the first life table study of this species from Palearctic region to analyze the effect of its dispersal ability.
This is the first report of Synthesiomyia nudiseta (Wulp) (Diptera: Muscidae) on a human corpse discovered in a high-rise building in Malaysia. On 5 March 2008, a decomposing body of an adult female was found on the top floor of a thirteen-story building in Kuala Lumpur, Malaysia. Her body was colonized by S. nudiseta larvae, which were normally associated with corpses found indoors at ground level. The post-mortem interval (PMI) was estimated at approximately 5 to 9 days. This case is significant as it demonstrates that this species can locate a dead body even in a high-rise building. Further findings of fly distribution especially in high-rise buildings should be reported to assist entomologists in PMI analysis.
A forensic entomological study was conducted using monkey carcasses (Macaca fascicularis Raffles) that were placed in either an outdoor or indoor environment at a coastal area in Tanjung Sepat, Selangor, Malaysia during May until August 2008. We collected pupae of Chrysomya rufifacies (Marquart) from the carcasses and kept them individually. The emergence of 13 parasitic microhymenopteran, from one of the pupae occurring within a week were identified as Exoristobia philippinensis Ashmead (Hymenoptera: Encyrtidae). Another observation was made whereby a pupa of C. rufifacies was predated by a muscid larva, Ophyra spinigera (Stein). The larva squeezed into the pupa and consumed the contents. This paper report C. rufifacies as a new host record for E. philippinensis in Malaysia and highlighted the predatory behavior of O. spinigera larva in natural environment.