Forensic Entomology in Animal Cruelty Cases.

Forensic entomology can be useful to the veterinary professional in cases of animal cruelty. A main application of forensic entomology is to determine the minimum postmortem interval by estimating the time of insect colonization, based on knowledge of the rate of development of pioneer colonizers and on insect species succession during decomposition of animal remains. Since insect development is temperature dependent, these estimates require documentation of the environmental conditions, including ambient temperature. It can also aid in the detection and recognition of wounds, as well as estimate the timing of periods of neglect. Knowledge of the geographic distribution of insects that colonize animal remains may suggest that there has been movement or concealment of the carcass or can create associations between a suspect, a victim, and a crime scene. In some instances, it can aid in the detection of drugs or toxins within decomposed or skeletonized remains. During animal cruelty investigations, it may become the responsibility of the veterinary professional to document and collect entomological evidence from live animals or during the necropsy. The applications of forensic entomology are discussed. A protocol is described for documenting and collecting entomological evidence at the scene and during the necropsy, with additional emphasis on recording geographic location, meteorological data, and collection and preservation of insect specimens.

The development of the black blow fly, Phormia regina (Meigen).

The black blow fly, Phormia regina (Meigen) is a primary species commonly utilized to indicate a postmortem interval, or more appropriately a "time since colonization". Due to the importance of this species as a secondary myiasis producer in livestock operations, and more recently as a time since death indicator in the field of forensic entomology, a considerable amount of data on its growth and development has been generated. However, the developmental time as reported by these studies varies greatly, and current more detailed data is needed for use in medicocriminal entomology. Hourly developmental data is presented under constant temperatures of 10, 15, 20, 25, 30, 35 and 40 degrees C, and cyclic temperatures of 10-15, 15-25, 25-35 and 35-45 degrees C. This study is in agreement with the results reported by Kamal [Comparative study of thirteen species of sarcosaprophagous Calliphoridae and Sarcophagidae (Diptera). I. Bionomics, Ann. Entomol. Soc. Am. 51 (1958) 261] and Melvin [Incubation period of eggs of certain musciod flies at different constant temperatures, Ann. Entomol. Soc. Am. 27 (1934) 406] only at temperatures of 25 degrees C and below. Bishopp [Flies which cause myiasis in man and animals: some aspects of the problem, J. Econ. Entomol. 8 (1915) 317] reported a shorter developmental duration for larval stages than what was produced with our laboratory rearings.

Key to third-instar chrysomyinae (Diptera: Calliphoridae) from carrion in the continental United States.

The introduction of 4 Chrysomya Robineau-Desvoidy spp. to the Americas has made obsolete previously published keys to Nearctic calliphorid larvae, particularly those covering the subfamily Chrysomyinae. To assist forensic entomologists, ecologists, and public health workers, we provide a key to 3rd instars of 8 chrysomyine species reported from or likely to occur in carrion within the continental United States. The rare (in the United States) species Cochliomyia aldrichi Del Ponte, C. minima Shannon, and Chloroprocta idioidea (Robineau-Desvoidy) are not included because specimens and suitable descriptions were unavailable.

Effects of temperature on Sarcophaga haemorrhoidalis (Diptera: Sarcophagidae) development.

Growth curves were studied for the larva and pupa of Sarcophaga haemorrhoidalis (Fallen) under cyclic temperatures with means of 15.6, 21.1, 26.7, and 35 degrees C, and a constant temperature of 25 degrees C. Development from 1st instar to adult under all regimes ranged from 252 to 802 h. A constant temperature of 25 degrees C produced a range of pupation times from 93 to 153 h, with adult emergence ranging from 252 to 502 h. A maximal preferential temperature of 30 degrees C was determined for maggots by using a gradient system. This study shows that S. haemorrhoidalis can be used as an indicator species when establishing a postmortem interval as long as the investigator accounts for the developmental variation prevalent within this species.

Underwater cave diving fatalities in Florida: a review and analysis.

Although no formal accident data reference system exists, the cave diving deaths in Florida from 1962-1991 and 1995-July 1996 (data for 1992-1994 were unavailable) is reviewed. These cases reveal that the number of diver fatalities is cyclical in nature with a periodicity of eight years. Because we are currently only a year past the cycle low, this analysis allows predictions to be made that indicate a rise in fatalities over the next five to seven year period. This study reveals that a lack of experience and failure to follow proper safety precautions are the leading causes of fatalities in cave diving accidents. A one page accident information reporting form is proposed to aid in the initial and accurate reporting of a fatality and to standardize data collection for future research.

Effects of temperature on Chrysomya rufifacies (Diptera:Calliphoridae) development.

Growth curves were studied for the egg, larva, and pupa of Chrysomya rufifacies (Macquart) under mean cyclic temperatures of 15.6, 21.1, 26.7, and 35.0 degrees C and a constant temperature of 25.0 degrees C. Development from egg to adult under all regimes ranged from 190 to 598 h. A constant temperature of 25 degrees C produced a range of pupation times from 134 to 162 h, with adult emergence ranging from 237 to 289 h. The maximal preferential temperature of 35.1 degrees C was determined for maggots using a gradient system. Highly predictable developmental time, minimal larval length variation, and low cohort variation emphasize the utility of this species in entomological-based postmortem interval determinations. Therefore, C. rufifacies should be of primary forensic importance when recovered alone or in conjunction with other species of Calliphoridae.

Effects of temperature on Cochliomyia macellaria (Diptera:Calliphoridae) development.

Growth curves were studied for the egg, larva, and pupa of the secondary screwworm, Cochliomyia macellaria (F), under mean cyclic temperatures of 15.6, 21.1, 26.7, 32.2, and a constant 25.0 degrees C. Development from egg to adult under all regimes ranged from 170 to 588 h. A constant temperature regime of 25 degrees C produced a range of pupation times from 92 to 142 h, with adult emergence ranging from 196 to 261 h. The maximal preferential temperature of 39 degrees C was determined for maggots by using a gradient system. The minimal variation in the range of larval lengths and development time makes this species suitable for establishing relatively narrow confidence intervals when constructing a postmortem interval estimate for use in legal investigations.