Influence of substrate tissue type on larval growth in Calliphora augur and Lucilia cuprina (Diptera: Calliphoridae)

The size of fly larvae is an important variable in the use of these insects to estimate postmortem interval. Furthermore, the nutritional intake of larvae is likely to vary subject to the part of a corpse on which they are feeding. A study was therefore conducted to investigate the effect of type of food substrate on larval growth in two species of forensically important Australian blowflies. After collection on sheep's liver in the laboratory, different groups of larvae of Lucilia cuprina (Wiedemann) and Calliphora augur (Fabricius) were grown on sheep's liver, meat, and brains, and their body lengths compared. Results indicated that the development of larvae fed sheep's liver was adversely affected compared with larvae fed meat and brain; they moulted later, reached maximum length more slowly and sometimes produced significantly smaller pupae. These findings, similar to those of another recent study, have obvious implications for postmortem interval determinations. Estimates may be considerably skewed if the site of collection of larvae at a death scene contains tissue types different to those used in reference experiments. We therefore recommend caution in forensic analyses that interpret crime scene data using developmental studies performed with a single type of larval food substrate.     

Conditions of non‐development: The case of Lesotho

A peculiar combination of social and economic factors entailed by the proximity of South Africa creates, for Lesotho, a syndrome of non‐development that may usefully be visualised as a vicious circle in three parts—Poverty, Migration, Ideology—and is so described here. It is the purpose of this paper to demonstrate that the economic facts of village life in Lesotho (and in countries with certain characteristics in common with Lesotho) are perpetuated by their effect on the individual villager. The analysis enters a caveat to the theory of ‘aspiration effect’ [Firth and Yamey, 1963], extends the concept of frustration gap’ [McLoughlin, 1970] and adds a dimension to the cognitive map of migrant ideology [Philpott 1968].     

Three Forms of Interpersonal Trust: Evidence from Swedish Municipalities

Social trust is usually treated as a dichotomy between particularized and generalized trust. In this article it is argued that a third distinct form, community trust, is neither particularized nor generalized and bounded in space rather than persons. Factor analysis of survey data from 33 Swedish municipalities (N = 6,453) distinguishes between particularized, generalized and community trust. Furthermore, regression analyses show that the three trust forms have partly distinct antecedents and linked to different types of behaviours. While generalized trust best predicts leaps of faith in relation to strangers, community trust is the only trust form significantly predicting taking part in local problem solving. Finally, multilevel analysis shows that community trust is the trust form most vulnerable to changes with respect to ethnic diversity and socioeconomic equality.     

The utility of mitochondrial DNA sequences for the identification of forensically important blowflies (Diptera: Calliphoridae) in southeastern Australia.

The applicability of mitochondrial DNA (mtDNA) sequencing was investigated for the identification of the following forensically important species of blowflies from southeastern Australia: Calliphora albifrontalis, C. augur, C. dubia, C. hilli hilli, C. maritima, C. stygia, C. vicina, Chrysomya rufifacies, Ch. varipes and Onesia tibialis. All breed in carrion except O. tibialis, which is an earthworm parasitoid. Emphasis was placed on Calliphora species because they predominate among the carrion-breeding blowfly fauna of southern Australia and their immatures are difficult to identify morphologically. A partial sequence of the mitochondrial COII gene was determined for all species and for COI for C. albifrontalis, C. augur, C. dubia and C. stygia only. Five other species of blowflies, Chrysomya albiceps, Ch. rufifacies, Protophormia terraenovae, Lucilia illustris and L. sericata, for which sequence data were already available, were also included. Analysis of the COI and COII sequences revealed abundant phylogenetically informative nucleotide substitutions that could identify blowfly species to species group. In contrast, because of the low level of sequence divergence of sister species, the data could not distinguish among taxa from the same species group, i.e. the species within the C. augur and C. stygia groups. The molecular data support the existing species group separation of the taxa within Calliphora. Because of the speed and accuracy of current nucleotide sequencing technology and the abundant apomorphic substitutions available from mtDNA sequences, this approach, with the analysis of additional taxa and genes, is likely to enable the reliable identification of carrion-breeding blowflies in Australia.     

Context Effects in Forensic Entomology and Use of Sequential Unmasking in Casework

Context effects are pervasive in forensic science, and are being recognized by a growing number of disciplines as a threat to objectivity. Cognitive processes can be affected by extraneous context information, and many proactive scientists are therefore introducing context‐minimizing systems into their laboratories. Forensic entomologists are also subject to context effects, both in the processes they undertake (e.g., evidence collection) and decisions they make (e.g., whether an invertebrate taxon is found in a certain geographic area). We stratify the risk of bias into low, medium, and high for the decisions and processes undertaken by forensic entomologists, and propose that knowledge of the time the deceased was last seen alive is the most potentially biasing piece of information for forensic entomologists. Sequential unmasking is identified as the best system for minimizing context information, illustrated with the results of a casework trial (n = 19) using this approach in Victoria, Australia.     

Tracking Movement and Temperature Selection of Larvae of Two Forensically Important Blow Fly Species Within a “Maggot Mass”

The current study responds to the lack of understanding about the temperatures experienced by individual blow fly larvae within “maggot masses.” The temperature selection of both aggregating (in a mass) and nonaggregating larvae was compared and their pattern of movement assessed. Infrared imaging determined the temperatures within a mass and in the vicinity of the constituent individual larvae, whose movements were tracked by dyeing their tissues red. Individual Chrysomya rufifacies larvae selected temperatures above 27°C, significantly higher than the temperature selected by Calliphora vicina larvae (24.5°C). However, this same difference was not seen within a mass, with both species selecting temperatures around 28°C. Larval movement in a mass was nonrandom, indicating that larvae actively select their position in a mass. Furthermore, larvae have a strong tendency to select the hottest part of a mass; therefore, maximum mass temperatures might provide a reliable proxy for the actual temperatures experienced by larvae.     

Stampede to judgement: persuasive influence and herding behavior by courts

We model appeals courts as Bayesian decision makers with privateinformation about a supreme court's interpretation of the law;each court also observes the previous decisions of other appealscourts in similar cases. Such 'persuasive influence' can cause'herding' behavior by later appeals courts as decisions progressivelyrely more on previous decisions and less on a court's privateinformation. We provide an example drawn from a recent UnitedStates Supreme Court decision finding unconstitutional a basicprovision of a law previously found constitutional by six circuitcourts. Herding on the wrong decision may remain uncorrected,since review of harmonious decisions is rare.     

Width as an alternative measurement to length for post-mortem interval estimations using Calliphora augur (Diptera: Calliphoridae) larvae

The length of fly larvae collected from corpses is often used to help provide an entomological estimate of time since death. However, 'head-curling' by larvae can affect the accuracy of length measurements. To investigate a possible resolution to this problem, larvae of Calliphora augur were grown on sheep's liver at two constant temperatures (20 and 25 degrees C). Replicate samples were collected at set time intervals until pupation. Body length and width were measured for individual larvae and examined as predictors of age. It was found that body width, as measured at the junction of the fifth and sixth abdominal segments, is comparable with body length for age prediction of maggots of C. augur grown at these temperatures. Furthermore, conversion of width to length can be done with 95% accuracy from a simple linear model.