scholarly journals Competition Among Three Forensically Important Blow Fly Species (Diptera: Calliphoridae): Phormia regina, Lucilia sericata, and Chrysomya rufifacies

2020 ◽  
Vol 49 (6) ◽  
pp. 1473-1479
Author(s):  
Amber E MacInnis ◽  
Leon G Higley

Abstract Avoiding competition is thought to explain insect successional patterns on carrion, but few studies have looked at competition directly. We use replacement series experiments with three species of blow flies: Phormia regina (Meigen) (Diptera: Calliphoridae), Lucilia sericata (Meigen) (Diptera:Calliphoridae), and Chrysomya rufifacies (Macquart) (Diptera:Calliphoridae) to characterize competitive relationships. From experimental results, P. regina showed a significant competitive advantage over L. sericata. Infestation of carrion differs between L. sericata and P. regina; specifically, L. sericata oviposits on carrion without any delay, while P. regina typically delays oviposition. Our findings are consistent with the notion that differences in oviposition times represent a mechanism for L. sericata to avoid potential competition. Competition by C. rufifacies differs since C. rufifacies, in the event of a limited food supply, will prey on other maggot species. In replacement series experiments, C. rufifacies killed all P. regina in mixed treatments, representing an ultimate competitive advantage. In the United States, these two species do not often overlap because of differences in seasonal distribution. However, with climate change, phenological separation may grow less distinct. Surprisingly, in replacement series experiments with C. rufifacies and L. sericata, no competitive interactions were observed. In other studies, L. sericata has been shown to form clusters away from predaceous maggots, allowing improved survival, which may account for the absence of predation by C. rufifacies. Finally, this study shows that replacement series models are useful in measuring competition, supporting the notion that interspecific competition between necrophagous insect species may have driven life history traits of those species.

2021 ◽  
pp. 1-29
Author(s):  
Tijn van Beurden ◽  
Joost Jonker

Analysing Curaçao as an offshore financial centre from its inception to its gradual decline, we find that it originated and evolved in close concert with the demand for such services from Western countries. Dutch banks and multinationals spearheaded the creation of institutions on the island facilitating tax avoidance. In this they were aided and abetted by their government, which firmly supported the Antilles in getting access to bilateral tax treaties, notably the one with the United States. Until the mid 1980s Curaçao flourished, but then found it increasingly difficult to keep a competitive advantage over other offshore centres. Meanwhile the Curaçao connection had enabled the Netherlands to turn itself into a hub for international revenue flows that today still feed both Dutch tax income and specialised financial, legal and accounting services.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 280
Author(s):  
Krystal R. Hans ◽  
Sherah L. Vanlaerhoven

Estimates of the minimum post-mortem interval (mPMI) using the development rate of blow flies (Diptera: Calliphoridae) are common in modern forensic entomology casework. These estimates are based on single species developing in the absence of heterospecific interactions. Yet, in real-world situations, it is not uncommon to have 2 or more blow fly species developing on a body. Species interactions have the potential to change the acceptance of resources as suitable for oviposition, the timing of oviposition, growth rate, size and development time of immature stages, as well as impacting the survival of immature stages to reach adult. This study measured larval development and growth rate of the blow flies Lucilia sericata (Meigen, 1826), Phormia regina (Meigen, 1826) and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae) over five constant temperatures (15, 20, 25, 30, 35 °C), in the presence of conspecifics or two-species heterospecific assemblages. Temperature and species treatment interacted such that L. sericata larvae gained mass more rapidly when in the presence of P. regina at 20 and 30 °C, however only developed faster at first instar. At later stages, the presence of P. regina slowed development of L. sericata immatures. Development time of C. vicina immatures was not affected by the presence of P. regina, however larvae gained mass more slowly. Development time of P. regina immatures was faster in the presence of either L. sericata or C. vicina until third instar, at which point, the presence of L. sericata was neutral whereas C. vicina negatively impacted development time. Phormia regina larvae gained mass more rapidly in the presence of L. sericata at 20 °C but were negatively impacted at 25 °C by the presence of either L. sericata or C. vicina. The results of this study indicate that metrics such as development time or larval mass used for estimating mPMI with blow flies are impacted by the presence of comingled heterospecific blow fly assemblages. As the effects of heterospecific assemblages are not uniformly positive or negative between stages, temperatures or species combinations, more research into these effects is vital. Until then, caution should be used when estimating mPMI in cases with multiple blow fly species interacting on a body.


2017 ◽  
Vol 5 (2) ◽  
pp. 84
Author(s):  
Juan José Uchuya Lopéz ◽  
Raad Yahya Qassim

Brazil and the United States are the leading soybean grain producing and exporting countries in the world. Although crop production cost is significantly lower in Brazil than in the United States due to more advanced crop production technology, this competitive advantage vanishes in view of the higher logistics costs in Brazil than in the United States, in view of the dominance of road transportation in Brazil, whilst river and rail transportation are prevalent in the United States. In order to regain its competitive advantage, there is a clear need for a redesign of the inland supply chain in Brazil through the use and expansion of existent inland waterways and rail networks. In this paper, an optimal supply chain redesign methodology is presented to achieve the aforesaid objective, with a focus on Mato Grosso which is the largest producer and exporting state in Brazil. This methodology is in fact applicable to multiply echelon global supply chains in general.


2019 ◽  
Vol 56 (5) ◽  
pp. 1231-1238
Author(s):  
K A Williams ◽  
M H Villet

AbstractThe seasonal activity of adults of eight forensically important blow fly species [Calliphora croceipalpis (Diptera: Calliphoridae), Jaennicke, Lucilia sericata (Meigen) (Diptera: Calliphoridae), L. cuprina (Wiedemann) (Diptera: Calliphoridae), Chrysomya chloropyga (Wiedemann) (Diptera: Calliphoridae), Ch. albiceps (Wiedemann) (Diptera: Calliphoridae), Ch. marginalis (Wiedemann) (Diptera: Calliphoridae), Ch. putoria (Wiedemann) (Diptera: Calliphoridae), Ch. megacephala (Fabricius) (Diptera: Calliphoridae)] was quantified from collections in Makhanda, South Africa. Flies were collected in traps baited with chicken liver and placed in the field at eight locations for four consecutive days each fortnight for 14 mo. The seasonal distribution of each species compared well to published seasonal distributions of these blow flies elsewhere in South Africa, with evidence of year-to-year variation within seasons that might be explained by weather. This information is important for determining when and where certain species are likely to occur and will be of use in forensic investigations and myiasis management plans.


Weed Science ◽  
1997 ◽  
Vol 45 (2) ◽  
pp. 229-233 ◽  
Author(s):  
Bielinski M. Santos ◽  
Thomas A. Bewick ◽  
William M. Stall ◽  
Donn G. Shilling

Replacement series experiments were conducted under greenhouse conditions to evaluate effects of population densities and proportions on the intraspecific and interspecific interference of either purple nutsedge or yellow nutsedge with tomato cv. Sunny, under nonlimiting conditions of water and nutrients. When grown with either nutsedge species for 40 d, tomato dry weight per plant increased and dry weight per plant of nutsedge decreased as their relative proportions decreased in mixture. Relative yield analysis indicated tomato is a stronger competitor than either nutsedge species. Both nutsedges appeared to be weak interspecific competitors but strong intraspecific competitors. Attenuated light on a purple nutsedge canopy showed that tomato additions can reduce light received by the weed compared to pure nutsedge stands.


2020 ◽  
Vol 57 (4) ◽  
pp. 994-1005
Author(s):  
Justine E Giffen-Lemieux ◽  
Koji Okuda ◽  
Jennifer Y Rosati ◽  
Rabi A Musah

Abstract The attraction of necrophagous insects, particularly blow flies, to corpses and carrion is of ecological, economic, and agricultural importance, although the mechanisms by which it occurs are not well understood. Much of the published research on blow fly attractants has focused on volatiles emitted from carrion surrogates, but little attention has been given to the possibility that blow fly eggs themselves may emit chemical cues that are responsible for conspecific and heterospecific insect attraction. In this study, the headspace volatiles emitted from eggs representing two aggregated oviposition events that were collected 1 mo apart from two species of the Calliphoridae family (Order: Diptera), Lucilia sericata (Meigen), and Phormia regina (Meigen) were analyzed via solid-phase microextraction-facilitated GC-MS. The volatiles’ profiles were found to be consistent between samples representing the same species, but unique between the two species. Over 100 molecules covering a wide range of compound classes that included alcohols, aldehydes, esters, amines, ketones, and organosulfur compounds were identified. The profile of volatiles emitted from the L. sericata eggs contained several alkanes and aldehydes, whereas salient features of the P. regina headspace included numerous esters and ketones. Between the two species, 42 compounds were shared, several of which were carboxylic acids. Little overlap between the range of compounds detected and those reported to be emitted from decomposing remains was observed.


1987 ◽  
Vol 65 (5) ◽  
pp. 1158-1166 ◽  
Author(s):  
F. Michael Barrett

A tyrosinase, enzyme A, and a laccase, enzyme B, have been partially purified from larval cuticle of the flesh fly Sarcophaga bullata. Enzyme A (EC 1.10.3.1, o-diphenol: O2 oxidoreductase) oxidizes o-diphenols but not p-diphenols, is strongly inhibited by phenylthiourea, and has a pH optimum around pH 6.5–7.0. Assays on intact cuticle suggest that it becomes maximally activated at pH between 8 and 9. Enzyme B (EC 1.10.3.2, p-diphenol: O2 oxidoreductase) oxidizes both o-diphenols and p-diphenols, is not inhibited by phenylthiourea but is inhibited by concentrations of sodium azide that have little effect on enzyme A, and has a pH optimum near pH 4.5. Enzyme A was identified in extracts of cuticle from nine other species representing five orders. Enzyme B was much less readily extractable but was partially purified from larval cuticle of Phormia regina, Musca domestica, and Lucilia sericata. A summary of all species studied to date makes possible the test of a hypothesis about the distribution of these cuticular phenoloxidases within the Insecta.


1972 ◽  
Vol 4 (2) ◽  
pp. 145-151 ◽  
Author(s):  
W. R. Lyster

The seasonal distribution of deaths in the United States has progressively altered since 1940. The proportion of deaths in the first half of the year has declined. During the 1940s there were 7·44% more deaths in the first half than in the second half of the year, but during the 1960s the difference was only 4·85%.The continuous shift in the seasonal distribution of the crude death rates from all causes is in association with a similar movement in the monthly fertility rates of the United States.


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