An account is given of work published during the past 10 years incriminating species of phlebotomine sandflies as vectors of Leishmania species which infect man. An assessment is made of the degrees of certainty of the vectorial roles of eighty-one species and subspecies of sandflies (thirty-seven Old World and forty-four New World) in the transmission of twenty-nine leishmanial parasites of mammals. At least one species of sandfly is considered to be a proven vector of each of ten parasites. Of the eighty-one sandfly taxa, evidence is judged to be sufficient to incriminate nineteen as proven vectors (eleven Phlebotomus species and eight Lutzomyia species or subspecies) and evidence for a further fourteen (nine Phlebotomus species and five Lutzomyia species or subspecies) is considered to be strong. The suggested criteria for incrimination of a vector are anthropophily and common infection with the same leishmanial parasite as that found in man in the same place. More weight should be given to natural infections persisting after the digestion of a bloodmeal than those in the presence of blood. Supporting evidence is a concordance in the distribution of the fly and the disease in man, proof that the fly feeds regularly on the reservoir host, a flourishing development of the parasite in infected flies and the experimental transmission of the parasite by the bite of the fly.

Phlebotomine vectors of the leishmaniases: a review.

This article reports a test of a structural model of the antecedents of genocide and politicide (political mass murder). A case–control research design is used to test alternative specifications of a multivariate model that identifies preconditions of geno-/politicide. The universe of analysis consists of 126 instances of internal war and regime collapse that began between 1955 and 1997, as identified by the State Failure project. Geno-/politicides began during 35 of these episodes of state failure. The analytic question is which factors distinguish the 35 episodes that led to geno-/politicides from those that did not. The case–control method is used to estimate the effects of theoretically specified domestic and international risk factors measured one year prior to the onset of geno-/politicide. The optimal model includes six factors that jointly make it possible to distinguish with 74% accuracy between internal wars and regime collapses that do and those that do not lead to geno-/politicide. The conclusion uses the model to assess the risks of future episodes in 25 countries.This study was commissioned in 1998 by the Central Intelligence Agency's Directorate of Intelligence in response to President Clinton's policy initiative on genocide early warning and prevention. It was designed by the author and carried out using her data with other data and analytic techniques developed by the State Failure Task Force. Statistical analyses reported here were done by Michael Lustik and Alan N. Unger of Science Applications International Corporation (SAIC), McLean, Virginia. The author is senior consultant to the Task Force, which was established in 1994 in response to a request from senior U.S. policymakers to design and carry out a data-driven study of the correlates of state failure, defined to include revolutionary and ethnic wars, adverse or disruptive regime transitions, and genocides and politicides (for the latest report on Task Force research see Goldstone et al. 2002). The author acknowledges the advice of other Task Force consultants and analysts throughout the research process. The views expressed here are those of the author and do not represent the official views of the U.S. government, the U.S. intelligence community, or the Central Intelligence Agency.The author especially thanks Ted Robert Gurr for his critiquing early drafts and using the findings to construct the table that identifies high-risk countries and groups. His insistence about the importance of the study prompted me to revise the manuscript a number of times, despite my initial reluctance, given the years of work that had gone into its preparation. It was especially hard to condense this effort from its original 75 pages. The paper also benefited from a careful reading by Mark I. Lichbach of a previous report and from comments of anonymous reviewers for the American Political Science Review.

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No Lessons Learned from the Holocaust? Assessing Risks of Genocide and Political Mass Murder since 1955

Plant-based repellents have been used for generations in traditional practice as a personal protection measure against host-seeking mosquitoes. Knowledge on traditional repellent plants obtained through ethnobotanical studies is a valuable resource for the development of new natural products. Recently, commercial repellent products containing plant-based ingredients have gained increasing popularity among consumers, as these are commonly perceived as “safe” in comparison to long-established synthetic repellents although this is sometimes a misconception. To date insufficient studies have followed standard WHO Pesticide Evaluation Scheme guidelines for repellent testing. There is a need for further standardized studies in order to better evaluate repellent compounds and develop new products that offer high repellency as well as good consumer safety. This paper presents a summary of recent information on testing, efficacy and safety of plant-based repellents as well as promising new developments in the field.

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Plant-based insect repellents: a review of their efficacy, development and testing

Background: The aim of this study is to describe the major evolutionary historical events among Leishmania, sandflies, and the associated animal reservoirs in detail, in accordance with the geographical evolution of the Earth, which has not been previously discussed on a large scale.
Methodology and Principal Findings
Leishmania and sandfly classification has always been a controversial matter, and the increasing number of species currently described further complicates this issue. Despite several hypotheses on the origin, evolution, and distribution of Leishmania and sandflies in the Old and New World, no consistent agreement exists regarding dissemination of the actors that play roles in leishmaniasis. For this purpose, we present here three centuries of research on sandflies and Leishmania descriptions, as well as a complete description of Leishmania and sandfly fossils and the emergence date of each Leishmania and sandfly group during different geographical periods, from 550 million years ago until now. We discuss critically the different approaches that were used for Leishmana and sandfly classification and their synonymies, proposing an updated classification for each species of Leishmania and sandfly. We update information on the current distribution and dispersion of different species of Leishmania (53), sandflies (more than 800 at genus or subgenus level), and animal reservoirs in each of the following geographical ecozones: Palearctic, Nearctic, Neotropic, Afrotropical, Oriental, Malagasy, and Australian. We propose an updated list of the potential and proven sandfly vectors for each Leishmania species in the Old and New World. Finally, we address a classical question about digenetic Leishmania evolution: which was the first host, a vertebrate or an invertebrate?
Conclusions and Significance: We propose an updated view of events that have played important roles in the geographical dispersion of sandflies, in relation to both the Leishmania species they transmit and the animal reservoirs of the parasites.

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A Historical Overview of the Classification, Evolution, and Dispersion of Leishmania Parasites and Sandflies

Summary: Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi and causes potentially life-threatening disease of the heart and gastrointestinal tract. The southern half of the United States contains enzootic cycles of T. cruzi, involving 11 recognized triatomine vector species. The greatest vector diversity and density occur in the western United States, where woodrats are the most common reservoir; other rodents, raccoons, skunks, and coyotes are also infected with T. cruzi. In the eastern United States, the prevalence of T. cruzi is highest in raccoons, opossums, armadillos, and skunks. A total of 7 autochthonous vector-borne human infections have been reported in Texas, California, Tennessee, and Louisiana; many others are thought to go unrecognized. Nevertheless, most T. cruzi-infected individuals in the United States are immigrants from areas of endemicity in Latin America. Seven transfusion-associated and 6 organ donor-derived T. cruzi infections have been documented in the United States and Canada. As improved control of vector- and blood-borne T. cruzi transmission decreases the burden in countries where the disease is historically endemic and imported Chagas' disease is increasingly recognized outside Latin America, the United States can play an important role in addressing the altered epidemiology of Chagas' disease in the 21st century.

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Trypanosoma cruzi and Chagas' Disease in the United States

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°C and a constant temperature of 25.0°C. Development from egg to adult under all regimes ranged from 190 to 598 h. A constant temperature of 25°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°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 Chrysomya rufifacies (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.

Effects of Temperature on Cochliomyia macellaria (Diptera: Calliphoridae) Development

We determined the degree of personal protection provided by citronella, linalool, and geraniol in the form of commercially available candles or diffusers, both indoors and outdoors. Under the uniform conditions of the experiments, all substances repelled significantly more mosquitoes than the unprotected control. Furthermore, the repellents tested were more active when in the form of a continuous release diffuser than in candle form. All candles were 88 g containing 5% of the active ingredient and all diffusers contained 20 g of 100% active ingredient. Indoors, the repellency rate of citronella candles was only 14% while the repellency rate of citronella diffusers was 68%. The repellency of geraniol candles was 50% while the diffusers provided a repellency rate of 97%. No linalool candles were available for study but linalool diffusers repelled mosquitoes by 93%. Outdoors, citronella diffusers placed 6 m from mosquito traps repelled female mosquitoes by 22%, linalool repelled females by 58%, and geraniol repelled females by 75%. Trap catches were significantly reduced again when diffusers were placed 3 m from the traps. We concluded that geraniol had significantly more repellent activity than citronella or linalool in both indoor and outdoor settings.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1948-7134.2009.00002.x

Efficacy of the Botanical Repellents Geraniol, Linalool, and Citronella Against Mosquitoes

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.

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

Centers For Disease Control and Prevention (CDC) light traps were modified for use with light-emitting diodes (LED) and compared against a control trap (incandescent light) to determine the effectiveness of blue, green, and red lights against standard incandescent light routinely used for sand fly surveillance. Light traps were baited with dry ice and rotated through a 4 x 4 Latin square design during May, June, and July, 2006. Trapping over 12 trap nights yielded a total of 2,298 sand flies in the village of Bahrif, 6 km north of Aswan on the east bank of the Nile River in southern Egypt. Phlebotomus papatasi comprised 94.4% of trap collections with five other species collected in small numbers. Over half (55.13%) of all sand flies were collected from red light traps and significantly more sand flies (P 4 x more than blue and green light traps. Results indicate that LED red light is a more effective substitute for standard incandescent light when surveying in areas where P. papatasi is the predominant sand fly species. Each LED uses approximately 15% of the energy that a standard CDC lamp consumes, extending battery life and effective operating time of traps. Our prototype LED-modified traps performed well in this hot, arid environment with no trap failures.

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Jerry F. Butler

Papers

Effects of Temperature on Chrysomya rufifacies (Diptera: Calliphoridae) Development

Effects of Temperature on Cochliomyia macellaria (Diptera: Calliphoridae) Development

Efficacy of the Botanical Repellents Geraniol, Linalool, and Citronella Against Mosquitoes

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

Response of phlebotomine sand flies to light-emitting diode-modified light traps in southern Egypt.