No abstract

To quantify the potential capability of transporting and passing infective pathogens of some blowflies (Diptera: Calliphoridae), Mihályi's danger-index (p < 0.10; D = 4.28, 4.44 and 5.66 respectively) and C. megacephala, C. vicina and P. sericata appear to represent the heaviest potential sanitary risk with the highest index value (p < 0.10; D = 15.54, 16.88 and 12.49 respectively).Key words: sanitary entomology -disease transmission -Argentina Many flies, particularly those linked to the human settlements, are important disease vectors (Brown 1997, Chavasse et al. 1999, Graczyk et al. 1999, Fischer et al. 2001. The blowflies (Diptera: Calliphoridae) are important vectors in the transmission of many pathogenes of human and domestic animals (Greenberg 1971).Passive transport was demostrated for eggs of Taenia sp., Entamoeba coli, Giardia lamblia (Mariluis et al. 1989), Mycobacterium paratuberculosis and so on (Fischer et al. 2001). Also the participation of the Calliphoridae flies in myiasis (Guimarães et al. 1983, Leclerq 1990, Guimarães & Papavero 1999, Kumarasinghe et al. 2000, Costamagna et al. 2002 is of interest to sanitary entomologists.Around the middle of the last century, some researchers proposed to quantify and discriminate the communicativity of mature flies. Gregor and Povolny (1958) made a sharp distinction in the communication and noncommunication in synanthropic flies, and Nuorteva (1963) proposed to express numerically the synanthropy degree by means of the synanthropic index (SI).The SI ranges between +100 and -100, the former representing the highest degree of synanthropy. Negative values indicate avoidance of man.Mihályi (1967) did not consider the SI sufficiently informative, in a sanitary sense, and for this reason he makes up a "danger-index" keeping in mind three aspects of the behavioural and morphological characteristics of the insect vectors: the undergoing infection, the passing infection and body size of the vector.The idea of a direct relationship between body size and the capability of contamination and transmission of pathogens seem to be supported by several researches around the world (Mariluis et al. 1989, Brown 1997, Graczyk et al. 1999, Fischer et al. 2001.The aim of this work is to quantify the potential infection and transmission of pathogenes of some blowflies species from Buenos Aires province (Argentina) using the Mihályi's index. In addition, a modification to the original equation of the Danger-Index is proposed in order to insert into the index information on the synanthropy of the species.The taxocoenoses of Calliphoridae in Hudson (34º45'S, 58º25'W), province of Buenos Aires, Argentina, was studied from 1993 to 1995 (Centeno 2002). From these captures, a total of 177 specimens including 7 species of Calliphoridae and 1 of Muscidae (Musca domestica L.) were separated for measuring. The number of specimens taken from each species is summarized in the Table. To calculate the body size (volume) of each fly, the measurements of their three dimensions were made usi...