by S.G. Medvedev

(References prepared by M.W. Hastriter)

Primary Literature on Flea Distribution

There is extensive literature devoted to the geographical distribution of different flea taxa. However, a comprehensive analysis of the features of flea faunas of various zoogeographical regions and subregions, and of their links, has never been conducted. This problem was partly considered by Traub (1980) in justifying his hypothesis of the faunistic links between South America and Australia. Data on the world fauna of fleas were published in a series of monographs devoted to the Rothschild collection of fleas in the British Museum of Natural History (Hopkins & Rothschild, 1953, 1956, 1962, 1966, 1971; Mardon, 1981; Smit, 1987) and a monograph of the family Ceratophyllidae (Traub et al., 1983). Flea distribution and their host associations were presented also in a series of papers by Lewis (1972, 1973, 1974a, 1974b, 1974c, 1975). Later, data on new species and subspecies were added (Lewis & Lewis, 1985; Lewis, 1993).

Important monographs and publications on the faunas of various countries follow: Afghanistan (Lewis, 1973), Angola (Ribeiro, 1975), Australia (Dunnet and Mardon, 1974), Brazil (Linardi and Guimãraes, 2000), Canada, Alaska and Greenland (Holland, 1949, 1984), Chile (Beaucournu and Gallardo, 1991, 1992), China (Cai, 1997, Liu et al., 1986; Xie, 2000,Yu et al., 1990,), Czechoslovakia (Rosicky, 1957), Egypt (Lewis, 1967), Finland (Smit, 1969), France (Beaucournu and Launay, 1990), Germany (Peus, 1967, 1968, 1970, 1972), Greece (Beaucournu, 1988), India (Sharif, 1930), Iraq (Hubbard, 1960), Israel (Theodore and Costa, 1967), Italy (Berlinguer, 1964), Japan (Sakaguti, 1962; Sakaguti and Jameson, 1962), Korea (Tipton and Southwick, 1972), Libya (Cooreman, 1973), Madagascar (Beaucournu and Fontenille, 1993), Middle East (Lewis and Lewis, 1990), Mongolia (Goncharov, et al., 1989), Morocco (Hastriter and Tipton, 1975), New Guinea (Holland, 1969), New Zealand (Smit, 1979), Panama (Tipton and Mendez, 1966), Poland (Skuratowicz, 1964, 1967), Russia (Ioff and Skalon, 1954; Ioff, 1965; Skalon, 1970; Tiflov et al., 1977), Saudi Arabia (Lewis, 1982), South America (Johnson, 1957; Macchiavello, 1948), Turkey (Peus, 1977), USA (Fox, 1940; Hubbard, 1947; Lewis et al., 1988), Ukraine (Jurkina , 1961), Venezuela (Tipton and Machado-Allison, 1972), Yugoslavia (Slovenia)(Brelih, 1978).

In 1996-2000, geographic distribution patterns and parasite-host relations within the limits of the entire flea order were analyzed by means of special information analytical system PARHOST1 (Medvedev, 1996; 1997ab; 1998, 2000ab, 2002). According to these data, the distribution of 1,940 species of world fauna of the order Siphonaptera belonging to 240 genera of 18 families were analyzed. In analyzing the flea distribution, a modified Sclater-Wallace division of land into seven regions was used (see the figure in Medvedev, 1996). A summary of significant results are listed below (refer to literature for details).

Important Characteristics of the Distribution of Fleas

I. Zoogeographic regions are highly endemic for particular groups of fleas.

Ninety-four percent of species are endemic to their regions and so similarities and peculiarities of faunas are best analyzed at the generic level.

II. Size of faunas are noticeably different.

The fauna of the Palaearctic region has the greatest diversity, including 96 genera and 892 species, which constitutes 38% of the total number of species known, and 38% of the known genera. The number of species in the Nearctic (299 species), the Afro-Tropical (275), and the Neotropical (289) regions are quite similar. The Indo-Malayan fauna has 191 species, and the Australian fauna 68 species. Regarding the total number of genera, the Nearctic holds the second place (68 genera); the Neotropical – the third (55); the Indo-Malayan – the fourth (52); the Afro-Tropical –the fifth (43), and the Australian – the sixth place (26).

III. Distribution of endemic genera (Tables 1 and 2).

The greatest numbers of endemic genera are found in the Neotropical (31) and the Australian (15) regions, which constitutes 56% and 58% of the total number of genera, respectively. The percentage of endemic genera is high in the Afro-Tropical (60.5%) and the Indo-Malayan (42.3%) regions, whereas for the Palaearctic and Nearctic regions the respective figures are 45% and 36.8%.

The greatest similarity index (SI)(Jaccard's and Chekanovskogo-Sørrensen formulas were used to estimate the similarities of faunas) at the generic level is that between the Palaearctic and Nearctic faunas (22.3%). The Nearctic fauna is also similar to the fauna of the Neotropical (SI 21.7%), and the Palaearctic fauna, to the fauna of the Indo-Malayan (SI 17.4%). The SI between the Indo-Malayan and the Afro-Tropical regions is 11.7%, and that between the Indo-Malayan and the Australian regions 13.0%.

TABLE 1. Similarity Index of Faunas of Seven Zoogeographical Regions (SI)(Jaccard's formula was used to estimate the similarities of faunas)
Zoogeographical Region Indo-Malayan Palaearctic Nearctic Neotropical Afro-Tropical Australian
Palaearctic 17.4 X
Nearctic 3.4 22.3 X
Neotropical 0.9 6.3 21.7 X
Afro-Tropical 11.7 12 0.9 2 X
Australian 13 1.6 0 1.2 6.1 X
New Zealand 5.4 0 0 3.3 2 14.2

TABLE 2. Similarity Index of Faunas of Seven Zoogeographical Regions (SI)(Chekanovskogo-Sørrensen's formula was used to estimate the similarities of faunas)
Zoogeographical Region Indo-Malayan Palaearctic Nearctic Neotropical Afro-Tropical Australian
Palaearctic 29.7 X
Nearctic 6.6 36.5 X
Neotropical 1.8 11.9 35.7 X
Afro-Tropical 21 21.5 1.8 4 X
Australian 23 3.2 0 2.4 11.5 X
New Zealand 10.3 0 0 6.5 4 25

IV. Majority of flea species are concentrated in temperate and subtropical regions and mountain landscapes.

A great number of endemic species and genera are distributed in Eastern-Asian, Central-Asian, Western-American, Patagonian, Papuanian (New Guinean) and Eastern-African zoogeographical subregions. The evolution of fleas in regions of deciduous, mixed and coniferous forests, and tundra, as well as rainforest was less successful. V. 240 known flea genera are spread in 128 types of distribution ranges that may be joined in 23 groups.

The maximal number is 25 types of distribution ranges comprising two zoogeographic divisions; 22 types of ranges comprise three divisions, 19 types comprise one division. The largest number of types of distribution ranges covers the Palearctic and also the Nearctic, Indo-Malayan and Afrotropical regions. The largest number of variants (8) of combinations of zoogeographic divisions forming types of distribution ranges is typical of the Palearctic and Holarctic groups of types of distribution ranges.

VI. Two geographical classifications of flea’s families.

It has been established that 7 of 18 known families of fleas have narrow distribution ranges that cover one zoogeographic subregion or region. The same numbers of families have distribution ranges occupying 2 to 3 zoogeographical regions (see above). According to sizes of areas, the 18 families of fleas may be divided into 4 groups: 1) families distributed in 1-2 subregions (Coptopsyllidae, Xiphiopsyllidae, Chimaeropsyllidae, Malacopsyllidae, Macropsyllidae, Lycopsyllidae), 2) families with less restricted areas (Ancistropsyllidae, Vermipsyllidae), 3) families with broad areas (Leptopsyllidae, Pulicidae, Tungidae, Rhopalopsyllidae, Stephanocircidae, Stivaliidae, Pygiopsyllidae), 4) families with nearly worldwide areas (Hystrichopsyllidae, Ceratophyllidae, Ischnopsyllidae).

The 18 families comprise: a) families characteristic of the Northern Hemisphere (Coptopsyllidae, Vermipsyllidae, Ancistropsyllidae), b) families occurring mostly in the Northern Hemisphere (Leptopsyllidae, Ceratophyllidae, Hystrichopsyllidae), c) families characteristic of tropical and subtropical zones of the earth (Pulicidae), d) families associated with the tropical region of the Eastern Hemisphere (Xiphiopsyllidae, Stivaliidae), e) species occurring mostly in the Southern Hemisphere (Tungidae, Pygiopsyllidae, Rhopalopsyllidae), f) families found only in the Southern Hemisphere (Stephanocircidae, Lycopsyllidae, Macropsyllidae, Malacopsyllidae), and i) families having worldwide distribution (Ischnopsyllidae).

VII. Genera and families of peculiar structure including a small number of taxa comprising concentrated in the southern hemisphere, large number of taxa are concentrated in the northern hemisphere.

A group of genera and families including few taxa can be distinguished within the order. Their peculiar morphological characteristics and narrow distribution ranges suggest they belong to a more ancient flea fauna. These taxa are concentrated in the Southern Hemisphere T in South America (Tungidae, Malacopsyllidae), Africa (Xiphiopsyllidae, Chimaeropsyllidae) and Australia (Lycopsyllidae, Macropsyllidae). On the contrary, flea genera (Ctenophthalmus, Neopsylla, Rhadinopsylla, Megabothris, Nosopsyllus, Amphipsylla, Frontopsylla, etc.) and families (Ceratophyllidae, Leptopsyllidae, and most part of Hystrichopsyllidae s.l.), to include a larger number of taxa, are concentrated in the Northern Hemisphere – Eurasia and North America.

VIII. The number of flea species in the Palearctic is much larger than the number of flea species in other regions.

Eventually it should be noted that the number of taxa of flea fauna of the Palearctic is several times larger than that of faunas of other regions. In the Palaearctic, there are 1.5 species of fleas for each host species, whereas an inverse proportion is noted for other regions. This disparity may be a reflection of the far greater collection and reporting in the Palaearctic region than in other regions.

IX. Extensive diverse landscapes of the Palearctic favored the dispersal of the flea order.

Without rejecting the statement of more complete knowledge of the fauna of the Palearctic as compared to fauna of other regions, we may admit that speciation processes were proceeding more dynamically over extensive areas and in diverse landscapes of the Palearctic in the period of glacial regressions and transgressions. The fauna of the Palearctic is younger as compared to faunas of regions situated further south.

Goals for Future Research on Distribution of Fleas

The results of distribution of fleas in 41 zoogeographical regions and subregions are preliminary. The further accumulation of published and new data in DB permits investigation of these problems in more precise detail. Data on records (to include coordinates) are necessary for further publications.