Z Rodríguez/⁺, EC Moreira*, PM Linardi**, HA Santos**

Departamento de Farmacologia *Departamento de Medicina Veterinária Preventiva, Escola de Veterinária **Departamento de Parasitologia, Instituto de Ciências Biológicas (ICB), Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte MG, Brasil

Received 22 January 1999
Accepted 7 June 1999

Key words: Siphonaptera - bat fleas - Hormopsylla fosteri - Molossops abrasus

Among the 15 currently recognized families of the order Siphonaptera (RE Lewis 1998 J Med Entomol 35: 377-389), Ischnopsyllidae is specific to a single order of hosts, Chiroptera, representing about 5% of the known records (AG Marshall 1981 The Ecology of Ectoparasitc Insects, Academic Press, London, 459 pp.). Only five genera and five species of Ischnopsyllidae occur in Brazil (PM Linardi & LR Guimarães, Sifonápteros do Brasil, Museu de Zoologia USP, in press).

One of these genera, Hormopsylla, is constituted by four species, as recently recognized in the review of MW Hastriter and R Guerrero (1998 Proc Entomol Soc Wash 100: 247-251), infesting bats of the family Molossidae, as well as vespertilionid and phyllostomid bats. Three species are restricted to the Neotropical region; the other reaches the southern Neartic region.

Only H. fosteri (Rothschild, 1903) has been recorded in Brazil, in the states of São Paulo, Minas Gerais, Paraíba and Rio Grande do Norte. The Brazilian hosts includes Molossus bonariensis, Desmodus rotundus rotundus and Phyllostomus hastatus (Linardi & Guimarães loc. cit.).

According to Hastriter and Guerrero (loc. cit.), specimens of Hormopsylla are rare in collections. In contrast to the fleas which infest other groups of hosts, bat fleas are not common on bats (Marshall loc. cit.). Mammals fleas are commonly found on their hosts' bodies often in considerable numbers, even on small hosts some populations may also be quite large, as noted on insectivores: 932 Archaeopsylla erinacei from a single hedgehog (FGAM Smit 1958 Brit Mus Nat His Econ Ser 3A: 1-20); lagomorphs: 769 Spilopsyllus cuniculi from a rabbit (RCH Shepherd & JW Edmonds 1976 Aust Wildl Res 3: 29-44); rodents: 219 Xenopsylla cheopis from a rat Rattus rattus (HB Morlan 1952 Am Midl Nat 48: 74-93), or 80 Malareaus telchinus from a mouse Microtus californius (HE Stark & VI Miles 1962 Am J Trop Med Hyg 11: 525-534). For Chiroptera, the greatest number of fleas found on a single bat has been 34, for the species Nycteridopsylla pentacteno and Plecotus austriacus (L Hurka 1965 Vest Czl Spol Zool 29: 239-243).

Another question regarding the infestation on bats would be the probable competitive exclusion among ectoparasites, as claimed by RL Wenzel and VJ Tipton (1966 Some relationships between mammal hosts and their ectoparasites, p. 677-723. In RL Wenzel & VJ Tipton, (eds), Ectoparasites of Panama, Field Mus Nat Hist, Chicago) and SC Barker (1994 Int J Parasitol 24: 1285-1291). For this reason, Chiroptera infested with fleas seldom have any mites; likewise, New World mollossid bats with polyctenids have no nycteribiids or streblids, and nycteribiids and streblids rarely occur on the same host.

From a single female, adult and non pregnant of M. abrasus captured in the municipality of Belo Horizonte, State of Minas Gerais, in 17 Sept. 1998, 123 fleas (90 females and 33 males) of H. fosteri were recovered (Fig.1). This number represents the peak load of infestation by bat fleas up till now recorded for species of Chiroptera. When related to the sites of infestation on the host's body (Fig. 2), the fleas presented the following distribution: ears (36%); head (24%); thorax (17%); other sites (23%). Considering the size and weight of the host, the load of infestation might be an important parameter for studies evaluating the direct impact of ectoparasites on bats. Since the greater number of fleas was observed on the regions of head and ears, the host might be conducting some grooming activity. M. abrasus also constitutes a new host record for H. fosteri.

Copyright 1999 Fundacao Oswaldo Cruz - Fiocruz