A new species of Tunga perforating the osteoderms of its armadillo host in Argentina and redescription of the male of Tunga terasma.

A new species of Tunga (Siphonaptera: Tungidae) collected from armadillos in Argentina is described. The new species is characterized by large and pigmented eyes, the presence of two bristles on antennal segment II, two bristles at the base of the maxilla, and a discoid neosome compressed anteroposteriorly. The gravid female is located in the carapace of the host, perforating the osteoderms. The new species resembles Tunga penetrans and Tunga terasma in general appearance. However, it differs by the greater anteroposterior compression of the neosome, a more angular head, and a manubrium with a pointed proximal end and convex ventral margin (the proximal end of the manubrium is rounded or slightly pointed in T. terasma, and the ventral margin is straight in both T. penetrans and T. terasma). In addition, specimens of T. penetrans have more bristles in antennal segments II and III, and lack bristles in the posterior tibia. This is the first report of a species of Tunga perforating the osteoderms of its host and thereby showing a high degree of specialization. Tunga terasma is recorded for the first time in Argentina; the male is described again and the characteristics of the species amended. This information may be useful in epidemiological studies of diseases caused by species of Tunga.

Patterns of diversity and abundance of fleas and mites in the Neotropics: host-related, parasite-related and environment-related factors.

The effects of host-related, parasite-related and environmental factors on the diversity and abundance of two ectoparasite taxa, fleas (Insecta: Siphonaptera) and mites (Acari: Mesostigmata), parasitic on small mammals (rodents and marsupials), were studied in different localities across Brazil. A stronger effect of host-related factors on flea than on mite assemblages, and a stronger effect of environmental factors on mite than on flea assemblages were predicted. In addition, the effects of parasite-related factors on flea and mite diversity and abundance were predicted to manifest mainly at the scale of infracommunities, whereas the effects of host-related and environmental factors were predicted to manifest mainly at the scale of component and compound communities. This study found that, in general, diversity and abundance of flea and mite assemblages at two lower hierarchical levels (infracommunities and component communities) were affected by host-related, parasite-related and environmental factors, and compound communities were affected mainly by host-related and environmental factors. The effects of factors differed between fleas and mites: in fleas, community structure and abundance depended on host diversity to a greater extent than in mites. In addition, the effects of factors differed among parasite assemblages harboured by different host species.

Occurrence of the off-host life stages of Tunga penetrans (Siphonaptera) in various environments in Brazil.

To explore the local transmission dynamics of Tunga penetrans in brazil, 134 soil samples from various environments were collected in three different endemic regions of the country and checked for the presence of the flea's larvae, pupae and adults. the samples, which came from an urban slum in the north-east, a village of xavante indians in the central-west and a community of yanomami indians living in traditional longhouses (malocas) in the north, were categorized as indoor, outdoor or indoor-outdoor (the latter representing samples collected in the malocas). The proportion of samples found positive for T. penetrans was lowest in the slum (9.3%) and highest in the Yanomami village (32.0%; P=0.01). Soil samples collected below bedsteads or hammocks or from the indoor resting places of dogs were significantly more likely to be positive than the indoor samples collected at other sites (65.0% v. 35.0%; P=0.02). There was no evidence indicating that the presence of T. penetrans in a soil sample was markedly affected by soil temperature, air temperature or air humidity. As no life stages of T. penetrans were found in any outdoor sample, it seems likely that, in resource-poor settings in Brazil, most transmission of T. penetrans occurs indoors. Control measures against the off-host life stages of T. penetrans should therefore be targeted at particular indoor micro-environments.

Blood-feeding of Tunga penetrans males.

The jigger Tunga penetrans (Linnaeus, 1758: type-species of the family Tungidae) is the smallest known species of flea (Siphonaptera), causing serious ectoparasitosis of humans and domestic animals. The adult female Tunga lodges in the epidermis of the mammalian host, grows by neosomy, becomes gravid and expels eggs. Relatively little is known about the free-living male Tunga adults. Among impoverished communities of Fortaleza in north-east Brazil, we observed T. penetrans males as well as females penetrating the skin of human hosts. After penetrating the epidermis for a few hours, evidently for capillary feeding from the dermis, males withdrew their mouthparts and crawled away, whereas the females remained completely embedded, hypertrophying to become gravid, eventually dying in situ after oviposition. Caged rats were placed on the sandy soil and examined periodically for Tunga infestation. On five rats we obtained 140 females embedded and we detected 75 males biting, with rat erythrocytes observed in the proventriculus and midgut of all five males dissected and examined microscopically. This confirms that T. penetrans males are hamatophagous ectoparasites of mammals.

The use and misuse of the "impact factor" as a parameter for evaluation of scientific publication quality: a proposal to rationalize its application.

We present a critical analysis of the generalized use of the "impact factor". By means of the Kruskal-Wallis test, it was shown that it is not possible to compare distinct disciplines using the impact factor without adjustments. After assigning the median journal the value of one (1.000), the impact factor value for each journal was calculated by the rule of three. The adjusted values were homogeneous, thus permitting comparison among distinct disciplines.

The use and misuse of the "impact factor" as a parameter for evaluation of scientific publication quality: a proposal to rationalize its application

We present a critical analysis of the generalized use of the "impact factor". By means of the Kruskal-Wallis test, it was shown that it is not possible to compare distinct disciplines using the impact factor without adjustments. After assigning the median journal the value of one (1.000), the impact factor value for each journal was calculated by the rule of three. The adjusted values were homogeneous, thus permitting comparison among distinct disciplines.

Small rodents fleas from the bubonic plague focus located in the Serra dos Orgãos Mountain Range, State of Rio de Janeiro, Brazil.

Eleven species of fleas were collected from 601 small rodents, from November 1995 to October 1997, in areas of natural focus of bubonic plague, including the municipalities of Nova Friburgo, Sumidouro and Teresópolis, State of Rio de Janeiro, Brazil. Among 924 fleas collected, Polygenis (Polygenis) rimatus (Rhopalopsyllidae) was the predominant species regarding the frequency, representing 41.3% (N:382), followed by P. (Neopolygenis) pradoi, representing 20% (N:185) and Craneopsylla minerva minerva (Stephanocircidae), representing 18.9% (N:175). The host Akodon cursor harbored 47.9% of these fleas. Other six host species were infested by 52.1% of the remaining fleas. Fleas were found on hosts and in places within the focus not previously reported by the literature.

Morphometric and phenetic studies of five geographical populations of Lutzomyia whitmani (Diptera: Psychodidae) in Brazil.

A morphometric survey examined adult specimens of Lutzomyia whitmani (Antunes & Coutinho) captured at 5 municipalities in southeastern and northeastern Brazil to compare the populations. The localities were Ilhéus (Bahia), Martinho Campos (Minas Gerais), Corte de Pedra (Bahia), Baturité (Ceará), and Amaraji (Pernambuco): all are known foci of American cutaneous leishmaniasis. Fifteen males and 15 females from each population were analyzed morphometrically for 42 and 37 characters, respectively. Statistical data alone were insufficient to discriminate among the 5 populations. Further analysis generated phenograms that indicated there were 2 spatial clusters: the 1st was composed of specimens from Ilhéus (Bahia) and Baturité (Ceará) and the 2nd of specimens from Martinho Campos (Minas Gerais), Corte de Pedra (Bahia), and Amaraji (Pernambuco). Although insufficient to define the taxonomic status of the populations studied, the results delineated the existence of biogeographical structuring within L. whitmani. Complementary studies on the susceptibility to Leishmania braziliensis infection in the 5 populations are in progress to clarify the relationship between the 2 biogeographical clusters and American cutaneous leishmaniasis transmission in those Brazilian regions.

The type specimens of sucking lice (Anoplura) deposited in the entomological collection of Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil.

This study presents a list of 34 Anoplura type specimens deposited in the Werneck Collection of Instituto Oswaldo Cruz, Rio de Janeiro, RJ, Brazil. It includes 18 holotypes, 16 allotypes, 88 paratypes and 10 neotypes, distributed among the genera: Enderleinellus, Fahrenholzia, Haematopinus, Hoplopleura, Linognathus, Microthoracius, Pecaroecus, Polyplax and Pterophthirus. The types are related according to their respective data and literature.

Recognition of the tick genus Anocentor Schulze, 1937 (Acari: Ixodidae) by numerical taxonomy.

We report on an evaluation of the systematic position of the tick Anocentor nitens (Neumann), examining particularly whether Anocentor should be regarded as a subgenus of Dermacentor or as a separate genus. Twelve species of Ixodidae were analyzed phenetically by using 24 characters of adult ticks. A phenogram indicated 3 clusters, with Anocentor more closely related to Rhipicephalus than to Dermacentor. The results of this study endorse the validity of the monotypic genus Anocentor.

[Infestation by Pediculus humanus (Anoplura: Pediculidae) in a metropolitan area of southeast Brazil]. / Infestação por Pediculus humanus (Anoplura: Pediculidae) no Município de São Paulo, SP, Brasil.

Adults, nymphs and nits of the Pediculus humanus were found in a frame-house infesting the clothes and bedding of three inhabitants in a shanty town in S. Paulo county, S. Paulo State. A total of 198 nits were found glued in 15.0 cm2 of fibres of the infested clothing, giving a ratio of 13.2 nits/cm2. Having in view that the precarious living conditions, promiscuity, absence of basic sanitation and negligence of the sanitary authorities in various Brazilian cities, this situation should not be underestimated. This find should be more frequent than an isolated observation.

Xenopsylla cheopis em cäes do Brasil: primeiro relato / Xenopsylla cheopis on dogs from Brazil: first report

For the first time, Xenopsylla cheopis (Rothschild) is recorded on dogs from Brazil, at the prevalence of 1.1 per cent in the city of Uberlândia, Minas Gerais State. Having in view the high occurrence of commensal rats in that municipality, as well as the opportunities for contact with domestic animals, this report should not be underestimated

Interrelationship between ectoparasites and wild rodents from Tijucas do Sul, state of Paraná, Brazil.

Sixteen species of ectoparasites were collected from 50 wild rodents, from August 1990 to August 1991, in an area of Araucaria augustifolia forest, in the municipality of Tijucas do Sul, State of Paraná, Brazil. Ectoparasites infested 98% of the rodents, with the highest indices of infestation found in the drycool season. Species that occurred in single or multiple infestations were recorded. Ectoparasite/host associations were significant (p < 0.01) for Gigantolaelaps wolffsohni/Oryzomys nigripes, Polygenis pradoi/Oxymycterus sp. and Amblyopinus sp./Oxymycterus sp. The following represent new host records: Polygenis (Polygenis) tripus from Akodon serrensis and Hoplopleura sciuricola from Sciurus aestuans. New geographic records are given for two species of flea and one sucking lice.

Effects of larval nutrition on the postembryonic development of Ctenocephalides felis felis (Siphonaptera:Pulicidae).

Dry blood from mammals and birds was used as larval diet for the development of the cat flea, Ctenocephalides felis felis (Bouché), in the laboratory. Diets that contained host blood and cornmeal heated at 40 degrees C for 30 min were inadequate for most larvae to form pupae. Development time from 1st instar to adult ranged from 30 to 33 d. Except for the diet containing Mastomys blood, the diets that consisted of blood alone from other hosts air dried at room temperature contained sufficient nutritional value to allow adults to be obtained from > 51.7% of larvae fed these diets. Adults were obtained from > 81% of pupae. Although the Mastomys or mouse blood contributed to better diets than the dog or pigeon blood through shorter developmental time from 1st instar to adults, greater numbers of pupae and adults were obtained from diets that contained dog and mouse blood. Highly significant differences existed between pigeon and Mastomys blood in relation to the number of cocoons formed and between pigeon and dog blood or pigeon and mouse blood in relation to adult emergence. Differences between dog and mouse blood in the larval diet were significant only in relation to mortality that occurred to the pupae.

Some ectoparasites of commensal rodents from Huambo, Angola.

Eight species of ectoparasites were collected from 166 commensal rodents, including Rattus rattus (L.), Rattus norvegicus (Berkenhout), and Mus musculus (L.), from January to December 1986, in Huambo, Angola. The oriental rat flea, Xenopsylla cheopis (Rothschild), was the predominant species with respect to mean intensity and prevalence. Other fleas collected were Ctenophthalmus (Ethioctenophthalmus) machadoi Ribeiro, Dinopsyllus (Dinopsyllus) smiti Ribeiro, and Echidnophaga gallinacea (Westwood). The mite Laelaps (Echinolaelaps) muricola Trägärdh, the louse Polyplax spinulosa (Burmeister), one species of Ixodes Latreille, and one species of Ornithonyssus Sambon were also recorded. The following represent new host records: C. machadoi from R. rattus and R. norvegicus, D. smiti from M. musculus, and L. muricola from R. rattus and M. musculus. For the first time, the monthly flea indices throughout the year are presented for Angola.

Ectoparasites of some wild rodents from Paraná State, Brazil.

Forty-four cricetid rodents belonging to four species from Paraná State, Brazil, were karyotyped and examined for ectoparasites. Thirteen species of ectoparasites, including five mites, one louse, and seven fleas, are recorded for the first time from Paraná. New host records are described for four species of mites, one sucking louse, and seven fleas.