Schikhobalotrema solitaria sp. n. and S. acanthuri Yamaguti, 1970 (Haplosplanchnidae: Digenea) in Brazilian marine fishes

Schikhobalotrema solitaria sp. n. is described from Stephanolepis hispidus (Linnaeus, 1758), and is characterized by the relation between oral sucker and pharynx 1:1,1. This Relation in the other species ranges between 1:0.3-0.6. It is more similar to S. manteri Siddiqi & Cable, 1960 in the distribution of vitellaria, differing from it in the size of vitelline follicles, extension of uterus and in the size of the eggs. S. acanthuri Yamaguti, 1970 is referred for the first time in South America in Mugil liza Valenciennes, 1836 representing a new host record.

Infecção por Enterobius vermicularis em populações agro-pastoris pré-colombianas de San Pedro de Atacama, Chile

Enterobius vermicularis eggs were found in human coprolites collected from the archaeological site of San Pedro de Atacama, North of Chile, in occupational layers dated from 1,000 BC. Agricultures and herding were begining at this period of time in this region of South America. The paleoparasitological data amplifies the knowledge about the distribution of human oxyuriasis in Pre-Columbian America.

Diseminación de enteroparasitos por Calliphoridae (Insecta, Diptera)

It is establish the dissemination enteroparasite by Calliphoridae in a district situated around by Federal Capital of Argentina. The species implicated in this dispersal are: Phaenicia sericata (meigen, 1826); Calliphora vicina Robineau-Desvoidy, 1830; Chrysomya chloropyga (Wiedemann, 1818) and Phaenicia eximia (Wiedemann, 1819). Fifty two flies was studies, thirty four (65%) to belong at the family Calliphoridae. Of this thirteen (38%) have eggs of taeniid and cysts of Entamoeba coli (Grassi, 1879) and Giardia lamblia Styles, 1915.

Trypanorhyncha from sharks of southern brazilian coast: Eutetrarhynchus vooremi sp. n. and two other species parasites of Mustelus (Pisces, Triakidae)

In the present paper, Eutetrahynchus vooremi sp. n., a cestode of the order Trypanorhyncha is proposed. The new species was recovered from sharks under the genus Mustelus (Pisces, Triakidae) and was compared to E. ruficollis, E. lineatus, E. leucomelanus, E. litocephalus and E. macrotrachelus. The main character, among others, considered to differ the species refers to the eggs filament, size of proglottids, tentacular hooks and lenght of pars postbulbosa. Two other known species are studied: Callitetrarhynchus gracilis (Rudolphi, 1819) from M. canis (Mitchill, 1815) and Nybelinia (N.) lingualis (Cuvier, 1817) from M. schmitti Springer, 1939 representing new host records.

Sarcopromusca pruna (Diptera: Muscidae) as an egg transport host of Dermatobia hominis (Diptera: Cuterebridae) in the cacau region of Bahia, Brazil

Sarcopromusca pruna appears to be the predominant transport host for Dermatobia hominis eggs among cattle herds in central eastern Bahia, Brazil. In the study area, two seasonal peaks of S. Pruna abundance coincide with those of Dermatobia, from mid July through late September and from mid November until early January, two periods of moderate monthly rainfall between anual extremes. Among more than 26,000 flies examined during the study, 75 (all female S. pruna) bore Dermatobia eggs. Certain aspects of Dermatobia behavior and ovoposition habits in the field are also discussed.

A morphological, isoenzymatic and behavioural study of ten populations of Anopheles(Nyssorhynchus) albitarsis Lynch-Arribalzaga, 1878 (Diptera: culicidae) including from the type-locality - Baradero, Argentina

Anopheles (Nyssorhynchus) albitarsis Lynch-Arribalzaga, 1878 shows morphological and behavioural variations which results in it being sometimes considered as a major malaria vector and at other times as playing no important role in epidemiology. With the aim of clarifying the taxonomy of the species, comparative morphological and isoenzymatic studies were made in populations from the type-locality, Baradero, Argentina and from 9 different localities inBrazil. Morphological studies consisted of the observation of eggs in scanning electron microscopy, of complete chaetotaxy of larvae and pupae and of the detailed drawing of male and female adults. Only Guajara-Mirim and Rio Branco populations, described previously as Anopheles deaneorum sp.n., showed morphological differences. Isoenzymes were studied using 4th instar larvae homogenate and agarosegel electrophoresis. Eleven enzymatic loci were analyzed. By calculation of Nei's Genetic Distance (D), the populations could be separated into 5 groups: i)Baradero, ii)Marajo, iii)Boa Vista, iv)Angra, Itaguai and Paraipaba and v)Guajara-Mirim and Rio Branco. These groups belong to 2 major clusters called I and II, separated by D = 0.345. In the I cluster are groups i, ii and iii and in II clusteriv and v. In I, D=0.246 separates i and ii from iii, while i is separated by D =0.181 from ii. In II, D = 0.223 between iv and v. Only the population of group vcould be distinguished morphologically from the others, leading to the description of an independent species An. deaneorum.

Comparative studies on the growth and reproductive performances of Rhodnius prolixus reared on different blood sources

Host blood source was found to affect both the development and the reproductive performance of Rhodnius prolixus. The insects were reared on citrated human, rabbit, chicken, sheep and horse blood sources, through a membrane feeder, during an entire life cycle, from eggs to adults. Development and reproduction in terms of the number of unfed insects, number of moulting, mortality intermoulting period, number of egg/female, conversion of blood into egg (mg meal/egg) and percentage of hatch as effective physiological parameters were investigated. Our results showed that human or rabbit blood meals were more nutritionally efficient than the other blood samples used because (i) the insects developed faster, presented low mortality and about 80% of them reached the adult stage; and (ii) females oviposited an average of at least 100% more eggs. The inefficiency of chicken and horse blood sources as diets for R. prolixus was manifested in (i) a decrease of the amount of ingested blood and (ii) only a reasonable nutritional quality. The inadequacy of sheep blood was observed by a mortality extremely high, poor moulting response and drastic reduction in egg production.

Estudos bionomicos de Cavernicola lenti Barrett & Arias, 1985 (Hemiptera, Reduviidae, Triatominae)

In the biological study, the development of the biological cycle of the insect under different feeding conditions was evaluated. The insects were fed on either mouse blood (c) or pigeon blood (p) using two types of rearing techniques (individual or group) at 28(graus) C and 90% relative humidity (which is equivalent to their natural environment). A fifth cycle studied, was fed on mouse blood reared on group, and mantained at laboratory environmental temperature. In the five cycles analyzed, it was found that groups on mouse blood at near natural conditions developed more rapidly (between 60 and 73 days) and had a lower rate of mortality (16.66%). The daily handling and changes in environment, of the individually reared insects, for observation of biological characteristics (no. and duration of bloodmeal, defecation and first fed of each stage) had a negative influence. None of the individuals fed on mouse or pigeon blood reached adult hood. It was found that the longevity and the fertility rate were significantly superior on couples maintained individually on mouse blood. These males had an average lifespan of 110,26 days and the females had an average lifespan of 104,46 days. The average number of eggs laid by each female was 21,26. Four couples kept in groups (five couples in each group) under the same condition, the longevity for males was 51,86 days and for females was 81,06 days. An average of 10,5 eggs were laid by each female. However, the percentage of fertile eggs was higher in couples kept in groups (72.15%) than in the individual couples (57.68%).

Fecundity, parity, and adult feeding relationships among Nyssorhynchus malaria vectors from Venezuela

Relative to their pre-engorgement weights, nulliparous Anopheles nuneztovari consumed significantly smaller blood meals than A. marajoara, A. triannulatus or A. aquasalis. When females were deprived of sugar before blood feeding, only one-quarter of A. nuneztovari, but more than two-thirds of A. marajoara, A. triannulatus and A. aquasalis matured eggs. Sugar feeding before blood, or two sucessive blood meals by sugar-deprived females, increased the proportion of nulliparous a. nuneztovari which developed eggs, but not significantly so. Nearly all individuals of nulliparous, sugar-fed A. marajoara, A. triannulatus and A. aquasalis matured eggs after one blood feeding. Among A. nuneztovari, A. marajoara and A. aquasalis that matured some eggs in the laboratory, there were no positive correlations between the number of eggs developed and relative vlood mealsize. However, blood meals larger than the mean size significantly increased the chance that A. nuneztovari would develop some eggs. Mean fecundities of gravid A. nuneztovari and A. marajoara reared in the laboratory were significantly lower than those of the same species captured at human bait in nature. Post-engorgement access to sugar by A. nuneztovari (captured at human bait) did not influence fecundity, but significantly enhanced survivorship and the proporticon of individuals which retained eggs. Release-recapture experiments revealed that relatively small blood meals are typical of A. nuneztovari only during the first gonotrophic cycle. We suggest that multiple blood feeding, seemingly necessary for most A. nuneztovari to develop a first clutch of eggs, may increase the probability of infection with Plasmodium vivax where this mosquito species is a primary vector.

Le nombre de reines chez les fourmis et sa conséquence sur l'organisations sociale

Nearly half of all ant species form polygyne societies (cohabitation of more than a single egg-laying queen). These queens are generally smaller and store fewer fat reserves than queens from monogyne colonies. Most queens in polygyne colonies (70-100 pour 100) are inseminated, although this proportion varies among species, and even among populations of the same species. They exhibit mutual tolerance and they all contribute to the reproductive effort of the colony. Nevertheless, their individual fecundity is considerably reduced compared with that of queens from monogyne colonies. This reduction in fecundity seems to be due to some form of mutual inhibition, in some cases the secretion by each female of a substance suppressing egg production in other queens has been implicated. In a few species, queens are organized into a hierarchy such that certain queens lay more eggs than others or even monopolize egg-laying (functional monogyny). Polygyny is linked to a particular life history. It rarely results from the association of several foundresses (primary polygyny). Usually, it is due to the adoption of young queens by an established nest just after a nuptial flight. This secondary polygyny means that the dispersal of the species is limited and is achieved by the budding of a mother nest. Thus colony founding is dependent; with workers accompanying young queens in establishing new colonies. Observation of closely related species exhibiting different social organizations, some monogyne and others polygyne, shows a possible link between queen number and ecological conditions: polygyne forms are more frequent in unstable habitats susceptible to rapid change, such as that caused by human activity. The existence of polygyne societies is an intriguing evolutionary mystery. Research into the origin and maintenance of polygyny focuses on patterns of speciation in relation to queen number and the different theories put forth for the evolution of eusociality, mainly kin selection and mutualism.

Composición en ácidos grasos de huevos y larvas de dentón (Dentex dentex L.) de hasta 40 días en condiciones de cultivo

Total lipid content and fatty acid (FA) composition of common dentex eggs spawned at different times and larvae reared under different culture conditions until 40 days post hatch (dph) were analysed in order to get a general pattern of lipid composition during larval development. Results were grouped according to the developmental stage of the larvae instead of age in dph. Saturated and monounsaturated fatty acids decreased along larval development, while polyunsaturated fatty acid (PUFA) content increased. The ratio of docosahexaenoic acid (DHA) / eicosapentaenoic acid (EPA) shifted from 4 – 5 in early developmental stages to lower than 1 after metamorphosis. Results suggest a subdivision of the larval development into two stages of opposite FA requirements.

Gastromermis cordobensis n. sp. (Nematoda: Mermithidae) parasitizing Simulium lahillei Patterson & Shannon (Diptera: Simuliidae) in Argentina

Gastromermis cordobensis n. sp (Nematoda: Mermithidae) a parasite of larvae of the blackfly Simulium lahillei Paterson & Shannon (Diptera: Simuliidae) in Argentina, is described. Diagnostic characters of this species include a mouth ventrlly shifted; six cephalic papillae; eigh hypodermal chords; small and pear shaped amphids; a long and S-shaped vagina; a singl spicule, which is long, has non-uniform walls, and a tip with sculpture; three rows of genital papillae, the middle one with 18 pre-anal and 10 post-anal papillae, the lateral rows have 36 papillae each; oval eggs; and post-parasitic juveniles with long thin tails. Pre-parasitic and parasitic juveniles are included in the description.

Estudos morfológicos de Cavernicola lenti Barrett & Arias, 1985 (Hemiptera, Reduviidae, Triatominae)

In order to widen the present knowledge of this species, was done a detailed description of eggs and all nymphal stages as well as the external genitalia of the males and females using light and scanning electron microscopy. The characteristics were compared with another species of the same genus C. pilosa Barber, 1937. Observations on the male internal genitalia were also done.

Two alternate mechanisms contribute to the persistence of interdependent lineages in Pogonomyrmex harvester ants.

Some populations of Pogonomyrmex harvester ants comprise pairs of highly differentiated lineages with queens mating at random with several males of their own and of the alternate lineage. These queens produce two types of diploid offspring, those fertilized by males of the queens' lineage which develop into new queens and those fertilized by males of the other lineage which mostly develop into functionally sterile workers. This unusual mode of genetic caste determination has been found in 26 populations and a total of four lineage pairs (F(1)-F(2), G(1)-G(2), H(1)-H(2) and J(1)-J(2)) have been described in these populations. Despite the fact that a few interlineage queens are produced, previous studies revealed that there is a complete lack of genetic introgression between lineages. Here we quantify the proportion of interlineage queens produced in each of the four lineage pairs and determine the fate of these queens. In the F(1)-F(2), G(1)-G(2) and H(1)-H(2) lineage pairs, interlineage queens were produced by a minority of colonies. These colonies exclusively produced interlineage queens and workers, suggesting that interlineage eggs can develop into queens in these three pairs of lineages in the absence of competition with pure-lineage brood. An analysis of three key stages of the colony life cycle revealed that colonies headed by interlineage queens failed to grow sufficiently to produce reproductive individuals. In laboratory comparisons, interlineage queens produced fewer viable eggs, with the effect that they raised fewer workers and lost more weight per worker produced than pure-lineage queens. In the J(1)-J(2) lineage pair, we did not find a single interlineage queen, raising the possibility that interlineage eggs have completely lost the ability to develop into queens in this lineage pair. Hence, two distinct mechanisms seem to account for the complete lack of between-lineage gene flow in the F(1)-F(2), G(1)-G(2), H(1)-H(2) and J(1)-J(2) lineage pairs.

Intestinal parasites in Iaualapiti indians from Xingu Park, Mato Grosso, Brazil

Brine flotation and gravity sedimentation coproscopical examinations were performed in stool samples from 69 of the 147 Iaualapiti Indians of the Xingu Park, Mato Grosso State, Brazil. Intestinal [arasites were present in 89.9% of the population examined. High rates of prevalence were found for some parasite species. Ancylostomidae, 82.6%; Enterobius vermicularis, 26.1%; Ascaris lumbricoides, 20.3%; and Entamoeba coli, 68.1%. Infection by Trichuris trichuria, Schistosoma mansoni, Taenia spp. and Hymenolepis nana was not detected. Helminth's prevalence in children aged one year or less was comparatively low (33.3%). Quantitative coproscopy was done in positive samples for Ascaris and Ancylostomidae and the results expressed in eggs per gram of feces (EPG). Quantitative results revealed that worm burdens are very low and overdispersed in this Indian tribe, a previously unreported fact.