Variation of the oviposition preferences of Aedes aegypti in function of substratum and humidity.

Two Aedes aegypti (L.) populations were studied in the laboratory regarding the preference for three types of breeding sites, i.e., flasks containing only water, flasks with a plant and flasks with a stick. Each of these breeding units was placed in one cage and the choice of the oviposition sites was determined for individual females and three females per experimental unit at two humidity levels. Preference for ovipositing on the water surface was observed and varied according to experimental unit and humidity. Mean hatching of eggs in water surface was 46.6%. Experiments with three females showed a more marked difference than when only one female was used. Inter and intrapopulation variability regarding oviposition sites was observed. The discrimination between the different oviposition substrates, hatching in water surface and its implication for mosquito control are discussed.

Would Chrysomya albiceps (Diptera: Calliphoridae) be a beneficial species? / Seria Chrysomya albiceps (Diptera: Calliphoridae) uma espécie benéfica?

Chrysomya albiceps (Widemann) develops on animal carcasses and may cause secondary myiases. An adult female Merino sheep presented a lesion of roughly circular shape with a 7.5cm radius in the anterior part of the thorax. A large number of second-instar larvae was removed from the lesion in addition to first-instar larvae from the wool. A third-instar larva was also obtained from the same lesion site and in the laboratory gave origin to a Cochliomyia hominivorax (Coquerel) adult insect. The larvae retrieved from the lesion were natured in laboratory. Pairs consisting of 100 individuals were formed with the adult specimens obtained from the larvae and kept in two cages. In all of the 800 adults reared in the laboratory and examined (100 per generation) the propisternal seta was absent in the spiracle on both sides, this trait was highly stable. The 200 larvae examined, 15 per generation, did not present spines in the column of the ventral process of the penultimate abdominal segment and the column of the ventral process was triangular and the apex of the column process presented numerous spines. These characteristics allowed identifying these specimens as C. albiceps. However, since C. albiceps has the ability to damage intact tissues, it may be causing relevant aggravation when associated with C. hominivorax and can not be considered innocuous (AU)

Chrysomya albiceps (Widemann) é uma mosca que se desenvolve em carcaças e opcionalmente pode causar miíase secundária. Larvas de segundo estádio foram removidas de uma lesão existente em uma ovelha da raça Merino em Botucatu. Entre a lã, ao redor da lesão, foram encontradas larvas de primeiro estádio. Também no interior da lesão foi obtida uma larva de terceiro estádio. As larvas foram mantidas em laboratório e delas obtidos insetos adultos, com 50 casais formados e mantidos em gaiolas por oito gerações. De cada geração, 100 adultos eram sacrificados e examinados morfologicamente, com os seus caracteres confrontados com os de Chrysomya rufifacies. A larva de terceiro estádio deu origem a Cochliomyia hominivorax e as demais a C. albiceps. Foi verificado que C. albiceps, além de ser capaz de danificar tecido integro, é também uma possível predadora de larvas de C. hominivorax. A importância de C. albiceps para os animais domésticos e sua associação com C. hominivorax é aqui discutida. (AU)

Would Chrysomya albiceps (Diptera: Calliphoridae) be a beneficial species?

Chrysomya albiceps (Widemann) develops on animal carcasses and may cause secondary myiases. An adult female Merino sheep presented a lesion of roughly circular shape with a 7.5cm radius in the anterior part of the thorax. A large number of second-instar larvae was removed from the lesion in addition to first-instar larvae from the wool. A third-instar larva was also obtained from the same lesion site and in the laboratory gave origin to a Cochliomyia hominivorax (Coquerel) adult insect. The larvae retrieved from the lesion were natured in laboratory. Pairs consisting of 100 individuals were formed with the adult specimens obtained from the larvae and kept in two cages. In all of the 800 adults reared in the laboratory and examined (100 per generation) the propisternal seta was absent in the spiracle on both sides, this trait was highly stable. The 200 larvae examined, 15 per generation, did not present spines in the column of the ventral process of the penultimate abdominal segment and the column of the ventral process was triangular and the apex of the column process presented numerous spines. These characteristics allowed identifying these specimens as C. albiceps. However, since C. albiceps has the ability to damage intact tissues, it may be causing relevant aggravation when associated with C. hominivorax and can not be considered innocuous

Diversity of ectoparasites in sheep flocks in São Paulo, Brazil.

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of São Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the 'Associação Paulista de Criadores de Ovinos' (ASPACO; São Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.

Effect of management practices on screw-worm among sheep in São Paulo State, Brazil.

The screw-worm Cochliomyia hominivorax (Coquerel), whose larvae develop in wild and domestic animals as well as in man, is one of the major causes of myiasis in Brazil. Sheep raising is expanding in the state of São Paulo, where information about the infestation of screw-worm is necessary for appropriate control measures. The present data were obtained from questionnaires sent to all sheep breeders belonging to Associacão Paulista de Criadores de Ovinos--ASPACO (São Paulo State Association of Sheep Breeders). Response reliability was tested by random visits paid to 10.6% of the respondents. The results show that screw-worm is the most frequent ectoparasite in the flocks and is responsible for the greatest economic losses. Its occurrence is strongly associated with flock size, reaching 100% in flocks consisting of more than 500 animals. Infestation is higher in spring and summer and lowest in the fall. The number of cases increases in the presence of some management practices such as tail amputation. Furthermore, several other associations between the indicators surveyed were also found to be significant. The data obtained will permit the elaboration of strategies for the control of this parasitosis.

Primary myiasis in dog caused by Phaenicia eximia (Diptera:Calliphoridae) and preliminary mitochondrial DNA analysis of the species in Brazil.

A case of primary myiasis in a dog caused by Phaenicia eximia (Robineau-Desvoidy) in Brazil is presented. A young and healthy female dog, Canis familiaris, approximately 10 d old and still under maternal care, was found to have several eggs and 1st instars larvae in its abdomen and urogenital regions. Samples were collected in Campinas, São Paulo, and transferred to the laboratory for rearing and identification. A comparative analysis of the mitochondrial DNA (mtDNA) with 12 restriction enzymes in 2 sampled populations of P. eximia collected in different hosts (live dog and bovine carcass) and in the same locality revealed that 4, EcoRI, EcoRV, HaeIII, and MspI were suitable for detecting mtDNA markers in the 2 populations.

Prevalência de Demodex folliculorum e Demodex brevis em uma amostra da populaçäo de Botucatu, Säo Paulo, Brasil / The prevalence of Demodex folliculorum and Demodex brevis in a population sample from Botucatu, Säo Paulo, Brazil

Pela primeira vez no Brasil foi realizado um levantamento para se conhecer a distribuiçäo do D. folliculorum e d. brevis no homem. Uma amostra de 100 pessoas atendida em clínica estética foi examinada, procurando-se estudar a associaçäo entre a presença de ácaros e fatores como idade, raça e sexo do hospedeiro. O material colhido da regiäo facial dos indivíduos foi montado em lâminas com o meio de Berlese. Das 100 pessoas examinadas, 72 por cento foram positivas. Dos casos positivos, 51 por cento estavam infestadas pelo D. folliculorum, 2 por cento pelo D. brevis e 19 por cento apresentaram-se parasitados por ambas as espécies

[The prevalence of Demodex folliculorum and Demodex brevis in a population sample from Botucatu, São Paulo, Brazil]. / Prevalência de Demodex folliculorum e Demodex brevis em uma amostra da população de Botucatu, São Paulo, Brasil.

A survey was conducted to determine the prevalence of D. folliculorum and D. brevis for the first time in Brazil. In this study, association between the presence of mites and host factors (age, sex and race) were analysed. Samples were obtained from 100 individuals submitted to a facial cleaning in an aesthetic clinic in Botucatu city. All the samples were mounted in Berlese's medium and examined by dark-field phase microscopy. From 100 studied individuals, 72 were positive, among the positive cases, 51% showed D. folliculorum, 2% showed D. brevis and 19% both species. The parasite distribution in relation to sex was not taken in account because the sex ratio favoured females (90%). According to age, prevalence was high in all age groups. The factors influencing this distribution could be due. 1. the examination of extensive skin areas, 2. the group examined composed of individuals in treatment in an anaesthetic clinic could be more infested than a normal population, 3. the fact that in tropics, the prevalence is often high in all ages.

Suscetibilidade de Biomphalaria tenagophila de Belo Horizonte e adjacencias a infeccao com tres cepas de Schistosoma mansoni. / Susceptibility of Biomphalaria tenagophila from Belo Horizonte and neighborhood to infection with 3 strains of Schistosoma mansoni

Caramujos Biomphalaria tenagophila, descendentes de exemplares coletados nos Municipios de Belo Horizonte, Sabara e Nova Lima, Estado de Minas Gerais, foram infectados experimentalmente com tres cepas de Schistosoma mansoni: "LE", de Belo Horizonte; "SS", silvestre de Sabara e "SJ", de Sao Jose dos Campos (SP). Os caramujos de Belo Horizonte foram suscetiveis as cepas "LE" (4,0%) e "SJ" (22,0%). Os moluscos de Sabara (Ravena) foram resistentes a infeccao com as tres cepas do trematodeo. Os exemplares de Nova Lima foram resistentes a cepa "LE" e suscetiveis as cepas "SS" (2,0%) e "SJ" (6,0%). Os indices de infeccao experimental foram semelhantes aos registrados por outros Autores para B.tenagophila de Minas Gerais. As cercarias da cepa "SJ", obtidas de B. tenagophila de Belo Horizonte, foram infectantes para camundongos e o numero medio e distribuicao dos vermes foram normais. Discute-se a importancia desses moluscos como hospedeiros em potencial do S. mansoni, nessa regiao