Algumas espécies da família Culicidae são importantes vetores de doenças em humanos e em outros animais. Estágios imaturos são filtradores não seletivos de partículas orgânicas e microrganismos. Estudos da diversidade microbiológica podem contribuir para a descoberta de novas substâncias que podem ser usadas em indústrias farmacêuticas, para alimentação ou para controle biológico. O objetivo deste estudo foi isolar e identificar os fungos associados a larvas de Culicidae encontradas em diferentes tipos de criadouros (natural e artificial), como casca de frutos, buracos em pedras, lagoas, plantas aquáticas, bráctea de palmeira e potes de cerâmica, em vários municípios da Amazônia Brasileira, principalmente no Amazonas e em Rondônia. O total de 38 isolados foram obtidos a partir de larvas de Aedes aegypti (L.), Aedes fluviatilis (Lutz), Trichoprosopon digitatun (Rondani), Anopheles argyritarsis argyritarsis Robineau-Desvoidy, Anopheles darlingi Root, Aedeomyia squamipennis (Lynch Arribálzaga), Mansonia titillans (Walker) e Uranotaenia sp. Os fungos que ocorreram nas larvas de Culicidae foram: Acremonium kiliense, Aspergillus sydowii, Fusarium sacchari var. sacchari, Fusarium merismoides var. merismoides, Gliocladium viride, Paecilomyces sp., Penicillium citrinum, Penicillium sclerotiorum, Penicillium melinii, Penicillium oxalicum. Características macro-microscópicas dos isolados foram apresentadas, assim como informações sobre a distribuição geográfica.

Several species of the family Culicidae are important vectors of diseases in humans and other animals. Immature stages are filter-feeders of organic particulate matter and microorganisms. Studies on microbial diversity can contribute to the discovery of new substances that can be used in the pharmaceutical industry for food or for biological control. The aim of this study was to isolate and identify the fungi associated with Culicidae larvae found in different habitats (natural and artificial), such as fruit shells, rock holes, lakes, aquatic plants, palm bracts and ceramic pots, in several municipalities of Brazilian Amazonia, especially in the states of Amazonas and Rondônia. A total of 38 fungal lineages were isolated from larvae of Aedes aegypti (L.), Aedes fluviatilis (Lutz), Trichoprosopon digitatum (Rondani), Anopheles argyritarsis argyritarsis Robineau-Desvoidy, Anopheles darlingi Root, Aedeomyia squamipennis (Lynch Arribálzaga), Mansonia titillans (Walker) and Uranotaenia sp. The following fungi occurred associated with the larvae of Culicidae: Acremonium kiliense, Aspergillus sydowii, Fusarium sacchari var. sacchari, Fusarium merismoides var. merismoides, Gliocladium viride, Paecilomyces sp., Penicillium citrinum, Penicillium sclerotiorum, Penicillium melinii and Penicillium oxalicum. Macro- and microscopic characteristics of the lineages are presented, as well as information on their geographical distribution.

Eight species of Harpellales and three species of Eccrinales (Zygomycota: Trichomycetes) were found associated with the digestive tract of arthropods from terrestrial and aquatic environments in the central Amazon region of Brazil. New species of Harpellales include: Harpella amazonica, Smittium brasiliense, Genistellospora tropicalis in Simuliidae larvae and Stachylina paucispora in Chironomidae larvae. Axenic cultures of S. brasiliense were obtained. Probable new species of Enterobryus (Eccrinales), Harpella, and Stachylina (Harpellales) are described but not named. Also reported are the previously known species of Eccrinales, Passalomyces compressus and Leidyomyces attenuatus in adult Coleoptera (Passalidae), and Smittium culisetae and Smittium aciculare (Harpellales) in Culicidae and Simuliidae larvae, respectively. Comments on the distribution of some of these fungi and their hosts in the Neotropics are provided.

Number of larval instars, age structure and environmental effects on these parameters represent basic information in the study of insect population biology. When species have economic importance, this information is essential in order to choose the best period to apply different control methods and to determine the stages of the life cycle of the insect that are most susceptible to each treatment. The family Simuliidae has many species of medical/veterinary importance in the world, and some studies in the temperate region have suggested that the number of larval instars and the larval size can vary according to the season, gender and some environmental factors, such as temperature and diet. This study, with the zoophilic species Simulium perflavum Roubaud, is the first in the Neotropics observing some of these factors and will serve as a template for other species of medical importance in the region. S. perflavum larvae were collected in five streams in Central Amazônia (Manaus and Presidente Figueiredo counties, State of Amazonas), in Sept./Oct. 1996 (dry season) and Feb./Mar. 1997 (rainy season). These larvae were measured (lateral length of head capsule and width of cephalic apodema) to determine the number of larval instars (n=3985), to compare the larval size between seasons and genders (last and penultimate larval instars, n=200). Seven larval instars were determined for this species using frequency distributions, t-tests and Crosby´s growth rule. Significant differences were not detected (t-test, p>0.05) in larval size between seasons and genders. Our results differ from some found in temperate regions suggesting that in the Neotropical region the larval size in different seasons and different genders remains constant, although some environmental parameters, such as diet, change depending on the season.

Stomach contents of Simulium perflavum Roubaud larvae were analyzed and compared with plankton and periphyton collected in five streams, in Central Amazonia (Manaus and Presidente Figueiredo counties), in Sep./Oct.1996 (dry season) and Feb./Mar. 1997 (rainy season). A total of 1,400 last-instar larvae were dissected; the stomach contents were analyzed using different methods: fresh and after oxidation. A total of 87 taxa (algae, diatoms and rotifers) were found in the stomach contents. In each stream, qualitative samples of plankton and periphyton were collected; these were mounted between slides and cover slips. A total of 94 taxa of plankton and 54 taxa of periphyton were collected. One species of Rotifera was present in the stomach contents, plankton and periphyton. Cluster analysis based on species composition of the organisms present in the stomach contents grouped the streams into two major groups, each belonging to a different drainage area. Correlations based on presence/absence of species of microalgae in the stomach contents, plankton and periphyton indicated significant associations (p<0.05) between stomach contents and plankton and between plankton and periphyton (z test); the Sorensen coefficient and cluster analysis corroborate the same associations.