RESUMO Quatro deutoninfas de ácaros do bulbo (hipopus) da espécie Rhizoglyphus echinopus (Fumouze & Robin) (Acari: Acaridae) foram encontradas fixadas na cabeça de formigas da espécie Atta sexdens no Rio de Janeiro, Brasil. Essa espécie de ácaro está comumente associada a plantas ornamentais e plantas com bulbos e tubérculos. Os resultados desse estudo fornecem uma visão sobre a relação forética entre ácaros e formigas, indicando o papel destas últimas na dispersão dos primeiros. Apesar da abundância e da fauna diversa do ácaro em formigas, pouco se sabe sobre a diversidade, a biologia, a ecologia e a natureza dessa associação.

ABSTRACT Four deutonymphs of bulb mites (hypopus) from Rhizoglyphus echinopus (Fumouze & Robin) (Acari: Acaridae) were found attached to the head of Atta sexdens in Rio de Janeiro, Brazil. This mite species is commonly associated with ornamental plants and trees with bulbs, corms and tubers. The results of this study provided an insight into the phoretic relationship between mites and ants, indicating the role of the latter in the dispersion of the first. Despite the abundant and diverse mite fauna existing in ants, little is known about their diversity, biology, ecology and the nature of their associations.

Resumen Esta investigación se llevó a cabo para evaluar los efectos de los extractos de Rheedia longifolia (Clusiaceae), Garcinia xanthochymus (Clusiaceae), Plumbago scandens (Plumbaginaceae) Hovenia dulcis (Rhamnaceae), Malpighia glabra (Malpighiaceae), Euphorbia tirucalli (Euphorbiaceae) y Nerium adelfa (Apocynaceae) sobre la tasa incubación de los huevos de Dermacentor (Anocentor) nitens y Ripicephalus sanguineus (Acari: Ixodidae) en concentraciones de 1.000 ppm. Los extractos de R. longifolia, H. dulcis, M. glabra y E. tirucalli retrasaron significativamente la incubación de los huevos de R. sanguineus en tres días, pero los grupos tratados con los extractos de G. xanthochymus y P. scandens eclosionaron después de 14 días. Para las garrapatas D. (A.) nitens, los extractos de H. dulcis y N. adelfa retrasaron la eclosión de los huevos durante tres días, sin embargo, la acción de los extractos de R. longifolia, G. xanthochymus, P. scandens y E. tirucalli causó un retraso mayor de siete días. Para los dos tipos de garrapatas, los huevos del grupo control tardaron un día para eclosionar. Los extractos H. dulcis y M. glabra fueron eficaces in vitro en huevos de R. sanguineus (89 %) y D. (A.) nitens (100 %) y se pueden considerar como candidatos potenciales para el control biológico de estas garrapatas.

Abstract This investigation was carried out to evaluate the effects of the plant extracts of Rheedia longifolia (Clusiaceae), Garcinia xanthochymus (Clusiaceae), Plumbago scandens (Plumbaginaceae), Hovenia dulcis (Rhamnaceae), Malpighia glabra (Malpighiaceae), Euphorbia tirucalli (Euphorbiaceae) and Nerium adelfa (Apocynaceae) on eggs of Dermacentor (Anocentor) nitens and Ripicephalus sanguineus (Acari: Ixodidae) at concentrations of 1,000 ppm. The extracts had a significant effect on the hatching rate of eggs. The extracts of R. longifolia, H. dulcis, M. glabra and E. tirucalli delayed the hatching of R. sanguineus eggs by three days; however, the group treated with the extracts of G. xanthochymus and P. scandens did not hatch until day fourteen. For the tick D. (A.) nitens, extracts of H. dulcis and N. oleander delayed egg hatching by three days; however, the action of extracts from R. longifolia, G. xanthochymus, P. scandens and E. tirucalli caused a delay of seven days. For the control groups of both species, eggs hatched in one day. H. dulcis and M. glabra were effective in vitro on eggs of R. sanguineus and D. (A.) nitens (89 and 100 %, respectively), and can be considered to be potential candidates for the biocontrol of those ticks.

Resumen Muchas especies de artrópodos principalmente moscas (Diptera) y sus ácaros foréticos son atraídos por la carroña. Este es el primer registro de ácaros foréticos y parásitos Leptus sp., Macrocheles muscaedomesticae y Longoseius brachypoda, en moscas necrófagas en Brasil.

Abstract Many arthropod species, mainly flies (Diptera) and their phoretic mites are attracted by carrion. This is the first record of phoretic and parasitic mites Leptus sp., Macrocheles muscaedomesticae and Longoseius brachypoda associated with necrophagous flies in Brazil.

Abstract Background Having the right identification is essential in the field of entomology. The scanning electron microscopy allows rapid and accurate identification of different species of flies since a better visualization of the external morphology of immature and some adults is possible. The aim of this study is to describe some ultrastructures of three flies in the Mesembrinellidae family: Mesembrinella bellardiana; Mesembrinella bicolor and Mesembrinella semihyalina, all examined by scanning electron microscopy to help increase the anatomical database on flies and deal with phlylogenetic implications. Results The flies were examined under JEOL 6390LV scanning electron microscope (SEM). The microtrichia morphology of the antennae is similar to that of other and are present on all antennal surface with variable distribution. The chaetic sensilla were observed only in the scape (chaetic sensilla I) and pedicel segments (chaetic sensilla I-III). Three types of sensilla: trichoidea, basiconic and clavate were observed in the first flagellomere of M. bellardiana; and two types of sensilla: trichoidea and basiconic were noticed in M. bicolor and M. semihyalina. Olfactory pits were observed in both gender of M. bellardiana and female of M. bicolor . The maxillary palp of the Mesembrinella species in this study does not show sexual dimorphism. Conclusion This investigation provided new findings of some diagnostic structures of flies using SEM, since many of them could have not been observed just by the use of light microscopy.

O óleo essencial de Cymbopogon citratus, coletado no Brasil e em Cuba, foi caracterizado quimicamente e testado no desenvolvimento pós-embrionário de Musca domestica. A análise da composição química dos óleos essenciais (Brasil/Cuba), por Cromatografia Gasosa acoplada ao espectrômetro de massa (GC-EM), permitiu a identificação de 13 e 12 componentes principais, respectivamente; nove deles comuns aos dois. Em ambos os óleos, os principais componentes foram os isômeros geranial e neral, que, juntos, formam o composto citral. Esse corresponde a um total de 97,92%/Brasil e 97,69%/Cuba dos compostos identificados. O monoterpeno mirceno, observado na amostra cubana, apresentou grande abundância relativa (6,52%). O óleo de C. citratus (Brasil/Cuba) foi dissolvido em DMSO, obtendo–se as concentrações de 5, 10, 25, 75 e 100%; e o citral (16,8 mg) foi misturando com 960mL de DMSO. Tanto o óleo essencial como o monoterpeno citral foram aplicados topicamente nas neolarvas (1µL/larva). Os resultados mostraram uma concentração letal (CL50) de 4,25% e 3,24% para o óleo essencial brasileiro e cubano, respectivamente. As mortalidades do período larval e o de neo-larva a adulto foram dose-dependentes, tanto para os óleos como para o monoterpeno citral, podendo chegar a 90%. Ambos os óleos essenciais e citral causaram alterações morfológicas nos espécimes adultos.

Essential oil of Cymbopogon citratus collected from Brazil and Cuba was tested to a chemical characterization and then was tested on the post-embryonic development of Musca domestica. The chemical composition analysis by GC-MS of the oils from Brazil/Cuba allowed the identification of 13 and 12 major constituents respectively; nine of them common to both. In the both oils, the main components were the isomers geranial and neral, which together form the compound citral. This corresponds to a total of 97.92%/Brazil and 97.69%/Cuba of the compounds identified. The monoterpene myrcene, observed only in the sample of Cuba, presented a large relative abundance (6.52%). The essential oil of C. citratus (Brazil/Cuba) was dissolved in DMSO and tested at concentrations of 5, 10, 25, 50, 75 and 100% and citral was prepared by mixing 16.8 mg with 960 µL DMSO. Both essential oils and monoterpene citral were applied topically to newly-hatched larvae (1µL/larva). The results showed a lethal concentration (LC50) of 4.25 and 3.24% for the Brazilian and Cuban essential oils, respectively. Mortalities of larval and newly-hatched larvae to adult periods were dose-dependent for the two both oils as for monoterpene citral, reaching 90%. Both essential oils and citral caused morphological changes in adult specimens.

Ácaros aquáticos são parasitas comuns de alguns insetos aquáticos em habitats de água doce. Este é o primeiro registro do ácaro Arrenurus Dugès, 1834, como parasita de Odonata no Brasil. Ácaros aquáticos foram coletados em Miathyria marcella (Selys, 1857) e Ischnura fluviatilis (Selys, 1876).

Water mites are common and widespread parasites of some aquatic insects in freshwater habitats. This is the first record of acari Arrenurus Dugès, 1834, as a parasite of Odonata in Brazil. Water mites were sampled from Miathyria marcella (Selys, 1857) and Ischnura fluviatilis (Selys, 1876).

The life cycle and reproductive patterns of Triatoma rubrofasciata were studied along with laboratory conditions for the establishment of a prolific colony. The insects were divided into four groups: two of them were maintained at room temperature (20.5°C to 33°C and 85% ± 5% of relative humidity), the other two in a climatic chamber (CC) (temperature: 29°C, humidity: 80% ± 5%). The groups were fed weekly or fortnightly on Swiss mice. The females from the group kept in the CC and fed weekly had longer life span, as well as a higher number of eggs, fertile eggs and hatchings; the group kept in the CC and fed fortnightly had a shorter life span for the 1st, 2nd and 3rd instars and a lower mortality rate for all instars. It was concluded that a constant high temperature (CC at 29°C) is the most suitable condition for the maintenance of a colony of T. rubrofasciata regardless of the interval between repasts.