First trials exploring the potential of phytoseiid mites in managing lychee erinose mite, Aceria litchii (Keifer) (Acari: Eriophyidae), infestations on lychee plants.

Phytoseiid mites have been frequently found in association with the lychee erinose mite, Aceria litchii, on lychee plants in Brazil, suggesting that they are promising candidates as biological control agents against this pest. Here, we investigated whether phytoseiids would suppress A. litchii infestation, i.e. formation of erinea, on lychee plants under field conditions. Four groups of A. litchii-infested plants were randomly distributed in the field, with each group receiving either Phytoseius intermedius, Amblyseius herbicolus, A. herbicolus supplemented with cattail pollen or no predator. During a three-month period, the released predators, along with others present in the surrounding environment, were allowed to freely walk among all plants. In each plant, we evaluated the occurrence of phytoseiid species, their abundance, and the dynamics of erinea formation. A total of 2,097 mites, including 13 other phytoseiid species were identified. The most abundant species were Iphiseiodes zuluagai and Euseius ho, rather than the two predator species that were released. A. herbicolus and P. intermedius failed to establish populations in the majority of the plants, regardless of the presence of pollen, suggesting their ineffectiveness in controlling A. litchii infestations. While there was a significant difference in the proportion of erinea among the four treatments, this contrast was not associated with the presence of phytoseiids, suggesting that other factors might have hindered erinea formation on lychee plants. The reasons behind this outcome are further explored and discussed.

Influence of temperature on the population size of Aceria litchii (Acari: Eriophyidae) and the development of its galls.

The lychee erinose mite, Aceria litchii (Keifer), is a tiny eriophyid mite known to induce the formation of open galls (erinea) on lychee plants, Litchi chinensis Sonn. In lychee infested by A. litchii, four stages of erineum are observed, based on erineum color: hyaline, white, amber and dark brown. The cause of the color change in erinea is unknown, but it might be linked to the extent of A. litchii infestation. Artificially infested lychee seedlings were used to determine the developmental time, trichome density, and mite population size in each of the four erineum stages. The effect of temperature (15, 25, and 35 °C) on A. litchii population size and erineum developmental time was also investigated. Overall, each erineum stage lasted approximately 50 days and the population size of A. litchii increased gradually through the hyaline, white and amber stages, and a strong decline was observed in dark brown erinea. Visual comparisons of the low-temperature scanning electron microscope (LT-SEM) images revealed that the trichome density was lower in the hyaline stage than in the other stages. Temperature influenced mite population size and amber erinea developmental time. Mite population was lower at 35 °C than at 15 and 25 °C, suggesting that high temperatures promote detrimental effects on A. litchii. Amber erinea developed slower at 15 °C than at 25 and 35 °C. Possible effects of the temperature on A. litchii population in lychee plants are discussed.

Arthropods associated with the lychee erinose mite, Aceria litchii (Acari: Eriophyidae) on lychee trees in Minas Gerais, Brazil.

Lychee fruit production (Litchi chinensis) has been threatened in many regions of the world where the presence has been reported of the litchii erinose mite, Aceria litchii (Keifer). This study aims to identify the arthropod community associated with A. litchii on lychee plants in Minas Gerais, Brazil, and to seek for potential natural enemies associated with this mite pest in this region. We sampled lychee leaves infested with A. litchii in commercial and non-commercial lychee orchards during seven consecutive months, covering the dry and wet seasons of the year. Arthropods found in association with A. litchii on lychee leaves were collected and identified. The results indicate that a great diversity and abundance of mites and hexapods are associated with A. litchii. A total of 985 and 1872 specimens of mites were identified in commercial and non-commercial areas, respectively, belonging to the families Cheyletidae, Cunaxidae, Eupodidae, Iolinidae, Stigmaeidae, Phytoseiidae, Tarsonemidae, Tenuipalpidae, Tetranychidae, Tryophtydeidae, Tuckerellidae, Tydeidae, Winterschmidtiidae and Xenocaligonellidae and the suborder Oribatida. Among them, Phytoseiidae was the most abundant and diverse family with a total of 11 species identified, in which Phytoseius intermedius was the most abundant predatory mite species collected. Minor specimens of hexapods were also been, belonging to the orders Collembola, Blattodea, Coleoptera, Diptera, Hemiptera, Hymenoptera, Psocoptera and Thysanoptera. The presence of a high community of predatory mites in association with A. litchii deserves attention and our results indicate that studies to test the potential of these species and the adoption of management practices that enhance this ecological service must be carried out to achieve satisfactory control of the lychee erinose mite in lychee plants.

Communities of arthropods associated with the composting process of the organic solid waste produced in a landfill in Brazil.

Composting is a process recommended as a way to recycle the organic part of the solid waste in which several micro and macroorganisms act as decomposers of the organic matter, in a process that takes around 120 days and faces roughly three different phases. Because we do not know the community of arthropods associated with the compost produced in one of the biggest landfills placed in Brazil, here we collected and identified the community of arthropods present in each phase of the organic compost. Our hypothesis is that the abundance and diversity of arthropods are different within each phase of the compost and we hope to find particular groups of arthropods that can be used as indicator of specific phases. In total, we identified the taxa of 1204 arthropods (insects, arachnidan and diplopods). We found that diversity and abundancy of arthropods were indeed different for each maturation phase of the compost, but we did not find families that are good indicators of each phase. In addition, to be certain about the safety of the compost produced, we investigated the presence of microorganisms in the final product and we found considerable levels of Escherichia coli and Enterococcus faecalis in some samples. Finally, we argue that the presence of these macro and microorganisms during the process may be beneficial or harmful. Since their presence decreased greatly by the end of the process, we acknowledge that composting works efficiently as a way to recycle the organic part of the waste generated in Brazil.

Evaluation of (fli:GFP) Casper Zebrafish Embryos as a Model for Human Conjunctival Melanoma.

Purpose: Conjunctival melanoma (CM) is a rare malignant disease that can lead to recurrences and metastases. There is a lack of effective treatments for the metastases, and we set out to develop a new animal model to test potential therapies. Zebrafish are being used as a model for many diseases, and our goal was to test whether this animal could be used to study CM. Methods: Three human CM cell lines (CRMM-1 and CM2005.1, which both harbor a B-RAF mutation, and CRMM-2, which has an N-RAS mutation) were injected into the yolk sac, around the eye, and into the duct of Cuvier of transgenic (fli:GFP) Casper zebrafish embryos. Fluorescent and confocal images were taken to assess the phenotype and the behavior of engrafted cells and to test the effect of Vemurafenib as a treatment against CM. Results: While the cells that had been injected inside the yolk sac died and those injected around the eye sporadically went into the circulation, the cells that had been injected into the duct of Cuvier colonized the zebrafish: cells from all three cell lines proliferated and disseminated to the eyes, where they formed clusters, and to the tail, where we noticed extravasation and micrometastases. Vemurafenib, a potent agent for treatment of B-RAF V600E-positive melanoma, inhibited outgrowth of CRMM-1 and CM2005.1 cells in a mutation-dependent way. Conclusions: The (fli:GFP) Casper zebrafish embryo can be used as an efficient animal model to study metastatic behavior of human CM cells and warrants further testing of drug efficacy to aid care of CM patients.