The characterization of entomopathogenic microorganisms is important for the selection of more effective strains for use in integrated pest-control programs. Five Nomuraea rileyi strains (SA86101, GU87401, SR86151, CG128 and VA9101) were characterized using random amplified polymorphic DNA (RAPD) analysis, virulence studies and assessment of chitinolytic and proteolytic activity. RAPD analysis divided the strains into two groups with a similarity coefficient of 0,76%, group 1 consisting of strains SA86101, GU87401 and SR86151 and group 2 of strains CG128 and VA9101. The LT50 varied from 165h with strain VA9101 to 246h with strain GU87401. Chitinolytic and proteolytic activity of the fungi after 144h growth in minimal medium were tested using colloidal chitin as substrate. All strains exhibited enzyme activity, with strain VA9101 having the highest chitinase activity (0,0040 mumol/mL/min the 40ºC) and strain SA86101 the highest proteolytic activity. No relationship was found between RAPD analysis, virulence and chitinase or protease activity.
Caracterizaram-se cinco linhagens de N. rileyi por análise de RAPD, avaliação da virulência e atividade enzimática (quitinolítica e proteolítica). Pela técnica de RAPD foi possível distinguir, entre as cinco linhagens avaliadas, dois grupos com similaridade 0,76: grupo I (linhagens SA86101, GU87401, SR86151) e grupo II (linhagens VA9101 e CG128). O TL50 variou de 165 horas com a utilização da linhagem VA9101 a 246 horas com GU87401. Todas as linhagens apresentaram atividade quitinolítica e proteolítica, destacando-se quanto à produção de quitinases a linhagem VA9101 (com 0,0040 mimol/mL/min a 40ºC) e em relação à protease, a linhagem SA86101. Não foi possível evidenciar relações entre virulência, análise genética e atividade enzimática

A major shoot-specific monoterpene indole alkaloid produced by Psychotria brachyceras, brachycerine, is regulated by either wounding or jasmonate application. Highest concentrations of the alkaloid are found in inflorescences, suggesting a defence role. Brachycerine has antimutagenic and antioxidant properties, capable of quenching singlet oxygen, hydroxyl radical, and superoxide. This study aimed at characterizing the putative role of brachycerine in P. brachyceras responses to wounding and herbivory. Damage to leaves increased the content of brachycerine locally. Wounding did not affect phenolics content in P. brachyceras leaves, and no tannins were detected in the species. In generalist herbivore bioassays, neither brachycerine nor P. brachyceras extracts showed toxic effects. In vivo hydrogen peroxide staining assay showed less wound-generated peroxide accumulation in alkaloid treated tissues. This pattern was confirmed in quantitative assays measuring tissue hydrogen peroxide concentrations. Data indicate that brachycerine is not a herbivore deterrent, but rather an indirect chemical defence, modulating oxidative stress caused by mechanical damage.

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Aiming to contribute to knowledge of the immature instars of Neotropical Lepidoptera, this study details the morphology of the egg and last instar larvae of Aucula magnifica (Schaus, 1904) (Lepidoptera: Noctuidae: Agaristinae), emphasising the structures of the corium and the chaetotaxy. There is also a report of the occurrence of entomopathogenic action of Nomuraea rileyi (Farlow) Samson fungi on the larva.Keywords: caterpillar, entomopathogenic fungi, morphology, chaetotaxy.Aucula magnifica (Schaus, 1904) (Lepidoptera: Noctuidae: Agaristinae): morfologia do ovo e da larva de último ínstar ResumoEste estudo objetiva contribuir para o conhecimento dos estágios imaturos dos lepidópteros neotropicais. Nele é feito o detalhamento da morfologia das fases de ovo e de larva de Aucula magnifica (Schaus, 1904) (Lepidoptera: Noctuidae: Agaristinae), dando ênfase ao estudo das estruturas do córion e da quetotaxia da larva de último ínstar. Além disso é relatada a ocorrência da ação entomopatogênica do fungo Nomuraea rileyi (Farlow) Samson sobre suas larvas.Palavras-chave: lagarta, fungo entomopatogênico, morfologia, quetotaxia.