Abstract Plutella xylostella (L.) is responsible for considerable vegetable crop losses in the metropolitan region of Manaus, Brazil. In recent decades, essential oils have been investigated as an alternative to synthetic insecticides. The genusPiperis widely distributed in Amazonia and essential oils from these plants have insecticidal properties. This study describes the chemical composition of the essential oils fromPiper capiterianumandPiper krukoffiias well as the lethal and sublethal effects onP. xylostella. The phytotoxicity of the oils on the host plant was also evaluated. Globulol was the major constituent of theP. krukoffiioil ando-cymene was the major constituent of theP. capitarianumoil. The oil fromP. capiterianumexhibited greater toxicity to larvae and eggs. This oil also presented greater repellant action, feeding deterrence and mild phytotoxicity to the host plant (Brassicae oleraceae). The findings suggest that this oil can be used in the preparation of a formulated insecticide for the management ofP. xylostellain different development phases. However, further studies are needed to evaluate the effect of this oil on crops under field conditions as well as non-target organisms and determine the cost-benefit ratio of a product formulated withP. capitarianumoil.

ABSTRACT Humiria balsamifera is an infraspecific complex of high phenotypic variation and widely distributed in northern South America. Leaf traits are traditionally considered the most relevant taxonomic characters for varietal level delimitation in the group. However, substantial phenotypic overlap among vegetative characters complicates taxonomic diagnoses in this complex. The objective of this study was to quantify and analyze phenotypic variation among individuals of the complex at a continental scale using uni- and multivariable analyses to assess whether morphometric analyses detect discontinuities. Secondarily, these quantitative data were used to test whether phenotypic similarity was related to geographic distance. Twenty- five quantitative and 27 qualitative character traits did not overtly reveal a topology corresponding to traditional varietal classification, nor to geographic structure. However, petiole length alone revealed a definitive separation of H. balsamifera var. guianensis (together with another recognized species Humiria wurdackii, and variety H. balsamifera var. laurina) from the rest of the taxa. Our results highlight substantial morphological overlap among vegetative and reproductive characters including those used in identification keys, and no morphological discontinuities suitable for clearly separating taxa within the complex were encountered demonstrating a future need to integrate multiple sources of information, including molecular data, to resolve this complex.

RESUMO Pycnolejeunea é um gênero pantropical e está representado no Brasil por nove espécies, de acordo com o presente tratamento. Pycnolejeunea chocoensis M.E. Reiner & Gradst., descrita recentemente para Colômbia, está sendo citada pela primeira vez para o Brasil. Descrições são apresentadas para todas as espécies e ilustração apenas para Pycnolejeunea contigua (Nees) Grolle, Pycnolejeunea chocoensis, Pyconolejeunea papillosa X.-L. He e Pycnolejeunea porrectilobula C.J. Bastos & O. Yano. Uma chave para identificação das espécies de Pycnolejeunea que ocorrem no Brasil é também apresentada.

ABSTRACT Pycnolejeunea is a pantropical genus represented in Brazil by nine species, according to the present treatment. Pycnolejeunea chocoensis M.E. Reiner & Gradst., recently described for Colombia, is being cited for the first time for Brazil. Descriptions are given for all species and illustrations only for Pycnolejeunea chocoensis, Pycnolejeunea contigua (Nees) Grolle, Pycnolejeunea papillosa X.-L. He and Pycnolejeunea porrectilobula C.J. Bastos & O. Yano. A key to the species of Pycnolejeunea occurring in Brazil is also presented.

Resumo Excursões botânicas recentes no norte do Brasil resultaram em 38 registros novos para estados brasileiros e o país. Resumido, sete (cinco hepáticas e dois musgos) espécies são novos registros para o Brasil, 18 sendo novos registros para o estado do Amazonas (10 hepáticas e oito musgos) e 20 para o estado de Roraima (16 hepáticas e quatro musgos).

Abstract Results from recent botanical excursions in northern Brazil include 38 new state and country records. In summary, seven (five liverworts and two mosses) taxa are newly confirmed for Brazil, 18 (10 liverworts and eight mosses) new to Amazonas state and 20 (16 liverworts and four mosses) new to Roraima state.