Resumo O objetivo deste trabalho foi selecionar genótipos de Lippia sidoides que apresentem maiores atividades em larvas e fêmeas ingurgitadas do carrapato Rhipicephalus (Boophilus) microplus. Os genótipos estudados foram LSID006, LSID102, LSID103 e LSID104. O genótipo LSID104, o único a conter o monoterpeno carvacrol como um dos principais constituintes, foi o que apresentou o menor efeito larvicida (CL50 2,99 mg/mL). O genótipo LSID006 apresentou menor efeito sobre fêmeas ingurgitadas (CL50 12,46 mg/mL), entretanto foi quimicamente similar ao genótipo LSID102, que apresentou a maior atividade carrapaticida (CL50 2,81 mg/mL). Conclui-se que a semelhança química dos genótipos não se correlaciona com a atividade carrapaticida contra R. (B.) microplus. O óleo essencial de L. sidoides é um agente natural potente e os resultados deste trabalho proporcionam um melhor entendimento para o desenvolvimento de produtos com base neste produto natural, devendo ser considerado os efeitos sinérgicos ou a ação de compostos presentes em menores concentrações.

Abstract The aim of this study was to select different genotypes of Lippia sidoides with the highest activity against larvae and engorged females of the tick Rhipicephalus (Boophilus) microplus. The germplasms studied were LSID006, LSID102, LSID103 and LSID104. The LSID104 genotype, that presented carvacrol as a major constituent, was the germplasm with the worst larvicide effect (LC50 2.99 mg/mL). The LSID006 genotype was the least effective against engorged females (LC50 12.46 mg/mL), and it was chemically similar to the LSID102 genotype, which presented the highest acaricide activity (LC50 2.81 mg/mL). We conclude that chemical similarity of the germplasms was not correlated with acaricide activity against R. (B.) microplus. The essential oil of L. sidoides is a potent natural agent. However, the findings of this work provide a better understanding for product development based on this natural product, which must consider synergic effects or the action of minor compounds.

In order to evaluate the effects of environmental factors on the content of secondary metabolites, the chemical profiles of infusions from leaves of seven genotypes of Lippia gracilis Schauer, sourced from two locations (Sergipe and Bahia state) and collected during different seasons: summer (with and without irrigation) and winter, were determined by HPLC-DAD. The fingerprint chromatograms were analyzed by PCA to evaluate similarities and differences among the samples. Results revealed differences among genotypes collected and cultivated under the same conditions, suggesting that three genotypes have greater resistance to drought conditions.