Metarhizium species can be mutualistic symbionts of plants. They are able to colonize roots, promote plant growth and provide protection against pests. We previously found Metarhizium robertsii and M. brunneum associated with coffee roots in a diversified coffee system. Here, we investigated whether these fungi, when inoculated in coffee seedlings, can associate with roots, improve seedling growth and indirectly protect against the coffee leaf miner (CLM) Leucoptera coffeella (Lepidoptera: Lyonetiidae). We performed a greenhouse experiment with coffee seedlings using suspensions of each Metarhizium species applied as soil drenches to potted seedlings. We also challenged these plants with CLM infestation (two adult couples per plant). We recovered Metarhizium spp. from most of the seedling roots 43 days after fungal inoculation. Plants inoculated with M. robertsii showed a 30% leaf area increase compared to the control. Both isolates promoted protection against CLM in coffee seedlings, reducing the percentual of leaf area mined and prolonging CLM development time by two days versus controls. Besides this protection provided by Metarhizium, M. robertsii also improves seedling growth. Therefore, these Metarhizium species could be considered for the development of inoculants for coffee seedlings.

Metarhizium (Hypocreales: Clavicipitaceae) has a multifunctional life cycle, establishing as a plant endophyte and acting as entomopathogenic fungi. Metarhizium robertsii and Metarhizium brunneum can be associated with coffee plants and provide enhanced protection against a major pest of coffee, the coffee leaf miner (CLM) (Leucoptera coffeella). This association would be an easily deployable biological control option. Here we tested the potential of inoculating coffee seeds with M. robertsii and M. brunneum collected from the soil of coffee crops in the Cerrado (Brazil) for control of the CLM and the enhancement of plant growth with a commonly used fungicide. We conducted the experiment in a greenhouse and after the seedlings grew, we placed them in a cage with two couples of CLMs. We evaluated the CLM development time, reproduction, and plant growth traits. We observed a longer development time of CLMs when fed on plants inoculated with both isolates. In addition, the CLMs laid fewer eggs compared to those fed on plants without fungal inoculation. Plant growth was promoted when seeds were inoculated with fungi, and the fungicide did not affect any evaluated parameter. Coffee seed inoculation with M. robertsii and M. brunneum appears to provide protection against CLMs and promote growth improvement.

A cochonilha-da-roseta, Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae), constitui um problema fitossanitário na cultura do café. O controle mais usual dessa praga é o químico, o que pode acarretar, além de problemas socioambientais, a seleção de indivíduos resistentes. Com isso, torna-se necessário o controle alternativo. Dessa forma, o objetivo deste trabalho foi estudar, em condições de laboratório, o potencial inseticida de diferentes partes da planta de Jatropha curcas , em variadas concentrações, sobre P. citri . Discos de folhas de café conilon com 10 cochonilhas (ninfas e adultos) foram pulverizados direta e indiretamente com auxílio da torre de Potter, com pressão de 15 Lb/pol², aplicando 6 mL de solução por repetição. Testaram-se sete concentrações do óleo e de extratos, tanto na aplicação direta quanto na indireta, com 10 repetições por tratamento, sendo avaliada a mortalidade em função do tempo. Todas as estruturas de pinhão-manso, em ambas as vias de aplicação, apresentaram índices de mortalidade satisfatórios de P. citri , alcançando 91,6% de mortalidade nas concentrações de 1,5, 2,0 e 3,0% do óleo na aplicação direta.