Search

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. [ABSTRACT FROM AUTHOR]

Leucoptera coffeella (Lepidoptera: Lyonetiidae) is one of the main pests in coffee crops. The economic injury level (EIL) is the lowest density of the pest at which economic damages match the costs of control measures. The economic threshold (ET) is the density of the pest at which control measures must be taken so that this population does not reach the EIL. These are the main indices used for pest control decision-making. Control of L. coffeella is carried out by manual, tractor, airplane or drone applications. This work aimed to determine EILs and ETs for L. coffeella as a function of insecticide application technology in conventional and organic Coffea arabica crops. Data were collected over five years in commercial C. arabica crops on seven 100 ha central pivots. The cost of control in organic crops was 16.98% higher than conventional. The decreasing order of control cost was manual > drone > airplane > tractor application. Coffee plants were tolerant to low densities (up to 15% mined leaves) of the pest that caused losses of up to 6.56%. At high pest densities (54.20% mined leaves), losses were high (85.62%). In organic and conventional crops and with the use of different insecticide application technologies, EIL and ET were similar. The EIL and ET were 14% and 11% of mined leaves, respectively. Therefore, these indices can be incorporated in integrated pest management programs in C. arabica crops. The indices determined as a function of insecticide application technology in organic and conventional coffee are important as they serve producers with different technological levels. Additionally, EILs and ETs can contribute to more sustainable production, as control methods will only be employed when the pest density reaches these indices. [ABSTRACT FROM AUTHOR]

Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) has the potential for controlling pest insects in the laboratory, although little is known about its interaction with beneficial species such as bees. Here we report an infestation of T. putrescentiae and its predatory effect in colonies of the stingless bee Frieseomelitta varia (Hymenoptera, Apidae, Meliponini) in Minas Gerais State, Brazil. After the mite infestation, the F. varia colonies became weak and the population died. Because T. putrescentiae develops preferentially in warm and damp environments, special care should be taken when performing in vitro rearing (e.g., sterilizing transfer needles, tweezers, and incubators) of F. varia. Moreover, stingless bee colonies maintained in meliponaries should be periodically monitored, in order to prevent not only mite infestation but diverse health issues. [ABSTRACT FROM AUTHOR]

O sistema de defesa induzido de plantas é ativado quando herbívoros se alimentam das mesmas. Alternativamente, herbívoros podem se adaptar a espécies de plantas filogeneticamente próximas ao seu hospedeiro de origem. O objetivo deste trabalho foi comparar o desenvolvimento de Thyrinteina arnobia em plantas de goiaba (hospedeiro de origem) e de eucalipto (hospedeiro novo) em campo. Adicionalmente, estudou-se a biologia deste inseto em laboratório fornecendo folhas de eucalipto previamente danificadas por lagartas de T. arnobia e folhas sem danos. A sobrevivência larval em eucalipto, 78,00%, foi superior à de goiaba, 29,33%. O ciclo larval foi de 27,90 dias em goiaba e de 30,30 dias em eucalipto. Em testes de laboratório, o ciclo larval em eucalipto limpo, 36,39 dias, foi maior do que em eucalipto danificado, 32,89 dias. A mortalidade larval em eucalipto danificado foi de 30,00% e de 10,00% em eucalipto limpo. Os resultados indicam que a goiaba não é um bom hospedeiro para T. arnobia possivelmente por apresentar um sistema mais efetivo de defesa. Embora o eucalipto possa ser um hospedeiro mais favorável ao desenvolvimento e estabelecimento do inseto, pode também reduzir populações do herbívoro ativando o seu sistema de defesa induzido.