A new species of the genus Brachytydeus Thor sensu André (Acari: Tydeidae) and a key to all known species from Peru.

Brachytydeus juanjosei sp. nov., a new species of Neotropical Tydeidae, is illustrated and described from females, males, and a tritonymph collected from the leaves of a native forest tree, Neltuma piurensis (Fabaceae), from Department of Piura in north-western Peru. The new tydeid mite was found all year long, but more frequently observed during spring in high populations (September/December). A key to the known Peruvian species of the subfamily Tydeinae is provided.

Bioactivity of an oxymatrine-based commercial formulation against Brevipalpus yothersi Baker and its effects on predatory mites in citrus groves.

The acaricidal bioactivity of an oxymatrine-based commercial formulation against Brevipalpus yothersi Baker (Acari: Tenuipalpidae), a vector mite of the Citrus leprosis virus (CiLV), and its impact on predatory mites were assessed. For this purpose, laboratory and field assays using bioacaricide concentrations ranging from 0.5 to 2.0 mg L-1 of oxymatrine were performed during the years from 2015 to 2016. Laboratory results showed that the oxymatrine-based commercial formulation does not cause deleterious effects on B. yothersi eggs; however, it causes high larval mortality. For adult females, the bioacaricide caused high acute toxicity and residual effect for at least 5 days after application. In the field, the bioacaricide exhibited high acaricidal activity against B. yothersi, with efficacy levels similar to that of synthetic acaricide spirodiclofen (48 mg L-1) until 49 days after the application. The application of the bioacaricide did not negatively affect the population levels of phytoseiid predatory mites. Therefore, our results suggest that the oxymatrine-based commercial formulation is an important tool for management of the citrus leprosis mite in citrus groves.

Zein Nanoparticles as Eco-Friendly Carrier Systems for Botanical Repellents Aiming Sustainable Agriculture.

Botanical repellents represent one of the main ways of reducing the use of synthetic pesticides and the contamination of soil and hydric resources. However, the poor stability and rapid degradation of these compounds in the environment hinder their effective application in the field. Zein nanoparticles can be used as eco-friendly carrier systems to protect these substances against premature degradation, provide desirable release characteristics, and reduce toxicity in the environment and to humans. In this study, we describe the preparation and characterization of zein nanoparticles loaded with the main constituents of the essential oil of citronella (geraniol and R-citronellal). The phytotoxicity, cytotoxicity, and insect activity of the nanoparticles toward target and nontarget organisms were also evaluated. The botanical formulations showed high encapsulation efficiency (>90%) in the nanoparticles, good physicochemical stability, and effective protection of the repellents against UV degradation. Cytotoxicity and phytotoxicity assays showed that encapsulation of the botanical repellents decreased their toxicity. Repellent activity tests showed that nanoparticles containing the botanical repellents were highly repellent against the Tetranychus urticae Koch mite. This nanotechnological formulation offers a new option for the effective use of botanical repellents in agriculture, reducing toxicity, protecting against premature degradation, and providing effective pest control.

Resíduos de calda sulfocálcica sobre a eficiência de acaricidas no controle de Brevipalpus phoenicis / Lime sulfur residue on acaricide efficiency in the control of Brevipalpus phoenicis

O objetivo do trabalho foi verificar a influência dos resíduos de calda sulfocálcica sobre a eficiência de acaricidas empregados no controle de Brevipalpus phoenicis. Inicialmente, o experimento foi instalado em um pomar de citros, em que foram selecionadas 10 plantas que continham frutos com verrugose. Realizou-se a aplicação de calda sulfocálcica (8g i.a. L-1 de água) em cinco plantas e as outras cinco plantas permaneceram sem aplicação de produto fitossanitário. Protegeram-se, com copos de plástico transparente de 500mL, 64 frutos nas plantas tratadas com calda e 64 frutos nas plantas não-tratadas, totalizando 128 frutos protegidos. Decorridos 30 dias da aplicação, os frutos foram colhidos e levados para o laboratório. Estes frutos foram parcialmente parafinados, deixando-se em cada fruto uma arena de 2,5cm de diâmetro com verrugose e sem parafina, delimitada com cola entomológica. Em seguida, procedeu-se à aplicação sobre os frutos em Torre de Potter dos seguintes acaricidas nas concentrações expressas em mg de ingrediente ativo por litro de água: propargite a 720mg, óxido de fenbutatina a 400mg, cyhexatin a 250mg, azocyclotin a 250mg, fenpyroximate a 50mg, dicofol a 960mg e dinocap a 738mg e a testemunha sem aplicação de acaricida. Após 1, 7 e 16 dias da aplicação, transferiram-se para cada fruto 10 ácaros B. phoenicis para avaliar a mortalidade. Constatou-se que os resíduos de calda sulfocálcica não prejudicaram a eficiência dos acaricidas avaliados no controle de B. phoenicis.

The objective was to assess the influence of lime sulfur residues on the acaricidal efficiency against Brevipalpus phoenicis mite. Initially, the experiment was conducted in a citrus orchard where 10 plants presenting scab fruits were selected. Secondly, the application of lime sulfur (8mg a.i. L-1 of water) was performed in five plants, and the other five plants remained without application. Next lime sulfur application, 64 fruits in the plants with lime sulfur application were protected with plastic cups and others 64 fruits also were protected in the plants without lime sulfur application with plastic cups. After 30 days of field application, fruits were harvested and transported to the laboratory. These fruits were partially waxed, leaving an arena of approximately 2.5cm in diameter with scab and without paraffin and entrapped with entomological glue. Afterwards, acaricides application were done following the concentration expressed in mg of active ingredient per liter of water: propargite (720mg), fenbutatin oxide (400mg), cyhexatin (250mg), azocyclotin (250mg), fenpyroximate (50mg), dicofol (960mg), dinocap (738mg) and control treatment by using the petri dish-Potter tower method. After 1, 7 and 16 days of application, ten B. phoenicis were transferred per fruit, in order to evaluate their mortality, 24 and 48 hours after the transferences. The lime sulfur residue did not affect the acaricides efficiency.