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Among the citrus production industry, Mexico represents the fifth largest producer worldwide as of 1 Mar 2022 data (Producción de cítricos en México, Biblioteca de Publicaciones Oficiales del Gobierno de la República, Gobierno, www.gob.mx [last accessed 3 Jun 2022]). Among insect pests affecting citrus orchards, the citrus blackfly Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) causes great economic losses to this industry. Biological control with parasitoids is used principally to manage this pest. In this study, we evaluated a simple and inexpensive technique for citrus blackfly biocontrol in citrus orchards. Conidia from the entomopathogenic fungus Aschersonia sp. were collected from citrus leaves with Aschersonia sp. infecting citrus blackfly nymphs in 1 locality in Quintana Roo State, Mexico. Conidia were suspended with vigorous shaking in a 0.1% Tween solution to achieve a concentration of about 1.0 × 108 conidia per mL and sprayed on citrus blackfly uninfected nymphs in 1 selected (high citrus blackfly population) Quintana Roo locality when relative humidity was about 95%. After about 55 d, fungus had killed the treated nymphs, and had infected and killed other citrus blackflies causing an epizootic in the application area. This technique was scaled up by citrus producers to 30 ha with similar results. During 2019, relative humidity was lower than 60%, and citrus blackfly-uninfected or Aschersonia sp.-infected nymphs were not detected. During 2020, the relative humidity was higher than 80% and we did not detect Aschersonia sp. Infected- or uninfected-citrus blackfly nymphs in the previously treated area. In conclusion, collection and application of Aschersonia sp. conidia on uninfected citrus blackfly nymphs may result in an epizootic, if relative humidity is 80% or higher, and Aschersonia sp. remains and disseminates along with this insect pest. Entre la industria de producción de cítricos, México representa el quinto productor a nivel mundial según datos del 01 de marzo del 2022 (Producción de cítricos en México, Biblioteca de Publicaciones Oficiales del Gobierno de la República, Gobierno, www.gob.mx [último accedido 3 Jun 2022]). Entre las plagas de insectos, la mosca prieta de los cítricos, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) puede provocar grandes pérdidas económicas a esta industria. El control biológico con parasitoides es el método más utilizado para controlar esta plaga. En este estudio, evaluamos una técnica sencilla y económica en huertos de cítricos para el control biológico de la mosca prieta de los cítricos. Se recolectaron conidios del hongo entomopatógeno Aschersonia sp. de hojas de cítricos con Aschersonia sp. infectando ninfas de mosca prieta de los cítricos, en una localidad del estado de Quintana Roo. Los conidios se suspendieron con agitación vigorosa en una solución de Tween al 0.1% para lograr sobre 1.0 × 108 conidios por mL y se aplicaron mediante aspersión sobre ninfas no infectadas con mosca prieta de los cítricos, en una localidad seleccionada de Quintana Roo (alta población de mosca prieta de los cítricos), cuando la humedad relativa era sobre el 95%. Después de 55 días, el hongo ya habían matado a las ninfas tratadas e infectado y matado a otras mosca prieta de los cítricos, causando una epizootia en el área de aplicación. Se escaló esta técnica por los productores de cítricos en 30 hectáreas, lo que resultó en un biocontrol similar. Durante 2019, la humedad relativa fue inferior al 60% y la mosca prieta de los cítricos y no se detectaron ninfas sin infectar o infectadas por Aschersonia sp. Para 2020, la humedad relativa fue superior al 80% y se detectaron tanto la mosca prieta de los cítricos como ninfas infectadas por Aschersonia sp. en la zona previamente tratada. En conclusión, la recolección y aplicación de conidios de Aschersonia sp. sobre ninfas de mosca prieta de los cítricos no infectadas, podrían provocar una epizootia si la humedad relativa es del 80% o mayor y Aschersonia sp. podría permanecer y diseminarse entre esta plaga de insectos. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) produced by the neem tree (Azadirachta indica A. Juss.; Sapindales: Meliaceae) are known to alter growth and development of several insects. Additionally, the insect's gut microbiota and immune response are key components in insect development and have been linked to increased resistance to insecticides. In the present study, larval mortality, immune response, and intestinal bacteria changes in the cabbage looper, Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae), induced by VOCs of dried and milled neem leaves, stems, and bark were investigated. Exposure of neonates to 10 g of mixed dried leaves and stems resulted in 79 and 63% mortality of laboratory and field T. ni strains, respectively. In addition, differences were observed in larval weights and pupal sizes during 30 d of incubation. Further studies included transcript amplification of enterobacteria genes and genes related to immune responses and chemical synthetic insecticide resistance. Midguts from the VOC-exposed laboratory strain of T. ni larvae over-transcribed cytochrome P450 (CYP4L4), PGRP, lysozyme, attacin, cecropin, defensin, gallerimycin, and lebocin, compared with unexposed control larvae, whereas ribosomal protein S5 (internal control) and caspase transcripts did not show changes. These samples revealed reduced enterobacteria transcript amplification (27%), suggesting bacterial repression. The effect of neem VOCs on the immune response may in part explain the inhibitory effect on the molting process, in which chitin is broken down to release the old cuticle between instars. Because neem leaves, stems, and bark are widely used as fertilizers, their potential application in pest management programs for controlling T. ni on host crops (cauliflower, broccoli, or cabbage) is discussed. [ABSTRACT FROM AUTHOR]