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(F. Smith) (Hymenoptera: Formicidae) is a significant agricultural pest in Mexico. This study tested the insecticidal activity of ethanol extracts from the sarcotesta of three (Magnoliaceae) species endemic to Mexico against . Contact and ingestion bioassays were performed using various ethanol extract concentrations. After 72 h of exposure, (Iltis & A.Vazquez) A.Vazquez & Carvajal showed the highest contact toxicity at 2.0 mg/mL, 0.2 mg/mL, and 0.02 mg/mL, with a lethal concentration to 90 % mortality (LC ) of 0.02 mg/mL. A.Vázquez & Gómez-Domínguez exhibited toxicity at 2.0 mg/mL and 0.2 mg/mL, with LC  = 0.1 mg/mL, while A.Vázquez, Domínguez-Yescas & L.Carvajal showed toxicity at 4.0 mg/mL and 0.04 mg/mL, with LC  = 0.4 mg/mL. The ethanol extracts also demonstrated significant toxicity by ingestion. The most effective concentrations for was 2.0 mg/mL with LC  = 0.24 mg/mL, while for , they were 2.0 mg/mL, 0.2 mg/mL, and 0.02 mg/mL (LC  = 0.06 mg/mL). For , the most effective concentrations were 4.0 mg/mL, 0.4 mg/mL, and 0.04 mg/mL (LC  = 0.07 mg/mL). Chemical analysis revealed the presence of alkaloids, terpenes, and phenols in the extracts. This study suggests that the tested sarcotesta extracts have great potential as effective botanical pesticides against , implying promising insights for developing agricultural pest management strategies.

The diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), is a key pest of Brassicaceae. Chemical insecticides are the main method used for P. xylostella management, however, the moth has developed resistance to many insecticides, including biological agents such as Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt) products. Alternative methods need to be adopted to reduce reliance on insecticides. Diatomaceous earth (DE) is a silica powder that kills arthropods by damaging the lipid layer of the epicuticle and causing water loss. The objective of this study was to assess the effect of DE alone and in combination with Bt insecticides by recording mortality and feeding of P. xylostella larvae to determine if the addition of DE to Bt products improved Bt performance. Seven P. xylostella populations (a susceptible laboratory colony and six field colonies) were subjected to seven treatments: DE alone, B.t. kurstaki Berliner and B.t. aizawai Luthy alone and in combination with DE, emamectin benzoate 5G (commercial standard), and untreated control. Two types of bioassays were conducted. A leaf dip method was used to evaluate the effect of exposure to the treatments once the material had dried on the leaf substrate, and the Potter spray tower method was used to evaluate the effect of direct contact of treatments on P. xylostella larvae. DE alone increased P. xylostella mortality compared to untreated controls in four out of seven populations in leaf dip bioassays. DE did not significantly reduce leaf consumption when used alone or in combination with Bt treatments. There was no evidence of DE improving Bt performance. DE showed moderate effectiveness in increasing mortality of some Florida populations of P. xylostella under laboratory conditions. This suggests that its impact under field circumstances may be worthy of further investigation. La palomilla dorso de diamante, Plutella xylostella L. (Lepidoptera: Plutellidae), es una plaga clave de Brassicaceae. El principal método utilizado para el manejo de P. xylostella son los insecticidas químicos; sin embargo, la polilla ha desarrollado resistencia a muchos insecticidas, incluidos agentes biológicos como los productos Bacillus thuringiensis Berliner (Bacillales: Bacillaceae) (Bt). Por esto, es necesario adoptar métodos alternativos para reducir la dependencia de insecticidas. La tierra de diatomeas (DE) es un polvo de sílice que mata a los artrópodos al dañar la capa lipídica de la epicutícula y provocar pérdida de agua. El objetivo de este estudio fue evaluar el efecto de la DE sola o en combinación con insecticidas Bt a través del seguimiento de la mortalidad y la alimentación de larvas de P. xylostella para determinar si la adición de DE a los productos Bt mejora el rendimiento de Bt. Se evaluaron siete poblaciones de P. xylostella (una colonia de laboratorio susceptible y seis colonias de campo) a siete tratamientos: DE sola, B.t. kurstaki Berliner y B.t. aizawai Luthy solo y en combinación con DE, benzoato de emamectina 5G (estándar comercial) y control sin tratar. Se realizaron dos tipos de bioensayos. Para evaluar el efecto de la exposición a los tratamientos se utilizó el método de inmersión de hojas una vez que el material se había secado sobre el sustrato foliar; para evaluar el efecto del contacto directo de los tratamientos sobre las larvas de P. xylostella se usó el método de torre de aspersión Potter. En cuatro de siete poblaciones en bioensayos de inmersión de hojas, la DE por sí sola aumentó la mortalidad de P. xylostella en comparación con los controles no tratados. La DE no redujo significativamente el consumo de hojas cuando se usó sola o en combinación con tratamientos Bt. No hubo evidencia de que la DE mejorara el rendimiento de Bt. En condiciones de laboratorio, la DE mostró una eficacia moderada en el aumento de la mortalidad de algunas poblaciones de P. xylostella de Florida. Esto sugiere que su impacto en situaciones de campo puede requerir más investigación.

Chlorpyrifos (CPF) is a pesticide widely used in Colombia´s agriculture, including crops, farm animals and pets, despite it has been banned for use in the European Union and the United States. Studies demonstrate that even low blood levels of CPF -which do not inhibit blood acetylcholinesterase- can lead to child developmental and neurological disorders such as smaller head circumference and brain alterations, and psychomotor and cognitive deficits related to learning ability, attention and memory. In adults, CPF is an endocrine disruptor and breast carcinogen. High direct and indirect economic costs have been associated with CPF exposure. Not only farmers and their families -who have the highest exposures- but the general population consuming crops sprayed with CPF are also at risk. For these reasons CPF was recently banned by the European Union (2020) and the USA (2021). Pesticide regulation policies vary greatly depending on which and how scientific studies are used to assess health risks. Pesticide evaluations funded by the chemical industry should be rectified to avoid conflicts of interest. Furthermore, political alignment with the interests of the industry should not take precedence over independent scientific evidence. It is discouraging, to say the least, that until stricter health laws are passed in Colombia, CPFs and related pesticides will continue to be imported from those countries that have already banned them. Colombian scientists should raise their voice to challenge blind acceptance of profits over unintended consequences, and efforts to prevent pesticide´s abuse should be encouraged.

Biological control of house flies, Musca domestica L. (Diptera: Muscidae) has the potential to improve the efficacy and sustainability of integrated pest management. In a previous study, we demonstrated that three bacteria species (Serratia marcescens Bizio [Enterobacteriales: Enterobacteriaceae], Photorhabdus temperata Fischer-Le Saux et al. [Enterobacteriales: Enterobacteriaceae], and Pseudomonas protegens Ramette et al. [Pseudomonadales: Pseudomonadaceae]) are extremely virulent, inducing rapid morbidity rapid morbidity and high mortality in adult house flies when injected into the hemocoel but show little effect when applied topically. Here we tested the hypothesis that topical application of these species in combination with the entompathogenic fungus Beauveria bassiana (Bals. Criv.) Vuill. (Hypocreales: Cordycipitaceae) would result in an increased and rapid mortality if fungal penetration of the fly cuticle allowed for increased delivery of the bacteria into the fly hemocoel. Bacteria and B. bassiana were tested either by application at the same time or by sequential application of the two pathogens 48 h apart. Results indicated little evidence for synergy between B. bassiana and any of the bacterial pathogens. However, P. protegens caused early mortality (<50 % at 3 days) when applied alone and in combination with B. bassiana. A modified disc diffusion assay indicated that P. temperata and P. protegens had inhibitory effects on the vegetative growth of B. bassiana suggesting the release of antifungal molecules by the bacteria. Results with P. protegens were sufficiently encouraging to warrant further investigation of this species and its associated toxins as house fly biological control tools. El control biológico de la mosca doméstica, Musca domestica L. (Diptera: Muscidae) tiene el potencial de mejorar la eficacia y sostenibilidad del manejo integrado de plagas. En un estudio anterior, demostramos que tres especies de bacterias (Serratia marcescens Bizio [Enterobacteriales: Enterobacteriaceae], Photorhabdus temperata Fischer-Le Saux et al. [Enterobacteriales: Enterobacteriaceae] y Pseudomonas protegens Ramette et al. [Pseudomonadales: Pseudomonadaceae]) son extremadamente virulentas, induciendo una rápida morbilidad y una alta mortalidad en moscas domésticas adultas cuando se inyecta en el hemocele, pero estas muestran poco efecto cuando se aplica tópicamente. Es este estudio probamos la hipótesis de que la aplicación tópica de estas especies en combinación con el hongo entompatógeno Beauveria bassiana (Bals. Criv.) Vuill. (Hypocreales: Cordycipitaceae) daría como resultado un aumento y una mayor rapidez de mortalidad si es que la penetración del hongo en la cutícula de la mosca permitiera una mayor entrega de bacterias al hemocele de la mosca. Las bacterias y B. bassiana se probaron mediante aplicación simultánea o mediante aplicación secuencial de los dos patógenos con 48 horas de diferencia. Los resultados indicaron poca evidencia de sinergia entre B. bassiana y cualquiera de los patógenos bacterianos. Sin embargo, P. protegens causó mortalidad temprana (<50 % a los 3 días) cuando se aplicó sola y en combinación con B. bassiana. Un ensayo de difusión en disco modificado indicó que P. temperata y P. protegens tenían efectos inhibidores sobre el crecimiento vegetativo de B. bassiana, lo que sugiere la liberación de moléculas antifúngicas por parte de las bacterias. Los resultados con P. protegens son suficientemente alentadores como para justificarunamayorinvestigación de esta especie y sus toxinas asociadas como herramientas de control biológico de la mosca doméstica.

Efficacies of topical applications and dry residues of 9 common ready-to-use (RTU) insecticides were evaluated against brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) at intervals of exposure of 1 and 48 h. Permethrin and acetamiprid, were further evaluated to determine if H. halys recovered after an initial exposure. Topical applications of carbaryl, permethrin, insecticidal soap, petroleum oil, and acetamiprid, and residues of permethrin and acetamiprid increased mortality of adults. Topical applications of spinosad, essential oils, carbaryl, permethrin, insecticidal soap, petroleum oil, and acetamiprid, and residues of carbaryl, permethrin, and acetamiprid increased mortality of nymphs. Topical applications of carbaryl, neem oil, insecticidal soap, and acetamiprid increased egg mortality. In general, nymphs were more susceptible to insecticides than adults. Adult H. halys recovered after exposure to topical applications, but not dry residues of permethrin. Clearly, several RTU insecticides in the marketplace demonstrated potential to help gardeners manage H. halys.

Toxicity, repellency, and laboratory performance of consumer bait formulations were evaluated for control of 7 insecticide-resistant, field-collected strains of the German cockroach, Blattella germanica (L.) (Blattodea: Ectobiidae) in continuous exposure and Ebeling choice box assays. Solid and gel baits contained avermectin, dinotefuran, fipronil, or hydramethylnon as active ingredients, and were active for control of all German cockroach strains. However, the laboratory susceptible strain was generally more sensitive (lower median lethal times or LT50 values) than the field-collected strains. Resistance ratios in continuous exposure tests ranged from 0.37 for 0.01% fipronil (strain H) to 14.23 for 0.05% dinotefuran (strain DCC2). The LT50 values for most baits and strains generally were greater when tested in Ebeling choice boxes compared with continuous exposure tests. Resistance ratios ranged as high as 98.43 for 0.05% dinotefuran for control of strain DCC2. All strains had resistance to 0.05% dinotefuran bait, and the resistance ratios were greatest when tested in Ebeling choice boxes. All bait formulations had some repellency to most strains; however, repellency was never greater than 70% for any treatment–strain combination. Combining Ebeling choice box mortality and repellency data, maximum estimated performance index values (PIMax) reached 100, i.e., no repellency and complete mortality, for most treatments. There was not complete mortality of the majority of strains exposed to 0.05% dinotefuran bait and therefore the PIMax value did not reach 100. The rate of increase in performance index value over time or tPImax/2 ranged 0.26 and 7.85 d. Our results indicate that although all baits were toxic to multi-resistant strains of German cockroaches, there was significant resistance or tolerance to many formulations that would likely negatively impact field control. Se evaluó la toxicidad, repelencia y desempeño en el laboratorio de formulaciones de cebo de consumo para controlar 7 cepas resistentes a insecticidas de la cucaracha alemana, Blattella germanica (L.) (Blattodea: Ectobiidae) y recolectadas en el campo, en exposición continua y ensayos de cuadro de selección de Ebeling. Los cebos sólidos y en gel contenían avermectina, dinotefurano, fipronil o hidrametilnon como ingredientes activos y fueron activos para el control de todas las cepas de cucarachas alemanas. Sin embargo, la cepa susceptible de laboratorio fue generalmente más sensible (tiempos letales medianos o valores TL50 más bajos) que las cepas recolectadas en el campo. Los índices de resistencia en las pruebas de exposición continua oscilaron entre 0,37 para fipronil al 0,01 % (cepa H) y 14,23 para dinotefurano al 0,05 % (cepa DCC2). Los valores LT50 para la mayoría de los cebos y cepas generalmente fueron mayores cuando se probaron en cajas de elección de Ebeling en comparación con las pruebas de exposición continua. Las proporciones de resistencia oscilaron hasta 98,43 para dinotefurano al 0,05 % para el control de la cepa DCC2. Todas las cepas tuvieron resistencia al cebo con dinotefurano al 0,05 %, y las proporciones de resistencia fueron mayores cuando se probaron en las cajas de elección de Ebeling. Todas las formulaciones de cebo tenían cierta repelencia a la mayoría de las cepas; sin embargo, la repelencia nunca superó el 70 % para ninguna combinación de tratamiento y cepa. Al combinar los datos de mortalidad y repelencia del cuadro de elección de Ebeling, los valores máximos del índice de rendimiento (IRMax) estimado alcanzaron 100, es decir, sin repelencia y mortalidad completa, para la mayoría de los tratamientos. No hubo mortalidad completa de la mayoría de las cepas expuestas al cebo con dinotefurano al 0,05 % y, por lo tanto, el valor de IRMax no alcanzó 100. La tasa de aumento del valor del índice de rendimiento a lo largo del tiempo (IRTMax/2) varió entre 0,26 y 7,85 dias. Nuestros resultados indican que, aunque todos los cebos fueron tóxicos para las cepas multiresistentes de cucarachas alemanas, hubo una resistencia o tolerancia significativa a muchas formulaciones que probablemente tendrían un impacto negativo en el control de campo.

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is a serious threat to citrus production because it transmits the bacterium, Candidatus Liberibacter asiaticus Jagoueix (Hyphomicrobiales: Rhizobiaceae), that causes huanglongbing. Currently, there is no cure for huanglongbing, and vector management is implemented to reduce the spread of pathogen. In Florida, calendar-based insecticide application had been used widely for D. citri management, but the evolution of insecticide resistance in D. citri and associated reductions of natural enemy populations mandate more sustainable approaches. The objective of our study was to compare the effects of organic management versus intermittent use of conventional insecticides on population suppression of D. citri by natural enemies in Florida. We conducted a survey of natural enemies in citrus groves that were managed organically versus intermittently treated with conventional insecticides from Mar to Dec 2019. We also compared mortality of D. citri in those groves by deploying sentinel psyllids on leaf flush with or without exclusion cages. The abundance of natural enemies was recorded by visual observations made on tree branches for 2 min intervals. Finally, we estimated tree flush density and monitored adult D. citri populations. Survival of sentinel D. citri was significantly lower on uncaged flush when natural enemies had access to eggs and nymphs during spring, summer, and fall in organic groves; however, such a difference was not observed between caged and uncaged D. citri in intermittently sprayed groves, particularly during summer and fall. Similarly, organic sites had lower numbers of adult D. citri compared to intermittently sprayed sites throughout most of the sampling period, suggesting that natural enemies contributed to regulation of D. citri populations in organic groves more so than in the intermittently treated conventional groves. The most common natural enemies found were Coccinellidae, Chrysopidae, Formicidae, Eulophidae, Syrphidae, Dolichopodidae, and Arachnida. Among these groups, formicids were most abundant in organic groves, whereas dolichopodids and coccinellids were most abundant in intermittently managed groves. Our results suggest that intermittent spraying for D. citri with conventional insecticides could affect activity of natural enemies even though such practices did not entirely eliminate their populations.

Greenhouse whitefly, Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae), is a serious pest of numerous crops grown in greenhouses and field-grown strawberry in yr-round production areas in California, USA. Problems with insecticide resistance have prompted the search for more sustainable methods for their management. Here, we applied UV-C light treatments nightly for 16 s (19.2 J m–2) over a 6-wk period to tomatoes infested with T. vaporariorum and compared numbers of adults, nymphs, and eggs with those on untreated plants. All life stages of T. vaporariorum were significantly lower on tomatoes treated nightly with UV-C compared with unexposed plants. Additionally, there was no significant difference in chlorophyll fluorescence activity. Our results indicate that nightly UV-C treatments significantly reduce T. vaporariorum populations and offer a potential non-chemical method for their management on tomato.

Rhopalosiphum padi (L.) (Hemiptera: Aphididae) is one of the most significant cereal pests worldwide. Control of R. padi has relied heavily on chemical insecticides. We sampled 12 populations of R. padi from 11 provinces in China and analyzed their regional susceptibilities to 10 insecticides by using the leaf dip method. The R. padi populations showed susceptibility or minor resistance to chlorpyrifos, malathion, thiamethoxam, beta-cypermethrin, acetamiprid, and pymetrozine, but minor to moderate resistance to bifenthrin, decamethrin, and abamectin. Correlation analysis indicated positive and significant correlations between R. padi resistance levels to thiamethoxam and beta-cypermethrin, between R. padi resistance levels to chlorpyrifos and 4 other insecticides (decamethrin, abamectin, acetamiprid, and beta-cypermethrin), and between R. padi resistance levels to acetamiprid and 3 other insecticides (decamethrin, thiamethoxam, and beta-cypermethrin). Due to the widespread and variable nature of resistance in R. padi, we strongly urge rotation of insecticide classes to delay the onset of high levels of resistance.

Newer, selective insecticides with few negative impacts on natural enemies and competitor species are needed for effective, sustainable management of the western flower thrips, Frankliniella occidentalis (Pergande). The purpose of this study was to evaluate the impacts on natural enemies and competitor thrips species of insecticides used for control of western flower thrips in fruiting vegetables. Trials with tomato (Solanum lycopersicum L.) and with pepper (Capsicum annuum L.) were conducted to evaluate insecticide treatment effects on western flower thrips and natural enemies at the North Florida in 2008, 2009, 2010 and 2011. A number of insecticides from different classes showed moderate to high efficacy against western flower thrips. The broad-spectrum insecticides acetamiprid, methomyl, and tolfenpyrad demonstrated activity against the pest, while also reducing populations of the key predator of thrips in pepper, Orius insidiosus (Say) (Hemiptera: Anthocoridae). Insecticides that showed little impact on populations of O. insidiosus were cyantraniliprole, flonicamid, spirotetramat, and terpenes. Although only moderately active against the western flower thrips, they would be valuable additions to existing management programs for pepper. Insecticides with activity against western flower thrips also showed activity against Frankliniella tritici (Fitch). This non-damaging congener species is a beneficial because it out-competes the western flower thrips, especially in tomato where O. insidiosus is not a major factor in western flower thrips management. Numerous insecticides were identified with activity against the western flower thrips that are suitable for use in integrated pest management programs of fruiting vegetables.