Publications by authors named "Celso Omoto"

The evolution of resistance to insecticides poses a significant threat to pest management programs. Understanding the molecular mechanisms underlying insecticide resistance is essential to design sustainable pest control and resistance management programs. The fall armyworm, Spodoptera frugiperda, is an important insect pest of many crops and has a remarkable ability to evolve resistance to insecticides.

View Article and Find Full Text PDF

Background: The corn leafhopper, Dalbulus maidis, is an important pest in Brazil. While chemical control has traditionally been the cornerstone for managing this pest, field control failures have been reported for some insecticides. To understand if these failures are due to resistance, we evaluated the susceptibility of 11 field-collected populations of D.

View Article and Find Full Text PDF

Genome-wide long non-coding RNAs (lncRNAs) in low, moderate, and high pyrethroid insecticide-resistant and -susceptible strains of were identified in this study. Using 45 illumina-based RNA-sequencing datasets, 8394 lncRNAs were identified. In addition, a sublethal dose of deltamethrin was administered to a Korean-resistant strain (Kor-T).

View Article and Find Full Text PDF

Background: Laboratory-selected resistant strains of Euschistus heros to thiamethoxam (NEO) and lambda-cyhalothrin (PYR) were recently reported in Brazil. However, the mechanisms conferring resistance to these insecticides in E. heros remain unresolved.

View Article and Find Full Text PDF

Susceptibility monitoring to insecticides is a key component to implementing insecticide resistance management (IRM) programs. In this research, the susceptibility to teflubenzuron in (J.E Smith) was monitored in more than 200 field-collected populations from major corn-growing regions of Brazil, from 2004 to 2020.

View Article and Find Full Text PDF

Background: Spodoptera frugiperda (J. E. Smith) is a widespread agricultural pest with several records of resistance to different insecticides and Bt proteins, including the neurotoxic insecticides chlorpyrifos (organophosphate) and lambda-cyhalothrin (pyrethroid).

View Article and Find Full Text PDF

The Neotropical brown stink bug, Euschistus heros, is a major pest of soybean in South America. The importance of E. heros as a pest has grown significantly in recent times due to increases in its abundance and range, and the evolution of insecticide resistance.

View Article and Find Full Text PDF

Fitness costs associated with insect resistance to insecticides can be exploited to implement resistance management programs. However, most of these studies are restricted to evaluating biological traits on artificial diets. Here, we investigated the fitness cost associated with chlorantraniliprole in Spodoptera frugiperda (J.

View Article and Find Full Text PDF
Article Synopsis
  • Intra- and interspecific competition significantly influences ecological diversity, species distribution, and the evolution of traits like insecticide resistance.
  • Research indicates that competition among lepidopteran pests can intensify the development of resistance to insecticides, posing a threat to agricultural sustainability.
  • The study employed a computational model to demonstrate that competitive interactions can favor resistant individuals while diminishing those that are susceptible, highlighting an important yet overlooked aspect of evolutionary dynamics in pest management.
View Article and Find Full Text PDF
Article Synopsis
  • * A study tested the susceptibility of Hübner (a pest affecting soybean and cotton) to HearNPV, establishing a diagnostic concentration for monitoring pest populations and assessing any potential cross-resistance with certain insecticides.
  • * The findings indicated low variation in susceptibility to HearNPV across different populations, with high mortality rates at the tested concentration, and no cross-resistance with flubendiamide or indoxacarb, suggesting HearNPV as a potent tool in pest management strategies.
View Article and Find Full Text PDF

Fall armyworm (FAW), , is an important lepidopteran pest in the Americas, and recently invaded the Eastern Hemisphere. In Brazil, FAW is considered the most destructive pest of corn and cotton. FAW has evolved resistance to many insecticides and (Bt) proteins.

View Article and Find Full Text PDF
Article Synopsis
  • Bacillus thuringiensis (Bt) crops, like Cry1Ac soybean, have been successfully adopted globally, offering strong protection against insect pests while benefiting farmers economically.
  • In Brazil, the cultivation of Cry1Ac soybean has led to a significant decrease (up to 50%) in insecticide use for managing lepidopteran pests over several years.
  • The data indicates a regional suppression of harmful moth species, demonstrating both environmental and economic advantages associated with Bt crop adoption in Brazilian agriculture.
View Article and Find Full Text PDF

The interspecific variation in susceptibility to insecticides by lepidopteran species of soybean [Glycine max L. (Merr.)], cotton (Gossypium hirsutum L.

View Article and Find Full Text PDF

Widespread adoption of MON 87701 × MON 89788 soybean, expressing Cry1Ac Bt protein and glyphosate tolerance, has been observed in Brazil. A proactive program was implemented to phenotypically and genotypically monitor Cry1Ac resistance in Chrysodeixis includens (Walker). Recent cases of unexpected injury in MON 87701 × MON 89788 soybean were investigated and a large-scale sampling of larvae on commercial soybean fields was performed to assess the efficacy of this technology and the distribution of lepidopteran pests in Brazil.

View Article and Find Full Text PDF

The novel ingestion bioassay method was developed for detecting and monitoring resistance of by encapsulating an artificial liquid diet using Parafilm. This methodology was compared with the tarsal contact (vial test) and topical application methods for thiamethoxam, imidacloprid, and lambda-cyhalothrin. The best bioassay method for the neonicotinoid insecticides thiamethoxam and imidacloprid was ingestion.

View Article and Find Full Text PDF

The soybean technology MON 87701 × MON 89788, expressing Cry1Ac and conferring tolerance to glyphosate, has been widely adopted in Brazil since 2013. However, pest shifts or resistance evolution could reduce the benefits of this technology. To assess Cry1Ac soybean performance and understand the composition of lepidopteran pest species attacking soybeans, we implemented large-scale sampling of larvae on commercial soybean fields during the 2019 and 2020 crop seasons to compare with data collected prior to the introduction of Cry1Ac soybeans.

View Article and Find Full Text PDF

Background: Fall armyworm, Spodoptera frugiperda (J. E. Smith), is a relevant global pest due to severe damage caused on agricultural crops and its capacity to evolve resistance to insecticides.

View Article and Find Full Text PDF

Competition behavior involving agricultural pest species has long been viewed as a powerful selective force that drives ecological and phenotypic diversity. In this context, a Game Theory-based approach may be useful to describe the decision-making dilemma of a competitor with impacts to guarantee its superiority in terms of ecological dominance or sharing of the food resource with its competitor. In an attempt to elucidate the consequences of competitive dynamics for the ecological dominance of these species in refuge areas of Bt cotton, we conducted a study that was divided into two parts.

View Article and Find Full Text PDF

Background: Brevipalpus yothersi mite is the main vector of Citrus leprosis virus (CiLV), the causal agent of citrus leprosis disease. The acaricide spirodiclofen has been widely used to control this mite. However, failures in control using spirodiclofen have been frequently reported by citrus growers.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates how different crops in Brazil affect the host interactions and population dynamics of two types of moths, Helicoverpa armigera and H. zea, that attack crops like cotton and soybean.
  • Findings show that H. armigera has the highest survival rate on cotton, while noncotton crops are significant sources of H. armigera moths, particularly in regions growing winter maize.
  • The research concludes that variations in host usage and population dynamics across regions may be influenced by the availability of alternative plants and the moths' adaptation behaviors like diapause and migration.*
View Article and Find Full Text PDF

Background: 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), the main benzoxazinoid found in corn, elicits variable larval responses from different pest moths. For the widespread and highly polyphagous Spodoptera frugiperda (Lepidoptera: Noctuidae), the fall-armyworm (FAW), DIMBOA acts as a feeding stimulant and improves larval growth at low concentrations. The FAW present two host plant-related strains, corn and rice strains, related to host preference on corn and other Graminae or rice.

View Article and Find Full Text PDF

Spodoptera frugiperda is one of the main pests of maize and cotton in Brazil and has increased its occurrence on soybean. Field-evolved resistance of this species to Cry1 Bacillus thuringiensis (Bt) proteins expressed in maize has been characterized in Brazil, Argentina, Puerto Rico and southeastern U.S.

View Article and Find Full Text PDF