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Manoel G. C. Gondim – One of the best experts on this subject based on the ideXlab platform.
Acaricide-Mediated Colonization of Mite-Infested Coconuts by the Predatory Phytoseiid Neoseiulus baraki (Acari: Phytoseiidae)Journal of Economic Entomology, 2018Co-Authors: Vaneska Barbosa Monteiro, J. W. S. Melo, D. B. Lima, R N C Guedes, Manoel G. C. GondimAbstract:
Walking is important to dispersal on plants and colonization of new plants by predatory mites, and this activity is potentially affected by the presence of Acaricides. This possibility was investigated in coconut fruits infested with the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), where colonization by the predator Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae) was monitored. The following Acaricides were evaluated for influence on the process of colonization by the predatory mite: abamectin, azadirachtin, and fenpyroximate. Water-treated fruits were used for comparison. Experiments were conducted with and without freedom of choice on coconut fruits with the release and recapture of females of N. baraki marked with fluorescent ink. A confinement experiment was also carried out on coconut bunch rachis sprayed or not sprayed with the Acaricides. The predatory mite N. baraki avoided contact with acaricide-contaminated areas. After the predators were released on the fruits or bunch rachis, larger numbers were recaptured under the bracts than on the surface of the fruits. The number of predators recaptured in all experiments was lower in the treatments with Acaricides than in the control. Among the Acaricides tested, azadirachtin least affected N. baraki colonization. Therefore, the presence of the tested Acaricides indeed interferes with N. baraki dispersal within plants and the coconut fruit colonization.
Toxicity of Acaricides to and the behavioural response of Steneotarsonemus concavuscutum (Acari: Tarsonemidae)Crop Protection, 2018Co-Authors: Girleide Vieira França, D. B. Lima, Vaneska Barbosa Monteiro, Manoel G. C. GondimAbstract:
Abstract Steneotarsonemus concavuscutum Lofego and Gondim Jr. causes chlorosis, necrosis, deformation, resinosis and death of coconut fruit (Cocos nucifera L.). These types of damage are commonly interpreted to result from Aceria guerreronis Keifer. The control of mites in coconut fruits is carried out primarily by acaricide applications. However, no records exist on the effectiveness of Acaricides for S. concavuscutum control. Therefore, this study aimed to evaluate the toxicity of Acaricides registered for the control of A. guerreronis on S. concavuscutum, in addition to analysing the walking behaviour of tarsonemid mites when exposed to the products. The behaviour of mites exposed to Acaricides was studied with a video-tracking system in choice and no-choice arenas treated with Acaricides. The LC50 estimate for abamectin and fenpyroximate was 1.1 mg/L and 2757 mg/L, respectively. Azadirachtin, spirodiclofen and hexythiazox caused mortality of up to 25%. Only exposure to abamectin reduced the number of mites that reached the perianth and remained live, but no difference was observed in the number of eggs found at this site. No acaricide showed an ovicidal or sterilizing effect on the females. The total distance walked and the walking velocity were higher when S. concavuscutum was exposed to azadirachtin and lower when exposed to abamectin. All Acaricides irritated S. concavuscutum; however, repellence was observed in only 5% of the tested population for abamectin and azadirachtin. Among the products recommended for the control of A. guerreronis, only abamectin showed potential in controlling S. concavuscutum.
Population-level effects of abamectin, azadirachtin and fenpyroximate on the predatory mite Neoseiulus baraki
Experimental and Applied Acarology, 2016Co-Authors: D. B. Lima, Manoel G. C. Gondim, J. W. S. Melo, Raul N. C. Guedes, José E. M. OliveiraAbstract:
The coconut production system, in which the coconut mite Aceria guerreronis is considered a key pest, provides an interesting model for integration of biological and chemical control. In Brazil, the most promising biological control agent for the coconut mite is the phytoseiid predator Neoseiulus baraki . However, Acaricides are widely used to control the coconut mite, although they frequently produce unsatisfactory results. In this study, we evaluated the simultaneous direct effect of dry residue contact and contaminated prey ingestion of the main Acaricides used on coconut palms (i.e., abamectin, azadirachtin and fenpyroximate) on life-history traits of N. baraki and their offspring. These Acaricides are registered, recommended and widely used against A. guerreronis in Brazil, and they were tested at their label rates. The offspring of the exposed predators was also evaluated by estimating the instantaneous rate of population increase ( r _ i ). Abamectin compromised female performance, whereas fenpyroximate did not affect the exposed females (F0). Nonetheless, fenpyroximate strongly compromised the offspring (F1) net reproductive rate (R_0), intrinsic rate of population growth ( r _ i ), and doubling time (DT). In contrast, fenpyroximate did not have such effects on the 2nd generation (F2) of predators with acaricide-exposed grandparents. Azadirachtin did not affect the predators, suggesting that this acaricide can be used in association with biological control by this predatory species. In contrast, the use of abamectin and fenpyroximate is likely to lead to adverse consequences in the biological control of A. guerreronis using N. baraki .
Angelo Pallini – One of the best experts on this subject based on the ideXlab platform.
Acaricide-impaired functional predation response of the phytoseiid mite Neoseiulus baraki to the coconut mite Aceria guerreronis
Ecotoxicology, 2015Co-Authors: D. B. Lima, Manoel G. C. Gondim, J. W. S. Melo, R N C Guedes, J. E. M. Oliveira, Angelo PalliniAbstract:
Acaricides may interfere with a myriad of interactions among arthropods, particularly predator–prey interactions. The coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), and its phytoseiid predator, Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae), provide an opportunity to explore such interference because the former is a key coconut pest species that requires both predation and acaricide application for its management. The objective of the present study was to assess the effect of the Acaricides abamectin, azadirachtin and fenpyroximate on the functional response of N. baraki to A. guerreronis densities. The following prey densities were tested: 5, 10, 20, 40 and 80 preys. The type of functional response and prey handling time ( Th ) were not altered by the Acaricides. However, the attack rate ( a′ ) was modified by abamectin and fenpyroximate, and the consumption peak was reduced by abamectin. All of the Acaricides allowed for the maintenance of the predator in the field, but exposure to abamectin and fenpyroximate compromised prey consumption.
Fitness costs associated with low-level dimethoate resistance in Phytoseiulus macropilis
Experimental and Applied Acarology, 2013Co-Authors: D. D. M. Rezende, M. A. M. Fadini, H. G. Oliveira, C. M. Oliveira, J. W. S. Melo, R. N. C. Guedes, Angelo PalliniAbstract:
Phytoseiulus macropilis Banks (Acari: Phytoseiidae) is an effective predator of tetranychid mites, but there are no data on its response to pesticides. We investigated the resistance of the predatory mite P. macropilis to the Acaricides abamectin and dimethoate, and we examined the fitness costs associated with resistance. Two populations were tested: one from conventional cultivation and another from an area not commercially exploited. After the application of Acaricides to the predator, we determined the lethal effects of the Acaricides, the instantaneous rate of population increase ( r _ i ), the predation on Tetranychus urticae Koch (Acari: Tetranychidae) and its ability to locate prey in an olfactometer. P. macropilis exhibited resistance to dimethoate only. The low level of resistance (9.4x) of the predator did not affect their ability to locate prey. However, the dimethoate resistant population was not as effective in contatining prey population when in lower density and exhibited a more pronounced decrease of r _ i in the presence of this acaricide, due to the reduced oviposition of the predator, a likely consequence of the different genetic background of this population.
Survival and behavioural response to Acaricides of the coconut mite predator Neoseiulus baraki.Experimental and Applied Acarology, 2012Co-Authors: D. B. Lima, Angelo Pallini, J. W. S. Melo, R N C Guedes, Herbert A.a. Siqueira, Manoel G. C. GondimAbstract:
The coconut mite, Aceria guerreronis Keifer, is a major pest of coconut palm in the world. The control of this pest species is done through acaricide applications at short time intervals. However, the predators of this pest may also be affected by Acaricides. Among the predators of A. guerreronis, Neoseiulus baraki (Athias-Henriot) has potential for biological control. The objective of this study was to assess the effect of Acaricides on the survival and behavior of N. baraki. The survivorship of N. baraki was recorded in surface-impregnated arenas. Choice and no-choice behavioral bioassays were carried out using a video tracking system to assess the walking behavior of the predator under acaricide exposure. Although all Acaricides negatively affected the survival of N. baraki, chlorfenapyr and azadirachtin caused lower effect than the other Acaricides. No significant differences in walking behavior were observed under exposure to fenpyroximate, chlorfenapyr and chlorpyrifos on fully-contaminated arenas. Azadirachtin and chlorpyrifos caused repellence. Irritability was observed for all Acaricides, except for abamectin. Chlorfenapyr was the most suitable product for managing the coconut mite because of its low effect on survival and behavior of N. baraki.
Martín Javier Eguaras – One of the best experts on this subject based on the ideXlab platform.
Sublethal effects of Acaricides and Nosema ceranae infection on immune related gene expression in honeybeesVeterinary Research, 2016Co-Authors: Paula Melisa Garrido, Martín Javier Eguaras, Martín Pablo Porrini, Karina Antúnez, Belén Branchiccela, Giselle María Astrid Martínez-noël, Pablo Zunino, Graciela Salerno, Elena IenoAbstract:
AbstractNosema ceranae is an obligate intracellular parasite and the etiologic agent of Nosemosis that affects honeybees. Beside the stress caused by this pathogen, honeybee colonies are exposed to pesticides under beekeeper intervention, such as Acaricides to control Varroa mites. These compounds can accumulate at high concentrations in apicultural matrices. In this work, the effects of parasitosis/acaricide on genes involved in honeybee immunity and survival were evaluated. Nurse bees were infected with N. ceranae and/or were chronically treated with sublethal doses of coumaphos or tau-fluvalinate, the two most abundant pesticides recorded in productive hives. Our results demonstrate the following: (1) honeybee survival was not affected by any of the treatments; (2) parasite development was not altered by acaricide treatments; (3) coumaphos exposure decreased lysozyme expression; (4) N. ceranae reduced levels of vitellogenin transcripts independently of the presence of Acaricides. However, combined effects among stressors on imagoes were not recorded. Sublethal doses of Acaricides and their interaction with other ubiquitous parasites in colonies, extending the experimental time, are of particular interest in further research work.
the presence of synthetic Acaricides in beeswax and its influence on the development of resistance in varroa destructorJournal of Apicultural Research, 2015Co-Authors: Sandra Karina Medici, Matias Maggi, Sergio Roberto Ruffinengo, Edgardo G Sarlo, Juan M Marioli, Martín Javier EguarasAbstract:
After honey production, beeswax ranks second as regards hive product used in industry and cosmetics. In Argentina, the use of commercial wax adulterated with paraffin and other olefins for comb foundation is a common practice. As regards beehives, the progressive accumulation of synthetic Acaricides in wax has caused adverse effects on bees, mainly on individuals at different stages of development. Another issue associated with the use of synthetic Acaricides is the phenomenon of resistance. This study aimed to determine the presence of adulterants and acaricide residues in commercial wax used in Argentina. Furthermore, the relationship between coumaphos content in wax and the development of mite resistance reported in recent years in Argentina was investigated. The results demonstrate that paraffin is the most common contaminant substance present in recycled beeswax and commercial wax used for comb foundation in the country. Coumaphos was also found to be the most common acaricide present in wax; 87% in …
immune related gene expression in nurse honey bees apis mellifera exposed to synthetic AcaricidesJournal of Insect Physiology, 2013Co-Authors: Paula Melisa Garrido, Martín Pablo Porrini, Karina Antúnez, Pablo Zunino, Mariana L Martin, Martín Javier EguarasAbstract:
The mite Varroa destructor is an ectoparasite affecting honey bees worldwide. Synthetic Acaricides have been among the principal tools available to beekeepers for its control, although several studies have shown its negative effects on honey bee physiology. Recent research suggests that those molecules strongly impact on immune signaling cascades and cellular immunity. In the present work, LC50 in six-day-old bees were determined for the following Acaricides: tau-fluvalinate, flumethrin, amitraz and coumaphos. According to this obtained value, a group of individuals was treated with each acaricide and then processed for qPCR analysis. Transcript levels for genes encoding antimicrobial peptides and immune-related proteins were assessed. Flumethrin increased the expression of hymenoptaecin when comparing treated and control bees. Significant differences were recorded between coumaphos and flumethrin treatments, while the first one reduced the expression of hymenoptaecin and abaecin, the last one up-regulated their expressions. No significant statistically changes were recorded in the expression levels of vitellogenin, lysozyme or glucose dehydrogenase among bees treated with Acaricides and control bees. This work constitutes the first report, under laboratory conditions, about induction of immune related genes in response to synthetic miticides.