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Celso Omoto - One of the best experts on this subject based on the ideXlab platform.
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Growth of selected insecticide-degrading bacterial isolates obtained from the gut microbiota of insecticide-resistant lines of Spodoptera frugiperda at different insecticide concentrations (10, 20, 40, 80 or 160 μg/mL).
2017Co-Authors: Luis Gustavo De Almeida, Celso Omoto, Luiz Alberto Beraldo De Moraes, José Roberto Trigo, Fernando Luis CônsoliAbstract:Isolates A) IIL-Cl29 (Leclercia adecarboxylata), B) IIL-Lc09 (Pseudomonas stutzeri), C) IIL-Dm05 (Arthrobacter nicotinovorans), D) IIL-Sp19 (Pseudomonas psychrotolerans), and E) IIL-Luf14 (Microbacterium arborescens) were isolated and cultivated on insecticide-based media containing, respectively, chlorpyrifos ethyl, lambda-cyhalothrin, deltamethrin, spinosad and Lufenuron.
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Natural (ND), bacterial (BD) and total (TD) degradation of lambda-cyhalothrin, deltamethrin, chlorpyrifos ethyl, Lufenuron and spinosad (spinosyn A e D) after 5 days of cultivation of bacterial isolates from the larval gut of insecticide-resistant li
2017Co-Authors: Luis Gustavo De Almeida, Celso Omoto, Luiz Alberto Beraldo De Moraes, José Roberto Trigo, Fernando Luis CônsoliAbstract:Natural (ND), bacterial (BD) and total (TD) degradation of lambda-cyhalothrin, deltamethrin, chlorpyrifos ethyl, Lufenuron and spinosad (spinosyn A e D) after 5 days of cultivation of bacterial isolates from the larval gut of insecticide-resistant lines of Spodoptera frugiperda.
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genetic basis of spodoptera frugiperda lepidoptera noctuidae resistance to the chitin synthesis inhibitor Lufenuron
Pest Management Science, 2016Co-Authors: Antonio Rogerio Bezerra Do Nascimento, Juliano Ricardo Farias, Daniel Bernardi, Renato J Horikoshi, Celso OmotoAbstract:BACKGROUND An understanding of the genetic basis of insect resistance to insecticides is important for the establishment of insect resistance management (IRM) strategies. In this study we evaluated the inheritance pattern of resistance to the chitin synthesis inhibitor Lufenuron in Spodoptera frugiperda. RESULTS The LC50 values (95% CI) were 0.23 µg Lufenuron mL−1 water (ppm) (0.18–0.28) for the susceptible strain (SUS) and 210.6 µg mL−1 (175.90–258.10) for the Lufenuron-resistant strain (LUF-R), based on diet-overlay bioassay. The resistance ratio was ≈ 915-fold. The LC50 values for reciprocal crosses were 4.89 µg mL−1 (3.79–5.97) for female LUF-R and male SUS and 5.74 µg mL−1 (4.70–6.91) for female SUS and male LUF-R, indicating that the inheritance of S. frugiperda resistance to Lufenuron is an autosomal, incompletely recessive trait. Backcrosses of the progeny of reciprocal crosses with the parental LUF-R showed a polygenic effect. The estimated minimum number of independent segregations was in the 11.02 range, indicating that resistance to Lufenuron is associated with multiple genes in S. frugiperda. CONCLUSIONS Based on genetic crosses, the inheritance pattern of Lufenuron resistance in S. frugiperda was autosomal, incompletely recessive and polygenic. Implications of this finding to IRM are discussed in this paper. © 2015 Society of Chemical Industry
Rudolf Schenker - One of the best experts on this subject based on the ideXlab platform.
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an insect growth inhibitor Lufenuron enhances albendazole activity against hydatid cyst
Veterinary Parasitology, 2011Co-Authors: Martin Breijo, Rudolf Schenker, Fernanda Isnardi, Monica Brauer, Mariana Ferrari, Ana Maria FerreiraAbstract:Abstract The aim of this work was to evaluate the potential of Lufenuron, a benzylphenylurea with ability to interfere with the formation of insect exoskeleton, as a therapeutic drug for larval echinococcosis (hydatid disease). For this purpose Lufenuron, alone or in combination with albendazole, was administered to CD1 mice bearing Echinococcus granulosus hydatid cysts in the peritoneal cavity. Neither of the drugs alone was able to exert parasiticidal effects. However, in combination with albendazole, Lufenuron reduced the growth of cysts (30–40% in cyst diameter respect to control, p
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efficacy of pre treatment with Lufenuron for the prevention of microsporum canis infection in a feline direct topical challenge model
Veterinary Dermatology, 2002Co-Authors: Karen A Moriello, Douglas J Deboer, Jenifer L Blum, Rudolf Schenker, Lynn M VolkAbstract:We previously observed a trend towards clinically milder or delayed Microsporum canis infections in cats pre-treated with Lufenuron, suggesting a possible effect of this drug in limiting dermatophyte growth. We sought to determine the effect of pre-treatment with Lufenuron on development of M. canis infections induced via exposure to an infected cat. Lufenuron suspension (100 to 140 mg kg−1 orally, once monthly; or 40 mg subcutaneously, every 6 months) or placebo was administered to groups of eight juvenile cats. After 4 months of treatment, cats were challenged by introducing cats with mild, experimentally induced M. canis infections into the rooms. The extent of any resulting infection was monitored for 22 weeks after challenge. All cats became infected with M. canis. Cats treated with Lufenuron had significantly lower infection scores during the early weeks following exposure, and there was a more prolonged initial progression phase of the infection. Once infections reached peak intensity, they resolved over a similar time period in both treated and control groups. We conclude that Lufenuron, when used at the dose schedule and under the conditions in this study, did not prevent dermatophyte infection by exposure to an experimentally infected cat. The delay in establishment of infection may reflect an inhibitory effect of Lufenuron on the organism that is measurable, but not sufficient to prevent development of infection under these conditions. This study was supported by Novartis Animal Health.
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effect of Lufenuron on chorionic and cuticular structure of unhatched larval ctenocephalides felis siphonaptera pulicidae
Journal of Medical Entomology, 1999Co-Authors: Roger W Meola, Susan R Dean, Shirlee M Meola, Helga Sittertzbhatkar, Rudolf SchenkerAbstract:When adult cat fleas, Ctenocephalides felis (Bouche), were fed concentrations of < or = 0.08 ppm Lufenuron in cattle blood, egg hatch did not differ significantly from the controls. However, as the concentration of Lufenuron in blood increased from 0.125 to 1.0 ppm egg hatch decreased to 64 and 2%, respectively. Most of these eggs contained fully developed larvae. Microscopic examination of unhatched larvae, revealed that the cuticle epidermal cells, chorion, and vitelline membrane all were affected by Lufenuron treatment. Larvae often produced 2 separate cuticles in response to treatment. The 1st cuticle consisted of an indistinct layer of epicuticle and a procuticle composed of randomly deposited chitin microfibrils. After the 1st layer of procuticle separated from the epidermal cells, a 2nd layer of procuticle was deposited. It was not possible to determine whether the egg tooth was functional during larval hatch. The surface of the egg tooth appeared normal, but the cuticle may have had structural abnormalities similar to those seen in other areas of the exoskeleton. Structural defects appeared to be due to the cytotoxic effects of Lufenuron. The epidermal cells of treated larvae showed evidence of disintegration (i.e., the nuclei and mitochondria appeared to be degenerating and the amount of endoplasmic reticulum and other cytoplasmic organelles was decreased). The chorion of Lufenuron-treated larvae consisted of an outer layer, middle and inner layers that were thinner and less electron dense than those of controls, and lacked the innermost chorionic layer found in the control larvae. The vitelline membrane also was thinner than that of the controls. Larval hatching was prevented by ruptures in the cuticle, which opened during eclosion resulting in the loss of hemolymph and desiccation of the larva. Evidently, tearing of the cuticle was caused by abnormal formation of the procuticle that was not strong enough to withstand the cuticular expansion and muscular movement of the larva within the egg shell.
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mode of action of Lufenuron on larval cat fleas siphonaptera pulicidae
Journal of Medical Entomology, 1998Co-Authors: Susan R Dean, Roger W Meola, Shirlee M Meola, Helga Sittertzbhatkar, Rudolf SchenkerAbstract:Adult cat fleas, Ctenocephalides felis (Bouch6), were fed suboptimal in vitro concentrations of Lufenuron in blood to allow hatching of flea larvae for cytological study. At concentrations of 0.125, 0.25, and 0.5 ppm, larval hatch was 64,15, and 4%, respectively. Larvae hatching from eggs laid by adults fed Lufenuron at concentrations of 0.025,0.08, or 0.125 ppm did not differ significantly from the control. However, many larvae from the 0.08-ppm group and higher concentrations died during the 1st instar. Examination of these larvae revealed that they were dying from desiccation caused by bleeding from microscopic lesions in the cuticle or the inability to complete the molt to the next instar. Electron micrographs showed that Lufenuron often disrupted formation of the endocuticle resulting in the deposition of an amorphous mass of randomly oriented chitin microfibrils. Other larvae formed normal endocuticle but were unable to digest the old endocuticle or produce new procuticle after apolysis. Failure of larvae to digest old cuticle or form new cuticle was caused by degeneration of the epidermal cells needed for the synthesis of molting fluid and chitin.
Herbert A A Siqueira - One of the best experts on this subject based on the ideXlab platform.
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field resistance of plutella xylostella lepidoptera plutellidae to Lufenuron inheritance and lack of cross resistance to methoxyfenozide
Crop Protection, 2020Co-Authors: Lucas S Arruda, Agna R S Rodrigues, Natalia C B Bermudez, Lilian M S Ribeiro, Jaconias Escocio Lima Neto, Herbert A A SiqueiraAbstract:Abstract Plutella xylostella (L.), commonly known as diamondback moth, is one of the most important pests of Brassicaceae in Brazil. This study aimed to assess the susceptibility of P. xylostella and pattern of resistance inheritance to Lufenuron, an insect growth regulator (IGR) that impairs the insect molting, as well as the cross-resistance to methoxyfenozide (Nonsteroidal ecdysone agonist). Concentration-mortality bioassays were performed using the leaf dipping method towards field collected populations and genotypes used in the genetic crossings. Populations of this pest, from the mesoregion of Pernambuco (Brazil), were highly resistant to Lufenuron. The recommended concentration of Lufenuron caused more than 80% mortality of larvae of two populations [Piedade (PDD) and Recife (REC-S)]. Methoxyfenozide caused more than 80% mortality of larvae of all assessed populations, suggesting no cross-resistance between insect growth regulators. The population of Bezerros (BZR-R) was the most resistant (11,283-fold) to Lufenuron compared with REC-S population (standard reference). Resistance to Lufenuron was inherited as autosomal, incompletely recessive, and monofactorial trait, suggesting that a single gene or a set of genes tightly linked is involved in resistance. Methoxyfenozide is an alternative molecule suggested for the control of P. xylostella in areas where resistance to Lufenuron has evolved. Furthermore, information provided in this work should fine-tune insecticide resistance management (IRM) programs to delay the evolution of resistance to chitin synthesis inhibitors like Lufenuron, where resistance frequency is incipient.
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lethal and sublethal effects of Lufenuron on sugarcane borer diatraea flavipennella and its parasitoid cotesia flavipes
Ecotoxicology, 2015Co-Authors: Ana Paula Pereira Fonseca, Edmilson Jacinto Marques, Jorge B Torres, Liliane Marques Da Silva, Herbert A A SiqueiraAbstract:The combination of chemical and biological controls is a historic goal of integrated pest management, but has rarely been achieved due to lethal and sublethal impact of insecticides on natural enemies altering their performance. In this context, the susceptibility of the yellow sugarcane borer, Diatraea flavipennella (Lepidoptera: Crambidae), to the insect growth regulator Lufenuron and the consequent effects upon its endoparasitoid Cotesia flavipes (Hymenoptera: Braconidae) encountering exposed but surviving larvae were studied. Neonate and 10-day-old larvae were subjected to one of seven concentrations of Lufenuron (1.56, 3.12, 6.25, 12.5, 25.0, 50.0 and 100 mg a.i./L). Further, effects of Lufenuron to the host larvae and to the parasitoid were assessed using low lethal LC20 and LC50. Lufenuron at concentrations up to 12.5 mg a.i./L allowed partial survival of borer larvae; and concentrations over 12.5 mg a.i./L caused 100 % larval mortality before pupation in both ages. Neonate larvae exhibited lower pupal weights only at concentrations 12.5 mg a.i./L; while 10-day-old larvae treated with the LC50 exhibited delayed development. Egg viability was reduced for adult borers from surviving larvae of both ages treated with low lethal concentrations. The parasitoid C. flavipes successfully parasitized surviving low lethal treated larvae. Among the studied life history characteristics of C. flavipes, only a delayed development was observed. The results showed that Lufenuron can be effective against D. flavipennella at concentrations over 25 mg a.i./L, and that surviving larvae can be successfully parasitized by C. flavipes. The insecticide Lufenuron and the parasitoid C. flavipes seem to be compatible for sugarcane borer control.
Antonio Rogerio Bezerra Do Nascimento - One of the best experts on this subject based on the ideXlab platform.
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genetic basis of spodoptera frugiperda lepidoptera noctuidae resistance to the chitin synthesis inhibitor Lufenuron
Pest Management Science, 2016Co-Authors: Antonio Rogerio Bezerra Do Nascimento, Juliano Ricardo Farias, Daniel Bernardi, Renato J Horikoshi, Celso OmotoAbstract:BACKGROUND An understanding of the genetic basis of insect resistance to insecticides is important for the establishment of insect resistance management (IRM) strategies. In this study we evaluated the inheritance pattern of resistance to the chitin synthesis inhibitor Lufenuron in Spodoptera frugiperda. RESULTS The LC50 values (95% CI) were 0.23 µg Lufenuron mL−1 water (ppm) (0.18–0.28) for the susceptible strain (SUS) and 210.6 µg mL−1 (175.90–258.10) for the Lufenuron-resistant strain (LUF-R), based on diet-overlay bioassay. The resistance ratio was ≈ 915-fold. The LC50 values for reciprocal crosses were 4.89 µg mL−1 (3.79–5.97) for female LUF-R and male SUS and 5.74 µg mL−1 (4.70–6.91) for female SUS and male LUF-R, indicating that the inheritance of S. frugiperda resistance to Lufenuron is an autosomal, incompletely recessive trait. Backcrosses of the progeny of reciprocal crosses with the parental LUF-R showed a polygenic effect. The estimated minimum number of independent segregations was in the 11.02 range, indicating that resistance to Lufenuron is associated with multiple genes in S. frugiperda. CONCLUSIONS Based on genetic crosses, the inheritance pattern of Lufenuron resistance in S. frugiperda was autosomal, incompletely recessive and polygenic. Implications of this finding to IRM are discussed in this paper. © 2015 Society of Chemical Industry
Arash Zibaee - One of the best experts on this subject based on the ideXlab platform.
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effects of hexaflumuron Lufenuron and chlorfluazuron on certain biological and physiological parameters of helicoverpa armigera hubner lepidoptera noctuidae
Biocatalysis and agricultural biotechnology, 2019Co-Authors: Mahdieh Khorshidi, Reza Farshbaf Pour Abad, Moosa Saber, Arash ZibaeeAbstract:Abstract Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is one of the most economically devastating pests of agricultural crops around the world. In this study, the effects of hexaflumuron, Lufenuron and chlorfluazuron were evaluated on some biological and physiological parameters of H. armigera larvae. Effects of the insecticides were assessed by adding different concentrations into the larval artificial diet. Dose-response bioassay showed LC50 values of 6.16, 61.31 and 31.75 mg ai/l for hexaflumuron, Lufenuron and chlorfluazuron, respectively. Subsequently, sublethal effects of hexaflumuron, Lufenuron and chlorfluazuron were assessed using LC10 concentration to find their possible effects on the biological and physiological parameters of H. armigera larvae. The results showed significant changes in biological parameters, where the mean larval and pupal weights significantly decreased following treatment, while their developmental time significantly increased compared to the control. Meanwhile, the longevity of adult males and females, number of laid eggs per female, and rate of egg hatch were significantly reduced due to the insecticide treatments. The activities of alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transferase, acid- and alkaline phosphatases, lactate dehydrogenase, glutathione S-transferase were increased following the treatments. Sublethal exposure of the insecticides on larvae led to lower amounts of glycogen, triglyceride and protein compared to the control.
