Ultrastructural Observations on the Gonads and Neurosecretory Cells of<i>Schistocerca gregaria</i>After Treatment with Lufenuron (CGA-184699)

Ghazawy, N.A.

doi:10.1665/034.021.0202

Cited by 9 publications

(7 citation statements)

References 28 publications

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“…Thus, the results of this study indicate that buprofezin and the pyriproxyfen are involved in dismantling germ cells and the connective tissue component of both external and internal sheaths. These results are similar to those of Ghazawy (2012), who also reported correlations between the action of the chitin biosynthesis inhibitor lufenuron and the ultrastructure and formation of testicular cysts of S. gregaria.…”

Section: Testis Analysessupporting

confidence: 90%

“…Reports of products that inhibit chitin biosynthesis and that are involved in the losses of reproductive potential and development of insect ovaries and testes exist (CHANGMANN et al, 2008;GHAZAWY, 2012).…”

Section: Studies In Whitefly (Trialeurodes Vaporariorummentioning

confidence: 99%

“…Little is known about the distribution pattern of lipids within the oocyte; it is known only that there is an increase in the amount of lipid droplets depending on the stage of oocyte development (i.e., a more developed oocyte has a higher amount) (SANTOS, 2001). In studies with Schistocerca gregaria Forsskål (Orthoptera: Acrididae), the chitin biosynthesis inhibitor lufenuron affected the follicular layer organization and the arrangement of nutritive material in developing oocytes (GHAZAWY, 2012). Therefore, it is believed that the possible action of buprofezin may be related to a physiological change in the storage or even the synthesis and distribution of lipid material inside the oocyte.…”

Section: Ovariole Analysesmentioning

confidence: 99%

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Performance of reproductive system of Dichelops melacanthus (Hemiptera: Pentatomidae) subjected to buprofezin and pyriproxyfen: morphological analysis of ovarioles and testes

Cremonez

Pinheiro

Falleiros

et al. 2017

SCA

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The use of insecticides known as insect growth regulators, which are considered more selective to natural enemies, may be an alternative to integrated pest management of stink bugs of the main crops in Brazil. The objective of this study was to evaluate histological changes in the reproductive system of Dichelops melacanthus as well as female fecundity and egg fertility after use of growth-regulating insecticides. The insecticides used were buprofezin (a chitin biosynthesis inhibitor) at a sublethal concentration (LC 30 of 2.99 g L -1 ) and pyriproxyfen (a juvenile hormone analog) at a sublethal concentration (LC 30 of 8.35 mL L -1 ). A completely randomized experimental design was used, with 10 repetitions and 10 insects per experimental unit. Two bioassays were performed: in the first bioassay, fecundity (eggs/ female) and fertility (nymph eclosion) of the insects that survived the insecticides were evaluated; in the second bioassay, morphological alterations of the ovarioles of adult females and of the testes of adult male insects that survived the insecticides were evaluated. Buprofezin and pyriproxyfen did not affect the adult sex ratio or female fecundity. Pyriproxyfen reduced the percentage of ecloded nymphs (71.6%) compared with that of the control and buprofezin (96.4 and 90.6%, respectively) treatments and had an ovicidal effect, with direct and indirect action on embryogenesis. Morphological changes were observed in both treatments with buprofezin and pyriproxyfen. The alterations observed in female and male reproductive systems may occur by the action of buprofezin and pyriproxyfen on the morphology of both ovarioles and testes. Key words: Dose-response curve. Endocrine disruption. Green-belly stink bug. Insect growth regulators. Reproductive organ morphology. ResumoA utilização de inseticidas conhecidos como reguladores de crescimento dos insetos, considerados mais seletivos a inimigos naturais, pode ser uma alternativa no manejo integrado no que se refere ao controle de percevejos-pragas das principais culturas no Brasil. Os objetivos deste trabalho foram avaliar alterações histológicas causadas no aparelho reprodutor de Dichelops melacanthus e a fecundidade das fêmeas e fertilidade de ovos, após o uso de inseticidas reguladores de crescimento. utilizados foram buprofezina (inibidor da biossíntese de quitina), na concentração subletal CL 30 2,99 g L -1 , e o piriproxifem (análogo do hormônio juvenil) na concentração subletal CL 30 8,35 mL L -1 . O delineamento experimental foi inteiramente casualizado, com 10 repetições e 10 insetos por repetição. Foram realizados dois bioensaios: no primeiro foi avaliada a fecundidade (número de ovos/fêmea) e a fertilidade (número de ninfas eclodidas) dos insetos que sobreviveram aos produtos. No segundo bioensaio, foram avaliadas as alterações morfológicas de ovaríolos de fêmeas e testículo de machos de percevejos adultos, que sobreviveram à ação dos inseticidas. Buprofezina e piriproxifem não afetaram a razão sexual de adultos ou mesmo a fecundidade das ...

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Section: Testis Analysessupporting

confidence: 90%

Section: Studies In Whitefly (Trialeurodes Vaporariorummentioning

confidence: 99%

Section: Ovariole Analysesmentioning

confidence: 99%

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Performance of reproductive system of Dichelops melacanthus (Hemiptera: Pentatomidae) subjected to buprofezin and pyriproxyfen: morphological analysis of ovarioles and testes

Cremonez

Pinheiro

Falleiros

et al. 2017

SCA

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“…They also saw that nymphs treated with the insect growth regulator cascade showed a notable decrease in the number of cerebral NC as well as the number of neurosecretory particles carried by the axoplasm. Ghazawy [40] also found that treatment of fifth-instar Schistocerca gregaria with lufernuron, a chitin synthesis inhibitor, reduced the release of neurosecretory material from the brain NC in the pars intracerebral.…”

Section: Discussionmentioning

confidence: 94%

The Effect of Abamectin on Locusta Migratoria Neurosecretory Cells and Mid Gut, Using Ultrastructure Examination, Oxidative Stress Study, and In-Silico Molecular Docking

Ghazawy,

Afify,

Radwan

et al. 2023

Molecules

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(1) Background: Few studies have been carried out to appraise abamectin toxicity toward Locusta migratoria nymphs. (2) Methods: This study aimed to evaluate the cytotoxic effect of abamectin as an insecticide through examining the changes and damage caused by this drug, in both neurosecretory cells and midgut, using L. migratoria nymphs as a model of the cytotoxic effect. Histopathological change in the brain was examined in both normal and abamectin-treated fifth-instar nymphs. Neurosecretory cells (NSCs) were also examined where there were loosely disintegrated cells or vacuolated cytoplasm. (3) Results: The results showed distinct histological changes in the gastrointestinal tract of L. migratoria nymphs treated with abamectin, with significant cellular damage and disorganization, i.e., characteristic symptoms of cell necrosis, a destroyed epithelium, enlarged cells, and reduced nuclei. The observed biochemical changes included an elevation in all measured oxidative stress parameters compared to untreated controls. The malondialdehyde activities (MDAs) of the treated nymphs had a five- to six-fold increase, with a ten-fold increase in superoxide dismutase (SOD), nine-fold increase in glutathione-S-transferase (GST), and four-fold increase in nitric oxide (NO). (4) Conclusions: To further investigate the theoretical method of action, a molecular docking simulation was performed, examining the possibility that abamectin is an inhibitor of the fatty acid-binding protein Lm-FABP (2FLJ) and that it binds with two successive electrostatic hydrogen bonds.

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“…Tests with lufenuron presented a sperm reduction in males of Anthonomus grandis Boheman (1843) (Coleoptera: Curculionidae), the boll weevil, as well as ovarian changes in females (Costa, et al, 2017). The same compound was tested in S. gregaria, showing analyzes of ovarian and testicular disruption (Ghazawy, 2012). Tail et al (2008) observed, in diflubenzuron treatment of S. gregaria, a reduction in eggs number per ootheca and, with the observed results, formulated a hypothesis about the treatment have reduced the ecdysteroids levels in hemolymph, reflecting in ovarian synthesis reduction due to alterations in follicular chambers.…”

Section: Potential In Reproductive Modificationsmentioning

confidence: 87%

Existing potentials in Insect Growth Regulators (IGR) for crop pest control

Apolinário

Feder

2021

RSD

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The aim of this review is to explore the potentials existing in insecticides that are considered Insect Growth Regulators (IGR) for the control of insects considered crop pests, with an observation of the main mechanisms of neuroendocrine modifications, development and viability of the species used as study models. The data search on digital platforms, as well as the screening of materials about crop pests, resulted in 74 IGR references and their potentials. The analysis of the information found demonstrated a greater use in works of compounds belonging to chitin synthesis inhibitors class; and orders such as Hemiptera, Lepidoptera, Coleoptera, Orthoptera, Thysanoptera and Diptera were represented in the studies. The main types of activities reunited were morphological and anatomical modifications, reproductive modifications, alterations in developmental stage, alterations in developmental period, ovicidal activity, larvicidal/ninficidal activity and fagoinhibition. The congregated knowledge about the main pests used as study models, the main IGRs compounds and their biological potentials allow an evaluation of their use as an informative source for crop pest control methods.

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Ultrastructural Observations on the Gonads and Neurosecretory Cells ofSchistocerca gregariaAfter Treatment with Lufenuron (CGA-184699)

Abstract: BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.

Cited by 9 publications

References 28 publications

Performance of reproductive system of Dichelops melacanthus (Hemiptera: Pentatomidae) subjected to buprofezin and pyriproxyfen: morphological analysis of ovarioles and testes

Performance of reproductive system of Dichelops melacanthus (Hemiptera: Pentatomidae) subjected to buprofezin and pyriproxyfen: morphological analysis of ovarioles and testes

The Effect of Abamectin on Locusta Migratoria Neurosecretory Cells and Mid Gut, Using Ultrastructure Examination, Oxidative Stress Study, and In-Silico Molecular Docking

Existing potentials in Insect Growth Regulators (IGR) for crop pest control

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