Physiological Insecticidal Activity of Triflumuron as Insect Growth Regulator Against Spodoptera littoralis (Boisd.) (original) (raw)
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Bulletin of Entomological Research, 1995
The effects of the chitin synthesis inhibitor triflumuron, 2-chloro-N-[[[4-(trifluoromethoxy)phenyl]amino]carbonyl]benzamide, on the housefly, Musca domestica Linnaeus were examined in the laboratory. A dose of 1 μg of triflumuron applied topically to adult females of M. domestica resulted in egg hatch inhibition greater than 95%. At doses below 1 μg applied topically to adult females, subsequent hatched larvae were also highly sensitive to triflumuron; 0.5 μg applied topically produced 25% inhibition of egg hatch, but of the larvae that eclosed, only 20% survived to pupation. Hence, a dose of 0.5 μg applied to adults gave a total mortality of 85%. The effects of a single topical application of triflumuron declined over time in a dose dependent manner. After a dose of 1 μg, <5% of the first egg batch hatched, however, after 14 days egg hatch had risen to >90%. Topically applied triflumuron was most effective in inhibiting egg hatch when applied to females less than 3 days old....
Pakistan Journal of Agricultural Sciences, 2012
Red flour beetle, Tribolium castaneum, is a worldwide serious pest of dried, stored, durable agricultural commodities, and of many value-added food products and non-food derivatives of agricultural products. Sublethal effects of three concentrations (0.01, 0.02 and 0.04ppm) of triflumuron were evaluated on two field collected strains of T. castaneum at last larval instar for development and reproduction impacts. Larval mortality increased significantly both with increase in concentration and exposure period. Exposed larvae exhibited reduction in weight and increase in duration of larval developmental duration compared to control. Subsequent development of pupae and emergence of adults was seriously prohibited. However, the increase in fecundity and egg hatchability reduced significantly at all concentrations compared to control. Finally, subsequent development of surviving F1 larvae, pupae and adults was also severely interdicted. In view of these impressive ovicidal and reproduction inhibition effects of triflumuron against T. castaneum and having low toxicity to non-target organisms, it should be tested in flour mills, ware houses and food storages for the promising replacement of synthetic grain protectants e.g. pyrethroids and organophosphates
The effect of the chitin synthesis inhibitor lufenuron on the various developmental stages of red flour beetle Tribolium castaneum was determined by exposing them to different sub-lethal concentrations (LC10, LC20 and LC40) of lufenuron through diet for 24 hrs. There was a dose dependent effect on the larval weight, time taken for pupation, and adult emergence, percentage pupation and percentage adult emergence. When two day old larvae were fed on sub-lethal concentrations through diet a small proportion of pupal –adult intermediates were observed at LC20 and LC40. Adults emerging from the larvae fed on diet containing LC10, LC20 and LC40 of lufenuron did not show any variation in the fecundity and hatchability of eggs from that of control. The fecundity of adults fed with sub-lethal concentration of lufenuron (obtained against two day old larvae through diet) was not affected, however, percentage hatching and survival was affected. Interestingly there was a reversal of the effect within ten days of treatment with respect to percentage hatching and survival. When eggs were exposed to treated diet hatching was not affected. The present data suggest that lufenuron even at sub-lethal concentrations has a very good larvicidal and ovicidal activity in T. castaneum.
Egyptian Academic Journal of Biological Sciences, F. Toxicology & Pest Control, 2010
The present study aimed to evaluate the biological effect of insect growth regulator flufenoxuron (Cascade) as a chitin synthesis inhibitor against 2 nd and 4 th larval instars of Spodoptera littoralis, to determine its toxicity. Effect of sublethal doses LC 25 , LC 50 and LC 90 were used to investigate the enzymatic activities. The tested IGR significantly increased the larval and pupal durations, on the other hand decrease the percentages of pupation, adult emergency, fecundity and fertility of the eggs produced by the adult progeny. The tested compound significantly induced larval mortalities, which were dose dependant. Treatments of the 2 nd and 4 th larval instars with the tested IGR induced some morphogenic abnormalities in larval, larval-pupal and pupal stages, as well as pupal-adult intermediate. Some emerged adults have various degrees of malformations. All the treated larvae as 2 nd instar showed a high sensitivity to the tested IGRs more than 4 th instars. The treated larvae in both 2 nd and 4 th larval instars with the sublethal doses LC 25 , LC 50 and LC 90 showed a significant decrease in enzyme activities of acid phosphatase and the non-specific esterases, α,β esterases at different times intervals post treatments.
Egyptian Academic Journal of Biological Sciences. A, Entomology
Field evaluation for the efficacy of indoxacarb, spinetoram and methoxyfenozide against larval instars of S. littoralis, infested clover plants Trifoliuma lexandrium was studied at two different Governorates (Al-Qalyubia and El-Fayoum) during cultivation season 2012-2013.All three insecticides, of indoxacarb, spinetoram and methoxyfenozide had no great difference among themselves in reducing the larval population of S. littoralis with difference in the time needed to induce this reduction according to the mode of action of these insecticides.The initial reductionwas recorded after 1 day from spraying for indoxacarb and spinetoram while after 3 days from spraying for methoxyfenozide. Indoxacarb was the most effective insecticide followed by methoxyfenozide and spinetoram.Under semi-field conditions, results showed that, at Al-Qalyubia Governorate, persistence of indoxacarb is higher than other tested insecticides while, the half life of all tested compounds is short at El-Fayoum Governorate.Tolerance to the toxicity of the three tested insecticides increased as the larvae grew older from 2 nd to 4 th instar.Biochemical clarification was carried out in an attempt to disclose the effect of sub-lethal concentration (LC 50) of the three tested insecticides; on haemolymph contents of 6 th instar larvae of S. littoralis which was treated as 4 th larval instar with LC 50 of the tested insecticides and their effects on main components of insect metabolites and changes in protein patterns.
Egyptian Academic Journal of Biological Sciences. A, Entomology, 2013
In this studyflufenoxuron as insect growth regualtor and SpliNPV were used to investigate their toxicity on Spodopteralittoralis. Both 2 nd and 4 th larval instars of S. littoralis were exposed to the different concentrations of flufenoxuron and SpliNPV. The biochemical effect of IGR and SpliNPV on both 2 nd and 4 th larvae instar show changes in protein electrophoretic pattern in the current study reveals differences between the untreated samples and treated one, some proteins were missed or expressed at different stages which may be responsible for all the obtained deformation. The effect of these compounds on biochemical activities were revealed after studying electrophoretic protein (fractionated protein) using PAGE in order to determine their effects on the vital system of S. littoralis, which may indicate the formation of new proteins responsible for stimulating the immune system of the insect as a result of entering foreign objects inside the body of the insect.
Journal of Plant Protection and Pathology, 2017
Chlorpyrifos and Imidacloprid are belongs to two main groups of insecticides that are widely used in insect control. Many researches had been discussed the effect of both groups on non-target organisms and the environment. So, it necessary to reduce the used doses of this groups to save the environment. The effect of pre-treatment with lufenuron (chitin synthesis inhibitor) at sub lethal dose (LD 25) on the efficacy of Chlorpyrifos and Imidacloprid on Spodoptera littoralis was studied using topical application method. The toxicity of both Chlorpyrifos and Imidacloprid increased after 24hrs of pre-treatment with LD 25 of Lufenuron by 55 and 250 times for Chlorpyrifos and Imidacloprid, respectively compared with the toxicity of each compound alone. Histological studies showed that the treatment of 2 nd instar larvae with LD 25 of Lufenuron caused obvious separation of the hypodermis layer from the endocuticle, abnormalities in the epicuticle morphology , rupture in muscles, irregular and great disintegration of cuticle and hypodermis. In-vivo interaction of LD 25 values of Chlorpyrifos, Imidacloprid and Lufenuron with Alkaline and Acid phosphatase caused significant increase in the activity of Alkaline phosphatase while Acid phosphatase activity was significantly decreased in all treatment.
Journal of Applied Entomology, 1996
Triflumuron (TFM), a benzoylphenylurea (BPU) derivative, exhibited insecticidal activity when injected to newly ecdysed pupae of Tenebrio molitor. Mortality occurs by defect in adult ecdysis. Treatment resulted in a significant increase in the duration of pupal stage and caused a reduction in both cuticle thickness and incorporation of ''C-labelled precursor into chitin compared to controls. Moreover, TFM reduced the amount of cuticle chitin without any significant effect on protein level. Thus, TFM acts by preventing the chitin biosynthesis confirming the primary mode of action of the BPU insecticides.
Egyptian Academic Journal of Biological Sciences. A, Entomology, 2009
The present study was planned to investigate the histopathological effects of the chitin synthesis inhibitor chlorfluazuron against the 4 th larval instar of Tribolium castaneum (Coleoptera: Tenebrionidae) under electron microscope level. Toxicity of chlorfluazuron was evaluated under three different temperatures. The sublethal concentrations LC 40 were 2.118, 39.76 and 1.207 ppm, at 20, 29 and 38 • C respectively. Toxicity of this compound increased at relatively high temperature. Ultrastructural studies were carried out on the integument of the prepupae treated as larvae with LC 40 of chlorfluazuron. The treated samples revealed that exuviae of the old cuticle were existed above the new formed integument, some densely-stained material was deposited in endocuticle, procuticle lamellae were disorganized and partially degenerated. Disappearance of moulting fluid. The hypodermis was destructed and detached from endocuticle. Mitochondria were swollen and fusion. Lysis of lysosomelike bodies.
The exploit of insect growth regulators (IGR) for insect pest management are good option because they do not accumulate in the environment and are less toxic to man and domestic animals. At the present study, a chitin synthesis inhibitor from insect growth regulator; Hexaflumuron was tested for its toxicity and side effects on the 4th instar larvae of Helicoverpa armigera Hubner. Estimated LC 50 and LC 90 values of leaf dip bioassay of Hexaflumuron on these larvae after 120 hours of treatment were 8.47, and 82.26 mg /L, respectively. Hexaflumuron at doses of 1, 3.2, 9.8, 31.6, and 100 mg/L were caused significant mortality on prepupae and pupae as compared to untreated control. Also abnormalities in adults were observed with treated pupae. We conclude that the sub-lethal and lethal effects of Hexaflumuron might exhibit significant effects on the population of H. armigera and can be used to its management.