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1.
The chitin biosynthesis inhibitor diflubenzuron and its analog BAY SIR 8514 are equitoxic for eggs ofSpodoptera littoralis. BAY SIR 8514 residues on alfalfa fed toSpodoptera larvae were more toxic than diflubenzuron residues, whereas BAY SIR 8514 topically applied to these larvae was consistently twice as toxic as diflubenzuron, according to different criteria. 相似文献
2.
The contact effect of residues on glass of the chitin synthesis inhibitor BAY SIR 8514 againstSpodoptera littoralis (Boisduval) larvae was investigated and probitlog dosage curves were established. The ED50 for cumulative mortality up to the adult stage was 0.0017 g/m2 for 100-mg and 0.004 g/m2 for 200-mg larvae. The toxicity of BAY SIR 8514 through this route of administration was considerably higher than that of diflubenzuron found in previous work. 相似文献
3.
The activities of the chitin synthesis inhibitors, diflubenzuron and PH 60–38, against Spodoptera littoralis larvae were assayed by feeding treated alfalfa or poisoned wheat bran baits, by allowing the larvae to imbibe sucrose-containing aqueous dispersions of the compounds, and by injection into larvae. PH 60–38 was less active than diflubenzuron. On alfalfa, diflubenzuron had to be fed for at least 2 days to prevent formation of normal pupae and emergence of adults. For very big (480–540 mg) larvae, feeding diflubenzuron at concentrations of 50 mg/litre for 2 days or 2.5 mg/litre for 3 days prevented adult emergence. For 200–250 mg larvae, this was achieved by feeding concentrations of 100 mg/litre for 2 days, 5 mg/litre for 3 days or 3.5 mg/litre for 4 days. In all larvae > 150 mg, mortality in feeding experiments occurred in the prepupal or the pupal stage. Only with 30–50 mg and 100–150 mg larvae was there considerable mortality during moults between larval instars, the larvae being unable to liberate themselves from the old larval skins and head capsules. Diflubenzuron incorporated into wheat bran baits at concentrations of from 2.5 to 10 000 μg/g killed approximately 70–90% of the insects. When imbibed, diflubenzuron was much less toxic as a wettable powder than as a liquid formulation but the two formulations were equitoxic when injected into the larvae. 相似文献
4.
Phytoparasitica - The effect of BAY SIR 8514, diflubenzuron and Hercules 24108 on larval growth, pupation and emergence ofTribolium confusum was determined. BAY SIR 8514 was about twice as active... 相似文献
5.
The effect of a 24-h exposure of adults ofCarpophilus hemipterus to artificial diets treated on the surface with different concentrations of benzoylphenylureas, on the hatchability of eggs laid during the subsequent 14 days, was investigated. The order of persistence of sterilization at 5 ppm was chlorfluazuron (IKI-7899), 12 days > XRD-473, 10 days > diflubenzuron, 6 days > teflubenzuron (CME 134), 4 days. Three of the substances (chlorfluazuron, diflubenzuron and teflubenzuron) had no direct ovicidal effect whenC. hemipterus eggs were dipped in 1000 ppm dilutions, but the larvae that hatched from the treatments died within 2 days. 相似文献
6.
The effect of diflubenzuron as a residue on glass or applied topically to Spodoptera littoralis larvae was investigated. Diflubenzuron was active as a residue on glass against 100 and 200 mg larvae; the toxicity of residues was identical whether a dispersable formulation or a wettable powder or the technical substance were used. By topical application, diflubenzuron had an ED50 for cumulative percentage mortality up to the adult stage of 004 and 0066 μg/larva for 100 and 200mg larvae respectively. Neither the site of the topical application nor whether the larvae were kept singly or in groups of ten after the treatment had an influence on toxicity. The data indicate that diflubenzuron has contact toxicity to at least one insect species as well as the known stomach poison action. 相似文献
7.
The effect of IKI-7899 and diflubenzuron on larval development and emergence ofTribolium castaneum and ofSpodoptera littoralis was determined. The LC50 of IKI-7899 at adult emergence ofT. castaneum larvae fed the compound in their diet and the ED50 of S.littoralis larvae treated topically were approximately one-sixth those of diflubenzuron. 相似文献
8.
Diflubenzuron, PH 60-38, PH 6043, penfluron (PH 60-44), PH 6045, triflumuron, chlorfuazuron (IKI-7899), teflubenzuron (CME 134), XRD473 and Dowco 439 were tested for their efficacy against the larvae of the spiny bollworm,Earias insulana (Boisd.), in laboratory experiments. The compounds were incorporated at different concentrations in an artificial diet and 5-day-old larvae were introduced and grown on the treated diets until pupation and adult emergence. Teflubenzuron was active at 0.1 ppm, chlorfuazuron at 0.75 ppm and PH 60-38 at 10 ppm; triflumuron and diflubenzuron were active only at 50 ppm; all the rest of the compounds were even less active. When cotton bolls were dipped in teflubenzuron and offered to 6-day-old larvae in the laboratory, only 4% and 10% of the larvae penetrated inside the bolls treated with 50 and 25 ppm a.i., respectively, whereas 68% penetrated inside untreated bolls. 相似文献
9.
A. Ben-Aziz J. Meisner N. Aharonson K.R.S. Ascher 《Pesticide biochemistry and physiology》1976,6(1):58-64
The ingestion and excretion of sublethal doses of phosfolan, monocrotophos, parathion, and leptophos were studied in larvae of the Egyptian cotton leafworm, Spodoptera littoralis Boisd. Styropor (foamed polystyrene) lamellae treated with insecticide-sucrose mixtures were fed to the larvae and recovery of the undecomposed insecticides from the feces could be estimated by gas-liquid chromatography, without any cleanup of the sample. The insecticidal residues on Styropor were found to be stable for 5 days.As regards the percentage of insecticide recovered from the feces, two groups could be distinguished: (a) leptophos, practically complete; parathion, 59–67%; b) phosfolan, 10–23%; monocrotophos, 4–7%. A tentative hypothesis was advanced that both oral toxicity of the four compounds for S. littoralis larvae and their subsequent recovery in the feces were related to water solubility. 相似文献
10.
J. Halperin 《Phytoparasitica》1980,8(2):83-91
During 1973-76 trials were carried out to control the pine processionary caterpillar with Dimilin (25% diflubenzuron WP), and commercial treatments with this compound in the forest were followed up until 1978/79. Total mortality of the 1st-3rd instar larvae was obtained in 8-16-year-old Aleppo pine plots after an aerial spray of Dimilin at the rate of 300 g (75 g a.i.) in 50 liter water/ha; 500 g (125 g a.i.)/ha was required to kill all 3rd and 4th instar larvae. A ground spray with Dimilin at a concentration of 0.003% (0.00075% a.i.) in water of 6-year-old Aleppo pine trees infested by 1st-3rd instar larvae gave similar results. The period Dimilin persisted on the sprayed needles in the forest was up to 27 days, even after 91 mm of rain. 相似文献
11.
Chitin polymerization is catalyzed by cell-free enzyme complexes from the integument of Trichoplusia ni larvae and wing tissue of developing Hyalophora cecropia pupae obtained on extraction of homogenates for 16 hr at 5°C in 25 mM Tris-HCl buffer, pH 7.2, containing 10 mM MgCl2, 1 mM dithiothreitol, 10 mg/ml bovine serum albumin, and 4 mg/ml digitonin. In contrast, integumental preparations from Boarmia selenaria, Earias insulana, Heliothis virescens, Oncopeltus fasciatus, Spodoptera exigua, and Tribolium castaneum exhibit little or no chitin synthetase (CS) activity. H. cecropia CS requires magnesium ions but not N-acetyl-d-glucosamine for normal activity and is almost insensitive to nikkomycin and polyoxin D. CS activity is not detected in diapausing H. cecropia pupae but synthesis of this enzyme is induced or its activity is stimulated by the molting hormone, ecdysterone, indicating possible hormonal control. T. ni CS requires magnesium ions and N-acetyl-d-glucosamine for optimal activity and is sensitive to inhibition by uridine di- and triphosphates, polyoxins B and D, and particularly nikkomycin. T. ni integumental CS activity decreases in starved larvae or those about to pupate. Both T. ni and H. cecropia CS enzymes as prepared and assayed are sensitive to captan but not to the potent insecticides diflubenzuron and BAY SIR 8514, two effective benzoylphenyl urea in vivo chitin synthesis inhibitors. 相似文献
12.
Synergism of mixtures of pyrethroids with organophosphorus (OP) compounds in insects is reviewed, and the toxicity of such combinations againstSpodoptera littoralis (Boisd.) larvae is reported. Mixtures of one of the pyrethroids cypermethrin, fenvalerate or deltamethrin with one of the OP compounds monocrotophos, profenofos, azinphos-methyl or acephate were assayed at different ratios as 24-h-old dipping residues on alfalfa, which was fed toS. littoralis larvae for 48 h. With most of the binary mixtures containing various OP concentrations in excess of those of the pyrethroids, synergism was demonstrated. In the pairs fenvalerate — azinphos-methyl, deltamethrin — azinphos-methyl and deltamethrin — profenofos, however, no synergism was found. In a detailed investigation with pyrethroid concentrations causing 20% mortality and OP concentrations giving a kill of no higher than ;10%, the above findings on synergism were amply confirmed. A cypermethrinmonocrotophos mixture showed synergism also on cotton leaves sprayed in the field. Synergism could not be demonstrated by topical application of pyrethroid — OP mixtures. 相似文献
13.
Egg hatch of two nitidulids,Carpophilus hemipterus L. andUrophorus humeralis F., was affected by the chitin synthesis inhibitor triflumuron (Alsystin; BAY SIR 8514)via the adult stage of the beetle. This occurred by exposure to treated diets, by a brief dip of the adults in aqueous dilutions of the toxicant, or by contact with a treated plastic netting cage. Exposure of adults ofC. hemipterus for 24 h to 0.0125%, 0.00125%, 0.00025% or 0.000125% and ofU. humeralis to 0.0125% a.i.-treated diets completely prevented hatch of eggs laid during the subsequent 48 h on an untreated diet. Although at first sterile eggs were obtained with adults of either nitidulid species transferred to an untreated diet after 24 h exposure to the 0.0125%-treated diet, egg viability gradually recovered. The speed of recovery and the course of mortality of larvae that hatched from eggs laid by treated adults, indicated thatC. hemipterus was more susceptible thanU. humeralis to triflumuron. DippingC. hemipterus adults — males or females — in 0.0125% a.i. triflumuron also resulted in complete prevention of egg hatch. Similar results were obtained by a 1-h contact of adults with treated cages. Triflumuron had no direct ovicidal activity against the two species at the concentrations used but was very effective against larvae of both species. At 0.0125% a.i., 3-5-mm-long larvae ofU. humeralis were more tolerant than newly hatched larvae and than 3-5-mm-long larvae ofC. hemipterus. Application of 0.0125% a.i. triflumuron in a date palm grove did not prevent fruit infestation by nitidulid adults but, due to prevention of egg hatch, almost no larval development was observed. 相似文献
14.
The potency of two newBacillus thuringiensis (B.t.) preparations (coded ABG 6104 and ABG 6105) and of Dipel (B. thuringiensis var.kurstaki) was determined againstSpodoptera littoralis (Boisd.) 5th-instar larvae on a calcium-alginate diet. With this bioassay, the newB.t. products were more than twice as potent as Dipel. They were also 2–3 times more active than Dipel on alfalfa and cotton leaves in the laboratory. When applied in an alfalfa field at the rate of 312 mg/m2, ABG 6104 and ABG 6105 caused 40% mortality of 5th-instar larvae and reduced the weight of the survivors to 30–40% of the control; only half of this activity was obtained with Dipel. On cotton, the activity of all theB. t. products was low. NeonateS. littoralis larvae were effectively controlled on avocado seedlings; however, there was high mortality also in the untreated controls. All threeB. t. preparations had a similar effect onBoarmia (Ascotis) selenaria Schiff. on avocado leaves in the laboratory. Addition of a chitinase enzyme did not increase the pathogenicity of the microbial preparations in the latter tests. 相似文献
15.
K. R. Simon Ascher Manes Wysoki Nadia E. Nemny Leah Gur-Telzak 《Pest management science》1978,9(3):219-224
Small (70 mg) Boarmia selenaria larvae fed for 4 days on avocado leaves or alfalfa dipped in aqueous diflubenzuron suspensions suffered from severe developmental disturbances. Similar results were obtained with leaves sprayed in an avocado orchard, with which, in addition, the considerable persistence of diflubenzuron under field conditions could be demonstrated. The substance was also active by topical application against large (500–600 mg) B. selenaria larvae, whereas by contact it was only moderately toxic. Some other non-conventional control agents, viz., the antifeedant AC-24055 and several juvenile hormone analogues, were of medium and negligible activity, respectively, against this insect. 相似文献
16.
Fentin acetate (FA) at effective antifeedant concentrations does not have a high, immediate toxicity for 170–190 mg larvae of the Egyptian cotton leafworm (Spodoptera littoralis); the mortality of such larvae exposed to FA residues on leaves is not appreciably higher than that of larvae being starved. The antifeedant effect of FA is also not due to an influence on sensory receptors on the mouth parts. Protease and amylase are inhibited in vivo in larvae feeding on FA-treated leaves; the enzyme inhibition increases with the concentrations of the leaf-dipping suspensions. At 0.05% FA, protease and amylase activity was only about 20 and 30%, respectively, of that of the control larvae and was lower than in starved larvae.Antifeeding and enzymatic inhibition are also obtained by injecting FA into the haemocoel, results which indicate that FA does not inhibit the digestive enzymes directly, but seems to affect the enzyme production in the gut. This interpretation is strengthened by the finding that the addition of massive amounts of FA to the enzyme reaction mixture does not affect the enzyme activity. 相似文献
17.
Lethal and sublethal effects of two insect growth regulators (IGRs) buprofezin and pyriproxyfen were evaluated on larvae of cotton leafworm Spodoptera littoralis. Activity of chitinase and polyphenol oxidase (PPO) in surviving larvae after treatment was carried out in order to investigate the biochemical influences of these compounds. The compounds were low toxic against the larvae at 0.05, 0.1, 0.25, 0.5, and 1.0-fold of the field application rate. However, the overall mortalities within 6 days of feeding at 2.0-fold were 46.67% and 100% for buprofezin and pyriproxyfen, respectively. Larval weight gain was considerably decreased as concentration increased. Pyriproxyfen showed high antifeedant activity in a concentration-dependent manner, and larvae stopped to eat from the third day with high dose. Conversely, buprofezin did not significantly show antifeedant except with high concentration (3000 mg (a.i.)/kg diet) that gave 80.68%. The high doses of both compounds showed adverse effects on pupae, and emergence of adults. Buprofezin at the recommended dose (1500 mg (a.i.)/kg diet) caused 93.33% pupation and 53.33% emergence of adults. Otherwise, pyriproxyfen caused 21.33% pupation and zere emergence of adults at the recommended dose (75 mg (a.i.)/kg diet) compared to 100% pupation, and 96.30% emergence of adults in the control. Both compounds varied in their influences on chitinase and PPO activity, and these enzymes could have relation with toxicity of buprofezin and pyriproxyfen against S. littoralis larvae. 相似文献
18.
The residual effect of a dried methanolic extract of neem (Azadirachta indica A. Juss) seed kernels was investigated with larvae of the Egyptian cotton leafworm,Spodoptera littoralis (Boisd.), in field trials. Fodder beet was sprayed with 1% emulsions of the extract. The treated leaves were collected from the field 1, 3, 5 and 9 days after spraying and offered to the larvae for 48 h. Survival and mean weight of the larvae were recorded 2, 4, 6, 9 and 11 days from the start of exposure to the residues, and rate of pupation was calculated. The extract had a strong antifeedant effect and an intense insect growth-regulating (IGR) effect in field-treated leaves, especially with the 1- and 3-day-old residues. A positive correlation was found between the age of the residues and the mean percent of live larvae, larval weight and pupation rate of the larvae. 相似文献
19.
The effect of azadirachtin and salannin, two triterpenoids isolated from seeds of neem (Azadirachta indica A. Juss), on the feeding response ofSpodoptera littoralis (Boisd.) andEarias insulana (Boisd.) larvae, was investigated. Styropor (foamed polystyrene) lamellae were painted on both sides with a mixture of 5% sucrose with different concentrations of either azadirachtin or salannin dissoled in methanol-water (3∶7). Azadirachtin strongly suppressed feeding inS. littoralis larvae even at 0.001%, whereas salannin showed some antifeedant activity at 0.005% and above. Larvae ofE. insulana were deterred from feeding on azadirachtin-treated lamellae even at 0.005%, whereas salannin was effective only at 0.01% and above. Azadirachtin applied on cotton leaves deterred larvae ofS. littoralis from feeding at all concentrations ranging between 0.001 and 0.02%. 相似文献
20.
The mortality rates of Spodoptera littoralis eggs of different ages when dipped in aqueous dilutions of a liquid diflubenzuron formulation were investigated. Eggs 2-3 days old were less sensitive than younger eggs, 0-1 day old. The respiratory rate of eggs 0-1 day old, 1 or 2 days after treatment, was the same as in the control. Eggs in the control hatched on the next day; on this day, respiration in the treated eggs decreased rapidly, but further decrease was then gradual and the base line was not reached until 11 days after treatment, or 9 days after the maximum respiratory rate had been obtained. The curve with diflubenzuron resembled that obtained with parathion. 相似文献