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1.
Diflubenzuron, PH 60–43, PH 60–45, penfluron(PH 60–44) and triflumuron were assayed by a dipping technique for their toxicity toEarias insulana (Boisd ) eggs of different age Testing at a screening concentration of 0 1% a 1 showed that diflubenzuron, triflumuron and PH 60–43 were highly active, whereas PH 60–44 and PH 60–45 were nearly inactive With triflumuron the mortality of 0-1-day-old eggs was >90% even at 0 005%, at 0 001% it was 50% In 1-2-day-old eggs, a >90% kill was obtained even at 0 0005%, whereas at 0 00025% it was 86% PH 60–43 was also highly active, at 0 01% the kill of 0-1-day-old eggs was >90% Again, this rate of kill was obtained with 1-2-day-old eggs at a still lower concentration, 0 005% Both compounds were inactive against 2-3-day-old eggs, even at 0 1% 相似文献
2.
Four juvenile hormone analogs (JHAs), fenoxycarb. Pro-drone, R-20458 and dofenapyn, and three benzoylphenyl urea molt-inhibiting compounds (MICs), teflubenzuron, triflumuron and hexaflumuron, were evaluated in the laboratory at two concentrations (5 and 50 ppm) as to their effect on the Florida wax scale,Ceroplastes floridensis Comstock. In general, when the first nymphal stages were treated, the number of adults on treated guava plants at the end of the first generation was clearly reduced in comparison with that observed on untreated plants. The JHAs fenoxycarb and R-20458 arrested the development of the insect and no adults emerged at the end of the first generation. With 50 ppm of the JHA Pro-drone only 5.2% of the nymphs developed and transformed into adults. Triflumuron was superior to the other insect MICs in hampering development, as was dofenapyn. The adults emerging at the end of the first generation were used as parental scales for the next generation. Delayed adverse effects were observed on female fecundity and egg hatchability. There was a significant difference between the egg numbers laid by the females in the treatments and the control, and also between the different IGRs. No eggs hatched with dofenapyn and egg hatchability was 46% for teflubenzuronvs 88% for the control. Furthermore, in contradistinction to the control, insects on treated plants deposited only small amounts of wax in an irregular formation. 相似文献
3.
Ten insect growth regulators (IGRs): four juvenile hormone analogs (JHAs) — fenoxycarb, MV-678, R-20458 and dofenapyn, and
six molt inhibitors (MIs) — triflumuron, chlorfluazuron, hexaflumuron, teflubenzuron, Dowco 439 and flufenoxuron; and the
organophosphate malathion, were evaluated for residual activity in stored grain for 2 years against the rice weevil,Sitophilus oryzae (L.). Triflumuron, flufenoxuron, teflubenzuron, chlorfluazuron, hexaflumuron and fenoxycarb, each at a concentration as low
as 1 ppm a.i., were superior to 10 ppm malathion throughout the experiment. The six MIs, each tested at 50 and 100 ppm a.i.,
gave complete control for 2 years. Moreover, a concentration as low as 1 ppm a.i. of triflumuron, teflubenzuron, flufenoxuron
and chlorfluazuron had good residual activity for 1 year post-treatment and provided almost complete grain protection during
this period. Among the JHAs, fenoxycarb had the best residual activity. It gave almost complete control (96.6%) ofS. oryzae at 10 ppm for 18 months post-treatment. The other JHAs at the four test concentrations failed to produce this level of control.
The viability of the wheat grain was not affected by any of the insecticidal treatments, with 90% germination recorded in
treated and control, grains at all intervals tested. 相似文献
4.
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
5.
B. A. Peleg 《Phytoparasitica》1987,15(2):115-123
Various immature stages of male and female California red scale,Aonidiella aurantii (Maskell) (Homoptera: Diaspididae), were treated with avermectin B1 (MK-936) at concentrations ranging from 10 to 100 ppm. Treatments at 10 ppm completely arrested crawler development and 20 and 100 ppm caused 100% mortality of 48-h and 7-day-old male and female 1st instar nymphs, respectively. The development of the 2nd instar was slightly affected by MK-936 at up to 40 ppm. Sublethal doses of the chemical applied to immature stages caused no dramatic reduction in the fecundity of the subsequent, mature females. MK-936 applied to male prepupal and pupal stages and mated females did not prevent male emergence, nor did it affect the ability of males to copulate and inseminate female scales, or the female fecundity. The development and adult emergence of treatedAphytis holoxanthus DeBach (Hymenoptera: Aphelinidae) larvae and pupae parasitizingChrysomphalus aonidum L. scales were not influenced by a 9 ppm MK-936 treatment; leaves sprayed with this concentration had residual toxicity onA. holoxanthus adults for only 24 h post-treatment. Feeding byChilocorus bipustulatus L. (Coleoptera: Coc-cinellidae) on 0.9 ppm MK-936-treated Florida red scales resulted in 100% mortality of 2nd instars and induced sterility in the females. 相似文献
6.
The activities of the acylurea insect growth regulators, chlorfluazuron, teflubenzuron and difubenzuron, and the neurotoxic macrocyclic lactone, abamectin were assessed against a laboratory susceptible (FS) strain and a field (Cameron Highlands, Malaysia (CH)) strain of the diamondback moth, Plutella xylostella L. using a leaf-dip bioassay at 20°C. The time taken to achieve end-point mortality was found to vary considerably (9–17 days), being fastest with abamectin against the FS strain and slowest with difubenzuron against the CH strain. The order of activity (LC50 at F6/7) against second-instar larvae of both strains was: abamectin > chlorfluazuron = teflubenzuron ? difubenzuron. Subsequent assays (F14) with the acylureas, flufenoxuron and hexaflumuron against the FS strain suggested that the former was slightly more active than chlorfluazuron or teflubenzuron, the latter slightly less active. The CH population was found to be 12.6-, 6.7-, 6.4- and 2.3-fold less sensitive to difubenzuron, teflubenzuron, chlorfluazuron and abamectin respectively than the FS strain. Selection of sub-populations of the CH strain with chlorfluazuron (CHL-SEL) and teflubenzuron (TEF-SEL) for six generations (F6-11), resulted in LC50 resistance ratios of 109- and 315-fold respectively when compared with the FS strain, equivalent to an 18- and a 46-fold increase in resistance compared with the unselected CH strain. Marked cross-resistance was also demonstrated between chlorfluazuron and teflubenzuron in both sub-populations. However, there was no evidence of cross-resistance to dijlubenzuron and abamectin and little or no cross-resistance to flufenoxuron and hexaflumuron. Resistance to chlorfluazuron and teflubenzuron appeared to be relatively unstable in the TEF-SEL compared with the CHL-SEL sub-population (over 6–9 generations). However, reselection of the TEF-SEL population with chlorfluazuron (F18–20) led to a very rapid increase in resistance to chlorfluazuron and particularly teflubenzuron. For the latter compound, resistance factors of about 1000000 were obtained (F19, 21). Such values are probably only semi-quantitative, as above a certain level of resistance feeding bioassays with acylureas (compounds which are active to a significant extent by ingestion) are likely to become rate-limiting. 相似文献
7.
The effect of Margosan-O, a formulation of a natural insecticide obtained from the neem tree (Azadirachta indica A. Juss), on the development of and the penetration rate of larvae of the spiny bollworm,Earias insulana (Boisd.), into cotton bolls was investigated by (i) incorporating Margosan-O into a semisynthetic diet and recording mortality
until the adult stage; and (ii) spraying leaves and bolls with, or standing cotton seedlings or twigs of cotton with one boll
per twig in aqueous dilutions of Margosan-O in an attempt to protect leaves or cotton bolls from feeding or penetration, respectively,
by the larvae. Margosan-O was found to be effective when incorporated into the semisynthetic diet, even at low concentrations,
especially when it was offered throughout the larval life span. Survival rate and average weight of the larvae were much lower
on leaves treated with 0.5% or 0.2% Margosan-O, or exposed to its systemic effect at 0.5% or 0.25%, than on control leaves.
Larval penetration into Margosan-O-sprayed bolls at concentrations of 0.01– 0.5% wasca 30–45% of that into control bolls. Margosan-O was active also as systemic treatment: onlyca 35% of the larvae penetrated the 0.25%-treated bolls compared with the untreated ones. 相似文献
8.
In preliminary laboratory tests, the joint activity of six benzoylphenylureas (BPUs) was studied by investigating the activity of 90 of their binary mixtures against fourth-instar larvae of the cotton leafworm,Spodoptera littoralis (Boisd.), fed for 72 h on 10 ppm BPU-treated castor bean leaves. Experimental mixing ratios were 1:1, 1:4, and 1:9. At 10 ppm, the activity of the six BPUs was divided into two distinct groups. The first included the more active compounds (XRD-473, GR-333, and chlorfluazuron) while the second was composed of the relatively less active ones (diflubenzuron, triflumuron, and Dowco-439). Results of the assays indicated that only 18 of the 90 tested binary mixtures showed potentiation, whereas the majority, 70 mixtures, exhibited additive effects; two interacted antagonistically. Most of the potentiated pairs were at a mixing ratio of 1:9, pairing one strong BPU (at the low ratio) with a weak one (at the high ratio). The mixing ratio of 1:1 resulted in additive effects. 相似文献
9.
Survival rates of neonate larvae of the spiny bollworm,Earias insulana Boisd., on leaves, flower buds and bolls of ten high-gossypol (HG) [terpenoid-aldehyde] and Acala SJb2 cotton lines were 40-74%, 66-92% and 54-76%, respectively. Partial resistance of leaves of three cotton lines, no resistance of flower buds, and resistance of bolls of one line (HG-BR-8) to larval infestation were observed. Bolls which had their bases and bracts removed were heavily penetrated by larvae and more adults were obtained on them, as compared with intact ones. Complete development on cotton bolls, from hatching to the adult, took 25.6-32.6 days, with significant differences among some of the cotton lines. Growth on bolls of HG lines in the larval stage had no effect on oviposition by the corresponding adults. Fertility of these eggs was not affected. 相似文献
10.
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
11.
Diflubenzuron was tested for its efficacy against the eggs and larvae ofEarias insulana Boisd. in laboratory experiments. The toxicity obtained on dipping the eggs was only moderate and, moreover, the results were highly inconsistent. The mortality of larvae on an artificial diet into which the wettable powder had been incorporated, was relatively high. 相似文献
12.
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
13.
Four Bt cotton hybrids, each with one of four different events, viz., MRC 6301 Bt (cry1Ac gene), JKCH 1947 Bt (modified cry1Ac gene), NCEH 6R Bt (fusion cry1Ac/cry1Ab gene) and MRC 7017 Bollgard II (cry1Ac and cry2Ab genes) were compared for survival and development of Earias vittella (Fabricius) along with their isogenic non-Bt genotypes. None of the neonates were able to complete the larval period and reach pupal stage on squares of 90, 120 and 150 days old crop of all Bt hybrids. Likewise, on bolls also, zero per cent larval survival was observed in all Bt hybrids except JKCH 1947 Bt where 0.67 per cent larvae could manage to reach pre-pupal stage at 120 and 150 days old crop but failed to form cocoon and enter pupal stage. The surviving larva took more development time (3.7 to 5.4 days) as compared to larvae fed on bolls of JKCH 1947 non-Bt. The average survival period (ASP) of larvae was in order of 150 > 120 > 90 days old crop among the crop ages; JKCH 1947 Bt > MRC 6301 Bt > NCEH 6 R Bt > MRC 7017 Bollgard II among Bt hybrids; and bolls > squares between fruiting bodies. However, reverse was true for speed index of toxic effect. The concentration of Cry toxin varied significantly in squares and bolls and also among the crop ages. The amount of Cry toxin in squares and bolls had significant negative correlation with ASP of the E. vittella larvae. 相似文献
14.
Insecticides commonly used in cotton fields in Israel against lepidopterous pests were tested against eggs, as well as against 2nd-instar larvae and adults raised from eggs ofSpodoptera littoralis (Boisduval) collected in cotton fields in the Bet She’an Valley. Methomyl, chlorpyrifos, methidathion, monocrotophos, ethyl parathion, and methyl parathion were effective against eggs even at low doses, profenofos and phosfolan were less active, and azinphos-methyl was ineffective. The doses needed for 90% kill (LD 90 ) of the 2nd-instar larvae were 8.5, 35, 280, 1300 and 3400 g a.i./1000 m 2 for chlorpyrifos, methomyl, profenofos, methyl parathion and ethyl parathion, respectively; monocrotophos was inactive against 2nd-instar larvae even at relatively high doses. The LD 90 of adults was reached with 16, 32, 1700 and 6100 ga.i./l000 m2 of chlorpyrifos, methomyl, ethyl parathion and profenofos, respectively. Only chlorpyrifos and methomyl gave successful control of all three stages of the insect tested, at doses close to those generally used with aerial applications. 相似文献
15.
The potency of diflubenzuron is much greater in inhibiting growth and development of 1st instar larvae ofTribolium castaneum than of 4th instar larvae, as expressed by death at the apolytic stage and retardation of larval development. A dose-dependent decrease in the activity of trehalase, invertase and amylase was obtainedin vivo with the increase in diflubenzuron concentration. At 5 ppm dietary concentration, a reduction of 37 and 27% in invertase and trehalase activity, respectively, was obtained in 4th instar larvae fed for 3 days on treated diet. The amylase activity was affected to a lesser extent. The observed disturbances of trehalase activity might hamper the supply of glucose needed for chitin build-up and those of invertase and amylase activity might affect feeding. Diflubenzuron does not inhibit these enzymesin vitro; hence, thein vivo effect seems to result from general disturbances in carbohydrate metabolism. 相似文献
16.
Three insecticides, pyrethrins + piperonil butoxide (PBO), pymetrozine and triflumuron, were tested as potential alternatives
for controlling the Mediterranean fruit flyCeratitis capitata (Wiedemann) (Diptera: Tephritidae). The compounds were administered to adult flies in the laboratory by different uptake
methods at the recommended rates currently used in fruit crops in Spain. Pyrethrins + PBO (80 + 320 ppm a.i.) exhibited a
comparable knock-down effect to malathion (1,500 ppm a.i.) in the laboratory, irrespective of the method of application used.
After these results were obtained, the number of concentrations tested was increased to carry out a dose-response analysis.
Pymetrozine (300 ppm a.i.) and triflumuron (150 ppm a.i.) did not kill adults at the concentrations tested. However, pymetrozine
diminished the fecundity, especially when adults were fed the insecticide; egg hatch was decreased by 59.3% compared with
controls. Further experiments showed that increased period of ingestion and higher concentrations had a clear effect in reducing
both fecundity and fertility. The possible use of pyrethrins + PBO and pymetrozine to reduce populations ofC. capitata is discussed.
http://www.phytoparasitica.org posting July 22, 2006.
Corresponding author 相似文献
17.
In teflubenzuron and teflubenzuron/chlorfluazuron laboratory-selected sub-populations of a Cameron Highlands (1988) strain of Plutella xylostella L., resistance to teflubenzuron reached much greater levels than chlorfluazuron but declined at a correspondingly greater rate to give similar resistance levels after 10–13 generations. There was little evidence of cross-resistance to flufenoxuron and none to hexaflumuron in these populations. Reselection of a Cameron Highlands population with teflubenzuron after 22 generations resulted in a significant (P < 0.05) increase in resistance after three generations. In two more recently collected strains from lowland Malaysia, Sawi (1991) and Serdang (1992) high levels of resistance to teflubenzuron were found, but only the former showed any apparent resistance to chlorfluazuron. There was also evidence of resistance to diflubenzuron in the Sawi strain (Serdang not examined). Resistance to teflubenzuron appeared to be unstable in unselected sub-populations of both lowland strains. Selection of the Sawi strain with teflubenzuron did not effect cross-resistance to chlorfluazuron, while attempted selection with chlorfluazuron had no effect on resistance to either compound. Selection of the Sawi strain with diflubenzuron increased resistance to teflubenzuron but had no effect on resistance to chlorfluazuron. In contrast to the Sawi strain, selection of the Serdang strain with teflubenzuron resulted in cross-resistance to chlorfluazuron. Synergist experiments with piperonyl butoxide (PB) and S,S,S-tributyl phosphorotrithioate (DEF) suggested that resistance to teflubenzuron in the lowland strains may involve both microsomal monooxygenases and esterases. The ovicidal activity of teflubenzuron, chlorfluazuron, hexaflumuron and flufenoxuron was consistently less than their activity against second-instar larvae, hexaflumuron, followed by teflubenzuron, showing the greatest relative ovicidal activity. Hexaflumuron was markedly more active than teflubenzuron against eggs from acylurea-selected Cameron Highlands populations and there was some evidence that resistance to teflubenzuron may be expressed at a lower level in eggs than in larvae in one such strain. 相似文献
18.
The chitin synthesis inhibitors diflubenzuron and teflubenzuron have recently become ineffective for the control of Spodoptera exigua in floricultural crops. An extended laboratory test with second-instar larvae of S. exigua on Vicia faba plants was carried out to determine the influence of synergists on the biological activity of three benzoylphenyl ureas (BPUs). The co-application of piperonyl butoxide, an oxidase inhibitor, did not increase the activity of diflubenzuron, teflubenzuron or hexaflumuron. The best results were obtained with diethyl maleate, for suppressing glutathione S-transferase activity, and with dimethoate, as a hydrolase inhibitor. A joint application of diflubenzuron (at a concentration which resulted in 43% survival) with diethyl maleate or dimethoate gave only 6.2 and 8.9% surviving larvae, respectively. In addition, development to fourth-instar larvae was inhibited. The more stable teflubenzuron was synergized by both compounds to a much lesser extent than diflubenzuron. None of the synergists had a significant effect on the activity of hexaflumuron, which was the most potent insecticide of the three BPUs tested against S. exigua. 相似文献
19.
The potential of neem extracts to control the cabbage webworm,Crocidolomia binotalis Zell. (Lepidoptera: Pyralidae), was investigated in the laboratory. Neem, besides being an antifeedant at as low as 0.001% of the methanolic extract, was shown to be very toxic, as evidenced by high larval mortality and poor emergence. It also caused disruption of normal development: significant delays in larval moults, appearance of permanent larvae in the 3rd and 6th instars, and abnormal pupation. A possible interference with hormonal activity is discussed. 相似文献
20.
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