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1.
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
2.
The effect of 21 amino acids on the feeding response of larvae ofSpodoptera littoralis was investigated using the “Styropor method.” Lamellae of Styropor were treated(a) with different concentrations of amino acids,(b) different concentrations of amino acids mixed with 0.125 M sucrose, and(c) 0.125 M sucrose alone. The weight of Styropor consumed during 48 h served as the criterion of phagostimulation or phagodeterrency. With the sole exception of 0.125 M L-glutamic acid, no phagostimulation occurred in any of the amino acids tested in mixture with 0.125 M sucrose; none was phagostimulant when tested alone. Deterrency was found at 0.125 M in L-alanine, DL-alpha-amino-n-butyric acid, L-serine, L-cystine, L-methionine, L-tyrosine, and L-histidine, when mixed with an equimolar concentration of sucrose. Methionine was highly phagodeterrent also at 0.0625 M and, as was DL-alpha-amino-n-butyric acid, still active even at 0.0125 M. Chemical analysis showed that there was no decomposition of methionine applied on Styropor. 相似文献
3.
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
4.
Abstract Pyrethrins, the botanical insecticides and their synthetic analogues are well known for their power of producing very rapid paralysis (knockdown) in treated insects. The use of pyrethrins or synthetic analogues in agriculture to combat insect pests on field crops has been rather limited. The main reason for this is their non-persistence in field conditions. A recently developed synthetic pyrethroid NRDC 147, which is 10–100 times more stable in light than previous pyrethroids was tested in the laboratory and field against the Egyptian cotton leafworm Spodoptera littoralis (Boisd). Results indicate higher efficiency (LC50 320 ppm), compared with 460, 422, 1250, 180, 2150 and 265 ppm for cyolane, chlorpyrifos, leptophos, methomyl, monocrotophos and methamidophos respectively. The residual effect (LT50) is more than 7 days in the field for NRDC 147, while it was 5.8, 6.8 and 4.2 for cyolane, leptophos and methamidophos. 相似文献
5.
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
6.
CME 134, a new benzoylphenyl urea chitin synthesis inhibitor, was less active than diflubenzuron and BAY SIR 8514, when tested againstSpodoptera littoralis eggs by a dipping method. AgainstS. littoralis larvae the compound was tested by feeding treated alfalfa, topical application and contact with crystalline residues on glass, followed by observation until the adult stage. With both 200–250 and 360–440-mg larvae 100% mortality was obtained by one-day feeding of alfalfa treated with 0.15 ppm a.i. Topical application to 100- and 200-mg larvae showed CME 134 to be about five and nine times more active than BAY SIR 8514 and diflubenzuron, respectively. These differences were even much greater in the contact tests. Cotton field plots were sprayed with either CME 134 or diflubenzuron formulations, leaves were collected at different intervals and fed for one day toS. littoralis larvae in the laboratory. 0.0009% a.i. CME 134 residues gave complete kill of 30–50-mg larvae after 5 and 20 days, and 86% kill after 28 days of aging. With 0.003 and 0.009% a.i., complete kill was obtained in 200–250-mg larvae until 50 days after spraying. 相似文献
7.
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
8.
Factors involved in insecticide resistance were evaluated by using 14C-labeled methyl parathion and aldrin to compare rates of absorption and metabolism by Heliothis virescens (F.) larvae that were resistant (R) and susceptible (S) to methyl parathion. Tests with third-stage R and S larvae suggested that the rate of insecticide absorption from the cuticular surface was not a major resistance factor. Further evidence for this assumption was demonstrated by the resistance of R larvae to injected and orally administered doses of methyl parathion. Smaller amounts of unmetabolized methyl parathion and aldrin were recovered from S larvae, an indication that differences in metabolism were probably related to the resistance. 相似文献
9.
Chlorpyrifos (Dowco 179) and its dimethyl homologue, chlorpyrifosmethyl (Dowco 214), were used to study the influence of the O,O-dialkyl group of organophosphorus insecticides on toxicity, absorption, and metabolism among larvae of the tobacco budworm [Heliothis virescens (F.)] from strains that were resistant (R) and susceptible (S) to methyl parathion. In toxicity tests, chlorpyrifos and chlorpyrifosmethyl were more toxic than methyl parathion to 3rd-stage R larvae but less toxic to S larvae. Chlorpyrifosmethyl was more toxic (3–4 ×) than chlorpyrifos to both strains of larvae, and the results of absorption studies indicated that the toxicity differential of the homologues may be explained in part by the more rapid absorption of the dimethyl form. Studies of the in vivo metabolism of both Dowco compounds indicated that each was degraded mainly by the cleavage of the pyridylphosphate linkage. In vitro tests demonstrated that the NADPH-dependent microsomal oxidases were of primary importance in detoxification, while glutathione (GSH)-dependent mechanisms (aryl- and alkyltransferases) present in the soluble cell fractions were of lesser importance. O-dealkylation occurred only with chlorpyrifosmethyl. The R larvae demonstrated greater capability in detoxifying both compounds in the comparative in vivo and in vitro studies of metabolism, but the differences were more apparent during the 5th instar than during the 3rd instar. 相似文献
10.
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
11.
Infectivity of Spodoptera litura multiple nucleopolyhedrovirus (SpltMNPV) was compared between before (P0) and after (P1–P4) passage in subsequent generations through the gut of Eocanthecona furcellata. Viable virus was detected in E. furcellata feces up to 6 days after feeding on infected S. litura larvae. NPV mortality ranged between 93% and 10% when test larvae were exposed to polyhedra voided in feces collected after 1 and 6 days post-infected meal, respectively. The mean number of polyhedral occlusion bodies (POBs) in excreta and their infectivity (%) at all passages did not vary significantly. The comparison of observed LD50 and ST50 values among all passages did not reveal significant differences owing to their overlapping confidence limits. The gut-passed virus did not show a detrimental effect on survival rate, longevity, fecundity and percent egg hatchability of E. furcellata in the subsequent three generations. A field trial was also conducted to estimate virus dissemination through feces of predators that were fed upon prey infected with polyhedra before passage, after passage and healthy (control) prey and subsequently released on cabbage plants. An additional viral mortality up to the magnitude of 13–17% was noticed in the former two treatments. However, within these two treatments the viral mortality did not vary significantly. It was concluded that E. furcellata disseminated the virus through their feces into the ecosystem without any adverse effect to it and infectivity of the SpltMNPV is not altered after passage through the gut of the predator. 相似文献
12.
Six juvenile hormone analogues, compounds 6–9550, 8–4314, and 20–3600 of Dr. R. Maag Ltd., Switzerland, and compounds ZR-512, ZR-515 and ZR-619 of Zoecon Corp., U.S.A., were tested against big and medium-size larvae ofS. littoralis Boisd. by topical application. Compounds 6–9550 and 8–4314 were slightly active against big larvae and inactive against medium-size larvae; ZR-512 was moderately active against big and inactive against medium-size larvae. The other three compounds caused 90% mortality in big larvae: 20–3600 at 20μg/larva and ZR-515 and ZR-619 at 5μg/larva. ZR-512 and ZR-619 were less toxic for medium-size larvae than for big larvae, whereas 20–3600 was about equitoxic for larvae of both sizes 相似文献
13.
Ruscus hypoglossum andUrginea maritima (Liliaceae) are highly resistant toSpodoptera littoralis. The foliage of these plants contains a proline analog, L-azetidine-2-carboxylic acid (AZA): inUrginea at a concentration of 1.7% of fresh weight and inRuscus at a concentration of 0.019%. The concentration of AZA inUrginea accounts for its lethal effects onS. littoralis larvae and for the direct effect of an acetone-soluble 80% methanol extract on adultS. littoralis, as evidenced by reduced viability of eggs deposited. The toxicity ofRuscus extracts is only partly attributable to AZA content. 相似文献
14.
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
15.
Zerubabel M. Nyiira 《Pest management science》1974,5(1):7-10
Insecticide assays using larvae of Cryptophlebia leucotreta Meyrick (Lepidoptera: Tortricidae; subfamily Olethreutinae) showed that parathion-methyl and monocrotophos were more toxic than fenitrothion and endosulfan. The LD90 were 3.44 mg/kg and 11.0 mg/kg for parathion-methyl and monocrotophos, respectively. The order of relative efficiency of the insecticides was as follows: parathion-methyl, monocrotophos, fenitrothion and lastly endosulfan. When different spray machines were tested for spray deposition on well grown cotton plants, the motorised airblast sprayer effected a more satisfactory deposit recovery on the lower parts of the cotton plants where early and heavy infestation of C. leucotreta to the mature cotton bolls occurs. 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.
Comparisons were made between the amounts of abamectin and total radioactivity recovered from Spodoptera littoralis and Heliothis armigera larvae after topical application of [3H]abamectin. Penetration (as shown by wash-off experiments) did not differ significantly between the Spodoptera instars. Significantly more abamectin was recovered from ventral nerve cord samples of larvae showing symptoms of poisoning than from larvae not showing these symptoms. Fifth-instar S. littoralis larvae had a significantly lower proportion of radioactivity as abamectin in the ventral nerve cord than in sixth-instar S. littoralis or fifth- and sixth-instar H. armigera. The proportion of radioactivity present as abamectin (but not total radioactivity) was significantly increased when the fifth-instar S. littoralis larvae were pre-treated with piperonyl butoxide (PB) suggesting that the relative insensitivity of fifth-instar S. littoralis larvae to abamectin is due at least in part to greater metabolism, particularly by microsomal oxidases. Fat body samples consistently had a greater proportion of radioactivity as abamectin than the nerve cord and the former may act as storage sites for abamectin. 相似文献
18.
The aim of this investigation was to clarify whether pheromone traps could provide a reliable tool for early detection of aS. littoralis adult population and for indicating infestation by its larvae in the field. The aggregated pattern of distribution of adults is indicated by the fit of data to Taylor’s Power Law or to the negative binomial distribution. However, the relatively high k values obtained indicate thatS. littoralis adults are only slightly aggregated and sometimes almost randomly distributed. Trap position in the field and number of traps per area unit affected size of catches in both female-baited and synthetic-pheromone-baited traps. No relationship between size of catches and temperature, wind velocity or moon phase was detected. Variations in size of catches among traps was not affected much by the baited females. Pheromone traps proved to be a reliable tool for estimating fluctuations in population density and for indicating adult peaks. However, no correlation between male catches and infestation by larvae in the experimental plots was found. Pheromone traps may serve only as a warning device indicating the possibility of potential attack due to an increase in adult population level. Mercury vapor light traps were inferior to pheromone traps in detecting changes inS. littoralis population densities. Synthetic pheromone (“Litlure”) was somewhat less efficient in attracting males than virgin females; however, it is suitable for detecting fluctuations in theS. littoralis adult population. 相似文献
19.
Mohsen A. El-Guindy Mostafa M. Abdel-Sattar Abdel Rahman M. El-Refai 《Pest management science》1983,14(3):246-252
The joint action of insecticides, or of mixtures of insect growth regulators and insecticides, on the susceptible (S) strain and diflubenzuron-resistant (Rd) strain of the cotton leafworm Spodoptera littoralis Boisd. was investigated. The joint action of the insecticides and/or insect growth regulator mixtures was determined by mixing them in proportion to their activity equivalents at the LD25 or ED25 levels. A total of 15 mixtures of two synthetic pyrethroids, two organophosphorus, one carbamate and one organochlorine insecticides, were applied to the fourth-instar larvae of the S and Rd strains. The insecticide mixtures cypermethrin/methomyl and cypermethrin/endrin exhibited high and moderate levels of synergism on the S strain, respectively. However the mixtures chlorpyrifos/methomyl, phosfolan/methomyl, and phosfolan/endrin produced antagonism, while the other mixtures showed varying levels of additive effects. The response of the fourth-instar larvae of the S strain, to the joint action of diflubenzuron/juvenoid, diflubenzuron/insecticide, or insecticide/juvenoid mixtures, revealed that diflubenzuron produced high levels of synergism when combined with methoprene and progressively less with fenvalerate, methomyl and cypermethrin. On the other hand, the mixture diflubenzuron/triprene was antagonistic. Fenvalerate with the two juvenoids produced synergism while methomyl showed an additive effect with methoprene. However, the mixtures cypermethrin/methoprene, cypermethrin/triprene and methomyl/triprene produced antagonism. The mixtures that produced potentiation on the fourth-instar larvae of the S strain lost their high potency when tested against the Rd strain. The results also indicated that insecticide/juvenoid mixtures, when applied on 2-day-old pupae of the S strain, were synergistic, except in the case of cypermethrin/methoprene and methomyl/triprene mixtures, for which additive effects were observed. When the mixtures that had synergistic effects on the S strain were tested on the Rd strain, the results revealed that their synergistic effects were apparently reduced. This was attributed to the fact that the generalised levels of tolerance in the Rd strain towards various compounds may have influenced the several defence mechanisms to act against the synergistic action of the chemical mixtures. 相似文献
20.
Freeman L. McEwen Gwen Ritcey Heinz Braun Richard Frank Brian D. Ripley 《Pest management science》1980,11(6):643-650
Residues were determined at 8-h intervals during the 48 h after application of endosulfan, leptophos, methamidophos, methomyl and mevinphos to head lettuce; of endosulfan, methamidophos and methomyl to cauliflower; and of parathion to onions and carrots. Residues of phosalone and parathion were measured on apple leaves 0, 1, 2, 4, 8 and 16 days after application. In addition, the portion of the residue on apple leaves that could be dislodged was measured, as well as the residues on gloves used to handle the apple foliage. There were large differences in the rates of disappearance of the insecticides, differences that must be known in determining safe re-entry periods for workers. 相似文献