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1.
Callus was initiated from cotyledon, hypocotyl and shoot tip explants of neem seedlings (Azadirachta indica A. Juss.) that
were cultured on Murashige and Skoog (MS) agar medium supplemented with MS vitamins, casein hydrolysate, indole-3-acetic acid
and benzylamino purine. Shoots regenerated from hypocotyl-derived callus only. Mature 10-12-week-old callus regenerated both
shoots and somatic embryos (SEm). The antifeedant activity of different types of callus, leaves and SEm was determined with
larvae of the desert locust Schistocerca gregaria in a no-choice feeding bioassay. In vitro tissue-cultured neem had antifeedant
properties against the desert locust. To the best of our knowledge the antifeedant activity of neem somatic embryos extracts
is reported here for the first time. 相似文献
2.
Acridids belonging to different species and families exhibit large differences in their response to neem components. In this
context the antifeedant effect of a methanolic neem seed kernel extract (NSKE) and of azadirachtin (AZA) on fourth-instar
nymphs of the acrididEyprepocnemis plorans Charpentier (Saltatoria:Acrididae) was investigated. Nymphs were offered either saccharose-impregnated filter paper disks
or leaves of broad beans, treated with neem components. The amount of substrate consumed was determined by weighing the filter
paper or by measuring the leaf area. On filter paper both NSKE and AZA were highly active down to the 10−4% treatment. In the leaf treatment, however, AZA was definitely more active than NSKE, with 100% deterrence at 10−4% and 10−2%, respectively. The methanolic NSKE was somewhat more active than the commercial preparation ‘Neemark’. 相似文献
3.
为有效控制小菜蛾的危害,明确绿薄荷对小菜蛾的防治效果,采用95%乙醇对绿薄荷茎和叶进行索式抽提,并测定了茎和叶提取物12.5、25.0和50.0 mg/mL浓度下小菜蛾幼虫的拒食率和成虫产卵忌避活性。结果显示,绿薄荷茎和叶的乙醇提取物对小菜蛾幼虫的拒食和成虫的产卵忌避均有显著作用,提取物浓度越高,拒食率和产卵忌避率越大。当茎和叶提取物浓度为12.5 mg/mL时,小菜蛾的拒食率最低,分别为36.16%和59.81%,产卵忌避率最低,分别为46.18%和57.78%;茎和叶提取物浓度为50.0 mg/mL时,拒食率最高,分别为82.67%和87.15%,产卵忌避率最高,分别为88.29%和98.27%。茎和叶对应的拒食中浓度(AFC_(50))最高分别为18.93 mg/mL和15.97 mg/mL,产卵忌避中浓度(AOC_(50))最高分别为16.38 mg/mL和15.03 mg/mL。 相似文献
4.
The cardiac glycoside, digitoxin, from Digitalis purpurea L (Scrophulariaceae), a cardiac glycosidal (cardenolide) extract from Calotropis procera (Ait) R Br (Asclepiadaceae), azadirachtin and neem oil from Azadirachta indica A Juss (Meliaceae) were tested for their effects against larvae and adult stages of the camel tick, Hyalomma dromedarii Koch (Acari: Ixodidae). The contact LC50 values of the first three materials against adults were 4.08, 9.63 and >40.7 microg cm(-2), respectively, whereas the dipping LC50 values of the four materials were 409.9, 1096, >5000 and >5000 mg litre(-1), respectively. Contact and dipping LC50 values of the extract and azadirachtin against larvae were 6.16, >20.3 microg cm(-2) and 587.7 and >2500 mg litre(-1), respectively. Azadirachtin had no effects on egg production or feeding of adults up to 5000 mg litre(-1); however at 2500 mg litre(-1), it caused significant reduction in feeding activity of larve, prolonged the period for moulting to nymphal stage, and caused 60% reduction in moultability. Results of the two cardiac glycoside materials are comparable with those of several commercial acaricides. The risks and benefits associated with the use of cardiac glycosides are considered. 相似文献
5.
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
6.
Eunice J. Allan Janakie P. Eeswara Shaun Johnson A. Jennifer Mordue E. David Morgan Trevor Stuchbury 《Pest management science》1994,42(3):147-152
Callus produced from leaves of a Ghanaian strain of the neem tree, Azadirachta indica A. Juss has been shown to produce the natural insecticide azadirachtin when grown in a defined medium. The azadirachtin was isolated by standard procedures of solvent partition and column chromatography monitored by supercritical fluid chromatography. Biological activity was monitored with antifeedant tests using the desert locust (Schistocerca gregaria Forsk.). The azadirachtin was identified by chromatography on three independent chromatographic systems (SFC, HPLC & TLC) and two thin-layer colour tests. It has 100% antifeedant activity at < 0.04mg litre?1. The yield of azadirachtin was 0.0007% based on dry weight of callus. 相似文献
7.
8.
Srinivas K Lanka James A Ottea Jeffrey A Davis Amy B Hernandez Michael J Stout 《Pest management science》2013,69(2):250-256
BACKGROUND: Feeding assays using adult rice water weevils and foliage of plants treated as seeds with chlorantraniliprole and thiamethoxam at different rates were conducted to evaluate the systemic adulticidal and feeding effects. Dose–mortality relationships were determined for thiamethoxam seed treatments by combining leaf area lost due to feeding and insecticide residues analyzed by LC/MS/MS. Changes in adulticidal activity of thiamethoxam were also investigated by contrasting adult mortalities at the 5–6‐leaf and tillering stages of rice. RESULTS: Adult weevil mortalities and leaf consumption rates on foliage were affected in thiamethoxam but not in chlorantraniliprole treatments when rice was at the 6–7‐leaf stage. The LD50 for weevils feeding on thiamethoxam‐treated rice at the 2–3‐leaf stage was 447 pg insecticide weevil?1 (95% CL: 25–830 pg weevil?1) but was lower (142 pg weevil?1; 95% CL: 102–180 pg weevil?1) in experiments with 3–4‐leaf‐stage plants. Mortalities on leaves from 5–6‐leaf‐stage plants were consistently higher than on leaves from tillering plants. Thiamethoxam residues measured by ELISA increased with seed treatment rate and differed between plant stages. CONCLUSION: The LD50 values developed in this study are the first values for leaf‐feeding insects on foliage of plants treated as seeds with thiamethoxam. The attrition of adulticidal activity of thiamethoxam in foliage of older plants may help to explain the reduced effectiveness of seed treatments against rice water larvae that is seen at later stages of rice growth in field studies. The differential activity of these two seed treatments on adults suggests that adult mortality contributes to the field efficacy of thiamethoxam but not to that of chlorantraniliprole. Copyright © 2012 Society of Chemical Industry 相似文献
9.
植物保护剂保卫德对黄曲条跳甲种群的控制作用 总被引：8，自引：1，他引：8
通过室内外试验评价了植物保护剂保卫德(BIOACT-T35)对黄曲条跳甲Phyllotreta striolata(F.)种群的控制作用。结果表明,其控制作用主要表现在对成虫的显著忌避和拒食作用。10.00 ml/L的忌避作用为91.42％,选择性和非选择性拒食率分别为93.54％和85.79％,种群趋势指数(I值)由对照的3.8680降为0.3676,干扰作用控制指数(IIPC)为0.0950。采用状态空间分析法的模拟结果表明,其控制作用表现在种群发展初期对成虫的忌避作用。 相似文献
10.
11.
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
12.
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
13.
Nazir Javed Said El-Hassan Simon Gowen Barbara Pemproke Muhammed Inam-ul-Haq 《European journal of plant pathology / European Foundation for Plant Pathology》2008,120(1):53-60
Initial applications of 104 spores g−1 of Pasteuria penetrans, and dried neem cake and leaves at 3 and 2% w:w, respectively, were applied to soil in pots. Juveniles of Meloidogyne javanica were added immediately to the pots (500, 5,000 or 10,000) before planting 6-week-old tomato seedlings. The tomatoes were
sampled after 64 days; subsequently a second crop was grown for 59 days and a third crop for 67 days without further applications
of P. penetrans and neem. There was significantly less root-galling in the P. penetrans combined with neem cake treatment at the end of the third crop and this treatment also had the greatest effect on the growth
of the tomato plants. At the end of the third crop, 30% of the females were infected with P. penetrans in those treatments where spores had been applied at the start of the experiment. The effects of neem leaves and neem cake
on the nematode population did not persist through the crop sequences but the potential for combining the amendments with
a biological control agent such as P. penetrans is worthy of further evaluation. 相似文献
14.
Abstract Adults and immatures of the filbert aphid, Myzocallis coryli (Goetze), a major pest of hazelnuts worldwide, were exposed to foliage treated with different concentrations of a botanical insecticide, Margosan-O, derived from extract of neem seeds. Both mature and immature stages were highly sensitive to this compound. Acute toxicity causing immediate mortality of young nymphs, particularly at higher rates (50 ppm or more), and chronic effects resulting in reduced offspring production, lengthening of nymphal development time and reduced survival of subsequent generation were recorded. The offspring production of adult aphids fed on treated leaves was reduced in a dosage-dependent manner, nearly 50% at 2.5 ppm to over 80% at 62.5 ppm. However, no nymphal survival was recorded at 25 ppm or higher doses. A repellency effect was also recorded, butthe feeding deterrence response was weak at best. Field trials also showed a marked reduction of aphid numbers on treated foliage, suggesting the effectiveness of neem against this major pest of hazelnuts. 相似文献
15.
Ebenso IE 《Pest management science》2004,60(2):178-182
The effects of 350, 500 and 700 mg kg(-1) of crude extracts of neem, Azadirachta indica A Juss, on edible tropical land snails Archachatina marginata and Limicolaria aurora (Jay) were determined and compared with control using pawpaw, Carica papaya L as bait. Responses were measured through normal feeding, cessation of food intake, cessation of crawling, mucus secretion, lack of response to mechanical stimuli (mortality) and decomposition. Results showed no effects on the controls or snails exposed to neem seed oil extract. Crude extracts of bark, root and leaf of neem at 500 and 700 mg kg(-1) produced mortality after exposure for 48 h for L aurora and 72 h for A marginata. 相似文献
16.
Phytoparasitica - Laboratory tests showed that neem (Melia azadirachta L.) seed kernel suspension in water at 3% was effective as an antifeedant against all the five instars of the tobacco... 相似文献
17.
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
18.
The effect of the antifeeding compound AC-24,055 on the main digestive enzymes of Spodoptera littoralis was determined. The inhibitory effect of AC-24,055 on the amylolytic and proteolytic activity increased with concentration and was well correlated with the antifeedant activity. After 3-day feeding on sugar beet leaves treated with 0.1% AC-24,055, more than 90% suppression of both amylase and protease activity was obtained, whereas at some lower concentrations a slight increase in invertase activity, especially after prolonged feeding, was observed. At 0.1% AC-24,055 the inhibition of the proteolytic activity was considerably stronger than it was in starved larvae. These results suggest that the inhibitory effect on the digestive enzymes is due not only to starvation but also to the effect of the antifeedant. Protease and amylase inhibition was obtained also by injecting AC-24,055 into the larval hemolymph. Maximum inhibition of both amylase and protease, about 50% and 25%, respectively, was reached 2 days after an injection of 5 μg AC-24,055; it then decreased gradually and was abolished 4 days after injection.Adding massive doses of AC-24,055 to the enzyme reaction mixture did not affect the in vitro activity of protease, amylase, or invertase. This indicates that AC-24,055 affects the digestive enzymes indirectly, probably by inhibiting a physiological system affecting the production of these enzymes. 相似文献
19.
Two neem preparations and the bitter‐tasting synthetic chemical denatonium benzoate were tested in the laboratory as antifeedants against the diamondback moth, Plutella xylostella L. The effects of the three materials on Cotesia plutellae (Kurdjumov), a hymenopteran parasitoid of P xylostella, were also recorded. All three materials significantly reduced the food consumption of P xylostella larvae. Parasitoid cocoons were formed on approximately half of those larvae which had been exposed to female C plutellae, regardless of antifeedant treatment, but emergence of adult parasitoids from the cocoons was significantly reduced by antifeedant treatment. In terms of food consumption and mortality of unparasitised P xylostella larvae, and emergence of adult C plutellae, the effect of each antifeedant preparation was directly related to the concentration of material used, but the effects of the neem preparations were greater than those of denatonium benzoate. However, no adult P xylostella emerged on any antifeedant treatment, therefore some of the parasitoids survived antifeedant treatments which were fatal to the unparasitised hosts. © 2000 Society of Chemical Industry 相似文献
20.
The activity of two neem extracts, AZT and NEEM-AZAL (containing 30 and 3 mg azadirachtin ml?1 respectively) and synthetic azadirachtin (AZ) against second-instar larvae (L2) of Plutella xylostella L. was examined using leafdip bioassays. On Chinese cabbage, AZ was significantly (P <0.05) less toxic (3 to 4-fold; LC50 0.54 μg AZ ml?1) than either neem extract against a laboratory strain of P. xylostella (FS). The LC50 values for AZT against the FS and another laboratory strain (Wellcome) were not significantly different on Chinese cabbage. The activity of AZT against the FS and Wellcome strains was similar on Chinese cabbage and Brussels sprout. AZT was significantly less toxic (3-fold) on Brussels sprout against an acylurea-resistant field strain (Sawi) when compared with the FS strain on Chinese cabbage. Larval mortality (at day 13) was found to increase with increasing exposure time of P. xylostella (FS) larvae to AZT-treated Chinese cabbage, although there was little difference in mortality between 48 and 120 h exposure. When AZT, NEEM-AZAL and AZ were applied at a dose (1 μg AZ ml?1) which gave end-point mortalities between 50 and 90% (at day 13), all treatments delayed the development of a proportion of surviving larvae but no morphogenetic abnormalities were observed in larvae which reached pupation. Evidence for antifeedant (reduced weight gain) and repellant effects (choicechamber) for AZT were observed with L2 P. xylostella (Wellcome) on Chinese cabbage. AZT was also shown to have ovicidal activity against P. xylostella (Wellcome) at relatively high dose ranges (10-1000 μg AZ ml?1) as well as some contact activity (FS strain) in topical bioassays. In residual bioassays on glass with adults of the hymenopteran endo-larval parasitoid of P. xylostella, Diadegma semiclausum (Ichneumonidae), AZT showed little or no activity at rates up to 1000 μg AZ ml?1. In medium-volume (MV, 200 litre ha?1) and ultra-low-volume (c. 1 litre ha?1) spray bioassays on Brussels sprout, AZT gave 16-92% and 88-100% mortality respectively (Wellcome strain) at rates approximating to 1-20 g AZ ha?1. The residual activity of AZT and NEEM-AZAL against P. xylostella (FS) on Brussels sprout (MV spray) was observed to decrease appreciably after three days, the decline in activity being particularly marked for NEEM-AZAL. 相似文献