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2.
铜绿丽金龟对寄主植物挥发物的触角电生理及行为反应   总被引：2，自引：0，他引：2  
为深入了解铜绿丽金龟的取食行为,探索开发安全高效的植物源引诱剂,应用昆虫触角电位反应仪和Y型嗅觉仪测试其对不同寄主植物挥发物的趋向行为差异,并根据室内行为结果配制诱剂进行大田试验。结果表明:铜绿丽金龟雄虫对水杨酸甲酯和(1,1’-联环戊基)-2-酮的触角电位反应(electroantennography,EAG)值显著高于其它试剂;石竹烯和水杨酸甲酯能引起雌虫触角较强的电位反应;乙酸顺式-3-己烯酯和石竹烯分别对雄虫和雌虫有较高的嗅觉选择反应率,分别达0.95和0.94。综合EAG和嗅觉试验结果,选择对雌、雄虫均有较好引诱效果的反式-2-己烯醛、乙酸顺式-3-己烯酯、石竹烯、(1,1’-联环戊基)-2-酮和水杨酸甲酯进行田间试验,最终筛选到铜绿丽金龟雄虫的最适引诱剂为每诱芯360 mg乙酸顺式-3-己烯酯,雌虫的最适引诱剂为每诱芯360 mg石竹烯,日诱虫量分别可达33.00±1.53头和29.33±1.45头。  相似文献   

3.
Plant volatile compounds, including terpenes, are known to be involved in the rice defense system. In the present analysis of a terpene synthase, OsTPS18, in rice, we found that OsTPS18 was localized in the cytoplasm and synthesized the sesquiterpenes (E)-nerolidol and (E)-β-farnesene. The amounts of (E)-nerolidol and (E)-β-farnesene increased after jasmonic acid (JA) treatment. (E)-Nerolidol had significant antibacterial activity against Xanthomonas oryzae pv. oryzae (Xoo). These results suggest that (E)-nerolidol plays an important role in JA-induced resistance against Xoo and that it functions as an antibacterial compound in rice.  相似文献   

4.
Two analogues of the aphid alarm pheromone (E)-β-farnesene, a trifluorofarnesene and a difluoro-1-norfarnesene, were found to be highly active and were more readily detectable than the parent compound. For (Z)-hexadec-11-enal, a component of some lepidopteran sex attractant pheromones, replacement of the carbonyl oxygen with a difluoromethyl group to give a difluoroheptadecadiene resulted in loss of activity. A trifluoroacetoxyhexadecanolide was a more volatile analogue of the mosquito oviposition pheromone (?)-(5R,6S)-6-acetoxy-5-hexadecanolide and was highly active.  相似文献   

5.
Isomers of pyrethroids usually have different insecticidal activities. Permethrin, a non‐cyano pyrethroid, is not an exception and cis‐permethrin is much more active than the trans‐isomer against Triatoma infestans, vector of Chagas' Disease in Argentina. The large‐scale separation of cis‐ and trans‐permethrin was performed by successive recrystallizations from ethanol‐water mixtures. An aqueous suspension concentrate (flowable) formulation of pure crystalline cis‐permethrin was prepared and assayed for its insecticidal activity on wood and ceramic surfaces against nymph V of T infestans. This formulation was at least three times more effective than deltamethrin, with LC50 values on ceramic of 0.11 µg cm−2 and 0.33 µg cm−2 respectively. On wood surfaces, the LC50 value was 0.57 µg cm−2 compared with 3.20 µg cm−2 for deltamethrin. Against other insect species such as Periplaneta americana, Aedes aegypti and Culex quinquefasciatus, the suspension concentrate formulation of cis‐permethrin was, however, less effective than similar formulations of deltamethrin or β‐cypermethrin. © 2000 Society of Chemical Industry  相似文献   

6.
The herbicide isoproturon [3‐(4‐isopropylphenyl)‐1,1‐dimethylurea] was incorporated in alginate‐based granules to obtain controlled‐release (CR) properties. The basic formulation (sodium alginate (1.87%)–isoproturon (0.67%) in water) was modified by addition of different sorbents. The effect on isoproturon release rate, modified by the incorporation of natural and acid‐treated bentonite in alginate formulation, was studied by immersion of the granules in water while shaking. The release of isoproturon was diffusion‐controlled. The time taken for 50% of the active ingredient to be released into water, T50, was longer for those formulations containing added bentonite (5.98 and 7.43 days, for natural and acid‐treated (1 M H2SO4) bentonite, respectively) than for the preparation without bentonite (3.78 days). The mobilities of non‐formulated technical grade (98%) and formulated isoproturon were compared using soil columns. The use of alginate‐based CR formulations containing bentonite reduced isoproturon movement compared with the technical product. Sorption capacity of the soil for isoproturon was measured using batch experiments (0.29 litre kg−1) and the results obtained here in agreement with those obtained under dynamic conditions. © 2000 Society of Chemical Industry  相似文献   

7.
Controlled-release formulations of 14C-labelled thiobencarb herbicide were prepared in calcium alginate using kaolin as an inexpensive filler. The rates of release of the herbicide from these and from a commercial granular formulation were studied in static distilled water contained in open and closed vessels. The rate of release of the herbicide was much higher from the commercial formulation than from the controlled-release formulations. Increasing the proportion of kaolin to calcium alginate in controlled-release formulations reduced the rate of release of the herbicide. There was a significant loss of thiobencarb-related radioactivity from the water solution when the vessels containing the solutions were left uncovered and exposed to light. The loss of the herbicide seemed to be due to degradation and evaporation.  相似文献   

8.
BACKGROUND: The use of Trichogramma species is a potential key strategy in integrated pest management. However, its effectiveness depends on the use of chemicals that do not interfere with parasitism and parasite population growth. Here, a study was made of the effects of synthetic insecticides on Trichogramma pretiosum and Trichogramma exiguum in different hosts (Ephestia kuehniella, Plutella xylostella and Spodoptera frugiperda) and the influence of International Organisation for Biological Control (IOBC/WPRS) methodology in selectivity studies using different Trichogramma species. The insecticides used were commercial formulations (triflumuron at a concentration of 0.2 mL L?1 water, etofenprox at a concentration of 0.47 mL L?1 water and endosulfan at a concentration of 7.5 mL L?1 water); the control treatment consisted of distilled water. Eggs attached to cardboard cards were offered to parasitoids inside glass cages. Parasitised eggs, parasitism and adult emergence rates and parasitism reduction were evaluated. RESULTS: Endosulfan and etofenprox, classified as class‐4 toxic products, were extremely toxic to the parasitoids. Triflumuron, classified as a non‐toxic product, was selective to the parasitoids in eggs of all hosts. CONCLUSIONS: The methodology recommended by IOBC/WPRS influenced results regarding the use of different species of parasitoids, and the use of a single parasitoid species in their experiment is questionable. Copyright © 2011 Society of Chemical Industry  相似文献   

9.
Conidia, chlamydospores and mycelia of Coniothyrium minitans, Gliocladium roseum, Trichoderma harzianum and T. viride were obtained from liquid or solid culture and formulated within alginate pellets. Quantitative assessment of these pellets over a 12-week period showed a decrease in the number of colony-forming units (cfu) from about 107 to 103-104 g-1 air-dried pellets. Qualitatively, growth was assessed by direct plating the alginate pellets on rich (potato dextrose agar, PDA) and poor (water agar, WA) substrates. Rate of growth (mm day-1) from individual pellets was decreased by water potential in the range -0.25 to-2.8 MPa, with growth significantly less on WA than PDA for all species except G. roseum. All species grew from 95 to 100% of direct-plated pellets on PDA over the water-potential range tested. However, on WA, interaction between water stress (-2.8 MPa) and lack of nutrients resulted in a reduction, with less than 30% of pellets of some formulations showing growth. In contrast to the quantitative results, there was little change in the growth rate of test species from pellets over a 12-week period, particularly on PDA. Growth from pellets could not be conclusively demonstrated in unsterile soil. The shelf-life and viability of alginate pellets in soil is assessed.  相似文献   

10.
The stability of some diluted emulsifiable concentrate formulations in clear liquid fertilizers, as affected by the nature and concentration of the salt solutions, was checked by a static test. The time-induced changes in the concentration of the dispersed phase were estimated by visual observations and turbidity measurements. For each formulation a specific relationship between the electrical conductivity of all the fertilizer solutions and the emulsion stability was found. This was valid for a pH range between 4.6–6.3; in alkaline conditions the emulsion stability was relatively lower. A critical electrical conductivity range, above which irreversible destabilization occurred, was observed for each formulation: 100-120 dS m?1 for fenamiphos, 60-70 dS m?1 for metolachlor, 30-50 dS m?1 for chlorpyrifos, and about 45 dS m?1 for S-ethyl dipropylthiocarbamate (EPTC). The correlation observed between the emulsion stability and the electrical conductivity could be used in a simple and rapid qualitative test to estimate the physical compatibility between emulsifiable concentrate formulations and liquid fertilizers.  相似文献   

11.
BACKGROUND: Mosquitoes are the most important vectors of human pathogens. Wide‐scale use of pesticides has led to the development of resistance to most common insecticide groups. The need to develop novel products that have a low impact on human health and the environment is well established. The toxicity of selected semiochemicals with molecular structures indicative of insecticidal activity was determined against adult Aedes aegypti (L.) and Anopheles quadrimaculatus (Say). The two most active insecticides against Ae. aegypti were also evaluated against Ae. albopictus (Skuse). RESULTS: Fifteen semiochemicals classified as terpenoid alcohols, ketones or carboxylic esters showed toxicity to both mosquito species. Geranyl acetone (LC50 = 38.51 µg cm?2) followed by citronellol (LC50 = 48.55 µg cm?2) were the most toxic compounds to Ae. aegypti, while geraniol and lavonax, with LC50 values of 31.88 and 43.40 µg cm?2, showed the highest toxicity to An. quadrimaculatus. Both geranyl acetone and citronellol were highly toxic to Ae. albopioctus. No semiochemical showed fumigation activity against either species. All semiochemicals persisted for less than 24 h when tested on filter paper. CONCLUSION: Quantification of LC50 values of several semiochemicals against Ae. Aegypti, An. quadrimaculatus and Ae. albopioctus showed that semiochemicals not only modify insect behaviors but also hold potential as potent insecticides for mosquito control programs. Copyright © 2010 Society of Chemical Industry  相似文献   

12.
Controlled-release herbicide formulations have been shown to decrease the leaching potential of several herbicides under laboratory and field conditions. The utility and efficacy of these formulations may be improved by combining several herbicides and a fertilizer source in a single formulation. The objective of these studies was to develop granular alginate formulations that were composed of a combination of the herbicides atrazine and alachlor with the slow-release nitrogen source oxamide (ethanediamide). Controlled release of the herbicides was obtained by addition of selected minerals, including calcium bentonite, fine-grind bentonite, montmorillonite K10, kaolinite and iron (III) oxide. A formulation without clay was used as a comparison. The formulations tested had herbicide active ingredient contents ranging from ∽0·02 to 0·54% and a nitrogen content of 21%. Release of the herbicides was studied by equilibrating the formulations with deionized water on a rotary shaker at 200 rev min-1 and sampling at regular time intervals up to 104 hours. The minerals used in the different formulations influenced the herbicide active ingredient composition, as well as the release properties of the individual formulations. The atrazine content of the formulations decreased in the order calcium bentonite>fine-grind bentonite>kaolinite>montmorillonite=iron oxide>no clay. For alachlor the content decreased in the order of calcium bentonite>fine-grind bentonite>montmorillonite>iron oxide>kaolinite>no clay. Controlled release of atrazine (i.e. reduction in release rate) varied in the order calcium bentonite>iron oxide>montmorillonite>fine-grind bentonite= kaolinite>no clay, and for alachlor fine-grind bentonite>calcium bentonite>montmorillonite>no clay=kaolinite=iron oxide. A certain percentage of the applied active ingredient of both alachlor and atrazine was not recovered. From 5 to 27% of the active ingredient was not released, with the greatest retention by the bentonite formulations. Release of nitrogen was not strongly influenced by mineral type, although a trend indicated greater release with formulations containing kaolinite. © 1998 SCI  相似文献   

13.
The mobility of alachlor from alginate-encapsulated controlled-release (CR) formulations was investigated in two contrasting soil profiles. Two CR formulations of alachlor were prepared with the following components (1) base—sodium alginate+kaolin+‘Tween’ 20 (1+10+0·5 by mass) and (2) base+40 g kg−1 linseed oil. These were compared to technical grade alachlor and to a commercial alachlor EC formulation (‘Lasso’ 4EC). All herbicide treatments were labeled with [14C]alachlor and were applied to duplicate soil columns that were composed of a surface and a subsoil horizon. Each horizon was packed to a depth of 12·5 cm, giving a total column length of 25 cm. The columns were leached with 21 cm (420 ml) to 30 cm (600 ml) of 0·01M calcium chloride for a period of 7 to 10 days. Alachlor leaching from the EC formulations was the same as that from the technical material in both soils: 33% in the Evesboro and 10% in the Conover soil. The CR-Oil formulation leached 4 and 2% of the applied [14C]alachlor, compared to 12 and 3% for the CR-N formulation for the Evesboro and Conover soils, respectively. The CR-Oil formulation also increased the amount of [14C]alachlor retained in the soil surface horizon (105–114%), compared to CR-N (39–45%), technical material (14–23%) and EC (12–17%).  相似文献   

14.
In order to prepare a formulation to be used for controlled release, imidacloprid was incorporated into alginate granules by using calcium chloride as gellant. The formulation prepared (alginate–imidacloprid–water) was modified by the addition of different sorbents. The effects on release rate of the addition of natural bentonite desiccated at 105 °C, untreated, acid-treated with sulfuric acid solutions over a concentration range between 0.5 mol dm−3 and 2.5 mol dm−3, and a commercial humic acid, were studied by immersion of the granules in water under static conditions. The time taken for 50% of the active ingredient to be released into water, (T50), was calculated from the data obtained. On the other hand, the sorption–desorption processes of imidacloprid from a 0.01 M aqueous calcium chloride solution at 25 °C, by natural, acid-treated bentonite samples, and humic acid, have been studied by using batch experiments in order to evaluate the potential of these materials for their application in controlled-release formulations of pesticides. The experimental data have been fitted to the Freundlich equation in order to calculate the adsorption capacities (Kf). Kf values ranged from 1.76 mg kg−1 for the untreated bentonite up to 126.9 mg kg−1 for the humic acid. A correlation study was performed with T50, the surface area (S) and the Freundlich parameter (Kf) of the bentonite samples in order to know the factors that affect release rate of imidacloprid from bentonite granules. A linear correlation of the T50 values and both S and Kf parameters was observed. © 1999 Society of Chemical Industry  相似文献   

15.
BACKGROUND: As part of their indirect defense, plants under herbivore attack release volatile chemicals that attract natural enemies of the herbivore. This is a very well-documented phenomenon. However, relatively few studies have investigated the response of plants to different population levels of herbivores and their feeding duration. RESULTS: Working with larvae of the cabbage looper, Trichoplusia ni (Hübner), and tomato plants, Lycopersicon esculentum Mill cv. clarence, and using an ultrafast gas chromatograph (the zNose™) for volatile analyses, the authors studied the effect of larval density and feeding duration on levels of plant volatile emissions. Intense herbivory caused higher emission levels of the herbivore-induced plant volatiles (HIPVs) (Z)-3-hexenyl acetate, (E)-β-ocimene and β-caryophyllene than those caused by moderate herbivory. When herbivory had ceased following 12–24 h of larval feeding, plants kept releasing HIPVs at a high level for a longer period of time than they did following only 6 h of larval feeding. The plants' slow adjustment in their volatile emissions following prolonged larval feeding might be strategic, as such feeding is more likely to have ceased just temporarily. CONCLUSION: This information may help in the development of a pest monitoring system that is based on herbivore-induced plant volatiles. Copyright © 2011 Society of Chemical Industry  相似文献   

16.
Glasshouse trials had shown that the activity of metconazole formulations against cereal foliar diseases could be enhanced by alcohol ethoxylate adjuvants. A series of soluble liquid (SL) formulations of metconazole had been prepared containing adjuvant: metconazole ratios of 5:1, 7.5:1, 10:1, 15:1 m/m (SL1, SL2, SL3, SL4) which glasshouse trials had shown could give equivalent performance to an emulsifiable concentrate formulation, (ECM) of metconazole at application rates up to three- or four-fold lower than that of ECM alone. A field trials programme was undertaken to compare the performances of these SL formulations with ECM at 120 g AI ha?1, through a range of application rates (48, 60, 72, 84 g AI ha?1), in a non-orthogonal factorial trial design against diseases that occurred naturally (Septoria tritici Rob., Puccinia recondita Rob., Pyrenophora teres Drechs., Erysiphe graminis DC) or by artificial inoculation (Leptosphaeria nodorum Muell.), on either Triticum aestivum L. or Hordeum vulgare L. The results from trials in three locations showed that the commercially acceptable performance of ECM at 120 g AI ha?1, in giving high levels of control of P. recondita, S. tritici and L. nodorum (both prophylactic and therapeutic activity) on T. aestivum. and of E. graminis and P. teres on H. vulgare, could be matched or improved by SL2, SL3 and SL4 at 72 g AI ha?1. Furthermore, control of E. graminis f. sp. tritici Marchal by these SL formulations at this application rate was better than that by ECM at 120 g AI ha?1, though the levels of control still remained below commercial acceptability for therapeutic activity. Nevertheless, substantial reductions in the application rate of metconazole have been achieved by using one-pack adjuvant-containing formulations in field trials, while still maintaining excellent control of a range of cereal foliar diseases. The choice between these SL formulations could therefore be made on other grounds such as cost/performance and ease of formulation.  相似文献   

17.

BACKGROUND

Semiochemicals for monitoring, attracting or repelling pest and beneficial organisms are increasingly deployed in agricultural and forest systems for pest management. However, the use of aggregation pheromones and host‐plant attractants for the express purpose of increasing the efficacy of classical biological control agents of weeds has not been widely reported. Therefore, we conducted field‐based assays to determine if a specialized wax‐based matrix impregnated with an aggregation pheromone of the northern tamarisk beetle Diorhabda carinulata (Desbrochers) or host‐plant volatiles could increase the efficacy of D. carinulata.

RESULTS

The aggregation pheromone and host‐plant volatiles were formulated for field application using a wax‐based matrix. Reported release rates suggest that this matrix is a viable formulation for enhancing D. carinulata aggregations under field conditions. Pheromone‐treated saltcedar plants (Tamarix spp.) not only had higher densities of adult and larval D. carinulata, but also sustained greater levels of foliar damage than control plants. Increased damage from the focused feeding of D. carinulata caused an increase in foliar dieback and decrease in live canopy volume of semiochemical‐treated plants.

CONCLUSION

Field deployment of these semiochemical formulations could be useful in directing populations of D. carinulata for increased impact on Tamarix spp. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

18.
Previous investigations have shown that certain C12–C18 alcohol ethoxylates with between 5 and 20 moles ethylene oxide gave large enhancements to the therapeutic activity of emulsifiable concentrate (EC) and wettable power (WP) formulations of dimethomorph in controlling two-day-old infections of downy mildew (Plasmopara viticola, Berl. & deT) on glasshouse propagated vines (Vitis vinifera, L.). In a continuation of that work it has been shown that similar enhancements could also be obtained on vines that had been grown under outdoor conditions for two to three weeks before treatment (outdoor-hardened vines) and it is concluded that the treatments would therefore be effective on field vines. Mixtures of either ammonium sulfate or the silicone ethoxylate, ‘Silwet’ L77, with the best alcohol ethoxylates, ‘Genapol’ C050 or ‘Genapol’ C080, produced slight antagonism of the action of the ‘Genapols’ and therefore were of no benefit. Trials with one-pack formulations prepared containing the ‘Genapol’ adjuvants produced good dose response curves from which estimated doses for 90% fungal control (ED90 values) could be calculated by Logit analysis. These one-pack formulations were significantly more effective than the standard EC formulation (ED90=335 g AI ha−1, glasshouse vines and 445 g AI ha−1, outdoor hardened vines) with optimum enhancements with those formulations containing an adjuvant: dimethomorph ratio of either 9:1 on glasshouse vines (ED90= 13 g AI ha−1) or 6:1 on outdoor-hardened vines (ED90=30 g AI ha−1). This last result was significantly better than that obtained with a commercial formulation of cymoxanil, ‘Fytospore’, (ED90=86 g AI ha−1) and encouraged the recommendation that these one-pack formulations should be examined in field trials.  相似文献   

19.
Experiments were conducted in a glasshouse to evaluate the phytotoxicity of dibutylurea (DBU), a breakdown product of benomyl, benomyl formulations and constitutive ingredients of ‘Benlate’ Dry Flowable (DF) on whole cucumber (Cucumis sativus. Poinsett 76) plants. Benlate Wettable Powder (WP) and DF formulations did not affect the phytotoxicity of DBU. When commercially purchased (samples obtained from growers) DF and WP formulations containing equivalent DBU concentrations were compared for phytotoxicity, no statistical interactions between formulations were observed. Benomyl, DBU and DF inert ingredients were tested alone and in combination to assess their phytotoxicity. Only DBU at rates greater than 94 mg litre-1 caused a reduction in root and shoot growth. Also DBU applied alone or as a component of either Benlate formulation was shown to reduce the peak-to-terminal chlorophyll a fluorescence ratio measured in vivo by a plant productivity fluorometer. © 1998 SCI.  相似文献   

20.
BACKGROUND: Some twig beetles in the genus Pityophthorus (Coleoptera: Scolytinae) may vector pitch canker disease Fusarium circinatum (Niremberg & O'Donnell) of Pinus spp. (Pinaceae). Because Pityophthorus pubescens (Marsh.) has been found to be associated with F. circinatum in the Basque Country (northern Spain), various experiments were conducted to assess the beetle's behavioural responses to (E, E)‐α‐farnesene, (R)‐(+)‐limonene and (S)‐(?)‐verbenone to develop a potential inhibitor to host attraction. These experiments comprise electroantennographic and double‐choice olfactometer tests, as well as field assays in Pinus radiata D. Don stands. RESULTS: Both sexes of P. pubescens showed similar electroantennographic responses to different doses (from 1 ng to 1 µg in decadic steps) of each individual compound, with depolarisations to (S)‐(‐)‐verbenone (100 ng) being similar to those of the aggregation pheromone (+)‐trans‐pityol. In olfactometer assays, both sexes were significantly attracted to (+)‐trans‐pityol, but the attraction was reduced when increasing amounts of the chemicals were added to the pheromone. Particularly relevant was the repellent effect induced by (S)‐(?)‐verbenone at 1 ng dose and higher. In the field, (E, E)‐α‐farnesene, (R)‐(+)‐limonene and (S)‐(?)‐verbenone reduced significantly the number of beetles attracted to (+)‐trans‐pityol and racemic trans‐pityol, with (S)‐(?)‐verbenone being the most effective. CONCLUSIONS: (S)‐(?)‐Verbenone showed an interesting potential for use in the protection of P. radiata stands. A potentially effective strategy, which could be implemented in further, more in‐depth studies, could involve the use of this semiochemical as repellent and (+)‐trans‐pityol‐baited traps as attractant in a ‘push‐pull’ strategy. Copyright © 2012 Society of Chemical Industry  相似文献   

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