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81.
G. H. Canullo R. Rodríguez‐kábana J. W. Kloepper 《Biocontrol Science and Technology》1992,2(2):159-169
The efficacy of 2‐furfuraldehyde for control of Sclerotium rolfsii was studied in laboratory and greenhouse experiments. Mycelial growth of the fungus was reduced proportionally with concentrations of 0.1–0.5 ml furfuraldehyde l‐1 agar medium, and viability of sclerotia diminished on exposure to 2‐furfuraldehyde vapours. Detectable populations of bacteria and fungi, including Trichoderma spp., were reduced significantly (9=0.05) when furfuraldehyde was added to the agar used for soil dilution plates of untreated soil. Repeated treatments of natural soil with the fumigant significantly increased populations of Trichoderma spp. and bacteria, but diminished numbers of actinomycetes. Increasing dosages applied to soil artificially infested with S. rolfsii caused a reduction of disease on lentil, Lens culinaris. Results indicate that the compound, when applied to field soil, changes the composition of soil microflora and has potential for integrated control of S. rolfsii. 相似文献
82.
P. Syrett 《Biocontrol Science and Technology》1992,2(3):261-265
The weevil Sitona regensteinensis is being considered for biological control of Cytisus scoparius in New Zealand. Adult feeding tests demonstrated that while foliage of C scoparius was preferred, weevils fed also on Chamaecytisus palmensis and Lupinus arboreus. Tests with the root‐feeding larval stage have yet to be completed. 相似文献
83.
Tracey C. Bourner Enrique Vargas‐Osuna Trevor Williams Candido Santiago‐Alvarez Jenny S. Cory 《Biocontrol Science and Technology》1992,2(4):315-326
Agrotis segetum nuclear polyhedrosis virus (AsNPV) and granulosis virus (AsGV), propagated in laboratory cultures of A. segetum in England and A. ipsilon in Spain, respectively, were applied to plots of maize plants at the one‐ to four‐leaf stage of growth. Plots were arranged in a 6 x 6 Latin square design and infested with second‐instar A. segetum larvae (the common cutworm). Each virus was applied in separate treatments by two application methods; as an aqueous spray containing 0.1% Agral as a wetting agent, and as a bran bait. The NPV was applied at a rate of 4 X 1012 polyhedra/ha, and the GV at 4 X 1013 granules/ha. Soil and plants were sampled for larvae on three occasions following virus treatment: 24 h, 4 days and 11 days. The larvae were reared on diet in the laboratory, until death or pupation, to examine the rate and level of viral infection. Infection data showed 87.5% and 91% NPV infection and 12.5% and 55% GV infection in spray and bait treatments, respectively, in larvae sampled 24 h after treatment. In larvae sampled 4 days after treatment, the results were 78% and 100% NPV infection, and 13% and 6% GV infection. A total of only six larvae were retrieved on day 11. In both treatments larvae infected with AsNPV died significantly more rapidly and at an earlier instar than those infected with AsGV, indicating that AsNPV appears to have better potential as a control agent for A. segetum. 相似文献
84.
1 前言 从外地引进寄蝇或人工助长当地寄蝇种类防治农林害虫,是有效的生防手段之一,国外已有很多成功的报道。King等(1981)在路易斯安娜州蔗田中人工大量释放螟利索寄蝇(Lixophaga diatraeae)成虫防治第1代小蔗杆草螟(Diatraea saccharalis),不同地区的寄生率分别达到4.1、8.7和35.7%;由于降低了农药的使用量,奇痣窄径茧蜂(Agathis stigmatera)的自然寄生率也相应提高,很好地控制了蔗田害虫的发生。在寄蝇的田间释放技术方面,国外还没有详细的报道。在我国,利用寄蝇防治害虫的工作也是刚刚起步,很多具体问题有待于进一步研究。 相似文献
85.
T. N. Ananthakrishnan R. Senrayan S. Murugesan R. S. Annadurai 《Journal of biosciences》1991,16(3):111-119
Kairomones from moth scales tend to influence the parasitic potential byTrichogramma chilonis Ishii. Hexatriacontane, pentacosane, heptadecane, docosane and 2, 6, l0-dodecatrienal-3, 7, 11-trimethyl were identified
from the active moth scale extract ofHeliothis armigera Hubner (its natural host) andCorcyra cephalonica Stainton (a laboratory host). The significance of an array of compounds from moth scales with kairomonal activity for manipulating
entomophagous insects in biological control programmes is discussed. 相似文献
86.
DDT resistance in Anopheles gambiae declines with mosquito age 总被引:1,自引:1,他引:0
Adult Anopheles gambiae Giles mosquitoes from Zanzibar were tested on a standard discriminating dose of DDT which reliably kills susceptible mosquitoes. Adults from wild-caught larvae reared in the laboratory, and from the F1 progeny of wild-caught adults, showed less than 5% test mortality when newly-emerged, but mortality rose with age to over 90% when they were 12-14 days old. Wild-caught mixed-age adults showed an intermediate mortality rate of 25%, close to the rate predicted from laboratory results for a fully resistant population with an age-structure typical of this species in natural conditions. It is inferred that older, genetically resistant insects may be scored as susceptible, so that routine susceptibility tests with wild-caught adults underestimate the frequency of resistance. In Zanzibar, such tests probably helped to persuade spraying authorities to continue spraying DDT in spite of resistance. Resistance which is restricted to younger insects may nonetheless reduce the effectiveness of spraying. 相似文献
87.
Two species of bioluminescent fungi, Panellus stypticus and Omphalotus olearius were placed in contact with three different strains of interfungal pathogenic Trichoderma harzianum. Subsequent light emission by the luminous fungi and advance of the interfungal pathogens were compared. Relative differences among the pathogens were reflected in their rate of mycelial advance, the total area over which they produced spores upon the host fungi, and decreases in host bioluminescence. After ten days differences in the total surface areas of spore production varied from 1 to 53 per cent. Differences in the reduction of bioluminescence of the same material ranged over 2 orders of magnitude. Final reduction in luminescence ranged over 6 orders of magnitude. A marked reduction in bioluminescence was observed to precede the advance of spore production. The greatest reduction in luminescence was correlated with the presence of T. harzianum hyphae. Two strains of T. harzianum, NRRL 1698 and ATCC 58674, were effective against both bioluminescent fungi within the study period while a third strain, NRRL 13019, was only effective against Omphalotus olearius. 相似文献
88.
Angela B. Lange Ian Orchard Vicki A. Te Brugge 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1991,168(3):383-391
Summary The presence of a SchistoFLRFamide-like peptide associated with the oviducts of Locusta migratoria has been shown using sequential reversed-phase high performance liquid chromatography separation coupled with radioimmunoassay and bioassay. The peptide is present in areas of the oviduct which receive extensive innervation, with sixfold less peptide in areas that receive little innervation. Material with FMRFamide-like immunoreactivity (determined by radioimmunoassay) is also present in the oviducal nerve and VIIth abdominal ganglion.SchistoFLRFamide is a potent modulator of contraction of this visceral muscle, inhibiting or reducing the amplitude and frequency of spontaneous contractions, relaxing basal tonus, and reducing the amplitude of neurally-evoked, proctolin-induced, glutamate-induced and high potassium-induced contractions. The FMRFamide-like immunoreactivity within the oviducts which co-elutes with SchistoFLRFamide on two separations is also capable of reducing the amplitude of neurally-evoked and proctolin-induced contractions, and of inhibiting spontaneous contractions and relaxing basal tonus.The effects of SchistoFLRFamide upon this visceral muscle are not abolished by the -adrenergic receptor antagonist phentolamine and do not appear to be mediated by cyclic AMP. Thus the receptors for Schisto-FLRFamide are distinct from those of octopamine which mediate similar physiological effects but which are blocked by phentolamine and which are coupled to adenylate cyclase.The results indicate that SchistoFLRFamide, or a very similar peptide, which has previously been identified as a modulator of locust heart beat, is also associated with visceral muscle of the reproductive system, and may play a neural role in concert with octopamine, at modulating muscular activity.Abbreviations
BPP
Bovine pancreatic polypeptide
-
BSA
Bovine serum albumin
-
EJP
Excitatory junctional potential
-
FaRPs
FMRFamide-related peptides
-
FLI
FMRFamide-like immuno-reactivity
-
LMS
Leucomyosuppressin
-
RIA
Radioimmunoassay
-
RP-HPLC
Reversed-phase high performance liquid chromatography
-
TFA
Trifluoroacetic acid 相似文献
89.
Hartmut Böhm Hans-Georg Heinzel Hans Scharstein Gernot Wendler 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1991,169(6):671-683
The wind-orientated walk of carrion beetles Necrophorus humator F. was analysed under closed-loop conditions with a walking compensator and under openloop conditions with a paired tread wheel (Fig. 1).
相似文献
1. | On the walking compensator an animal runs stable courses with a preferred direction relative to an air current (velocity =; 100 cm/s, Fig. 2B-D). A change in the air-current direction causes a corresponding adjustment of the mean walking direction (Fig. 3). Such course adjustment works best for changes in the air-current direction by an absolute value of 90° (Table 2). |
2. | Under closed-loop conditions the animal shows deviations of less than ± 45° around its preferred direction relative to the wind (Fig. 2B-D). The characteristic curve which describes the animal's angular velocity as a function of the animal's walking direction relative to the air-current stimulus is therefore revealed only in this angular range (Fig. 3, top). |
3. | Under open-loop conditions, however, complete characteristic curves can be obtained because the animal's walking reaction in response to any given angle of air-current stimulus is measurable on the paired tread wheel (Fig. 4). The characteristic curves are approximately sinusoidal functions. They can either show a shift parallel to the ordinale by a superimposed direction-independent constant angular velocity alone or, at the same time, they can independently exhibit an angular shift along the abscissa (Fig. 5). |
4. | The walking tracks straighten with increasing air-current velocity (Fig. 6A, insets), i.e. the animal more rapidly compensates deviations from a preferred course. This corresponds to higher amplitudes of the characterisic curve and steeper slopes at the negative zero-crossing point under open- as well as under closed-loop conditions (Fig. 6). |
5. | Walking in an air-current field can be explained by a model of the course control system using a feedback loop (Fig. 7). This model operates according to a sinusoidal characteristic function on which is superimposed a Gaussian white noise process of angular velocity which is independent of walking direction. The model produces realistic walking tracks in an air-current field (Fig. 8). |
90.
W. Junger 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1991,169(5):633-639
Waterstriders on ponds and creeks compensate for displacement caused by wind or water current with periodical jumps against the direction of drift. This behavior is mediated by visual stimuli.
相似文献
1. | Waterstriders are able to detect the direction and extent of their displacement on an artificial canal when visual cues are reduced to a single point-like light source above the upstream end of the canal. They adjust the frequency and direction of the compensatory jumps to keep their mean position on the canal constant. The mean amplitude of the jumps is constant and independent of the stream velocity. |
2. | During drift compensation the light spot is kept in the frontal visual field at a fixed angle of elevation. This set angle differs among individuals and can be changed with time. |
3. | The station-keeping ability can hardly be explained by a velocity servo system since there is no accumulating position error. The average compensatory movements are governed by a discontinuously working position servo. |
4. | When the light spot is switched off, a few jumps are still performed. Jumps, therefore, are not triggered individually by visual cues. Waterstriders must possess an endogenous jump-generator. |