摘要:

AbstractSalient aspects of insect cuticle formation, hormone action, nutritional requirements, feeding stimulants, sex and aggregation pheromones are discussed in the light of their possible contribution to controlling storage pests. Agents decimating pest populations by suppression of growth and reproduction (rather than by rapid mortality) are defined as insectistatics. Their mode of action includes inhibition of chitin and sclerotin formation, hormonal imbalance induced by extrinsic juvenoids or ecdysoids, developmental disturbances due to nutrient or metabolite antagonists, accelerators of metabolism and symbioticides. Disruption of mating may be accomplished by pheromone trapping and disorientation, or prevention of sex attraction due to pheromone isomers.The relatively limited space and constant conditions in storehouses (moderate levels of humidity, temperature and ultraviolet light) as well as the rapid developmental rate and low population density of storage pests render them suitable for control by insectistatics and pheromones. Some of the latter are currently tested under natural conditions. The limitations of these biotechnical procedures are discussed.

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1974.tb02389.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractEvaluation of economic returns resulting from plant protection measures are receiving increased attention. Since control measures are likely to affect not only a single production but also future crops and may entail resistance phenomena, as well as other inconveniences, the entire lifetime of a control strategy should be considered in a cost/benefit analysis.Although all the needed parameters for such an evaluation are not available, simplified computer‐based models, now in use in advanced pest management studies, turned out to beextremely useful.The possibility of assessing the impact of control measures on single crops is reviewed in the light of recent studies (Headley, 1972, 1973, Davidson andNorgaard, 1973) and data stressing the economic advantages of pest management schemes in European orchards and U.S. cotton areas are studied.With increased prices for pesticides and application, the benefit derived from integrated control schemes becomes more eviden

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1974.tb02390.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractDetails are given of the performance of Vapona Pest Strips and of an automatic dichlorvos sprayer developed to prevent infestation of clean or fumigated stored commodities, for infestation control on stored carobs. Air concentrations after spraying a nominal dose of 10 μg/1 of total store space averaged approximately 1.0. μ g/l after 30 minutes and less than 0.3 μ g/l after 3 hours. Residues found on carobs after daily spraying of stores at 10 μ g/1 for 96 days were in the range of 0.2 ‐ 2.0 ppm.Ephestia cautellaWalk, andLasioderma serricorne(F.) become established in carobs after harvest and are the principle pests causing damage during storage. Effective control ofE. cautellawas obtained by using Shell Vapona Pest Strips at two strips/100 m3or by daily spraying of dichlorvos at 10g/1,000 m2(10μ g/1). No effect was observed against migrating larvae ofE. calidella(Guen.) orE. figulilellaGreg, nor againstBracon hebetorSay., the hymenopterous parasite attacking all threeEphestiaspecies.The automatic dichlorvos sprayer is equipped to apply a predetermined dose at time of peak flight activity, 18–20 hours each evening. On stored carobs, no spraying is needed after October because the commodity temperature falls below 200C, too low for active development of the pest species. 23 automatic sprayers are now used in Cyprus to protect the whole carob crop from stora

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1974.tb02391.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractStorage research, especially at small‐farm level, makes too little impact on policy, largely for want of evidence that the benefits of grain savings – especially to the poor and hungry – justify the costs of improved structures. The paper describes a pilot survey of the costs and benefits of alternative means of paddy storage in two South Indian villages. Preliminary results suggest that subsequent, ongoing work in a larger sample of villages will justify substantial outlays on improved stores for small farmers and even landless labo

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1974.tb02392.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe generally restricted habitats of stored product insects provide an ideal situation for control attempts with pheromones and pathogens. Problem areas can be located and monitored with traps containing pheromones and insecticides and controls can be applied in localized areas. The method is economical, effective and reduces the hazards involved with blanket application of pesticides.Another method that promises to be successful utilizes pheromones in an inoculation device that contains a pathogen. The insects that are attracted become contaminated with the pathogen and may subsequently spread it throughout the population. In this way the pathogen will be spread to a multitude of population niches. Preliminary studies have indicated that few, if any, insects survive the infection, that the disease is highly contagious and that males will become inoculated with spores in pheromone‐pathogen baited inoculation devices and will transmit the spores by contact to female

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1974.tb02393.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractMethods are reviewed for inspection of growing potato crops and of soil sampling for detection and estimation of potato cyst nematodes (Heterodera rostochiensisWoll. andH. pallidaStone). Modifications of the Dutch soil‐sampling method are now widely used in Europe, including U.K. The statistical principles of soil sampling forHeteroderacysts are discussed. It is concluded that the efficiency of the method for detection is best improved by increasing both the quantity of soil examined and the number of sampling points per area sampled; the quantity is the most important factor which determines the level of infestation that can be detected. The area represented by a standard sample should be the same as that for which a separate decision will be made; variations in this area are unimportant because in effect one is sampling from an infinite population. It is concluded also that effective systems of control on potato‐growing land, and removal of soil from exported plants and potatoes, offer better prospects than soil sampling for preventing transport of cysts; a combination of these methods provides the best safeguard, e.g. for seed potat

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1974.tb02394.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractIn 1955, the EPPOHeterodera rostochiensisConference held in Wageningen (Anon., 1955) came to conclusions and recommendations which are analyzed together with other papers issued by EPPO between 1951–1959.In the course of the 18 years which elapsed since the Conference, major advances have been made in the following fields:– Origin, spread and distribution of the nematode, numerical dynamics and distribution of the nematode.– Numerical dynamics and genetic density and flexibility of nematode populations.– Breeding resistant potato varieties.– Development of new nematicides and integrated control.– Ecological limitations.Progress achieved along these lines

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1974.tb02395.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractAlthough potato cyst eelworm has been known in Scotland for more than 60 years, infestations are fewer than might have been expected. In 22 years of soil testing, based on nominal 500 g samples and sampling units of up to 6 ha, 80% of the farms examined were found free from detectable infestation and 10%, i.e. half the infested farms, had one infestation only. Most populations were light; one third of all infested samples contained a single viable cyst and 80%, ten cysts or fewer. It is suggested that long rotations have kept eelworm populations in check over much of the country, but in some areas their effectiveness has been reduced by persistent groundkeepers. Surveys indicate thatHeterodera pallidaStone is uncommon and so the progressive use of resistant varieties, which are proving popular with seed growers for their commercial qualities, coupled with the long rotations generally practised, may well tip the balance even more favourably towards increased control.

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1974.tb02396.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractResearch is undertaken by the Tropical Stored Products Centre both overseas and in the United Kingdom on storage problems facing developing countries. Much of it is of a strictly applied nature although some longer‐term basic studies are also underway. Our research includes biological, chemical and engineering studies and may be concerned with any level of storage, from farm to central storage depot, and with any durable agricultural produce, whether for consumption H the country of production or for expor

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1974.tb02397.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe two most important aspects of the host‐parasite relation of the potato and the tomato versusHeterodera rostochiensisWoll. are discussed. Many transitory forms between very poor and good hosts have been found in wild and primitive forms of these crops. The nature and the mode of inheritance of forms are described and their consequences for breeding work discussed. Several patho‐types are found and it is argued that many more exist.Much variation has also been found in the amount of damage in good hosts when heavily attacked. Some varieties, both in potato and in tomato, have been found with a high degree of tolerance to dam

ISSN:0250-8052    

DOI:10.1111/j.1365-2338.1974.tb02398.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY