摘要:

SUMMARYObservations were made on the movement and mortality ofAgriolimax reticulatus(Müller) on plots with various densities of metaldehyde and methiocarb pellets. The optimum density of pellets was found to lie between 25 and 100/m2(pellets 20 and 10 cm apart). This confirmed an estimate derived from a theoretical model

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb04555.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYA wide range of insects can be confined on the horizontal surface of areas surrounded by oscillating rings or chambers. The ability to retain insects on a selected surface may be useful in the bioassay of insecticides using residual film and other techniques, by diminishing the amount of anaesthesia required and any unwanted fumigant effects.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb04556.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYControl of aphids by the four systemic insecticides, dimethoate, disulfoton, menazon and phorate, applied as granules below seed potatoes at planting, was investigated under different soil moisture conditions. Results confirmed previous conclusions that dimethoate and menazon are more effective in wet than in dry soils, whereas disulfoton and phorate are equally effective in both. However, even with dimethoate and menazon effects of moisture were small and were probably the result of several different interacting factors.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb04557.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYA relation was found between temperature and the survival of larvae ofTipula oleraceaandT. paludosawhen submerged in tap water alone or on turf growing on a sandy loam flooded with still or disturbed water (experiments with soil always starting with freshly flooded soil). Larvae under water alone usually survived until they starved, whereas larvae submerged on soil died in a relatively short time. The periods of survival at a depth of 25 mm were the same for both large and small larvae of either species at any one temperature. The regression of log.‐log. survival time on temperature was a straight line, mean arithmetic values ranging from about 5 h at 20 °C to 122 h at 0 °C. Survival times at 25 mm were not increased by disturbing the water and the times at greater depths were no different, providing the water was still. If the water was regularly disturbed then the greater the depth the longer the survival time at any one temperature.Survival times in deoxygenated water indicated that lethal conditions may not be entirely due to deoxygenation of the wa

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb04558.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYLarge varietal differences in the susceptibility of chrysanthemums toMyzus persicae(Sulz.) were confirmed. The cultivar B.G.A. Tuneful supported forty times as many aphids as Portrait. In the winter, aphids bred more slowly and stabilized at a lower density than in the summer, but retained the same characteristic varietal distribution patterns.The unintentional introduction of the parasiteAphidius matricariaeHal. resulted in extermination of the aphid within 15 weeks. Mummies appeared in a series of distinct generations 17 days apart with a sevenfold increase between peaks. As this increase was at first not as rapid as that of the aphid, reduction of the pest population was not possible until the aphids had become self‐limiting. Thus, although elimination was achieved, it was not economically satisfactory on susceptible varieties. The modifications needed to employA. matricariaefor commercial biological control under glass are discusse

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb04559.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYThe toxicity of malathion (2.5 % solution in kerosene) was determined by topical application to the hindwing base of mature adults ofSchistocerca gregariaandLocusta migratoria migratorioidesand of immature adults ofS. gregaria.Mature adults ofL. m. migrator ioideswere slightly more resistant to malathion than those ofS. gregaria.Immature adults ofS. gregariawere approximately as susceptible as mature ones (at LD89level) when the criterion for toxicity was taken as the ultimate death of the dosed insects, but the symptoms of poisoning developed earlier and more strongly in the immature insects.Penetration of malathion was least in the matureL. m. migratorioidesand highest in the immatureS. gregaria.The higher rate of activation of malathion in the immatureS. gregariawas, however, counterbalanced by a higher rate of hydrolysis.The toxicity reflected the rate of accumulation of malathion and/or mala‐oxon inside the insect bod

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb04560.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYDamage done byBotrytis tulipaedeveloped in a variety of ways after planting naturally and artificially inoculated bulbs, the fungus sometimes rapidly invading developing shoots, preventing their emergence. In other instances(a)leaves emerged above ground, but not before being severely infected (the traditional ‘primaries’),(b)leaves emerged uninfected but the flower stalks were attacked at a later stage causing mechanical weakness (and hence frequent snapping), or(c)leaves and flower stalks remained uninfected, with the development ofB. tulipaebeing restricted to its spread from mother to daughter bulbs, which also occurred in(a)and(b).More emerging shoots were infected when inoculated bulbs were grown at 10° and 15.5° than at 4 °C—an effect suggesting that greater numbers of foliar primaries would develop in mild winters.The underground transmission ofB. tulipaeindicates the need for eradicating infections in the bulb, the primary sources of this

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb04561.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYSimple methods for producing, handling and testing the viability of sclerotia were used on five fungi, three of which produced sclerotia freely in sand‐maizemeal cultures; the other two did not, and were grown on agar. After air drying, which did not affect viability, sclerotia were buried in the field in bags of nylon fabric. After recovery from soil they were surface‐sterilized with calcium hypochlorite and plated on a medium containing chloramphenicol and streptomycin sulphate. Some fungi, particularly those having basidiomycete affinities, are sensitive to high concentrations of chlorampheni

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb04562.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYCanker disease ofTheobroma cacaoL. caused byPhytophthora palmivora(Butler) Butler gives rise to serious damage in Fiji and is common in the S.W. Pacific area.Fusarium decemcellulareBiick(imperfect stage ofCalonectria rigidiuscula(Berk.&Br.) Sacc.) was constantly associated withP. palmivorain disorders of cocoa but was not found to be a primary pathogen. Most Amelonado cocoa trees were resistant to canker but there were differences in the reactions of other Forastero and of Trinitario types. The F1generation of a local Trinitario selection, itself resistant, showed segregation resulting in a proportion of very susceptible plants. Isolates ofP. palmivorafrom black pod, canker and green twigs were equally pathogenic, both to pods and seedling stems. Sporangial dimensions, particularly the length/breadth ratio, differed from those reported elsewhere. It is uncertain whether the reason that cocoa canker is more serious in some countries than others is because of differences in the pathogenicity ofP. palmivorastrains to bark or the genetic differences of the cocoa grown.

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb04563.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

SUMMARYDecreasing periods of atmospheric humidity in excess of 90 and 75 % r.h. by automatic control decreased the incidence ofC. fulvumandB. cinereaand sometimes increased tomato yields. The desired value of humidity was not always achieved but nevertheless environments which were both physically and biologically different were obtained with humidistats set at 90 and 75 % r.h. in glasshouses maintaining two temperature régimes–20 °C day and night, or 20 °C by day and 13 °C at night.LessB. cinereaandC. fulvumoccurred on tomatoes grown constantly at 20 °C than on those grown in conditions with lower night temperatures. In the latter regime the end‐of‐season incidence ofC.fulvumvasdecreased from 25.0% where humidity was not controlled to 2.8% and 0.0% where humidistats were set at 90 and 75 % r.h. In the same conditions the proportion of blemished fruit damaged byB. cinereadecreased from 2.6% to 1.6

ISSN:0003-4746    

DOI:10.1111/j.1744-7348.1970.tb04564.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY