bluuebunny/crossref_metadata_2025_split huggingface dataset:
STUDIES IN BACTERIOSIS
Authors: LACEY MARGARET S. 
Published: February 2008

SUMMARY

Strains of a bacterium causing fasciation of sweet peas have been isolated from galls on Nicotiana glutinosa, asparagus, Heuchera sanguinea and Gladiolus in addition to the host plants reported in a previous paper. These four new strains all produced fasciation on inoculation into sweet‐pea seedlings.
Histological examination of sweet‐pea seedlings 2–11 weeks after inoculation showed that abnormal growth occurred in the hypocotyl region. In certain areas bacterial zoogloea formed a film on the outside of the tissue, and some penetration of bacteria into the epidermal cells, and in later stages into the intercellular spaces, was observed.
Reisolation tests confirmed the evidence from the microscopical examination, that the pathogen is mainly confined to the exterior of the tissue.
A comparison is made between the action of the sweet‐pea organism and Bad. tumefaciens in causing abnormal plant growths.
EXPERIMENTS ON THE RESISTANCE OF THE FLOUR MOTH (EPHESTIA KVHNIELLA ZELL.) TO ABNORMALLY HIGH TEMPERATURES
Authors: MANSBRIDGE G. H. 
Published: February 2008

SUMMARYExperiments are described on the resistance to heat of E. kühniella in all its stages.With eggs exposed to 45oC. (113o F.) and 47oC. (116‐5o F.) it is seen that:

One‐day‐old eggs are more resistant than older ones.
Eggs are more resistant to heat at low than at high humidities.
Eggs appear to be able to cool themselves at low humidities in a high temperature by the evaporation of water.
After heating, eggs can regain water they have lost if they are kept in a moist atmosphere.
After heating at low humidities, there is a bigger survival if the eggs are kept in a moist atmosphere than if they are kept in a dry atmosphere.
There is great variation in stock direct from a mill. Eggs from different pairs of moths may have widely different degrees of resistance.
Stock which has been inbred in the insectaries for twelve generations, shows less variation in resistance than stock direct from a mill.

Larvae are much less resistant than eggs. Newly hatched larvae and all larvae until they are full grown have about the same resistance. Last‐stage larvae are far more resistant than other larvae. Pupae are more resistant than feeding larvae. Adults are the most susceptible stage to heat. At low humidities the females are more resistant than the males.Experiments on all stages in undisturbed cultures show that a temperature of 45–46o C, maintained for 3 hours, kills all stages.This work was carried out under the direction of Prof. J. W. Munro, to whom I am grateful for his constant encouragement. I have to thank Mr G. V. B. Herford for his help in devising and constructing the apparatus and reading through the typescript, and I am also indebted to Dr 0. W. Richards for his helpful advice on many occasions, and to Mrs Richards who kindly supplied me with a highly inbred strain of E. kühniella. Lastly I thank Dr G. Fraenkel for many important suggestions, especially those contained in the discussion.
THE USE OF NUMBERS OF INFECTIONS FOR COMPARING THE CONCENTRATION OF PLANT VIRUS SUSPENSIONS: THE EFFECT OF CARBON ON THE PRODUCTION OF LESIONS BY VIRUSES OF THE TOBACCO MOSAIC GROUP
Authors: BALD J. G. 
Published: February 2008

SUMMARY

Tests were made of the spreading power of suspensions of plant juice, finely divided carbon, a commercial spreader, and water on leaves of Nicotiana glutinosa and paraffin wax surfaces.
The contact angle of the suspensions of the plant juice and the “spreader” was lower than that of water and suspensions of carbon.
When rubbed over the surface the plant juice and “spreader” gave good contact compared with the water, and the particles of carbon adhered to the surface carrying with them a film of water.
The effect of carbon and plant juice in raising the number of lesions when present in the inoculum may be explained by the better contact of the inoculum with the leaf surface.
Carbon in the form of lamp‐black caused an equal rise in number of lesions with purified suspensions of three viruses.
The same virus sample at a number of dilutions showed approximately equal rises in number of lesions in the presence of a uniform amount of lamp‐black. When the lamp‐black was diluted in the same ratio as the virus, the effect diminished.
The extent of the rise given by carbon was shown to be largely a function of the leaf tissues, probably of the nature of the leaf surface. Differences were observed between plants and between leaves of the same plant.
ANAEROBIC SPORE‐FORMERS IN GRASS AND GRASS SILAGE
Authors: ALLEN L. A. , HARBISON J. 
Published: February 2008

SUMMARYThe number of anaerobic spores in fresh grass appears always to be small but, in silage made from such grass, this group of organisms increases in numbers after the first few days until approximately 1,000,000 or rather more per g. are present, and these high numbers are maintained usually for several weeks. In silages made from young spring grass Clostridium sporogenes was isolated at all stages of ripening, and no other types were found in comparable numbers. In silage made from autumn grass, however, which had a considerably higher moisture content owing to inefficient drainage in the silos, and in silage made from similar grass to which various substances containing available carbohydrates had been added at the time of ensiling, strains of saccharolytic anaerobes were isolated in addition to Cl. sporogenes.
THE CHOCOLATE SPOT DISEASE OF BEANS (VICIA FABA L.) CAUSED BY BOTRYTIS CINEREA PERS
Authors: WILSON A. R. 
Published: February 2008

SUMMARYChocolate spot disease of broad and field beans in Britain is caused by forms of Botrytis cinerea. This disease should not be confused with the chocolate‐coloured lesions of Aphis injury, frost injury, mechanical injury, etc., and leaf spot (Cercospora Fabae and Ascochyta Fabae). All forms of Botrytis cinerea tested and some other species of Botrytis were capable of causing chocolate spot. B. cinerea will attack other species and genera of the Leguminosae, producing in some instances lesions similar to those of chocolate spot disease of beans.Chocolate spot infection is of two types, “aggressive”, causing blackening and death of part or the whole of the shoot system, and “non‐aggressive”, causing discrete or coalesced chocolate‐coloured lesions. The former type of attack is responsible for the greater part of the damage done by epidemics of the disease.Under suitable environmental conditions, there is a progressive increase in the total number of visible lesions over a period of at least 5 days after treatment with a suspension of Botrytis spores. When a dilute spore suspension is used “non‐aggressive” infection occurs. When a dense suspension is used, “progressive” infection results in “aggressive” infection: if, however, plants are removed after 24 hours to an environment unsuited to infection, the attack remains “non‐aggressive”While hyphae are abundant in the lesions of “aggressive” infection only a sparse mycelium is present in those of “non‐aggressive” infection.The maximum temperature for infection is about 30° C, the optimum about 20° C. and the minimum between +1 and ‐1° C. A water film is essential for infection, and any factors increasing the rate of evaporation of this film inhibit or decrease infection.The optimum conditions for “aggressive” infection are (a) the presence of large numbers of spores of the pathogen, (b) rain, (c) high humidity and rain to maintain the water film on the foliage for some days, (d) little or no wind and (e) a temperature between 15 and 20° C.Statistical treatment of data has established a correlation between rainfall and the severity of chocolate spot disease. Epidemics are correlated with abnormally heavy rainfall during the critical months of April, May, June and July.Spores of B. cinerea will remain viable on the leaf surface for periods of more than a month under adverse conditions.Any factor tending to weaken the crop, such as sour soil, potash and phosphate deficiency and waterlogging of the soil, renders it more liable to “aggressive” infection. In addition, chocolate spot disease appears to be favoured by a dense stand of beans and shelter from the prevailing wind.No economic method of control has been found. Care should, however, be taken to see that the crop is not weakened or in any way rendered more liable to attack.
THE BIOLOGY OF LEPTOBYRSA RHODODENDRI HORVATH (HEMIPTERA, TINGITIDAE), THE RHODODENDRON LACEBUG: FEEDING HABITS AND THE HISTOLOGY OF THE FEEDING LESIONS PRODUCED IN RHODODENDRON LEAVES
Authors: JOHNSON C. G. 
Published: February 2008

SUMMARY

Brief mention is made of the plants attacked by Leptobyrsa rhododendri Horv. and of the problem of immunity and susceptibility of rhododendrons to attack by the bug.
The methods and habits of feeding of L. rhododendri on rhododendrons are described. The principal feeding method consists in probing the leaf with the stylets and results in the production of a characteristic, whitish mottling on the upper leaf surface (lesion I). A less common feeding method, in which no probing occurs, often produces a brown spot (lesion II).
The character and histology of lesions I and II are described. Lesion I consists mainly of empty palisade cells with an occasional cell showing a similar reaction to saliva as cells in lesion II. Lesion II is composed mostly of unbroken cells which show a browning of the cell contents and the cell walls: apart from the change in colour, the cells in lesion II have, in sections, a normal appearance for at least 3 days after the production of the lesion. No stylet sheath is present in lesion I or lesion II. Toxic action of the saliva appears to play only a small part in the production of extensive damage, most of which results from the emptying of palisade cells (lesion I).
L. rhododendri is a mesophyll feeder and the object of the stylets is the palisade tissue of the leaf. Vascular bundles are only accidentally pierced and never become plugged as the result of salivary action.
Microchemical tests on the brown substance in lesion II are described.
Lesions very similar to lesion II can be made by scratching the surface of a rhododendron leaf with a needle. The production and spread of the brown area around a scratch is much slower than from the puncture made by a bug. The brown material in lesion II is probably produced by the oxidation of chromogens.
The lesions produced by L. rhododendri are discussed and compared with hemipterous lesions described by other workers.
THE USE OF LOGARITHMS IN THE INTERPRETATION OF CERTAIN ENTOMOLOGICAL PROBLEMS
Authors: WILLIAMS C. B. 
Published: February 2008

SUMMARYEvidence is brought forward that in comparing the numbers of insects caught under varying conditions, with particular reference to captures in a light trap, more consistent results are obtained if the geometric means are compared than by the use of arithmetic means. This is most conveniently done by summing the logarithms of the numbers instead of the numbers themselves. If any of the numbers in the series is zero it has been found practical to add one unit to all the captures in the series and so deal with log (n+1) instead of logn.The use of the logarithms prevents the swamping of the results in a series of observations by very high numbers on a single night. It also gives a more normal distribution of departures from a mean. As a result of the latter it is possible to apply the statistical formulae for standard deviation etc. which are not applicable to the skew curve obtained by the use of the departures of the numbers themselves from an arithmetic mean.
SOIL PROTOZOA; THEIR GROWTH ON VARIOUS MEDIA
Authors: DIXON ANNIE 
Published: February 2008

SUMMARYThe protozoan population of these tobacco soils were typical species generally found in soils. No soils were free of Protozoa, though very few were found in some of the lower depth samples and in the sandy soils.Though there was an indication that higher numbers of Protozoa were found in the chernozem soils, no definite connexion was observed between either the numbers of Protozoa or the species with the types of soil examined.The numbers generally showed a decrease with increasing depth of soil; there were a few exceptions to this.
STUDIES IN POTATO STORAGE: INVESTIGATION OF PHYSIOLOGICAL AND CHEMICAL CHANGES DURING THE DEVELOPMENT AND RIPENING OP POTATO TUBERS
Authors: SINGH B. N. , MATHUR P. B. 
Published: February 2008

SummaryAn attempt is made to correlate the stage of maturity of the tubers with certain characters in the ontogeny of the vines.Data obtained with regard to the physiological behaviour and the chemical composition of potatoes of different stages of maturity indicate the existence of three more or less distinct stages—adolescence, maturity and ripening—during the development of potato tubers.
BACTERIUM SALICIS DAY, THE CAUSE OF THE WATERMARK DISEASE OF THE CRICKET‐BAT WILLOW
Authors: DOWSON W. J. 
Published: February 2008

SummaryThe results of Day's original investigation of the watermark disease of the cricket‐bat willow have been, confirmed by repeated inoculations and reisolations of an organism agreeing with Bacterium salicis Day. The organism has been studied in pure culture and has been compared with a similar bacterium isolated from watermarked white willow from which it differs very slightly. The morphological, cultural and physiological characters of B. salicis are recorded and it is shown that in these respects B. salicis is closely akin to B. tracheiphilus and to a lesser degree to B. amylovorus.A new method is described for the determination of the optimum temperature for growth based upon acid production from sucrose.The author gratefully acknowledges his indebtedness to Prof. Brooks for his interest and helpful criticism throughout, to Mr W. R. Day for assistance in getting into touch with willow growers and to Mr J. Bryce for unstinted co‐operation in the field and for Fig. 1.
“ENATION MOSAIC” OF TOMATO CAUSED BY A VIRUS OF THE TOBACCO VIRUS 1 TYPE
Authors: AINSWORTH G. C. 
Published: February 2008

Summary“Enation mosaic” (caused by a strain of tobacco virus 1), a disease of tomato characterized by extreme leaf malformation and the development of leafy outgrowths from the undersides of deformed leaves, is described.An account of an investigation of the effects of environmental conditions on the symptoms of enation mosaic is given and the literature is reviewed and discussed.
THE ASPARAGUS MINER (MELAN AGROMYZA SIMPLEX H. LOEW) (AGROMYZIDAE; DIPTERA)
Authors: BARNES H. F. 
Published: February 2008

Summary

The history and identification of the asparagus miner. Melanagromyza simplex H. Loew, are outlined. The fly was described in 1869, and associated with asparagus in the United States of America in 1896 and 1897. In Europe it was recognized about the same date.
The salient points of the morphology of all stages are briefly described.
Its geographical range is the United States of America and Europe. In Europe it has been reported from Hungary, France, Germany and England. In U.S.A. the most numerous records are from the eastern states but it has also been reported from Iowa and California.
There are two generations a year at Harpenden, England. The flies of the first flight are on the wing from early June to the end of July, those of the second from the beginning of August until about the second week in September. Details of the life history are given.
The damage caused by the larvae mining the stems of asparagus is not considered important in cutting beds, although seedling beds might suffer more. When, however, the mining is followed by an attack by the larvae of Lonchaea flavidipennis Zett. the damage is more important.
An attempt to assess the local abundance of the flies by direct field observation is described.
Three parasites—the braconid, Dacnusa ?bathyzona Marsh.; a pteromalid, Sphegigaster sp.; and a eulophid, Pleurotropis epigonus Walk.—have been identified by Dr Ferriere and in addition an unidentified parasite has been reared. Brief observational notes have been given concerning these parasites. It is noted that Dacnusa rondanii Giard has previously been recorded as a parasite.
Control measures recommended by other workers have been mentioned.
THE HOLLYHOCK SEED MOTH (PLATYEDRA MALVELLA HÜBN.), TOGETHER WITH NOTES ON THE DISTRIBUTION OF APION RADIOLUS KIRBY AND AN ASSOCIATED GLINODIPLOSIS SPECIES
Authors: BARNES H. F. 
Published: February 2008

SummaryA survey has been made of the distribution of Platyedra malvella Hübn. in Great Britain and it has been found that the larvae are restricted on hollyhock to the south‐eastern counties of England. Apion radiolus Kirby and a gall midge Clinodiplosis species which are also found in the seed‐heads of hollyhock are generally distributed throughout England; the Clinodiplosis species also occurs in Wales and Ireland.The life cycle of Platyedra malvella has been described. There is only one generation a year. The moths are on the wing late in June until the beginning of August. The larvae feed on the seeds of hollyhock perforating the seeds characteristically. When full grown from the middle of August onwards, the larvae descend to the soil where they spend the winter in cocoons. In May the larvae become active again and tunnel through the soil. They spin up again towards the end of May and in June for pupation. The host plants are Althaea rosea, A. officinalis and there is at least one record on cotton.
THE INSECTICIDAL PROPERTIES OF SOME EAST AFRICAN PLANTS: MUNDULEA SUBEROSA BENTH.1 PART 2, CHEMICAL CONSTITUENTS
Authors: WORSLEY R. R. le G. 
Published: February 2008

SummaryA series of substances has been isolated from a sample of Mundulea bark consisting of rotenone, white crystals which are probably a mixture of l‐deguelin and tephrosin, yellow crystals which are probably dehydrorotenone, glucosides and alkaloids.Only the rotenone is appreciably toxic to aphides.The two sets of crystals having been obtained by use of alkali probably do not exist as such in the bark, but have been produced from a more toxic precursor, the existence of which must be assumed to account for the total toxicity of the sample.All attempts to isolate crystals other than rotenone without using alkali have failed completely.
AN INVESTIGATION INTO THE “STRIPE” DISEASE OF NARCISSUS
Authors: CALDWELL J. , JAMES A. L. 
Published: February 2008

SUMMARYThe wide variation in appearance of infected plants gives rise to the question whether the name “Stripe” is being applied to one or more diseases. The histological bases of the various types of symptoms are described, and it is shown that they are all produced by the same three factors acting with varying degrees of relative intensity.It is suggested that the disease is caused by a virus complex having at least three components. Inclusion bodies in the cells of diseased plants are described which resemble the X‐bodies associated with some virus diseases.This investigation is being carried out under the auspices of the Agricultural Research Council.
INFECTION EXPERIMENTS WITH CLADOSPORIUM FULVUM COOKE AND RELATED SPECIES
Authors: BOND T. E. T. 
Published: February 2008

SUMMARY1. Symptoms of infection on resistant and susceptible varieties of tomato (Lycopersicum esculentum Mill.) are briefly indicated, together with a numerical method of recording the progress of infection.2. The histology of infection on tomato varieties is described. Penetration is stomatal and no appressoria or other modifications are formed. The mycelium is intercellular and without haustoria, and develops normally only for so long as the host cells are alive.3. By the use of a controlled environment chamber, the frequency of penetration is shown to be far greater at a humidity fluctuating from saturation to 85 % than at constant saturation. The suggestion is made that penetration is controlled, in part at least, by a hydrotropic stimulus.4. The initial rate of spread of the mycelium within the host, immediately subsequent to penetration, is lower in the variety “Mainerop” than in “Giant Red” and is lower also in the basal region of the plant than in the middle. This behaviour runs parallel with the subsequent differences observed in the external symptoms of infection.5. Normal stomatal penetration occurs over a wide range of immune and “inappropriate” hosts.6. Symptoms of infection have been recorded only in the varieties of L. esculentum, in L. Humboldtii Dun., and in two strains received as L. racemigerum which, appear to be more closely related to the cultivated varieties than, to the true currant tomato.7. Confusion occurs as to the correct nomenclature of the currant tomato. The name Lycopersicum pimpinellifolium Mill, is preferred. L. racemigerum Lange (=Solanum racemigerum) and L. racemiforme Lange are synonyms.8. The extent and distribution of the mycelium in the currant tomato appears to be determined largely by the age and relative maturity of the leaf. The mycelium is intercellular and without haustoria, and can apparently remain alive in the leaf for a considerable period of time. No conidiophores are produced. No reaction of the host cells is observed except where, on account of structural considerations, host and parasite are brought into more immediate contact. Here, individual host cells are frequently necrotic.9. On many other Solanaceae, including species of Solatium, Hyos‐cyamus, Nicotiana, Schizanthus, and other genera, the course of events is essentially similar to that observed on the currant tomato.10. In other Solanaceae, and in plants belonging to the Scrophu‐lariaceae, Compositae, and Cucurbitaceae, an extensive mycelium is never developed, even under apparently favourable conditions.
STUDIES OF THE MOSAIC DISEASES OF CASSAVA
Authors: STOREY H. H. , NICHOLS R. F. W. 
Published: February 2008

SUMMARYThe symptoms of mosaic disease in cassava, although generally typical of the mosaic group, show wide variations, due in part to the varietal reaction of the plant, to its stage of development and to the environment. The most important cause of variations however is differences in the strains of the virus, of which we have recognized, through the study of symptoms, two groups of severe and mild strains.The viruses are transmitted across a graft, but we have failed to obtain mechanical transmission by needle or hypodermic injection.A Bemisia sp. can transmit both groups of strains. It can inoculate the plant only through immature leaves, less than about one‐quarter of their full length. The virus so inoculated does not pass out of the leaf until about 8 days have elapsed. On the basis of this knowledge a convenient and reliable single‐leaf cage technique has been developed.After the virus has entered the stem it passes rapidly to the base of this stem, but odp slowly into side branches from it or into other stems arising from the same original cutting.Infection of a plant with a mild strain of virus failed entirely to confer immunity from infection by severe strains introduced by grafting. If the severe strains were inoculated by insects there was an indication of some conferred resistance but insufficient to make the procedure practically useful in control.