bluuebunny/crossref_metadata_2025_split huggingface dataset:
The biology of Earias biplaga Wlk. (Lep., Noctuidae) on Theobroma cacao in Western Nigeria
Authors: Entwistle P. F. 
Published: July 2009

Earias biplaga Wlk. has been recorded to attack Theobroma cacao from the Ivory Coast to the Congo (Léopoldville) and also in San Thomé and is the only species of the genus to do so in Africa. Attack is most serious on seedlings in the field as the apical buds are destroyed.Eggs are laid on the stem mainly, especially on leaf bracts. The first half of the larval period is passed within the apical bud and the last half in feeding on unhardened flush leaves, or, in their absence, in burrowing down the stem below the apex or in devouring the epidermis of the upper stem.The length of the larval and pupal periods is inversely related to the mean maximum temperature; they are shortest in the dry season and longest in the wet season.Differences between the sexes exist in the wing coloration, and in the shape of the labial palps, the last segment of which is much longer in the female than in the male. The dry-season form, which has the forewings suffused with golden brown in the female and with yellow-green in the male, instead of the wet-season green, occurs from January to March in the region of Ibadan, Western Nigeria.The adults are largely nocturnal and they are attracted to ultra-violet light.Adults lived longer in the laboratory on a diet of sucrose in water (males, on average, 17 days and females, 28 days) than on water alone or without either. A mean of 95 eggs per female was recorded from sucrose-fed adults in the laboratory and the greatest number of eggs laid by a single female was 461. The peak period of oviposition was the fourth to fifth day after mating (fifth to sixth after emergence). A method of rearing E. biplaga in the laboratory is described.Six alternative host-plants in Nigeria, all in the Malvales, are listed, and one, Hibiscus esculentus, is a locally important food crop. Nine Hymenopterous parasites were found to attack E. biplaga in Western Nigeria, the most important being Trichogramma luteum (Gir.) which attacks the eggs, destroying over 90 per cent, of them at certain times of the year. All the other parasites, with one possible exception, appeared to attack only the larval stage of the host.
Scarab damage to grass and clover as influenced by depth of feeding
Authors: Davison R. L. , Roberts R. J. 
Published: July 2009

Third-instar larvae of Rhopaea morbillosa Blkb. (Melolonthinae) were maintained at fixed depths between wire-mesh screens in earthenware pots during a 12-week factorial experiment designed to study the relationship between depths of feeding and damage to roots and foliage yield of Lolium perenne and Trifolium repens under two soil-moisture treatments (10% and 20%), with and without fertilisers.Depth of feeding had a highly significant effect on relative root damage and foliage yield, and at all depths (18, 14, 12, 1, 2, and 4 in.) significantly greater root damage occurred under conditions more favourable for pasture growth.Ryegrass was deeper rooted and suffered more damage than clover. The degree of non-linearity of root distribution with depth affected damage to roots at all depths so that species in mixed swards should suffer damage in proportion to their deep-rootedness.It is clear that depth of feeding can confound experimental studies of damage by scarab larvae, and in the field it will influence the damage caused to pastures.
A survey of the Arthropod fauna of plum trees at East Malling in 1966
Authors: Ward Lena K. 
Published: July 2009

In an investigation of the fauna of plum at East Mailing Research Station in 1966, over 70 species of the commoner arthropods were listed.Different species of mite were found to prefer different parts of the tree, different parts of the leaf, and leaves of different ages on a shoot. Aculus fockeui (Nal. & Trt.) (Eriophyidae) was found to spread up the shoots during the early summer and to attain a density of over 100 per sq. cm. of leaf surface. Panonychus ulmi (Koch) was found to be commoner to the east of the tree, and leaf damage that it caused graded in severity across the plot. The species composition of populations of the Phytoseiid mites could differ markedly between trees in the same plot.A study of the population trends of the commoner species based on numbers per shoot revealed that the populations of aphids and their predators developed two peaks during the season. There was a relatively high incidence of Entomophthora infection on the aphids, and overwintering fungal spores were produced when the aphids died in crevices on the bark, but only short-lived cornidia when they died on the leaves. The population density of member species of the fauna varied considerably, the smallest phytophagous mites reaching levels of 200 per shoot, predacious mites 10.0 per shoot and predatory bugs such as Blepharidopterus angulatus (Fall.) only about 0.01 per shoot.
Prediction of outbreaks of coffee leaf-miners on Kilimanjaro
Authors: Bigger M. , Tapley R. G. 
Published: July 2009

Analysis of the results obtained from suction-trap catches of the coffee leaf-miners, Leucoptera meyricki Ghesq. and L. caffeina Wshbn. on an unsprayed block of coffee at the Coffee Eesearch Station, Lyamungu, on the slopes of Kilimanjaro, are given.By thermal summation methods it was possible to delimit successive generations of moths with some degree of accuracy and the generation catches were used for regression analysis with various meteorological factors. With L. meyricki, a negative correlation was shown between the rate of increase from one generation to the next and with both maximum and mean daily temperature, solar radiation and duration of sunshine taken as means over the period of each generation. In each case, the highest degree of correlation was found between the meteorological data in one generation and the rate of increase in the next.When the generation catches were plotted on a logarithmic scale it was found that linear regression lines could be fitted to the periods of both rise and fall of the annual outbreak. With L. meyricki, the rate of increase of the rise was negatively correlated with, and the rate of decrease of the fall positively correlated with, the size of the generation present at the beginning of the outbreak. It is therefore possible, knowing the size of the minimum generation, to predict the size of the coming outbreak. No such relationship could be proved with L. caffeina, probably because the catches of the key generations were very small, but when the catches of the two species were pooled the same relationship held. It is probable that parasites are the main factor governing the annual fluctuations.
Group effects on feeding in adult males of the desert locust,Schistocerca gregaria(Forsk.), in relation to sexual maturation.
Authors: Norris Maud J. 
Published: July 2009

It has previously been shown that the sexual maturation of males ofScliistocerca grcgaria(Forsk.) is accelerated by crowding with other individuals of similar or greater age, and that the maturation of males kept in single pairs with older mature males is accelerated as compared with that of isolated males or males kept in single pairs with other young males or females of their own age. The effects of these groupings on the levels of feeding and excretion are investigated in the present work.Crowded males ate and excreted more than isolated ones during the first ten days of adult life. Five males in a 9-litre cage are sufficient to induce almost the full effect of crowding, and marked effects are shown when only two males are present in such a cage.After the second or third week, the level of feeding declines. This occurs earlier in early-maturing individuals, so that for a short period the crowded males eat little more or even less than the isolated ones. When the isolated males in their turn become mature their feeding again falls slightly below that of the crowded ones. When all males are isolated, there is a significant tendency for those males which eat least from the beginning of adult life and which increase their weight least to become mature earliest.The proportion of the food utilised was not affected by density. It was higher during the early period of maximum consumption than it was after the level of feeding declined.
Studies on the bionomics of the jute stem girdler, Nupserha bicolor postbrunnea Dutt (COL., LAMIIDAE).
Authors: Dutt N. 
Published: July 2009

Nupserha bicolor postbrunnea Dutt has become established on olitorius jute (Corchorus olitorius), possibly from its wild food-plant, Sesbania aegyptiaca, and from jute it has spread to other agricultural crops. Incidence on the green-manure crop, Sesbania bispinosa, has increased so much in recent years that it has surpassed that on olitorius jute. The stem diameter most favourable for girdling and oviposition in S. bispinosa ranges from 3·1 to 5 mm., whilst in C. olitorius it is from 2·6 to 3 mm. In spite of this wide difference in preferred stem diameter, the ratio of mandibular length to depth of extra-medullary tissue of such stems in the two plants agrees well.All the varieties of capsularis jute (C.capsularis) are unacceptable to the adults though they are acceptable to the larvae. Adults obtained from larvae reared on varieties of capsularis jute also show aversion to capsularis types. The pest selects the susceptible olitorius from amongst capsularis jute when these are grown as a mixed crop. Amongst the olitorius varieties, C.G. is the most susceptible. Plants coming within the height range of 100 to 200 cm. are attacked more than others. Girdling causes suspension of unidirectional vertical growth, and this is followed by the appearance of a number of side branches, which are of little value from the point of view of fibre.
The variability of fly-round catches in field studies of Glossina.
Authors: Glasgow J. P. 
Published: July 2009

In an attempt at some assessment of the errors to which fly-round data obtained for the study of populations of Glossina are subject, three fly-rounds at Shinyanga, Tanganyika, were worked every weekday for four weeks. The species studied was G. swynnertoni Aust. One of the rounds was a ‘transect fly-round ’, the others, the older type, divided into a few long sections according to the vegetation. The catches showed no obvious trend during the experiment, suggesting that the true population had not altered in the period, but in all three rounds there were considerable day-to-day variations in catch and, in this respect, the transect fly-round did not differ from the older method. An analysis of variance of the transect fly-round data showed that the variance between days was greater than could be accounted for by random errorsBy considering separately the data collected on certain days of the week, it is concluded that a 7,500-yd. fly-round done once a week could not detect less than a five-fold change in the mean catch. To detect a two-fold change, a 15,000-yd. fly-round done twice a week would be necessary.The relation between fly-round catch and true density is discussed. This relation is usually termed ‘ availability ’. Earlier workers have shown that its mean value, over periods of about one month, is not necessarily constant; the present work shows that it varies in one place from day to day.
Insecticidal operations against Chironomid midges along the Blue Nile.
Authors: Brown A. W. A. , Mckinley D. J. , Bedford H. W. , Qutubuddin M. 
Published: July 2009

In 1956 and 1957, tests were made in the Sudan Eepublic of four methods of applying insecticides for the control of heavy infestations of midges, particularlyTanytarsus lewisiFreeman, which breed in the Blue Nile. During the winter season the adults occur in myriads in areas adjacent to the river in Khartoum and similar localities, resting in trees and shrubs by day and being attracted to artificial lights after duskAn emulsion containing 0·4 per cent. DDT applied from the ground to shadetrees in Khartoum at the rate of 0·5·1·0 lb. DDT per tree achieved local control of the midges for three days and detectable reduction for 10 days. An emulsion containing 12·5 per cent. DDT applied from an aircraft to the wooded riverfrontage at Khartoum at 2·1 lb. per acre reduced the numbers of adult midges for the next 15 days, but subsequent applications under conditions of greater air turbulence were ineffective.The application of DDT as a larvicide in oil solution from aircraft to the river 10 miles above Khartoum, at a concentration approximately equivalent to 0·1 p.p.m. in 2 hours' riverflow, did not appear to reduce the numbers of adults or immature stages at Khartoum, and was followed by some mortality of fish.
The eradication of Glossina morsitans submorsitans Newst. and Glossina tachinoides Westw. in part of a river flood plain in Northern Nigeria by chemical means. Part II.
Authors: Kirkby W. W. , Blasdale P. 
Published: July 2009

A stretch of river with its flood plain, a habitat of Glossina morsitans submorsitans Newst. and G. tachinoides Westw. in the Sudan savannah zone of Northern Nigeria, which is an important cattle-raising area, is described.An effective technique for the eradication of both species of tsetse has been developed, using a single application of a 5 per cent, aqueous suspension of DDT by knapsack sprayer in the places of dry-season concentration of the fly, and on the principal midday resting sites, viz., between ground-level and a height of 5 ft. on tree trunks greater than 6 in. in diameter.
Insecticide studies on the maize stalk borer, Busseola fusca (Fuller), in East Africa.
Authors: Walker P. T. 
Published: July 2009

Trials in East Africa (chiefly in Tanganyika) are described to show that the time taken for first-instar larvae of Busseola fusca (Fuller) to reach the more closely packed young leaves in the central axis of the maize plant is about ten days, and that insecticides are effective up to the end of this period. Results show that the best time for control is as near hatching of the eggs as possible, but with more persistent insecticides such as endrin, economic control is possible up to five days later.A method of testing insecticides as residual deposits, by allowing first-instar larvae to walk on them, is given, and it was found that isodrin, DDT, endrin and γ BHC are highly effective as residual films. The MLD's for one minute in contact are 1·8 mg./sq.m. for isodrin, 4–7 mg. for DDT, 8·3 mg. for endrin and about 20 mg. for γ BHC. Derris emulsion has no residual effect after drying and is only effective in the liquid state after contact with larvae for several minutes.In a series of field trials over three years, increases in yield of up to 2·6 times the control yields were shown to be possible, and averaged twice the control yield. Endrin was the most consistently effective insecticide, applied as a 2 per cent, dust and as a 0·03–0·04 per cent, emulsion spray. Two applications of endrin at an interval of two weeks were effective, but, for DDT, three applications of an emulsion containing 0·05 per cent. DDT at nine-day intervals were more effective than two while one may be of little value. An application of 2·5 oz./acre of DDT can be effective for 7–10 days, while 1·5 oz./acre of endrin can be effective for 14 days. In general, however, rates per application should not fall below 3·5 oz. DDT or 2 oz. endrin per acre, overall.The superiority of a 5 per cent. DDT dust over one of 2·5 or 1 per cent, makes it more economical in a high-yielding, heavily attacked area. Diazinon and malathion in emulsion sprays are less persistent than DDT.Trials with 4 per cent, malathion dust and 0·15 per cent, malathion emulsion spray were inconclusive on account of heavy damage by Spodoptera sp.Attempts to increase the persistence of malathion and γ BHC by the addition of chlorinated terphenyl resins were also inconclusive, but DDT in emulsion, with resin, appeared more effective than DDT alone.The economics of successful control measures at the prices obtaining at the time are discussed under the various trials.Chemical estimations of the deposits of insecticides retained on the plants showed that between 1·4 and 3·7 per cent, of the quantity applied per unit area can be recovered in this way.In a discussion of the significance of the results in control, it is suggested that spraying the stems only is half as effective as spraying the whole plant.The conditions and results relating to two aerial spray trials are given.The place of control of Busseola in agricultural practice is described, and some of the present results are quoted to show that yields can be increased by good farming practice as much as by control of Busseola.
A thermal preference method of bioassay of the toxicity of insecticidal films to house-flies.
Authors: Ward J. , Gillham E. M. , Potter C. 
Published: July 2009

Methods that have been used to confine insects to the test surface during exposure to insecticidal deposits are briefly reviewed, and their limitations are discussed. Some unsuccessful preliminary experiments on alternative methods are mentioned.A temperature-preference method of inducing house-flies, Musca domestica L., to remain on a treated surface is described, and the apparatus is illustrated. The treated surface forms the floor of a chamber; it is maintained at a higher temperature than the walls and lid. The flies are introduced by means of a plunger device.
Phase Variation and Rate of Development in the Algerian Race of the Migratory Locust (Locusta migratoria, L.)
Authors: Uvarov B. P. , Hamilton A. G. 
Published: July 2009

1. The Algerian race of Locusta migratoria, L., although never known to occur in the gregarious phase in nature can be transformed into almost typical ph. gregaria by breeding in crowded cages.2. Biometric characters of such individuals indicate a relationship of the Algerian race to the subsp. migratoria, but the data are insufficient for a final decision on this point.3. The rate of embryonic and hopper development in the Algerian race is the same as in the tropical African subsp. migratorioides when bred at the same temperature and relative humidity.4. The rate of sexual maturation is very much slower in the Algerian race than in the tropical one bred under the same conditions.
On the control of Household Ants
Authors: Thompson H. W. , Johnson L. R. 
Published: July 2009

1. Methods of controlling ants invading houses are discussed.2. Various methods have been tried, particularly against Monomorium pharaonis. The more general methods in use such as syrup baiting and the use of various insecticidal powders and sprays show at best a palliative effect and do not exterminate the pest. Destruction of the nest is effective where it can be carried out.3. The use of a thallium sulphate-syrup as a poison bait devised by Popenoe has been tried with success against M. pharaonis and A. (Donisthorpea) niger. This inexpensive method is likely to prove useful in places where it is not practicable to find and destroy the nest, which invariably involves considerable structural alterations.
The physical Ecology of Microplectron fuscipennis, Zett. (Hym. Chalc.)
Authors: Ullyett G. C. 
Published: July 2009

1. The influence of atmospheric humidity on the various stages in the life-cycle of Microplectron fuscipennis, Zett., is examined. Both the longevity of the adults and the extent of oviposition are found to be proportional to the saturation deficiency of the atmosphere. Under favourable temperature conditions, functional activities are at their maximum in a moist climate, but a wide tolerance is exhibited so far as oviposition is concerned. At normal humidities no effect on the developmental period of the parasite is apparent when the humidity is varied, and this is shown to be due to the protection afforded by the host cocoon.2. Temperature affects the parasite in a normal manner. The threshold of development is approximately at 8·3°C., and the zone of functional activity is from 15° to a little over 35°C. Optimum conditions for oviposition and development occur between 20° and 35°C. Death occurs at 40°C., while at the lower temperatures, near freezing point, starvation of adults takes place after a lengthy exposure. The hibernating parasite can withstand temperatures very much below freezing point, field records coming from countries where the winter temperature falls to so little as −37°C.3. The relation of Microplectron to climate is discussed and an explanation is offered of the wide variation in natural parasitism occurring in European countries.4. The actual and possible distributions of the parasite in Europe are discussed and a map is presented depicting the position as known at present.5. The possible distribution of the parasite in North America, after liberations have been made, is dealt with and it is shown that the present trend of dispersal of Diprion polytomum is in the direction of climatic conditions that are more favourable to the parasite than are those in the area where the parasite has already become established.
Fissure fills along faults: Variscan examples from Gower, South Wales
Authors: WRIGHT V. , WOODCOCK N. H. , DICKSON J. A. D. 
Published: July 2009

AbstractThe extent to which persistent, rather than transient, fissures (wide planar voids) can exist along upper crustal faults is important in assessing fault permeability to mineral and hydrocarbon-bearing fluids. Variscan (late Carboniferous) faults cutting Dinantian (Lower Carboniferous) limestones on the Gower peninsula, South Wales, host clear evidence for fissures up to several metres wide. Evidence includes dendritic hematite growth and elongate calcite growth into open voids, spar ball and cockade breccia formation, laminated sediment infill and void-collapse breccias. Detailed mapping reveals cross-cutting geometries and brecciation of earlier fissure fills, showing that fissures were formed during, rather than after, active faulting. Fissures therefore probably formed by geometric mismatch between displaced fault walls, rather than by solution widening along inactive faults.
Information, Trading Volume, and International Stock Return Comovements: Evidence from Cross-Listed Stocks
Authors: Gagnon Louis , Karolyi G. Andrew 
Published: July 2009

AbstractWe investigate the joint dynamics of returns and trading volume of 556 foreign stocks cross-listed on U.S. markets. Heterogeneous-agent trading models rationalize how trading volume reflects the quality of traders’ information signals and how it helps to disentangle whether returns are associated with portfolio-rebalancing trades or information-motivated trades. Based on these models, we hypothesize that returns in the home (U.S.) market on high-volume days are more likely to continue to spill over into the U.S. (home) market for those cross-listed stocks subject to the risk of greater informed trading. Our empirical evidence provides support for these predictions, which confirms the link between information, trading volume, and international stock return comovements that has eluded previous empirical investigations.
Welfare, Asylum and the Politics of Judgment
Authors: MORRIS LYDIA 
Published: July 2009

AbstractThis article examines 14 judgments over a ten-year period of challenge to the removal of welfare support from ‘late claimers’ for asylum. The case history spans a period of transition in Britain from the general principles of the Common Law to the implementation of the Human Rights Act (HRA) (Home Office, 1998), but indeterminacy is to the fore in such a developing area of law, allowing considerable scope for judicial interpretation. The focus of this article is therefore the cumulative dynamic of the judgments, their strategic delivery and their policy impact. The analysis demonstrates the force of general principles in yielding a solution, while also providing evidence of judgment as political dialogue over competing visions of society.