bluuebunny/crossref_metadata_2025_split huggingface dataset:
The development of Monoctonus paludum Marshall (Hym., Braconidae) in Nasonovia ribis-nigri on lettuce, and immunity reactions in other Lettuce Aphids
Authors: Griffiths D. C. 
Published: July 2009

Aphids belonging to the species Nasonovia ribis-nigri (Mosley), Aulacorthum circumflexum (Buckt.), Macrosiphum euphorbiae (Thos.), Myzus persicae (Sulz.) and A. solani (Kalt.) were exposed to attack by the parasite, Monoctonus paludum Marshall, and were sectioned and dissected at various time-intervals after attack in order to observe the developmental processes of the parasite.The egg was always laid in the posterior mass of fused ventral nerve ganglia in the thorax of the aphid host.The development of the parasite in N. ribis-nigri, its normal host on lettuce, is described.In the species A. circumflexum the development of the parasite was arrested after approximately 24 hours by the secretion around it of a thin brown capsule formed by certain of the host's blood cells.In the other three species, Macrosiphum euphorbiae, Myzus persicae and A. solani, no capsule formation occurred. The development of the parasite embryos was rather variable in these but it was common for parasites in Macrosiphum euphorbiae to reach the stage normal for 24-hour embryos and for parasites in Myzus persicae and A. solani to reach stages rather less advanced than this before degenerative changes set in.The degenerative changes in the parasite embryos are described for each species of aphid and the nature of these changes is discussed.
Studies of the sampling of Glossina pallidipes Aust. I.—The numbers caught daily on cattle, in Morris traps and on a fly-round
Authors: Smith I. M. , Rennison B. D. 
Published: July 2009

Two experiments in which G. pallidipes Aust. was caught on oxen, in Morris traps and on a fly-round in south-eastern Uganda are described.Fewer flies were caught in traps than on oxen, but the former took a higher proportion of females. The numbers in traps covered with natural-coloured hessian tended to be greater than in traps on which the hessian was painted black. A white ox attracted fewer flies than darker-coloured oxen, among which a red ox was the most attractive. Variations reflected in day and site effects indicated that the sexes were differentially affected by the factors controlling availability to the oxen and the traps. Fly-round data appeared to give an unsatisfactory estimate of the population density.The numbers caught by the various methods were, in general, not correlated and this casts doubt on the validity of fly-round or trap data as estimates of the number of G. pallidipes likely to attack cattle.
Studies of the sampling ofGlossina pallidipesAust.—II. The daily pattern of flies caught on cattle, in Morris traps and on A fly-round
Authors: Smith I. M. , Rennison B. D. 
Published: July 2009

A series of catches ofG. pallidipesAust. was made in 1½-hr. periods between 0800 and 1830 hr. each day during two experiments carried out in the early wet season (1957) and the late dry season (1958), at Lugala, Uganda, using tethered, small, shorthorned East African Zebu oxen, Morris traps and the standard flyround technique.Flies were attracted to the oxen in greater numbers in the morning and evening than at midday, the evening increase being marked in the wet season. The daily catches of both sexes on oxen, though starting at much the same level in both seasons, fell to lower levels at the hotter times of day during the dry season and rose only slightly in the evening. Traps, on the other hand, in both seasons caught most females between 1230 and 1400 hr. and least in the mornings. Male flies were trapped in greatest numbers between 1400 and 1530 hr. in the wet season, but only in comparatively small numbers at any time in the dry season, though there was a suggestion of maximum availability between 1100 and 1230 hr. during the latter. During the dry season, catches on the fly-round and on oxen showed a similar periodicity in the case of females, but not in that of males, fly-round catches of which declined from a peak at 0930–1100 hr.
Problems in the Assessment of Tsetse Populations
Authors: Morris K. R. S. 
Published: July 2009

SummaryA detailed tsetse-fly survey of 41,000 sq. miles in the inland savannah zone of the Gold Coast (Ghana) was completed in five years using an entirely African staff and working only six months each year.This undertaking was made possible because studies of the species of Glossina concerned, G. palpalis (R.-D.), G. tachinoides Westw. and G. morsitans sub-morsitans Newst., had provided knowledge of their habitat, food-hosts and activity rhythm, on which could be based a standard yet simple survey technique, within the compass of independent native teams.The restricted activity rhythm of the flies, subject to both daily and seasonal variations, meant that nothing less than a ‘day’ of eight hours of observation could be accepted as a valid sampling unit.With tsetse flies at low densities, a day's search was inadequate, giving only 40 per cent, reliability compared with 6-day observations. Four days' search gave 90 per cent, reliability and was adopted as the minimum period of search.Each survey team was under the charge of a Kecorder or Field Assistant, with fly-boys devoting the whole of their time to catching. Comparability of survey data was ensured by keeping teams to the same size, two fly-boys being the optimum, since it was found that the size of the catch was not always proportionate to the number of boys, the relationship varying according to a variety of factors.In surveying G. palpalis and G. tachinoides the ‘picket’ system of more or less stationary teams, measuring their catches by the ‘day ’, was found overwhelmingly superior to the ‘fly-round’ technique.The survey procedure described for savannah woodland country was not effective in sampling G. nigrofusca Newst. in the Ashanti forest or G. longipalpis Wied. in the coastal savannah, but Morris's ‘animal’ traps were found to take both species readily in places where they had not been detected or only occasionally caught by fly-boys. Experiments showed that trap catches were superior, both numerically and in giving a more representative sample of the tsetse population present. It was also shown that trapping could be a valuable means of studying the biology of these two ‘man-shy’ species of Glossina. Traps were also effective in taking G. pallicera Big. and G. medicorum Aust.The greater value of traps compared with fly-boys as a means of sampling various species of tsetse fly is discussed, and suggestions are put forward for developing trapping as a method of survey.The type of trap employed is regularly catching insects of several other families, including a number of species among the Tabanidae, and of several other orders.
The population dynamics ofCryptolestes ferrugineus(Stephens) (Col., Cucujidae) in flour and on Manitoba wheat
Authors: Ashby K. R. 
Published: July 2009

SummaryIf adults ofCryptolestes ferrugineus(Steph.), of which the females have already been fertilised, are cultured on flour at low densities, the rate of oviposition is independent of the density of adults and juvenile mortality is negligible. At high densities there is a heavy mortality amongst eggs and young larvae, and there is evidence that, providing no great degree of conditioning of the medium has occurred, an equilibrium is reached with the number of eggspluslarvae present at any time being independent of the density of adults. Cannibalism is undoubtedly a major cause of the juvenile mortality under these conditions. Where crowding of adults is so great that conditioning of the medium becomes important, the number of eggs plus larvae present at a given time after the cultures have been set up decreases with increasing density of adults, there being some indication of an inverse linear relation.Cultures ofC. ferrugineuson a mixture at 70 per cent. R.H. of sound grain and grain already slightly damaged byCrypiolestesare capable of initiating dense infestations in the laboratory, at least at moderate and high temperatures. Under optimal conditions the infestations develop within 15 days. Values deduced for the pre-adult period at various temperatures were similar to those obtained by Rilett (1949). At 17°C., development was extremely slow but the low temperature did not increase mortality. Cannibalism and competition by adults and fully developed larvae appear to play an important part in limiting the production and survival of the juvenile stages.Sound grain at 70 per cent. R.H. is unsuitable as a medium for culturingCryptolestesin the laboratory but it becomes suitable after relatively small additions of flour and damaged grains. At 33°C. at least, a point is suddenly reached where an infestation is initiated, the critical feature being increased survival of larvae rather than an increase in the number of eggs laid. An increase in humidity has a similar effect to adding food.Estimates of the production of CO2at various temperatures gave values higher than previously reported. From 21 to 33°C. the rate of increase of the respiration rate and the increase in the speed of development are proportional to rise in temperature. This is in accord with other indications thatC. ferrugineushas a high optimum temperature.
Experiments on the control of frit fly,Oscinella frit(L.), on late-sown oats with seed dressings and ‘late’ sprays
Authors: Legowski T. J. , Gould H. J. 
Published: July 2009

In plot trials with seed dressings on late-sown oats against shoot attack by frit fly,Oscinella frit(L.), chiefly near Cambridge, England, γ BHC, parathion, dieldrin, heptachlor, Rogor and WL 1650 (Telodrin) (1,3,4,5,6,7,8,8-octachloro-3a,4,7,7a-tetrahydro-4,7-niethanophthalan) (dry and wet) reduced the attack but the effect was variable and for the most part not appreciable.In 1952 and from 1956 to 1960, trials were made on the effect of late sprays of various insecticides applied to late-sown oats when symptoms of frit-fly attack were already conspicuous and sometimes severe. An advantage of this type of treatment over preventive sprays is that it ensures that the treatment is applied only where and when necessary. Single sprays of parathion, dieldrin, γ BHC and Rogor prevented or markedly reduced further attack and they were most effective when applied within about 15 days of the beginning of egg-laying and when plants were in the young seedling stage. Compared with the best treatment of two early preventive sprays of DDT there was only a slight reduction in yield. Parathion and to lesser extent γ BHC killed many larvae inside the shoots and probably prevented others from entering the shoots.
The control of the coconut pest Melittomma insulare (Coleoptera, Lymexylidae) in Seychelles.
Authors: Nye I. W. B. 
Published: July 2009

The larvae of the Lymexylid beetle, Melittomma insulare Fairm., bore into the bases of coconut palms. Associated with them are micro-organisms which cause extensive rotting of the bole, particularly at ground-level, and this results in the palm falling.During 1953–58, an attempt was made in Praslin Island, Seychelles, to obtain maximum control of this pest using paradichlorobenzene as a fumigant. At the time of this treatment, 77 per cent, of the 90,500 coconut palms in the island were infested. Of these, about five per cent, were felled as worthless mountainside palms and nine per cent, fell during or within a week of treatment.In 1960 it was found that a further 15 per cent, of the palms had fallen and of those still standing 53 per cent, remained infested. The continuing high loss of palms after treatment was due to the closed, moist fumigation chambers within the trunks encouraging the spread of rot, coupled with an incomplete kill of larvae.A new method of treatment is described in which the necrotic wood is excised and a formulation of coal tar creosote and coal tar liberally applied. Praslin Island was retreated, using this tar method, and a plan to treat all the coconut palms in Mahé, the main island of the group, was subsequently commenced. Losses of palms during and within a week of treatment have been reduced to less than one per cent., and results are quoted which show that a single treatment can reduce a serious infestation in which 80 per cent, of palms are more or less heavily attacked to one in which only 18 per cent, of the palms are attacked and, on average, contain only five larvae. The treatment ensures that the entrances to the tunnels of these are exposed to view, and accordingly the surviving larvae can easily be killed.
A morphological study of variation in Tyrophagus (Acarina), with particular reference to populations infesting cheese
Authors: Robertson Phyllis L. 
Published: July 2009

The difficulty of deciding the systematic status of variations within and between populations of Tyrophagus is considered in relation to the wide distribution of the genus and the many materials it infests.Variation within populations of what was thought to be one species infesting cheese is explained by the isolation of three closely similar forms which it is difficult, if not impossible, to separate by measurement alone. Frequency distributions overlap slightly for four linear measurement ratios on which separation is attempted, but differences between them are emphasised by differences in minute structural characters and they are therefore accepted as distinct species, identified as longior (Gervais, 1844), palmarum Oudemans, 1924, and putrescentiae (Schrank, 1781).Variation between populations attacking plant materials and other stored products in addition to cheese is accounted for to some extent by the recognition of three further Tyrophagus species, oudemansi Robertson, 1959, brevicrinatus Robertson, 1959, and tropicus Robertson, 1959.Within the species recognised, significant differences are recorded in dorsal hair characters and body proportions between populations on cheese produced in different geographical areas, and also between cheese populations and those infesting other materials, and these differences are thought to be at a racial level.T. longior, T. palmarum and T. putrescentiae are found to be distributed around the world, but as cheese pests they occupy somewhat different, although overlapping, geographical zones, since longior is a temperate-to-cool form, palmarum a temperate form and putrescentiae a subtropical or tropical form. The three are also found to occupy different, but overlapping ecological zones, making possible their association in mixed populations.Confusion in ecological data previously published on Tyrophagus is thought to be attributable in part to similarities in the morphology, geographical distribution and ecology of its species, and to their close association.
The susceptibility of tsetse flies to topical applications of insecticides. I.—Young adults of Glossina morsitans Westw. and chlorinated hydrocarbons
Authors: Burnett G. F. 
Published: July 2009

Solutions of six chlorinated-hydrocarbon insecticides in kerosene have been applied in drops of about 0·02 microlitre (µl.) to adults of Glossina morsitans Westw., 2–5 days old, one day after the first meal. This species is found to be unusually susceptible to this group of insecticides. In order of increasing toxicity they are: DDT and aldrin, γ BHC, dieldrin and endrin, Telodrin (1,3,4,5,6,7,8,8-octachloro-3a,4,7,7a-tetrahydro-4,7-methanophthalan). The LD50 of DDT was 0·0165 µg. (males) and 0·025 µg. (females), that of Telodrin was 0·00062 µg. (males). Susceptibility of the two sexes to DDT, γ BHC and dieldrin did not differ significantly. Two batches of flies tested with an interval of eight months differed by about two times in their response to dieldrin and γ BHC; but the response to DDT was unchanged. This difference was not seasonal.For practical use, dieldrin is the best and cheapest available insecticide, a fact confirmed in the field. Only Telodrin might replace it.
Observations on the biology and control of the cabbage stem weevil, Ceutorhynchus quadridens (Panz.), on trowse mustard (Brassica juncea)
Authors: Winfield A. L. 
Published: July 2009

During 1958–60, replicated insecticide trials were carried out in East Anglia in an attempt to assess seed losses on Trowse mustard (Brassica juncea) caused by larval infestations of the cabbage stem weevil, Ceutorhynchus quadridens (Panz.). The overwintered adult weevils invade the young growing crops during April and May, and the eggs are laid in the petioles over a period of weeks, depending both on temperature and crop stage, until about mid-June. Egg-laying began on mustard when the plants had produced six to seven broad leaves, but the actual time at which the first eggs were laid seemed to depend mainly on temperatures during May. In the insecticide trials, infestations averaged up to 26 larvae per plant, and none of the untreated plants entirely escaped attack.High rates of γ BHC (5 or 10 per cent, of the weight of seed) gave some control of stem-weevil larvae when kerosene was used as the sticker for the insecticide; 3 per cent, or 5 per cent, phorate and 5 per cent. Telodrin (1,3,4,5,6,7,8,8-octachloro-3a,4,7,7a-tetrahydro-4,7-methanophthalan) gave no control. The control by seed dressing was unreliable and is considered unsuitable for assessing yield losses caused by stem weevil.A single emulsion spray of dieldrin applied during May when the first adult feeding holes were found in the petioles, gave a good control of stem weevil and prevented egg-laying, and this technique seems promising for future work on damage assessment. It is thought, however, that sprays specifically directed against stem weevil would seldom be justified economically on commercial crops of Trowse mustard, but on April-sown crops the first dieldrin spray against blossom beetle, Meligethes aeneus (F.), may give some protection against stem weevil.The damage-assessment experiments gave no reliable indication of the effects of the stem weevil on yields of seed, in spite of their being sited in localities known to have a high weevil population. It was clear, however, that sowing date greatly influenced yields of seed; plants sown in March outyielded those sown in April or early May.
Studies of the sampling of Glossina pallidipes Aust. IV.—Some aspects of the use of Morris traps
Authors: Rennison B. D. , Smith I. M. 
Published: July 2009

Experiments carried out in south-eastern Uganda, as part of a series of investigations of factors affecting the catch of Glossina pallidipes Aust. by Morris traps, showed that this was not significantly affected by varying the interval between emptying the traps within the range 1½-24 hours or by varying the width of the entrance slit from ¼ to 1½ inches. Such exceptions as occurred could be attributed to unexplained variations in the intrinsic performance of individual traps. Almost no flies were trapped at night (1830–0630 hr.).Catches in traps with simulated defects (leaving the sleeve open or making holes in the cage gauze) were lower than in perfect traps; the catch was not significantly affected by the diameter of the sleeve opening, but was significantly lower in traps with 16 ½-in. holes in the cage gauze as against those with 2, 4 or 8. Escapes through such holes were observed whilst emptying the traps, when the recorder's approach disturbed the trapped flies, which were otherwise inactive. Frequent visits to the traps to empty them did not materially increase the number of flies effectively trapped, as might have been expected were flies escaping continuously or were the traps to catch flies accompanying the observer.When the interval between emptying traps exceeded 24 hr., losses of trapped flies occurred, to an extent that is unknown but sometimes substantial, as a result of predation by ants; this is the most likely source of significant variation in catches made by apparently identical traps, and can be overcome by mounting traps on greased, single legs. When thus protected, there was no significant difference in catch between traps cleared at intervals ranging from 12 hr. to eight days. The longer this interval, the greater the proportion of dead amongst captured flies; the median length of life after capture was about two days, this period varying slightly with sex and more substantially with undefined differences between sites and trapping periods.
Field infestation of cowpea (Vigna unguiculata) pods by beetles of the families Bruchidae and Curculionidae in Northern Nigeria
Authors: Prevett P. F. 
Published: July 2009

SummaryAn account is given of a study of infestation of cowpea pods in the field in Northern Nigeria by the weevil, Piezotrachelus varius (Wagn.), and the Bruchids, Bruchidius atrolineatus (Pic) and Callosobruchus maculatus (F.). Oviposition by Bruchids did not commence until the pods were fully formed and light green in colour, whilst infestation by P. varius originated in the young pods. Observations indicated that a high level of parasitism of Bruchid eggs occurred, but that the majority of Hymenopterous parasites emerging from within the pods were related to P. varius.When pods were harvested at regular intervals, large numbers of P. varius emerged from the early harvests only. B. atrolineatus was the predominant Bruchid species emerging, particularly from early harvests. In the case of a single final harvest of pods, large numbers of P. varius, and a higher level of infestation by B. atrolineatus than in pods collected at regular intervals, were recorded.Shelling of four batches of pods indicated a mean of 11 per cent, of seeds attacked by Bruchids in the case of single final harvests, and a mean of only 3·5 per cent, in the case of regular harvests as pods became dry. It is concluded that a considerable improvement in quality would result from an adoption of the latter method by farmers, provided that some method of control in respect of the harvested pods were introduced.From the observations made it is concluded that P. varius is a true field pest, B. atrolineatus primarily a field pest able to continue infestation in store to a very limited extent, and C. maculatus primarily a store pest able to commence its infestation in pods in the field and to build up in numbers rapidly during the immediate post-harvest storage period.The normal manner of cultivation precludes the use of field methods of control at oviposition peaks but observations suggest that elimination of secondary hosts of P. varius and B. atrolineatus might be worthwhile. A reduction in oviposition by C. maculatus by treatment of stored cowpeas in growing areas, and treatment of pods during the immediate post-harvest storage period, should considerably reduce the level of infestation by this species.