bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study of the Sandfly Population in Endemic Foci of Infantile Kala-azar in Italy
Authors: Adler S. , Theodor O.
Published: July 2009

The sandflies of the two largest Italian foci of visceral leishmaniasis, Naples and Catania, were studied.

The following species were found : P. papatasii, P. perniciosus, P. sergenti, P. vesuvianus, sp. n., P. parroti var. italicus var. n.

P. papatasii and P. perniciosus are the commonest sandflies in the areas examined.

Out of 1,547 ♀♀ dissected none showed a natural infection with Leishmania.

P. papatasii was infected with Italian strains of L. infantum by feeding on cultures through membranes. The infection rate was low, but in contrast to Indian strains of L. donovani in the same sandfly, the infection once established did not die out.
On the Reproduction of Organisms with overlapping Generations
Authors: Thompson W. R.
Published: July 2009

In the great majority of organisms, the reproducing individual does not engender all of its progeny simultaneously. Between the beginning and the end of the reproductive period there is usually a certain interval of time, during which the production of offspring continues in a manner depending, on the one hand, upon the specific characteristics of the organism, and on the other, upon the conditions under which it lives. From this simple fact follow some interesting consequences.

If the successive generations are separated by a long interval of time and conditions during this interval are of such a nature that the organism is inactive and in the condition of obligatory dormancy, known as diapause, then, in spite of the increase of the population, the generations will remain separate and distinct, and a comparison of the total populations in the successive reproductive periods will enable us to determine the rate of increase.

On the other hand, if the interval between generations is short and favourable to activity and the organism does not pass through a period of obligatory dormancy at this time, then, as the species increases, the successive generations will come to overlap, and the amount of overlapping will increase progressively as time goes on.

This is primarily due to the fact that when there is reproduction over a period of time-intervals, in a typical individual of the species, and conditions remain constant then the number of time-intervals during which births occur will increase from generation to generation.
The Ecology of Glossina morsitans, Westw., and two possible Methods for its Destruction.—Part I
Authors: Nash T. A. M.
Published: July 2009

Much of the first part of this paper is in the nature of a continuation of the work previously published by the author. (Bull. Ent. Res., xxi, 1930, pp. 201–256). For this reason only a brief description can be given of the locality, vegetation, game, and fly-round methods ; those desiring a fuller knowledge on these subjects are referred to the above-mentioned paper. Again, a certain amount of repetition has been unavoidable. Some results obtained from only one year's observation have now been confirmed during a period of four and a-half years, and so have been given again. It is felt that this repetition is justifiable as the results in question are of special value, in that they are derived from four and a-half years continuous observation upon the same fly-belt, the method employed being constant throughout the whole period.

The writer is in charge of Kikori Entomological Station, which he opened in March 1928 ; nine months later he was joined by his assistant Captain V. A. C. Findlay.

The native village of Kikori is situated at the foot of the Masai escarpment, which bounds the Masai Steppe on the west. Kikori lies about 45 miles north of Kondoa-Irangi (the principal centre of the district), its approximate bearings being Latitude 4° 21′ S. and Longitude 33° 19′E. ; its elevation is 4,158 feet above sea-level.
General Observations on Mosquitos in relation to Yellow Fever in the Anglo-Egyptian Sudan
Authors: Lewis D. J.
Published: July 2009

1. Owing to the history of yellow fever in the Sudan and the lines of communication which traverse the country, a general survey of the mosquitos, particularly the Culicines, is of practical interest. The known potential vectors of yellow fever are listed.

2. Observations on the man-biting or man-ignoring habits of some species are recorded and also notes on the bionomics ofTaeniorhynchus africanus, T. uniformis, Aëdes aegyptiand other species.

3. For purposes of description the country is divided into sub-divisions of the recognized faunal areas and notes are given on the Culicines of each.

4. Brief observations are made on mosquito control measures against yellow fever.
The Use of residual Films of DDT and Gammexane in Malaria Control
Authors: Ribbands C. R.
Published: July 2009

(1) Sprays that are atomised and mingled with air were unsuitable because they were wasteful in both material and labour.

(2) Knapsack oilers and modified stirrup pumps were efficient. Where labour is cheap hand-operated sprayers of this type are more economical than motoroperated machines.

(3) The relation between mosquito mortality and infectivity is discussed and it is calculated that any treatment which produces 75 per cent. mortality among the mosquitos exposed to it should effect malaria elimination.

(4) The effects of a DDT emulsion were much more durable than those of a similar quantity of DDT in kerosene solution. The difference was much less marked when Gammexane was used. Emulsions will probably displace kerosene solutions as vehicles for the application of residual films.

(5) The persistence of the effects of DDT was markedly increased by increased dosage, so that it will be most economical to apply DDT in heavy doses at long intervals.

(6) The persistence of Gammexane effects was not greatly increased by increased dosage because it evaporates much more quickly than DDT. It is not likely to be effective for much longer than 10 weeks.

(7) Treatments with DDT were usually effective against A. minimus for about twice as long as against A. vagus or Culicines, but treatments with Gammexane had similar effects on all species.
Further Notes on the Food-plants of Nigerian Insects, VI
Authors: Golding F. D.
Published: July 2009

The present paper, which is the last of the series, contains additional data obtained between November 1939 and December 1945.

In 1939, Helopeltis bergrothi, Reut., was found feeding on cacao pods and shoots at Owena by the writer; it was evident that this species was distinct from the cotton Helopeltis, which had been identified as bergrothi by the Imperial Institute of Entomology in 1924. The species attacking cotton is H. sanguineus, Popp., and this name should be substituted for bergrothi in the three papers on food-plants published in 1935, 1937 and 1940.
The Cotton Jassid (Empoasca libyca, Berg.) in the Anglo-Egyptian Sudan, and Experiments on its Control
Authors: Cowland J. W.
Published: July 2009

Empoasca libyca is a major pest of cotton in the northern and western blocks of the Gezira Irrigated Scheme.

Distribution of the species of the genus of Empoasca and Erythroneura lubiae is given, together with their food plants in the Sudan.

Damage caused by E. libyca is noted; an experiment carried out in 1935/36 showed that Jassids were able to cause such symptoms.

The life-cycle shows that the egg and nymphal stages are of short duration (8 days each) and followed by a long adult life (as long as 2 months) in which the female lays her eggs over a long period.

A new type of cage was used and is figured.

The effect of applications of Bordeaux mixture in reducing the Jassid population and amount of scorch is given as well as physiological data relating to the influence of spraying on different parts of the Jassid-infested cotton plants. It is shown that sprayed plants produced an appreciable increase in the number of green bolls formed and an increase of 11 per cent, in the weight of seed cotton per boll harvested. It is pointed out, however, that Bordeaux mixture has several disadvantages and other more suitable insecticides are being sought.

No Sakel varieties as yet have shown resistance to Jassid attack.
Final Survey of the wood-destroying Insects in public Buildings in Sweden
Authors: Trägårdh Ivar
Published: July 2009

Short summaries have previously been given (1938, 1940) of the results obtained during investigations on the wood-destroying insects in public buildings in Götaland and Svealand, the southern and middle parts of Sweden. The survey has since been continued in Norrland, the northern part of the country, and a short summary of the results obtained may now be given, together with a general survey of the conditions prevailing in the whole country.
Assessment of Malaria Control by Mosquito Prevalence
Authors: Hocking K. S.
Published: July 2009

The ultimate assessment of the efficiency of malaria control is by the number of cases of malaria contracted in the controlled area, but a method that gives a more immediate and definite information is required because of the:—

(i) Delay before the necessary information is obtained. For example, abandonment of larval control will not affect the number of malaria cases for more than a month;

(ii) Shifting populations. People will come into the area and develop malaria acquired outside and conversely people having acquired malaria inside the area will go outside before developing it;

(iii) Difficulty of distinguishing between relapses and newly acquired infections. The number of relapses has no connection with the efficiency of the control;

(iv) Lack of cases of malaria despite infection in a predominantly immune community in which the non-immune persons are protected by suppressive drugs, mepacrine and quinine. This is a common condition in very malarious areas.
The Oat Bird-Cherry Aphis, Rhopalosiphum padi, L., and Comparison with R. crataegellum, Theo. (Hemiptera, Aphididae)
Authors: Rogerson J. P.
Published: July 2009

1. An attempt has been made to elucidate the confusion existing about the biology, morphology and nomenclature of the Oat-Apple Aphis, Rhopalosiphum prunifoliae, Fitch. A close study of the problem confirms the observations made by Börner that at least two distinct species have in the past been included under the name of R. prunifoliae. The names Rhopalosiphum padi, L., and Rhopalosiphum crataegllum, Theo., are adopted for these species.

2. Detailed descriptions and figures of the different generations are given and a comparison shows that the two species can readily be distinguished from one another.

3. R. padi appears to be of greater importance as a cereal pest than R. crataegllum. The latter species is a widespread pest of pip-fruit.

4. An account is given of the overwintering of R. padi on Prunus padus, and the results of experiments on estimating the size of the ova-populations is shown.

The author is indebted to Mr. R. A. Harper Gray for allowing him facilities to carry out the investigation; also to Mr. J. A. Dunn for assistance in collecting some of the material and much general help.
Diagnoses of New Bornean Culicidae
Authors: Edwards F. W.
Published: July 2009

The following are preliminary diagnoses of new species of Culicidae from Kuching, Sarawak. The specimens were received from Mr. J. C. Moulton, and either were collected by the donor, or formed part of the old collection of mosquitos in the Sarawak Museum, which was for the most part obtained in the neighbourhood of Kuching by Messrs. J. Hewitt and J. E. A. Lewis. The types are all in the British Museum.
The Tabanidae of Southern Nyasaland with Notes on their Life-histories
Authors: Neave S. A.
Published: July 2009

The following notes on Tabanidae describe specimens collected and life-histories investigated during a recent visit to Southern Nyasaland on behalf of the Imperial Bureau of Entomology.
The Comparative Morphology of the Anophelines Nyssomyzomyia ludlowi, Theo., and N. rossi, Giles
Authors: Strickland C.
Published: July 2009

As some confusion exist in the minds of medical men in the Malay States as to the differentiation of the Anophelines ludlowi and rossi* it is probably worth while to give the following comparative notes of the two species, particularly as I believe that the larva of ludlowi has been previously held to be indistinguishabla from rossi, whereas it is in reality very distinct.
Notes on African Chalcidoidea—II
Authors: Waterston James
Published: July 2009

In the confusion existing as to the meaning of the various Entedonine genera, I think it best to define the sense in which Pleurotropis is employed in the following pages. The essential character of the genus is, I take it, the presence on the smooth propodaeum of two central keels, which diverge apically to meet the raised posterior edge of the segment. There are also present two lateral keels, as a rule strongly developed, running (inside the oval raised spiracle) along the edge from which the descent to the pleura begins. The lateral keels join the posterior edge above a generally slightly protruding angle inside the insertion of the metacoxae. The general shape of the propodaeum is transversely quadrate, not truncately triangular as in Entedon. The petiole, which joins the propodaeum by a distinct, though often very short, process, is pitted, quadrate or even sub-pentagonal in section. The proportion of the first abdominal tergal surface to the whole visible surface varies sexually and specifically from less than one-third to three-quarters.
A New Anopheline Mosquito from Sumatra
Authors: Stanton A. T.
Published: July 2009

In the course of an investigation of malaria in the Lampongs, a district of South Sumatra, in the months of May and June 1914, Dr. Schüffner captured a large number of Anopheline mosquitos, among them a series of specimens of a species which he recognised as new to Sumatra.
Some Injurious Indian Weevils (Curculionidae)
Authors: Marshall Guy A. K.
Published: July 2009

Colour black, with greyish brown scaling; the prothorax with a broad ill-defined darker stripe on each side; the elytra with a conspicuous white spot at the base of the suture, and an oblique whitish stripe about the middle, with vague and variable dark brown patches on each side of it.
The Mosquitoes Of Bwamba County, Uganda
Authors: Haddow A. J. , Gillett J. D. , Highton R. B.
Published: July 2009

1. During the past eight years field investigations on the epidemiology of yellow fever have been carried out in Bwamba County, a small heavily-forested area in the extreme west of Uganda.

During the course of this work yellow fever virus has been isolated from a human case, fromAëdes (Stegomyia) simpsoni, Theo., and from a mixed lot ofAëdesspp. taken in uninhabited rain-forest.

As it is known that yellow fever is endemic among the monkeys of the Bwamba forests and that a high rate of immunity is shown by certain species that rarely descend to the ground, it was concluded that an arboreal mosquito was the most likely transmitter of yellow fever among monkeys, and an investigation of the arboreal mosquito fauna was begun.
The Habits and control of the Red Locust in outbreak Areas and elsewhere
Authors: Michelmore A. P. G.
Published: July 2009

The best way of preventing locust outbreaks is to control them at their source. After a description of those habits of the Red Locust that have a direct bearing on control, an account is given of some of the results of three years' experience of control of this species in an outbreak area. The methods used in Rukwa are described in detail, and attention is drawn to their relative efficacy, advantages and difficulties. A number of other methods are also referred to and their values discussed. Control methods are considered with special reference to conditions in Rukwa and other outbreak areas, and in relation to large scale campaigns against large outbreaks. Conclusions on the relative values of the various methods are summarised below. These values depend both on the habits of the locusts and on the ecological, economic and social conditions of a country in which a campaign is to be waged. It must not be assumed that conclusions about control methods reached with one locust or in one country necessarily apply to another locust or another country.
An Account of a Black Aphid, Doralis Fabae (Scop.) Subsp. Armata (Hausmann), Found on Digitalis Purpurea, L.
Authors: Jacob F. H.
Published: July 2009

At the end of June, 1942, large colonies of a black aphid, indistinguishable from Doralis fabae (Scop.), were found on foxgloves growing on a hillside in Westmorland. This aphid was found commonly in the mountainous districts of Westmorland and Cumberland in 1943, Caernarvonshire in 1945, and Anglesey in 1946. Observations to be described below have indicated that in nature, this aphid spends the whole of its life on foxgloves, and experiments have shown that it does not readily feed upon the economically, important host plants of D. fabae.
Studies on Wheat Bulb Fly, Leptohylemyia Coarctata, Fall
Authors: Gough H. C.
Published: July 2009

A detailed quantitative study of the incidence and development of an attack of wheat bulb fly on a field in East Yorkshire is described. The numbers of larvae, puparia, plants, and shoots, and the percentage of plants and shoots attacked, were estimated on various dates. This information is graphically summarised in fig. 1. Similar information was obtained from other fields in 1944 and 1945. No single factor could be correlated with the effect of the attack on the crop.

The number of larvae ranged up to nearly 600,000 per acre, but high numbers did not invariably result in a poor crop. A high percentage of plants or shoots attacked was not necessarily associated with crop failure. The number of shoots per plant at the time the larvae hatch was important and in some cases attack stimulated tillering. It is suggested that a study of the rate at which damage occurs would lead to a better understanding of the reaction of any crop to pest attack.
Observations on the Chafer Grub Problem in the Lake District
Authors: Gray R. A. Harper , Peet W. V. , Rogerson J. P.
Published: July 2009

1. The Garden Chafer (Phyllopertha horticola) causes extensive deterioration of the fell grassland in the Lake District.

2. The flight period of the adult beetles occurs between the end of May and the latter end of June.

3. Eggs are laid in the soil at a depth of about 2½ inches, but the depth varies according to the nature of the soil. The eggs take from 27 to 30 days to hatch in the field.
A Laboratory Comparison of the Toxicity as a Contact Poison of DDT with Nicotine, Derris Products and the Pyrethrins
Authors: Potter C. , Tattersfield F. , Gillham E. M.
Published: July 2009

The toxicity of DDT as a contact spray under laboratory conditions has been tested on a number of insect species. The particulars of the species used are set out below.

The toxicity of the DDT spray was compared in every instance with nicotine. A rotenone or derris suspension was included in the tests on Myzus cerasi, Phaedon cochleariae, Pieris brassicae, Pteronus ribesii and Phymatocera aterrima, and a pyrethrin spray in the tests on Pieris brassicae, Pteronus ribesii and Phymatocera aterrima.
Observations on collecting Parasites ofCacoecia histrionana(Froel.) (Lep., Tortricidae)
Authors: Franz Jost M.
Published: July 2009

Cacoecia histrionanaFroel. a European relative of the North American spruce budworm,Choristoneura fumiferanaClem., was found in several localities on the north-eastern frontier of Bavaria in 1949, but was not abundant anywhere.

Details are given of its biology based upon observations made during large-scale collecting in the summer of 1949, which yielded approximately 2,100 larvae of C.histrionana.

An important characteristic of the species is the great variation in the stages of larval development present at any given time, which is apparently caused chiefly by the absence of diapause as a synchronising factor.

Approximately 4°C. was found to be the lower temperature limit for movement and feeding of larvae ready for overwintering.

Three samples of larvae taken in favourable localities showed that 0-15 to 0-70 larvae were present per metre length of spruce forest edge from ground level to a height of 2 metres. An estimate of the minimum population is made for a limited and well searched area.

From 1803 C.histrionanalarvae collected in the field, 15 species of primary parasites and four of hyperparasites were bred. Combining the result of three samples taken at different times the minimum reduction of the population after hibernation is calculated to be 66-8 per cent., the parasitism of pupae at least 13-5 per cent. Egg parasitism occurred.

Nine of the 20 parasites, known hitherto from C.histrionana, have been bred from other hosts of the same animal community.

The most important larval parasite wasMeteorus ruficepsNees which completes 2-3 generations in one generation of C.histrionana. A proportion of the population also overwinters in other Microlepidoptera, concentrating on C.histrionanain summer. Details of its life-history are given.

Occasionally some larvae were found that had probably died from disease but disease, as a mortality factor, was of little consequence in the observation area in 1949.

Mortality caused by parasites proved to be very important in affecting changes in the population density. This result does not agree with Eidmann's theory that the scarcity of C.histrionanais due to climatic control.
The Collection Of the Cactus Weevil, Cactophagus spinolae (Gylh.), in Mexico and its Dispatch to South Africa
Authors: Sellers Wendell F.
Published: July 2009

Collections of Cactophagus spinolae (Gylh.) were made in Mexico in 1946, 1947, and 1948 to supplement the biological control of prickly pear (Opuntia spp.) in South Africa. During these three years, 862, 1,396, and 15,584 adults, respectively, were dispatched to South Africa. The weevils were sent by air express in specially designed containers, and arrived in excellent condition.

This paper includes information on the distribution, life history and food preferences of C. spinolae. The need is stressed for anticipating the effects of transit conditions upon living insect material transported by aircraft.
Studies of Toxicity Of 3:5 Dinitro-ortho-cresol and its Sodium Salt to the Honey Bee
Authors: Glynne Jones G. D. , Edwards R. A.
Published: July 2009

Laboratory and field experiments were carried out to study the toxicity of 3:5 dinitro-ortho-cresol and its sodium salt to the honey bee.

The acid DNOC was shown to be a rapidly acting poison under a wide variety of conditions and its toxicity was not greatly affected by differences in temperature or humidity during or after treatment.

Although both the acid and salt were equally toxic as stomach poisons, considerable differences were observed between the two substances as aqueous sprays and dry films. The toxicity of the sodium salt as an aqueous spray was considerably influenced by the humidity of the environment after spraying; the higher the humidity the greater the kill.

The sodium salt was apparently non-toxic as a dry film and increasing the humidity of the environment had no effect until the saturation point was reached and the salt went into solution. At this point the salt was almost as rapid in action as the acid. The type of surface on which the film was deposited was also shown to affect the toxicity.

Experiments were carried out on the penetration of the two substances through beeswax and these confirmed that whilst the acid could penetrate the beeswax in all forms tested the salt would only penetrate in aqueous solution.
Changes in the Fat and Protein Content of the African Migratory Locust,Locusta migratoria migratorioides(R. & F.)
Authors: Cheu S. P.
Published: July 2009

The process of build-up of reserve substances inLocusta migratoria migratorioides(R. & F.) is very closely correlated with the feeding activity of the insect. Locusts attain their maximum body weight in the initial period before maturation. In the females there is one minor build-up period after each laying.

As measured by the weight of faeces produced, thegregariafemale consumes more food than thesolitariaduring development. It also has a lower rate of increase in body weight, maturation and oviposition.

Locusts start to build up fat soon after the final ecdysis. The fat content reaches its maximum in the early part of adult life, and then begins to decline in both sexes of both phases.

By far the greater part of the fat reserve thus built up in thegregariafemale is used upbeforeoviposition, and only a small amount goes to the making of the first egg-pod. The fat of the subsequent egg-pods (of both phases) is derived from the fat built up each time after a new egg-pod is laid.

Thesolitariafemales may mature their eggs at various stages in the development of the fat body. Those which have a longer pre-maturation period have a higher fat content.
Studies on Beetles of the Family Ptinidae
Authors: Howe R. W. , Burges H. D.
Published: July 2009

The biology ofN. hololeucus, T. globulus, G. psylloides, S. squamosumandE. hillerihas been studied to estimate their potentialities as pests of stored products.

They are widely distributed and feed on a very wide range of foodstuffs of both plant and animal origin.

Adult life is usually longer than the development period. Oviposition extends over most of the adult life. In warehouses all stages of development are present together.

At 70 per cent. R.H. the developmental period (egg laid to emergence of adult from its cocoon) comprises: 12 to 21 per cent. as the egg stage, 52 to 70 per cent. as larva, 12 to 16 per cent. as pupa and 6 to 19 per centg. as adult in cocoon.

The mean lengths of the various developmental stages, including the larval instars, have been found under several sets of physical conditions.
On “Supona”, a new Type of DDT Suspension
Authors: Van Tiel N.
Published: July 2009

The properties of two DDT suspensions of a new type, “Supona”-D and “Supona”-DB are described. These suspensions contain about 50 per cent. DDT or 39 per cent. DDT+ 13 per cent. technical BHC respectively in their concentrated forms, the active material being suspended in a complex colloidal oil-water system.

Experiments were carried out with “Supona”-D and a DDT emulsion containing about 30 per cent. DDT dissolved in a mineral oil phase for the control of Glossina palpalis. Both products were applied in dilutions containing 5 per cent. DDT.

Laboratory experiments with leaves of Camellia thea and Begonia sp. showed that the initial toxicity and stability in tropical sunlight of residues of “Supona”-D were somewhat less than those of the DDT emulsion. The resistance to rain, however, was better with residues of “Supona”-D.
Studies of British Anthomyiid Flies. VI.—The annual Cycle of Generations in some Anthomyiid Root Flies
Authors: Miles Mary
Published: July 2009

Field and laboratory studies have shown that the several root-infesting Anthomyiid flies differ greatly in the number of generations composing their annual cycle and in the minimum temperature conditions necessary for full activity.

Onion flies (Delia antiqua (Mg.) ) were mainly univoltine in laboratory cultures. Of 369 first-generation pupae studied in 1953, only 141 (about 40 per cent.) gave rise to flies in July-August and 228 (about 60 per cent.) entered a diapause, in which 196 (about 85 per cent, of those entering diapause) remained until the following spring. In 1954, 99 per cent, of the first-generation pupae from univoltine flies and 97 per cent, of those from bivoltine flies entered the overwintering diapause in July. It then appeared that exposure to low temperatures during the development of the first-generation larvae had induced diapause in the pupae. This was confirmed by the unexpectedly high proportion (49 per cent.) of wild first-generation pupae which entered the overwintering diapause in July in the cool summer of 1954. It was also established that the spring oviposition period for D. antiqua began about the end of May, and it appeared that, in the field, air temperatures of approximately 70°F. were necessary to stimulate egg-laying. First-generation flies emerged in the second and third weeks of July, their numbers depending on the temperature in June. A few second-generation flies, together with late first-generation flies, may emerge in September, but the temperature is then too low for oviposition and there seem to be no third-generation larvae.
The Extermination of the Tsetse Fly,Glossina morsitansWestw., at Abercorn, Northern Rhodesia
Authors: Glover P. E. , Jackson C. H. N. , Robertson A. G. , Thomson W. E. F.
Published: July 2009

European farms at Abercorn had been suffering from bovine trypanosomiasis carried byGlossina morsitansWestw., and the Tanganyika Department of Tsetse Research were asked in 1935 to advise.

Fly-pickets were established in 1936 to prevent carriage of flies on to the farms, and a belt of country was protected from fire, with the object of thickening the woody vegetation so as to make it unfavourable toG. morsitans. The fire-protected area was extended and continued until 1946; serious escape fires occurred in 1938 and 1941. During these first five years the reduction in catches at the pickets was only about one-third.

An intensive survey of the area was made in 1941, as the result of which concentrations of flies were identified in certain shallow valleys forming the headwaters of small tributary streams. Several of these were cleared of trees, with the result that the apparent density ofG. morsitanswas at once depressed not only in the valleys themselves but over wide areas of untouched woodland round about.

In 1942 and the following years these clearings were extended to new valley sites as they were discovered, both inside and outside the fire-excluded area, and always with striking effects. The last clearing of all was done in 1952.
The Mosquitos (Diptera: Culicidae) of the Seychelles
Authors: Mattingly P. F. , Brown E. S.
Published: July 2009

A list is given of all the species of mosquitos so far recorded from the Seychelles, with their distribution in so far as this is known. A number of new records are included based on collections made recently by one of us (E.S.B.).

One species and one subspecies new to science are here described for the first time. The first full descriptions of the male terminalia and pupae of certain other species are included.

Some notes are given regarding the taxonomy, bionomics and local distribution of the species concerned and the zoogeography of the groups to which they belong.

Appendices are devoted to corrections to the second edition of “The Mosquitoes of the Ethiopian Eegion”, Vol. I by G. H. E. Hopkins, and to the mosquitos of other islands in the western Indian Ocean.
A Note on the Parasitisation of the Oöthecae of Periplaneta americana (L.) by the Chalcid, Syntomosphyrum glossinae Wtstn.
Authors: Nash T. A. M.
Published: July 2009

Syntomosphyrum glossinae Wtstn., a Chalcid parasite of the pupae of tsetse flies in East and West Africa, is recorded parasitising the oöthecae of Periplaneta americana (L.) at the West African Institute for Trypanosomiasis Research, Kaduna, Northern Nigeria.
Entomological Studies, relating to Yellow Fever Epidemiology, at Gede and Taveta, Kenya
Authors: Lumsden W. H. R.
Published: July 2009

The theoretical objections to the explanation of the persistence of yellow fever virus in areas subject to a prolonged dry season by cycles involving only mosquitos and wild primates are discussed in relation to the results of field surveys in areas of this type in Kenya. The localities studied were Gede, on the coast about 65 miles north of Mombasa, and Taveta, near Mount Kilimanjaro.

The topography, climate, vegetation and human population of the areas are briefly described.

Gede was visited towards the end of the dry season, Taveta during the main wet season. Thus most of the data relating to conditions during the dry season are derived from Gede, the results from Taveta being used mainly for comparative purposes. The work included 24-hour baited catches at two levels, moving catches, and larval collections in all the main typical environments.

All the species of biting arthropod encountered at each locality are recorded; in each case most were mosquitos.

At Gede the only mosquitos which were abundant as biting adults were species which breed in sea water, Aëdes fryeri (Theo.) and A. pembacnsis (Theo.), and they were practically confined to the close vicinity of their breeding places. The vertical distributions and biting-cycles of these species are defined.

At Gede, mosquito larvae could readily be obtained by filling tree holes artificially with water but no naturally water-filled tree holes were discovered by intensive searches in all the natural environments present in the area. Nor were any water-containing leaf axils discovered.
The relative Control Values of different Percentage Mortalities
Authors: Solomon M. E.
Published: July 2009

Percentage mortality by itself is not a good measure of the practical value of an insecticidal treatment. In a relatively simple case, such as the fumigation of stored products, the control value can be expressed in terms of the time required for the reduced population to return to its former level of density, provided the mode of increase of the population is known.

Assuming that increase is at a regular exponential rate, the control values of different mortality percentages can be compared in terms of the calculated recovery times; thus, each of the values in the series 99·6, 93·75, 75, 50 and 29 per cent. mortality is twice as good as the one that follows it. Such relationships can be deduced from the graph provided, which is essentially a curve of constant exponential growth, made linear by the use of the logarithmic scale.

The above comparisons do not depend on the value of the constant rate of increase. If the rate of increase varies, control values can still be compared so long as it is possible to calculate the relative times needed for recovery from different levels of density.
Physiological Action of Drugs and Insecticides on Insects
Authors: Naidu Mohan Babu
Published: July 2009

The action of certain drugs and insecticides on the frequency of the beat of the isolated cockroach heart, immersed in an aerated physiological solution at 29°C., have been studied. The frequency of the heart-beat is counted by eye and the drugs applied in the physiological solution. Acetylcholine at a concentration of 5 × 10-8to 10-5causes a sustained acceleration of the heart-beat which is blocked by atropine (5 × 10-5) and is unaltered by hexamethonium (5 × 10-5), prolonged exposure to nicotine (5 × 1O-5) or ergotamine (3 × 10-6). In this range of concentration ACH has a “muscarine-like” action.

Adrenaline (3 × 10-6to 5 × 10-8) also causes an acceleration of the heart-beat, which soon passes off. Nor-adrenaline has the same action. Nicotine, hexamethonium or atropine do not modify the action of adrenaline, but ergotamine antagonises it.

Nicotine (5 × 10-5produces an acceleration of the heart-beat which declines with prolonged exposure until ultimately no effect is produced on reapplieation, but recovery occurs with sufficient washing. Hexamethonium antagonises the effects of low concentration of nicotine. It is concluded that nicotine acts on the cardiac ganglia. Since atropine substantially reduces the action of nicotine, it is suggested that the ganglia excited may be chiefly cholinergic.

ACH in high concentration (10-3) in the presence of atropine (5 × 10-5) has a stimulant effect which is abolished by nicotine. It is inferred that under these conditions, ACH is stimulating ganglia which may be adrenergic.
Variation in the Hatching-response of Aëdes Eggs (Diptera: Culicidae)
Authors: Gillett J. D.
Published: July 2009

Eggs of Aëdes do not necessarily hatch on becoming mature, even though conditions are known to be compatible with hatching. Even the eggs laid by a single female in a single batch and kept submerged in a single container may hatch in instalments over a very long period and, although on one occasion a high proportion of the eggs may hatch within a given period, on another, for no apparent reason, very few may hatch.

The problem of erratic hatching has been studied here mainly in Aëdes africanus (Theo.) and A. aegypti (L.). It is considered that mature eggs enter a state of diapause, the depth of which varies with the passage of time, and that the manner of this variation with time itself varies from egg to egg. Different batches of eggs laid by females of the same species vary in the proportion of the different kinds of egg present.

Variation in response of the eggs has been studied by the application of a suitable hatching-stimulus in equal daily doses. The stimulus used was sufficiently weak to allow variation in response to be manifested, but sufficiently strong to outweigh uncontrolled variables in the environment.
Notes on the Mosquitos of the Gilbert, Ellice and Tokelau Islands, and on Filariasis in the latter Group
Authors: Laird Marshall
Published: July 2009

It is confirmed that the scutellaris-growp mosquito of the Tokelau and Ellice Islands is Aëdes (Stegomyia) polynesiensis Marks. No other mosquitos are known from the former Group, but Culex (Culex). annulirostris Skuse, A. (Aëdimorphus) vexans nocturnus (Theo.) and A. (Stegomyia) aegypti (L.) are also recorded from Funafuti, Ellice Islands. C. annulirostris and A. vexans nocturnus are listed—apparently for the first time—from Tarawa, Gilbert Islands. Reference is made to the microfilaria rate at Nukunono in the Tokelau Group, and to some potential mosquito larval habitats, as yet unutilised, in all three Groups.
The Susceptibility of various Species of Mosquitos to DDT, Dieldrin and BHC
Authors: Wharton R. H.
Published: July 2009

The susceptibility of various mosquitos to DDT, dieldrin and BHC has been studied. Adult females were exposed in small tubes lined with filter papers impregnated with insecticide-oil solutions. Larvae were exposed to insecticideacetone suspensions in water.

Adult mosquitos tested in London showed no striking differences in susceptibility to DDT, though the median lethal concentration (MLC) of Culex pipiens molestus Forsk. (1·6 per cent.) was greater than the MLC of Aëdes aegypti (L.) (0·9), Anopheles maculipennis var. atroparvusvan Thiel (1·0), or A. quadrimaculatus Say (·7). C. p. molestus and Aë. aegypti showed the same order of susceptibility to dieldrin and BHC, with Anopheles m. atroparvus more susceptible to both insecticides.
Prevention of the spread of tomato yellow leaf curl virus transmitted by Bemisia tabaci (Gennadius) (Homoptera, Aleyrodidae) in Israel
Authors: Venezia Melamed-Madjar S. Cohen , Hameiri J.
Published: July 2009

In the Jordan Valley of Israel, spread of tomato yellow leaf curl virus in tomatoes by Bemisia tabaci (Gennadius) was delayed by three field treatments: (1) a straw mulch at the time of sowing; (2) sprays every four days with azinphos-methyl or methidathion; and (3) a combined treatment of a straw mulch after germination plus azinphos-methyl sprays at four-day intervals starting ten days after germination. The protective effect of straw mulch lasted about three weeks, and then sharply declined. In laboratory tests adult whiteflies were attracted more to straw than to tomato leaves, and more to fresh (yellow) straw than old (grey) straw exposed to field conditions for 25 days.
New field methods for studying the responses of tsetse flies (Diptera, Glossinidae) to hosts
Authors: Vale G. A.
Published: July 2009

Field studies with Glossina morsitans morsitans Westw. in Rhodesia showed that hand-net catches can reduce slightly the responses of males to mobile baits and can reduce female responses by three-quarters. Description is given of methods of operating baits in the absence of men and of methods of electrocuting flies as they fly near baits, alight on baits and respond to decoy tsetse. These techniques are more efficient and objective than hand-net catching.
Sugars available from flowers visited by the adult cabbage root fly, Erioischia brassicae (Bch.) (Diptera, Anthomyiidae)
Authors: Finch S.
Published: July 2009

Analysis by gas-liquid chromatography showed that flowers open at the time of the first generation of cabbage root flies, Erioischia brassicae (Bch.), contained nectars composed almost entirely of sucrose and fructose whereas those open during the second generation secreted fructose and glucose. There were qualitative as well as quantitative differences in the sugar composition of all the nectars analysed. In both generations, the most highly nutritive sources of nectars, 94% and 86% sugar solutions, were available from the umbellifers Anthriscus sylvestris and Heracleum sphondylium, respectively. Fructose and glucose were also the main sugars on pollen and anthers at the time of the second generation but, in addition, pollen samples contained large quantities of the sugar alcohol inositol. The surfaces of the pollen of the grasses Dactylis glomerata, Holcus lanatus and Arrhenatherum elatius all contained sufficient nutritive carbohydrates for maturation of the first batch of cabbage root fly eggs. One or more of the chemicals found only in water extracts of Arrhenatherum pollen was probably toxic to the flies. To obtain sufficient carbohydrates to mature the first batch of eggs, flies had to probe at least 1–2 mg of grass pollen each day, equivalent to the pollen produced daily by two flowering heads of Dactylis.
Seasonal fluctuations of a natural population of Diclidophlebia eastopi Vondrácek and D. harrisoni Osisanya (Homoptera, Psyllidae)
Authors: Osisanya E. O.
Published: July 2009

Nymph and adult populations of Diclidophlebia eastopi Vondráček and D. harrisoni Osisanya were counted weekly on 3- or 4-year-old trees, Triplochiton scleroxylon, in Nigeria during 1966–71. D. eastopi showed successively larger peaks in late January or early February, mid-August, and early or mid-September; the smallest populations were in mid or late March. D. harrisoni showed peaks in February, late July or early August, and late October or early November, the second peak being the largest. Multiple regression analysis of Diclidophlebia populations against rainfall, saturation deficit, temperature and time showed that temperature had the greatest, although slight, effect on D. eastopi, while saturation deficit, through the host-plant, had a marked effect on D. harrisoni. D. harrisoni populations were dependent on the availability of young leaves. It is concluded that, to avoid attack by Diclidophlebia, transplanting of Triplochiton seedlings should be in late February or early March.
Dispersal, seasonal flight activity and winter survival of the oak stem Phylloxerid Moritziella corticalis (Kalt.) (Homoptera, Phylloxeridae)
Authors: Barson G.
Published: July 2009

The dispersal and seasonal flight activity of the oak stem Phylloxerid (Moritziella corticalis (Kalt.)) was studied at three localities in southern England by means of field observations and by sticky trap and suction trap catches. Wind displacement of first-instar crawlers occurred mainly during the winter months (76.2%) when this stage of the life-cycle is most active and abundant. No desiccation of these larvae was observed. The flight period of the sexuparae extends from the end of July to the end of October, and in most years three peaks of flight activity were discernible. A succession of days with low temperatures sometimes prevented migration, but large catches usually followed these low temperature spells. Analysis has shown that the temperature threshold for flight was about 17·2°C. Individuals flying at the start of the flight period were significantly smaller than those flying at the end of the season, possibly because factors affecting the host-plant may also effect changes in breeding and development of the insect. In a frost gradient apparatus, the overwintering first-instar larvae of M. corticalis were cold hardy, the LT30 being -23·7°C.
The feeding performance of the IxodidRhipicephalus appendiculatusNeum. on rabbits, cattle and other hosts
Authors: Branagan Denis
Published: July 2009

A study was made between 1967 and 1971 at Edinburgh University and at EAVRO, Muguga, of the variability in feeding performance of all three instars ofRhipicephalus appendiculatusNeum., with a view to better prediction of transmissions ofTheileria parva. Variability could be definitely ascribed to factors within the ticks only when vigour was reduced after prolonged storage and when mating opportunity was withheld from attached females. Lower environmental temperatures prolonged engorgement, but it was arguable whether this effect was produced through the tick or through the host. All other sources of variability arose from influences within the host. The most significant of these were recognised in responses by rabbits in which resistance had been induced by successive infestations. Resistance was manifested by prolonged engorgement, by a reduction in numbers engorged and in degree of repletion, and by an increasing severity in host reaction. Three resistance mechanisms were suggested by host reactions—one appearing at the earliest stages of attachment, a second with the deposition of cement, and a third at the start of salivation. Each varied in efficacy, and each was capable of arresting an infestation. Cumulative and synergistic responses were ascribed to interactions between these mechanisms. Storage periods, sizes of infestations and sex ratios ofR. appendiculatuswere standardised within routine procedures, and abundant records of previous and subsequent performances on rabbits and cattle are presented for comparison and reference. Comparison of feeding performances on different animals suggests that cattle, buffalo, eland, waterbuck and oryx are as satisfactory as hosts as the rabbit, whereas Thomson's gazelle, wildebeest, sheep and goat are less so. Immature instars successfully completed engorgement on mongoose, cane rat, genet, domestic fowl and spur-fowl.
The inhibitory effect of seedling grasses on feeding and survival of Acridids (Orthoptera)
Authors: Bernays E. A. , Chapman R. F. , Horsey J. , Leather E. M.
Published: July 2009

The amounts eaten byLocusta migratoria migratorioides(R. & F.) on seedling grasses was less than on mature grasses in four other Acridids,Nomadacris septemfasciata(Serv.),Chortoicetes terminifera(Wlk.),Melanoplus sanguinipes(F.) andSchistocerca gregaria(Forsk.). Palatability of the young grasses increases with age, becoming maximal 6–10 weeks from the time of germination. Similar preferences were shown by other Acridids. Time-lapse film studies onLocustashowed that not only is less time spent feeding on seedling grasses, but that locomotor activity levels are considerably higher. Survival studies on the same species showed higher mortality on the seedlings as compared with the mature leaves at all stages of nymphal development, while on seedlings no individuals survived to the adult stage. Lipid-soluble materials were removed from seedling leaves with chloroform or acetone and this rendered them more acceptable, while the extract applied to mature leaves resulted in reduced palatability.