To permit detailed study of individual tsetse, either as insects or as the vectors of trypanosomiasis, a method has been devised which resulted in excellent survival and reproduction when tested on females or Glossina austeni Newst.

Each mated female was maintained in asmall cage comprising a stainless steel frame covered with non-absorbent black Terylene netting through which the larvae and faeces fell into a tray. Each cage was applied daily to the ear of a rabbit, and records were kept of the number of feeds, time taken to feed, numbers of larvae produced, lengths of interlarvel periods and weights of pupae.

The following conclusions are tentative as they are based on detailed studies of only eight females. Five of these produced larvae regularly at 8½- to 9-day intervals. Ninety-six interlarval periods were investigated. Although the mean interval between meals was two days, the flies tended to fast before larviposition and to engorge repeatedly afterwards.

Among nearly regular breeders, failure to larviposit did not seem to interrupt the normal feeding rhythum: the reproductive rhythum later re-integrated with the feeding ehythum. A tendency to deviate from the normal feeding pattern either by too frequent feeding after larviposition or by prologation of the fasting period before larviposition, may possible be related to pemature death, but flies which tend to feed on the day before larviposition centainly risk death from pupation in utero—a condition found in 5 per cent. of dead rabbit-fed flies; the complex of pressures which lead to this condition is described.

Limited data suggest that females which live to a great age enter a post-productive period when about 6½ month old; the feeding pattern breaks down completely, the fly fasting for periods of up to 11 days, or even longer in the immediate pre-death period. The maximum output of reasonably sized pupae is probably about 20 for G. austeni.

Pupal weight increased until the parent flies were about 90 days old, but there was much individual variation; thereafter the weight remained high, but among very old dlies it fell towards the end of reproductive life. Certain individuals tended to produce heavy pupae, a characteristic probable associated with the size of the fly and the total weight of blood taken up in each interlarval period—not with the frequency of feeding; a very infrequent feeder may, however, produce underweight pupae at irregular intervals.

Nanophyes sp. nr. nigritulus Boh. infests the aquatic weed, Jussieua repens (Onagraceae) in India, its larvae feeing and developing inside the fruits. Adults feed on the leaves and also on the pollen and nectar of flowers. Eggs are laid singly in the interior ovaries of flower buds or blossoms. The ovaries hypertrophy and develop into deformed fruits which, when severely infested, are also completely seedles. The number of eggs laid by six females was found to vary from 89 to 410. The female that laid 410eggs distributed them in as many as 167 flowers, 7 being the maximum number of flwers in which eggs were laid and 13 the maximum number of eggs laid per day. In the laboratory, one of the females lived for 207 days and one of the males for 93 days. The period hatched in 4–8 days, the larval period occupied 7–16 days and teh pupal period, 3–6 days. The larvae moulter three times and pupated in separate chambers that they formed before pupating. Adults emerged by biting holes in the wall of the fruit. The egg and immature stages of the weevil are briefly described. Three species of Pteromalid wasps belonging to Habrocytus, Trichomalopsis and an unidentifies genus, and a species of Eupelmus (Eupelmidae) attacked the larvae.

The larvae and pupae of Tryporyza innotata (Wlk.), T. incertulas (Wlk.), Chilo suppressalis (Wlk.), C. polychrysa (Meyr.) (Pyralidae) are described and notes are given on Sesamia ingerens (Wlk.) (Noctuidae) with particular reference to setal characters of the larvae. No obvious difference in chaetotaxy was found between T. incertulas and T. innotata, but the two species of Chilo could be distinguished on this basis. The pupae of the species of Tryporyza could be separated by differences in the shape of the labrum and those of the species of Chilo by differences in that of the thoracic tubercles.

A new genus and a new Malsxoodes farinosus Fennah, are erected to accommodate examples of a population of Tropidocephaline Delphacidae (Homoptera: Fulgoroidea) found infesting Molasses Grass (Melinis minyutiflora) at Kitale, Kenya.

Cartographical analysis of the distribution of recorded swarming populations of Locusta migratoria migratorioides (R. & F.) in western Africa for the first four years of the 1928–41 plague of this species has shown seasonal latitudinal displacements in each year with a nroth-to-northweastward movement of swarms during the monthe February-March to August-September, and a south-to-south-westward return during the priod October until the end of the year or January or Ferbruary of the following year.

Changes in the position of the northern limit of distribution of swatms in western Africa from month during 1931 have indicated a probable relationship between its position and that of the Intertropical Front, in its seasonal displacement, the position of the surface front being inferred from that of the 10-mm. isohyet. From February to September 1931, following the northward displacement of the Intertropical Front and the northward penetration of south-westerly winds, a general northward displacement of swarms occurred. Similarly, following the southward advance of northerly winds, there was a southward displacement of swarms.

There was an eastward movement in the main latitudinal displacement. This was particularly marked in 1929 and 1930. By September 1929, the infestation that in April had been restricted to parts of south-western Guinea and norther Sierra Leone had spread north-eastwards to cover the greater part of the Voltaic Republic and southern Mali; from December 1929 to January-February 1930, following the south-westward movement from late September to November 1929 which confined swarms to the countries bordering the Atlantic and the Gulf of Guinea. there was a spread eastwards along the coastal areas from south-eastern Ghana to southern and eastern Nigeria; and following the main northward movement of swarms which began in western AFrica in April 1930, there was, from May-June onwards, a pronounced eastward migration to the central and eastern parts of the continent. Each of these eastward movements occurred in areas where, at that particular time of year, the prevailing winds would be from the south-west.

The deduced movements suggest that swarms of Locusta in western Africa move downwind, and that the principal seasonal changes in the distribution of swarms in that area occur in response to the latitudinal displacement of the Intertropical Front and its associated wind field.

Alarodia nana (Möschler) (Lepidoptera, Limacodidae) is a major pest of Citrus in Jamaica. An outbreak of the larvae, the ‘ slug caterpillar ’, may result in severe defoliation. All stages are found on the foliage and are present throughtout the year; the adults are inactive by day and appear to be weak fliers.

Earlier attempts to breed the insect in the laboratory had been unsuccessful, and, whereas attempts at control had indicated that malathion was effective against the larvae, reingestation had invariably taken place, well-grown larvae being found five weeks after treatment.

In the present work, done in 1963–4, adults that emerged from field-collected cocoons held in wire-mesh cages over Citrus plants in the laboratory mated on the night of emergence and the females oviposited readily on the following night. A technique for rearing individual larvae and for measuring their head capsules is described. In the laboratory at a mean midday temperature of about 27°C., the incubation period of the eggs was 6–8 days, and the durations of the larval and pupal phases 25–42 and 14–19 days, respectively.

Results of a search for secondary host-plants from which reinfestation might take place were negative. Observations of emergence in the laboratory of adults from cocoons collected just before and just after the application to an orchard of a low-volume malathion spray derived from a 57 per cent. emulsifiable concentrate by dilution at the rate of 1: 80 in water showed that many pupae had survived the application, and suggested that reinfestation might arise from moths emerging from such pupae.

A field trial comprising two application of the low-volume spray of malathion was carried out; the second application, designed to destroy larvae derived from pupae that had survived the first application, was made after an interval of 312; weeks and was completely successcful.

An account is given of Corioxenos raoi, a new Stylopoid species that parasitizes Antestiopsis cruciata (F.) (Pentatomidae), a pest of jasmine in South India. The new species is distinguished from Corioxenos antestiae Blair, the only other known representative of the genus.

A Phlebotomine sandfly, morphologically closely related to Lutzomyia tuberculatus Mangabeira, 1941, caught in Surinam (Dutch Guiana) is described as new and is named Lutzomyia munangai ap. nov. Illustrations are given of the male genitalia.

Platynota flavedana Clem. (Lepidoptera, Torticidae), the ‘fruit-dropping caterpillar’ or ‘citrus tortrix’, is an important but sporadic pest of Citrus in Jamaica.

Damage is confined to part of the period between April and June, and in a heavy attack large numbers of young Citrus fruits, each bearing a scar or hole in the area shielded by the sepals, are found beneath the trees. At other times of the year the insect is present in the orchards in small numbers only.

In the field, the eggs, which are laid in clusters, were found on the leaves of Citrus, the larvae in webbing tunnels, usually beneath the sepals of young fruits but also between leaves drawn together with silk, and the pupae within the webbing. Fertilished females isolated in 3 × l-in. glass subes oviposited readily and continued to do so for rather less than a week. The incubation period of the eggs was 6.5 days. Preliminary experments showed that the young larvae require either new, rapidly growing leaves or young fruits of diameter less than ½ in., and a technique for rearing individual larvae in described. The durations of the larvae and pupal phases were 17–35 and 5–10 days, respectively.

In the past, chemical control measures had been attempted when large numbers of small fruits had already fallen. It is suggested that such measures cannot be effective because the hardness of texture, that makes them unsuitable for the development of young larvae. Some evidence is provided of effective control by natural factors, throught to be of a pathogenic nature, and it is recommended that the possibility of biological control should be investigated. The difficulties of fitting biological control into the pattern of routine fungicidal spray-applications is mentioned.

It is concluded that a comprehensive investigation of both chemical and biological control is necessary, and it is suggested that in areas where outbreaks of the pest occur at all regulary it would be wise, meanwhile, to apply an insecticide, preferably when the new leaves and flower buds are developing and at latest before completioon of petal-fall.

After exposure of nymphs of some Pyrrhocorid bugs to contact with certain papers or wood chips, abnormal adults are produced. Some have crumpled wings (distorted adults) and a proportion of these do not berrd, others have wing buds resembling those of a last-stage nymph and can never breed (juvenile adults). A study was made on Pyrrhocoris apterus L. and Dysdercus intermedius Dist. of the source of the factors causing these abnormalities, which were more severe in the latter species.

Exposure of nymphs to paper fro the Scientific American or the Sunday Express resulted in the production of 60–100 per cent. ‘juvenile’ adults, the others showing lesser deformities. Chips from the Baisam Fir (Abies balsamea) resulted in almost 100 per cent. ‘juvenile adults’ in Dysdercus and over 80 per cent. distorted adults in yPyrrhocoris. Chips from two other common American pulp trees (Pseudotsuga taxifolia and Tsuga albertiana) resulted in only a few distorted adults and no ‘juvenile adults’. Several chemial pulps were tested but none caused deformities, and it was conculded that the chemical processes removed all the active priniciples, even from the wood of the Balsam Fir. Mechanically produced pulp from the Balsam Fir was, in contrast, fully active. It was conculded that daily newspapers may contain enough mechanical pulp from active woods to produce the deformities, but that the active material must be in substances added later in manufacture to the papers used in the Scientific American, some copies of Nature, and tissues.

A number of tree products (mainly terpenoids) that are commonly added to paper in the final stages of manufacture were tested as extracts applied to filter paper. Tall oil rosin had little or on effect on the growth of either species, but it resulted in an increase in the number of eggs laid. Gum rosin had little effect on either species, except to produce a few distorted adults. Wood rosin likewise had little effect on P. apterus, but produced many distorted adults of D. intermedius, of which very few laid eggs. Bornly acetate, a common component of the tree orsins, produced some distorted adults of both species, and greatly reduced fertility in D. intermedius.

None of the qctive mqteriqls affected locusts (Schistocera gregaria Forsk. and Locusta migratoria migratorioides R. & F.) except that myrrh oil (a terpenoid) increased the rate of sexusl maturation.

In a study of the incidence of funnel ants (Aphaenogaster spp.) on the Atherton and Evelyn Tablelands of northern Queensland in 1959–61, 422 farms were surveyed, totalling over 98,000 acres of pasture, of which 10.8 per cent. proved to be infested with A. pythia Forel. The ants damage the introduced pasture grasses (Paspalum dilatatum and Pennisetum clandestinum) by removing soil from around their roots to from loose mounds, which smother the closely-grazedsward. Inferior species of grass and deep-rooted weeds are thus encouraged and affected areas become useless for dairying.

The natural habitat of A. pythia is wet sclerophyll forest which occurs in narrow belts fringing the rain forest and in pockets within it; the rain forest does not harbour the ant, but following its clearance and its replacement by pastures, A. pythia has spread out and colonised the latter. In areas of lower annual rainfall (under 50 in.) occupied dry sclerophyll forest and Eucalyptus woodland, A. pythia is replaced by A. longiceps F. Smith. Improved pastures have not been established here, but in the relatively restricted areas of infestation by this species, the large funnel-shaped orifices of its mounds create a hazard to stock.

The effects of temperature and humidity on the development of Oligonychus coffeae (Nietner) were studied by exposing the various stages of the mite to air in equilibrium with saturated solutions of appropriate salts in containers within thermostatically controlled cabinets. Adults and early stages were maintained on fresh tea shoots.

The pre-oviposition, oviposition and post-oviposition periods of adult females at 75–80% relative varied inversely with temperature, and averaged, respectively, 0.8, 5.9 and 1.4 days at 32° and 2.3, 30.6 and 2.0 days at 20°C. The mean number of eggs laid per female likewise varied inversely with temperature, from 12.0 at 32°C at 32° to 107.3 at 20°C.

No eggs hatched when incubated at 34°C., irrespective of humidity, or at 17% R.H., irrespective of temperature. Optimum conditions for incubation (those affording over 90% hatch) were provied by a combination of temperatures and relative humidities within the ranges 20–30°C. and 49–94%. When eggs were exposed daily for five days to temperatures of 37 or 40° for six hours at 72–94% R.H. and then transferred to room conditions (24–32°C., 64–88% R.H.), the percentage of eggs hatching was reduced from 94.7 (room conditions) to about 75 or 5–12, respectively.

The mean incubation period of eggs varied from 3.9 days at 32° to 10.8 at 20°C., and the mean duratio of the combined larval and nymphal stages from 4.9 days at 30° to 8.7 at 20°C. At 32°C., larval mortality was very high.

A mathematical treatment is proposed, utilising the methods and notation of matrix algebra, for evaluating the theroetical effects on the growth and structure of a population of the removal of individuals in particular age groups or stages in the life history. Formulae are derived to establish what proportions of given age groups or stages, individually or in combination, can be withdraw from the population whilst permitting its maintenance at a constant level. It is pointed out that these methods, appropriate to the situtation in which the population is exploited by a cropping procedure, can be extened to the special case of population control, in which it is desired to minimise or eliminate the population. The methods are illustated by numerical examples based on census observations on a growing population of Lasioderma serricorne (F.).

It has been shown that adults of Glossina morsitans Westw. that have fed from a bait ox in their natural environment digest their blood meals more rapidly than others that have emerged and been fed in the laboratory, even when both are maintained under identical environmental conditions after feeding.

In further experiments with G. morsitans in Rhodesia, flies caught in the field and fed in the laboratory were found to lose their ability to digest their meals rapidly. Measurements, made throughout three hunger cycles, of the rate of digestion, as reflected in the rate of excretion, of blood meals by field-caught flies fed on guineapigs in the laboratory showed that this was not significantly different from that of the normal, flied-fed flies during the first two hunger cycles but that during the third it fell to a level comparable to that of flise that emerged and were fed in the laboratory.

It is concluded that whatever may be the events that condition the field flies to digest their meals rapidly in the natural environment, these are repeated with the ingestion of each meal, and that laboratory conditions cause a rapid loss of this greater digestive capability.

The humidity responses of Trogoderma granarium Events were tested in humidity gradients set up in choice-chambers, each comprising a petri-dish with the lower half divided diametrically into two compartments containing sulphuric-acid soluctions affording different relative humidities and surmounted by a copper-gauze platform on which the insects, released centrally, could move about. Counts of the numbers in either half of the arena were made at 15–minute intervals over two hours.

In a gradient of 20–80 per cent. relative humidity, at 20°C., the average count was significantly greater on the drier side than on the moister one for larvae and adults tested in groups and for larvae and adult males, but not females, tested singly; the response was greater when the insects were tested in groups. Antennectomised adults, tested at 25°C. in a gradient of 20–100 per cent. relative humidity, showed no response, although intact control beetles showed a significant perference for the drier side. When adults were tested in groups at 25°C. in a range of gradients, from 20–10 to 20–100 per cent, a preference for the drier side was invariably shown, the response tending to be greater and to occur more rapidly in larvae than in adults, and as the humidity gradient steepened.

Between June 1964 and May 1965, samples of Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst. were caught in an area on the north-eastern shore of Lake Victoria in Uganda. Both males and females were classified into age-categories according to the degree of wear of the wings. Females were also classified into ovarian age-categories according to the exact or approximate number of ovulations that had taken place. All were examined for presence of infections with Trypanosoma, which were classified as vivax-type, congolense-type or brucei-type according to their location in the flies.

The percentage compositions of the samples by wing-fray category are compared. The mean wing-fray category of females of G. palpalis fuscipes and G. brevipalpis was somewhat lower, and that of females of G. pallidipes somewhat higher, than that of the corresponding males. However, the figures for infection rate in females of all three species were higher than in the corresponding males, significantly so in G. pallidipes and G. palpalis fuscipes, and it seems probable that the mean age of females, at least of the two latter species, was greater than that of males. Among females, the range of calendar ages of flies in the various fray categories was wide.

The physiological age-determination method, in which females older than about 42 days are classified iDto four age-categories, does not extend sufficiently far to give a reasonable pattern for the age-composition of any of the species at Lugala, and many of the individuals caught must have been more than about 80 days old.

Seasonal fluctuations in mean wing-fray and in the proportion of old flies in the population were correlated with changes in infection rate of females of G. palpalis fuscipes but not of females of G. pallidipes. Among males of neither species were seasonal fluctuations in mean fray correlated with changes in infection rate, though among those of G. palpalis fuscipes the two varied similarly between June and February.

Females of G. pallidipes and G. palpalis fuscipes about 31–42 days old had significantly fewer brucei-type infections than those over 42 days old, and either the developmental cycle in the field must normally be longer than that recorded in laboratory investigations or many of the flies must become infected when more than just a few days old.