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.

Investigations of the feeding activity, resting behaviour and seasonal distribution of Glossina morsitans Westw. were carried out at Lusulu Veterinary Research Station, Rhodesia, in 1961–63. Nine principal sampling sites were used, one in each of five distinct vegetation types and four at places where various pairs of types met. At each site, from dawn to dusk on several consecutive days in each of four seasons, tsete flies that had engorged naturally on a tethered ox were caught, marked and released, and meterorological readings were taken. Daylight observations of resting flies, both marked and unmarked, were made by searching the vegetation from ground level to a height of 25 feet (with the aid of ladders) and also by placing nets over inaccessible resting places, such as ant-bear holes, at the hottest time of day, thus trapping the flies that emerged later. Attempts to determine the night resting places by releasing flies marked with reflecting paint were unsuccessful.

The results showed that the feeding activity of G. morsitans was restricted to temperatures between 18°C., below which the flies were inactive, and about 32°C., above which they echibited a negative reaction to light. Feeding ceased abrupthy with the onset of darkness, and these was some evidence that activity was reduced by very high light intensity during the middle hours of sunny days. The diurnal pattern of feeding activity varied considerable from season to season but relatively little between vegetation types. A sex ration near equality was observed amongst flies caught feeding on oxen. The proportion of marked flies recaptured (i.e., feeding a second time on a bait-ox) was low, ranging from 0 to 12 per cent. according to vegetation type and season: it was higher for males than for females.

During daylight, the boles and branches of trees were used as resting places in all vegetation types, branches (especially horizontal ones) being preferred at most seasons. When temperatures rose above 32°C., however, the flies removed to resting places in deep shade, e.g., ant-beat holes, rock crevices, tor holes in trees and the fluted boles of dark-barked trees. Searching at night with electric torches failed to reveal the resting places used at that time.

The catches of feeding flies indicated that a wide range of vegetation types at Lusulu were inhabited by G. morsitans at all seasons and that, with the exception of males in riverine vegetation in the hot dry season, vurtually no concentration of flies took place in any specific vegetation at any time of year. These findings are discussed in relation to control by discriminative clearing.

Three field trials with endosulfan against coffee berry borer, Hypothenemus hampei (Ferr.), on both Coffea arabica and C. canephora are described. The insecticide was applied from motorized knapsack sprayers at 20 gal. per acre of an emulsified solution containing 0.2 per cent, active ingredient to the branches bearing the crop.

In two trials endosulfan applied twice at 21-day intervals significantly reduced the numbers of cherries containing living borers and the percentage of damaged cherries at the first pick. In the third trial a single application of endosulfan proved to be as effective as the double one. Increases in yield could not be detected. It was shown, by allowing insects to emerge from caged samples of cherries taken when picking began, that endosulfan did not affect the host/parasite ratio of either H. hampei or Geratitis coffeae (Bez.), nor did it increase the numbers of berry-boring caterpillars.

No off-flavours following treatment could be detected in liquoring trials of robusta coffee beans that were dry processed or pulped and washed.

Laboratory experiments in which adults of H. hampei were exposed above, but out of contact with, filter papers that had been dipped in an emulsified solution containing 0·2 per cent, endosulfan showed that it was acting at least as a partial fumigant and was more effective at 30°C. than at room temperature (21°C); spraying should thus preferably be carried out on warm, sunny days. In view of these findings, and as it is relatively non-toxic, endosulfan is recommended for control of H. hampei in Uganda when heavy attacks occur.

Observations on the eggs of the predatory Mirid Blepharidopterus angulatus (Fall.), which plays a part in the control of Panonychus ulmi (Koch) on apple, were carried out in 1963–64. The eggs required chilling at 4.4 or 7.2°C. (40 or 45°F.) for 14–16 weeks to terminate diapause. The reciprocal of the time in days for the first eggs to hatch showed a linear relationship with temperature. The temperature at the threshold of development was found by calculation to be 4.7°C.; 409 day-degress C. were required for the first larvae to hatch and 727 for 50 per cent. of them to hatch. From this information and the daily maximum and minimum temperatures, the expected dates of first hatch at East Malling were calculated for the years 1958–64 and found to agree well with the dates on which the first larvae were observed in the field.

An apparatus is described for applying a very small volume (0.1–1.0 μl.) of an insecticidal solution to an insect. It comprises a length of precision-bore glass capillary mounted, with a calibrated scale, in one end of a short tube having at the other end a perforated rubber bulb; the capillary is filled to the required scale mark by applying cotton wool saturated with the liquid to its tip, and the liquid expressed by squeezing the bulb, with the forefinger covering the hole in it. It can be used in conjunction with a calculator consisting of two concentric rotatable discs bearing two pairs of scales, on one of which the insect weight (in g.) is apposed to the per cent, concentration (w/v) of insecticide to be applied, which enables the volume (in μl.) required to yield a given dose (in μl./g.) to be read from the other pair of scales. Both devices have been used successfully in field testing with locusts and other insects.

Fourth- and fifth-instar hoppers and adults of Locusta migratoria migratorioides (R. & F.) were expected to three fluctuating remperature regimes in Weyco climatic cabinets and weighed daily. The regimes were 30 ± 0.25, 30 ± 10 and 30 ± 15°C., the change from one extreme to the other in the last two being made every two hours. Temperatures were accurately determined, by plantinum-resistance thermometers whose dimensions approximated to those of adult locusts, and were automatically recorded. The three thermorhythms were analysed by methods based on Fourier’s theorem, whereby a given wave form can be described in terms of a basic sine weve and a series of superimposed harmonics.

The rates of growth (weight increase) in the 4th-instar and adult at 30 ± 10°C/ were higher than at 30 ± 0.25°C. and were within 10 per cent. of the means of the rates at constant temperatures of 20 and 40°C., whereas the frowth rate in the 5th instar, and the pre-copulation and pre-oviposition periods of adults and their rate of weight loss when starved, were the same under both regime. At 30 ± 15°C., 5th-instar hoppers did not survive and, in comparison with the other regimes, the growth rates of 4th-instar hoppers and adults were very much lower, the pre-copulation period of adults was the same but the pre-oviposition period was much longer and their rate of weight loss when starved was doubled. Adults locusts were also tested at 30 ± 17.5°C., but most of them died within 24 hours and all within three days.

Cotton in Central Africa is subject to attack by numerous insect pests, and this has limited production. The pests include Diparopsis castanea Hmps., Heliothis armigera (Hb.), Earias spp. and Dysdercus spp. Methods of rearing these insects in the laboratory are described, preparatory to testing insecticides for their control. By means of an egg-dipping technique, the susceptibility of first-instar larvae of Diparopsis castanea to a wide range of insecticides was determined, and that of similar larvae of E. biplaga Wlk. to a smaller range. The most effective were methyl-parathion, carbaryl, menthyl-demeton, parathion, methiocarb, Zectran, isobenzan, endosulfan, BHC, endrin and phosphamidon. DDT was more effective against Earias than against Diparopsis, and toxaphene was relatively ineffective against both. Aftertakiing the mammalian toxicity of the insecticides and certain other factors into consideration, carbaryl, endosulfan, endrin and DDT were selected for further evaluation in the laboratory and the field.

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.

An account is given of the history of chemical control Phthorimaea operculella (Zell.) in potato fields in Rhodesia since the introduction of DDt prior to 1952. The failure of DDT and endrin, in routine spraying, to control field infestations is reproted, and some evidence that this is due to insecticide resistance is given. The results of critical field trials made in 1961, 1964 and 1965 to evaluate a range of insecticides for control of P. operculella and for their effects on populations of Macrosiphum euphorbiae (Thos.) are presented, together with the results of some laboratory tests. Good control of P. operculella in the field was obtained with sprays of azinphos-methyl at the rate of 0.5 lb active ingredient in 20 gal. water per acre, and two new compounds, methidathion and chlorfenvinphos, showed promise for the future.

Laboratory and field-cage studies were conducted in Texas in 1965 to evaluate treatments of the systemic insecticides, Azodrin (3-hydroxy-N-methyl-cis-crotonamide dimethyl phosphate), Bidrin (3-hydroxy-N, N dimethyl-cis-crotonamide dimethyl phosphate), American Cyanamid CL-47031 (cyclic ethylene (diethoxy-phosphinyl) dithioimidocarbonate) and Temik (2-methyl-2-(methylthio) propion-aldehyde O-(methylcarbamoyl) oxime), applied incorporated in lanolin to the stems of cotton plants against Heliothis zea (Boddie) and H. virescens (F.). Reductions in numbers of developing larvae of H. zea were substantial on individual plants the stems of which had been treated with Azodrin or CL-47031 and which were artificially infested with eggs. When first-instar larvae of H. zea or H. virescens were caged on plants 3, 7 or 14 days after stem treatment with 2.5, 5.0 or 100 mg. Azodrin, Bidrin or CL-47031 per plant, net mortalities ranged from 21 to 80 per cent after three days. The mortality of adults of H. zea provided with sucrose solutions containing 1 p.p.m. of the systemic insecticides indicated that Azodrin and Bidrin were about equally toxic and much more so than CL-47031 and Temik, and that of adults caged on individual plants in flower that had been treated with Azodrin or CL-47031 suggested that the moths may be killed by the systemic action of these insecticides translocated to the nectar. When adults of H. virescens were released on plants each treated with Azodrin at 25 or 30 mg. in large field cages, reductions in the numbers of eggs deposited, attributed to the effect on the moths of the insecticide in the nectar, and in the numbers of developing larvae, were substantial. Azodrin was the most consistently effective of the four insecticides evaluated.

Further tests of insecticides, mainly carbaryl, endosulfan, endrin and DDT, for possible use against pests of cotton in Central Africa are described. In laboratory tests in Rhodesia, carbaryl was the most effective against first-instar larvae of Diparopsis castanea Hmps. exposed on leaves, stems and bracts of effective against second-instar larvae of Heliothis armigera (Hb.), to which the insecticides were applied directly, and carbaryl the least.

When adults of Dysdercus intermedius Dist. and D. fasciatus Sign. were caged with treated bolls, carbaryl was the most effective, endrin the next and (against the former sp. only) endosulfan the least. Deposits on leaves from 0.5 per cent. sprays of carbaryl, DDT and endosulfan remained effective in dry conditions for two weeks, but application of 0.05–1.0 in of simulated rain reduced their effectiveness immediately, especially that of carbaryl. The effectiveness of deposits was also reduced by plant growth and was affected by plant habit; on a hairy variety the deposits persisted longer than on a glabrous one, partly because the hairs retained them and partly because they made movement of the larvae more difficult.

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.

In the laboratory, at a temperature of 30 ± 1°C. and 45 ± 2 per cent, relative humidity, the number of fertile eggs produced by females of Melanoplus sanguinipes (F.) that had copulated once and had then been reared alone in a cage was not significantly smaller than that produced by control pairs of males and females of this grasshopper. The solitary females laid more eggs than did the control females, but the eggs had a significantly lower percentage fertility. They also lived significantly longer, and one female produced eggs over a period of 140 days. Solitary and control females laid the same number of pods per day but the number of eggs per pod gradually decreased after the first two months of egg laying, particularly in the case of the control females, reflecting a decrease with time in the number of functional ovarioles.

Since 1956, samples of Lucilia cuprina (Wied.) from many parts of New South Wales have been tested annually for signs of resistance to organophosphours insecticides, which are used there to prevent fly-strike in sheep. For tests, 0.1 μg. diazinon per fly was applied topically; this discriminating dose was twice that required to kill 100 per cent. of susceptible flies. In 1965, some of the flies in a sample from Dubbo, in central-western N.S.W., survived the discriminating dose. Sensitivity tests of the progeny of the survivors (DB strain) and of a normal susceptible strain revealed that the LC50 of the DB strain was about three times that of the normal one. Further tests established that a roughly similar change in sensitivity had ocurred to other diethoxy (dichlofenthion, fenthion-ethyl, bromophos-ethyl, parathion) and to dimethoxy (fenchlorphos, parathion-menthyl, bromophos) organophosphors compounds. The change was therefore non-specific and, since it was also small, is regarded as an example of tolerance rather than of resistance.

Subsequent field surveys in 1965–66 showed that tolerance of L. cuprina to diazinon was widespread in N.S.W. The possibility that resistant strains will be selected out by continued use of organophosphorus insecticides is discussed.

In a collection of larvae of Culcine mosquitos made in northern Iraq in 1952–56 during the course of a survey of potential Amopheline breeding places in the area, the folowing genera and species were represented: Uranoaenia unguiculata Edw., Aedes caspius (Pall.) Culiseta longiareolata (Macq.), C. subochrea (Edq.), Culex theileri Theo., C.tritaeniorhynchus Giles, C. pusillus Macq., C. hortensis Fic. and C. mimeticus Noé. The last two species are reported here for the first time from Iraq. The records of Culiseta suochrea and Culec pusillus are based on a single larva of each.

Following heavy infestations of garden pea (Pisum sativum) by leadmining insects at an experimental farm near Baghdad in 1963, collections of infested leaves from crop plants and associated weeds were made in 1963–1965 in central and souther Iraq and teh insects emerging from them identified. These included the following six pieces of Agromyzid flies: Phytomyza atricornis Mg., Liriomyza congesta (Beck.), L. Brassicae (Ril), L. strigata (Mg.,) Liriomyza sp. and Agromyza nana Mg. Of these, P. atricornis was the most abundant and widely distributed, followed by L. congesta.

P. atricornis was found on a wide range of hosts, of which P. sativum and Taraxacum monochlamydeum wwre those most attacked. Six species of Hymenopterous parasites were recorded from P. atricornis and these are listed.

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.

Differences between sexes in the duration of larval and nymphal quiescence in Ixodid ticks were investigated in Israel in the laboratory. In H. dromedarii Koch the larval quiescence of the male was, on average about 4 hours longer than that of the female, but in Rhipicephalus sanguineus (Latr.) no significant difference was found. In five species a statistically significant difference in the length of nymphal quiescence was found between males and females; in three of them, R. sanguineus, R. secundus Fel.-Muh. and H. dromedarii, that of the male exceeded that of the female by 1/2 to 1 1/2 days and in the other two, H. marginatum Koch and H. excavatum Koch, the opposite was found, the difference being 1·3 and 3·7 days, respectively.

The stick-insect Graeffea crouanii (Le Guillou) is a pest of coconuts of local and sporadic importance in the south Pacific and there have been recent outbreaks on Taveuni Island, in the Fiji group. As there appear to be virtually no parasites of the nymphal stages, a preliminary search was made in 1960 for parasites of other palm-feeding Phasmatids in Melanesia. This revealed the presence of Tachinidae parasitising species of the genera Ophicrania and Megacrania, and in 1963–64 these were studied in the Solomon Islands. The Tachinidae comprise at least two species of Mycteromyiella: M. laetifica (Mesnil) attacking both O. leveri Günth. and a species of Megacrania in the western Solomons, and M. phasmatophaga Crosskey attacking 0. leveri and some other Phasmatid hosts on Guadalcanal. The early stages of both species of Mycteromyiella are briefly described and compared, with notes on their bionomics. There was no evidence of any egg parasite attacking Ophicrania in the Solomons.

O. leveri, which is very closely related to G. crouanii, has never caused significant damage to coconuts in the Solomon Islands, except on the small island of Savo, from which its Tachinid parasites appear to be absent. It is concluded that Mycteromyiella, especially M. laetifica, which appears to be fairly specific, may be an important factor in the control of O. leveri in the Solomons.

The principal hosts of O. leveri are the sago palm (Metroxylon salomonense) and species of arecoid palms in the forest, on all of which the insect has better scope for concealment than on coconuts. Collections of nearly 6,000 examples of O. leveri from sago palm on Kolombangara island, in the western Solomons, in August 1963-February 1964 showed an average parasitism by Mycteromyiella laetifica of 28 per cent. Eggs of the Tachinid are laid on nymphs of all instars as well as on adults. The host-survival rate was about 30 per cent, for nymphs and 50 per cent, for adults.

A small number of parasitised specimens of O. leveri from Kolombangara were released on Savo, but there was no evidence six months later that M. laetifica had become established there.

Breeding trials at Honiara showed that O. leveri could be reared successfully in captivity but not M. laetifica, which shows reluctance to mate in cages and has a narrow range of environmental tolerance in the pupal stage, in which a mortality of at least 70 per cent, seems unavoidable under the conditions practicable for transportation of this stage by air.

Between October 1963 and March 1964 nearly 960 puparia of M. laetifica were sent to Fiji. About half of them were used for breeding trials, which showed that the Tachinid could be reared through G. crouanii in captivity but could not be maintained. The rest were released on Taveuni, but a further outbreak of G. crouanii during 1965 yielded no evidence that M. laetifica had become established.

Material of M. phasmatophaga, which has a more restricted choice of environment than M. laetifica, but also a somewhat greater potentiality for killing its host, was obtained by exposing O. leveri on seedling coconut palms planted in the forest at Honiara. Quantities were insufficient for transmission to Fiji; 150 parasitised hosts were released on Savo but samples of O. leveri collected there six months later gave no indication of its establishment.

Despite this initial failure, it is considered that Mycteromyiella could bring about the control of G. crouanii in Fiji and other affected Pacific islands, and the means by which this might be achieved are discussed.