After checking the identity of numerous mealybugs of the genus Planococcus from the south Pacific, many of which were previously recorded as P. citri (Risso), it was established that the most widespread is the recently described species P. pacificus Cox. P. citri is present in some islands, but the collection dates are recent, suggesting a recent introduction. Although P. pacificus is known from the area since the first quarter of the present century, it may have been introduced also. P. lilacinus (Ckll.) possibly arrived from southern Asia and P. dioscoreae Williams from the eastern part of the Oriental Region. The known host-plants are listed.

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.

The following paper deals with a collection of Thysanoptera from various tropical countries, but especially Africa, received by the author from the Imperial Bureau of Entomology for determination. As most of the species before me are from new localities or from new food-plants, I have thought it desirable to give the data not only for the new species, but for all the others also.

These notes record some observations that were made during the anti-malarial campaign carried out by the British Army at Cimino, Taranto.

The intersting collection of Culicine mosquitos on which these notes are based was made during 1922 by Dr. H. P. Hacker, of the Malaria Bureau, Kuala Lumpur, Federated Malay States. Most of the material was obtained during an expedition to Cameron's Highlands, on the main range near Tapah, in September. A small amount of additional material from Ulu Gombak also yielded some specimens of interest.

The false codling moth is a polyphagous pest of various kinds or fruit, and it has expanded its geographical distribution and host range. The expanding host range could result in subspecies requiring varied pest management options. Laboratory no-choice cross-mating tests were conducted to establish whether Thaumatotibia leucotreta individuals from six areas and three host species, in South Africa, share mating characteristics and belong to the same subspecies or strain. The no-choice cross-mating tests indicated that all individuals in self- and out-crosses readily mated within 24 h with those derived from different hosts and areas. The mtDNA results confirmed that all individuals formed one group or clade. Overall, the results indicate that T. leucotreta individuals from the six areas and three host species in the Western Cape Province and two other provinces in South Africa represent a single genetical species. The results imply that similar control options can be effective across host ranges and distribution areas.

Glossina medicorum Aust. was collected in considerable numbers in thicket near to Accra, Ghana. The habitat was unusual in that the thicket rarely exceeded 15 ft. in height and big trees were entirely absent. Grassy open spaces within the thicket provided the feeding grounds and a list of possible hosts is given.

There was some suggestion of an association between the abundance of flies and the rainfall in 1958 but noti in 1959, while the size of the flies was inversely correlated with the saturation deficit.

Walnuts grown and shelled in the Dordogne and adjacent regions of France are exported to Britain and other countries. The inspection of cargoes arriving at Liverpool between July 1955 and July 1958 has shown that they may frequently be infested by a number of species of insect pests. Of the 20 species recorded, six occurred regularly. These were Oryzaephilus surinamensis (L.), Aphomia gularis (Zell.), Plodia interpunctella (Hb.), Cryptophagus subfumatus Kraatz, Nemapogon granella (L.) and Enarmonia sp. During that period, changes occurred in the levels of infestation on parcels and the relative abundance of the species. In particular, there was a considerable increase in the occurrence of O. surinamensis. Though the general levels of infestation were light, parts of 58 per cent, of the cargoes had to be fumigated to prevent pests being distributed to factories, bakeries and shops in Britain and on transhipped parcels to Canada, U.S.A. and the Eepublic of Ireland. Though many of the species found are already established in those countries where conditions are suitable for their development some are still limited in their distribution. These include A. gularis, a serious pest of nuts, dried fruit and cereals. If the further spread of this and the other pests is to be prevented there is need for a more general application of control measures in the country of origin with strict control and possibly fumigation of cargoes before shipment.

In a study of the effect of different concentrations of radioactive phosphorus (32P) in the larval medium on the growth and development of Culex pipiens molestus Forsk., 32P was found to have little noticeable effect on the growth of the larvae up to a concentration of 3·0 microcuries (μc.) of 32P per ml., but, above this concentration, larval growth was greatly retarded.

The period of larval development was increased at concentrations greater than 1·0 μc. of 32P per ml., and pupation occurred two weeks later than in the controls. In concentrations higher than 5·0 μc./ml., pupation was completely inhibited, larvae became sluggish, stopped feeding and finally died.

The effect of 32P in the larval medium on the emergence and radioactivity of the resulting adults was also studied. On the basis of this study, it is recommended that, for efficient utilisation of radio-phosphorus in large-scale field experiments, a concentration of 32P of 1·0 μc./ml. be employed so that emerging adult mosquitos may be sufficiently radioactive to be readily detectable.

Food availability is a fundamental factor determining an animal's potential fitness. Carry-over effects of food limitation from development to adulthood are known to influence reproduction, ageing, and tolerance to stress. We have examined the effect of stage-specific variation (before adult emergence or pre-emergence, post-emergence and post-mating) in food availability in Propylea dissecta (Mulsant). Larvae were reared separately on two different pre-emergence food regimes (abundant or restricted) until pupation. Newly emerged adults were further split into two groups and placed on abundant or restricted post-emergence regimes. After mating, females were split and reared on any one of two post-mating regimes. The results revealed that: (i) time to commence mating declined with increased food availability in pre- and post-emergence stages, (ii) mating duration increased with food availability post-emergence, (iii) highest reproduction output was observed in individuals who had abundant food pre- and post-emergence. However, food availability at the time of oviposition also had a strong influence on fecundity. Solo bouts of scarcity, regardless of which stage suffered them, were effectively managed in at least two of the three stages (pre-emergence, post-emergence, post-mating) had abundant food.

The number of eggs produced by females of Anobium punctatum (Deg.) (Col., Anobiidae) was determined at Auckland, New Zealand, during annual emergence in December 1957. The females were collected before mating and egg-laying occurred. Each female was weighed and then confined, with males, to an egg-laying block of sapwood of Podocarpus dacrydioides. The average number of eggs per female was 54·8, far higher than obtained from field-collected females, and additionally the egg-laying distribution was neither skewed nor censored. Following a short preoviposition period, eggs were laid rapidly, egg-laying being virtually finished by the 15th day after emergence. Females lived a few days after egg-laying had ceased, maximum length of life being between 24 and 31 days.

For about 60 per cent, of females the number of eggs laid was closely related to the initial weight of the female, but the remaining females laid fewer eggs in relation to their weight.

Allatectomy of newly emerged house-flies (Musca domestica L.) prevents maturation of the ovaries, and experiments were done to find whether this affected the sensitivity of the flies to insecticides.

The apparatus and operational procedure for removing the complex comprising the corpus allatum and corpora cardiaca are described.

Females of a diazinon-resistant strain (SKA) were allatectomised less than 12 hr. after emergence, and when three days old their sensitivity to diazinon, dieldrin and pyrethrum extract was tested by topical application. Approximately equal numbers of intact females were tested simultaneously, and untreated controls of both kinds of flies were included in every test. The failure of the ovaries to mature in allatectomised flies was confirmed by examination of a majority of the operated flies that lived for four days, and normal development of the ovaries of intact flies was similarly confirmed.

The results showed that there was no difference in sensitivity between allatectomised and normal flies. It is concluded that allatectomy does not affect susceptibility to the insecticides used. Since earlier work had shown that a 9- to 18-fold increase in resistance to diazinon takes place during the period from emergence to the third day afterwards, it is further concluded that this increase is unaffected by allatectomy and the failure of the ovaries to mature.

Egg-pods of the Red Locust (Nomadacris septemfasciata, Serv.) deposited on the 17th January 1933 at Mazabuka, Northern Rhodesia, were kindly sent by air-mail to the Imperial Institute of Entomology by Mr. W. Allan. On their arrival 14 days later, the eggs were found to be perfectly healthy, apart from some having been damaged by pressure. Entire egg-pods, with the surrounding soil, were placed in wet sand in flower-pots and put in a glass cage. The temperature in the cage was kept at 100°F. during the day and 80°F. during the night, but that of the sand was probably somewhat lower. Hoppers began to hatch on the 2nd of March and were kept at the same temperatures, with a humidity as near the saturation point as could be maintained. The first adult appeared on 8th April, and the majority of hoppers became adult by the 18th of April, six and a half weeks after hatching. Owing mainly to cannibalistic habits of the hoppers, only about 40 adults were obtained.

It was obviously impossible to plan any serious experiments with such a small number of locusts available, without risking the loss of the entire stock, and it was decided to use them for a preliminary experimental test of the conditions necessary for the sexual maturation. This particular problem is of great practical importance and no data bearing on it were available.

In a previous paper (Pospelov, 1926a) I pointed out that adult locusts (Locusta migratoria migratoria, L.) kept in a cage at a constant temperature of 35–38°C. (95–100°F.) and at sufficient humidity attained sexual maturity in a month, while those kept at 20–30°C. (68–86°F.) failed to mature even after three months.

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.

Cordia macrostachya (Jacq.) R. & S., is a Boraginaceous shrub indigenous to the West Indies, Central America, and northern South America. It was accidentally introduced into Mauritius about 1890, probably from British Guiana, and became a weed of major importance.

A comparative ecological study of Cordia in Mauritius and in Trinidad showed that its invading power in the former island rested upon a profuse production of viable fruits, whereas in Trinidad, where the plant is of no agricultural concern, fruit production was controlled by the combined action of a number of insects. It was accordingly decided to introduce suitable species of these insects into Mauritius.

The first to be introduced was a leaf-eating Cassidid beetle, Physonota alutacea, but as described elsewhere, this introduction, which took place in 1947–48, was not a success.

The introduction of the second species, Schematiza cordiae Barber, and its result, is described in the present paper. This Galerucid is also a leaf-feeder, but it will sometimes feed upon the inflorescences.

Through the agency of the Commonwealth Bureau of Biological Control, air consignments of Schematiza were received between June and September, 1947. Breeding was started, and after feeding tests in both Mauritius and Trinidad had established its specificity to C. macrostachya, the release of laboratory reared adults was commenced in March, 1948. In February, 1949, after about 18,000 had been released, breeding was no longer necessary for large populations had developed in the field and were inflicting severe injury to Cordia scrub. Dispersion of the insect over the island followed quickly, and was assisted by the collection and distribution of about 60,000 adults. Schematiza became extremely abundant so that by the middle of 1950 most expanses of scrub in the island had either been stripped of leaves and inflorescences, or had generally been severely defoliated.

As a result, much scrub is dead owing to a prolonged period without foliage, much is being subjugated by other vegetation, while partial defoliation and direct inflorescence attack have reduced the reproduction of other bushes.

This rapid control of C. macrostachya is attributed to the high fecundity of the Schematiza combined with its freedom from parasites and important predators, and to its suitability to the climates of all Cordia infested regions.

Random amplified polymorphic DNA (RAPD) analysis was applied to 120 individuals of Marchalina hellenica (Gennadius) representing six populations collected in northern, central and southern mainland Greece. One population was sampled on one species of fir tree and the others on two species of pine trees. Four random decamer primers were used to evaluate genetic variation among the populations examined. The results revealed intra- and interpopulation polymorphism both related to host type and region of origin. Phylogenetic analysis based on genetic distances estimated by the RAPD frequencies revealed an important genetic differentiation in samples collected on fir trees in southern Greece and to a lesser extent in samples from pine trees in central and northern Greece. Furthermore, considerable subdivision and restricted gene flow among the populations examined were observed. The results are discussed in relation to the biology and geographical distribution of M. hellenica in Greece.

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is recognized as an invasive pest in Europe and North America. In Mexico, it is one of the main insect pests of soft-skinned fruits such as blueberries, strawberries, raspberries, blackberries, plums, and guava. Previous studies have shown that D. suzukii uses visual and chemical cues during host plant searching. This knowledge has been used to develop traps and attractants for monitoring D. suzukii. In this study, five trap designs were evaluated to monitor D. suzukii under field conditions. Traps were baited with SuzukiiTrap®, Z-Kinol, an attractant based on acetoin and methionol, or apple cider vinegar (ACV) enriched with 10% ethanol (EtOH) with the synergistic action of carbon dioxide (CO2). Our results suggested that the attractant was the determining factor in capturing D. suzukii, while trap design seemed to play a modest role. We found that traps baited with Z-Kinol captured the highest number of D. suzukii compared to that caught by traps baited with SuzukiiTrap®, or ACV + EtOH + CO2. The highest catch numbers occurred in blackberry, followed by strawberry, raspberry, and blueberry. Traps captured more females than males. The results obtained may be useful for monitoring D. suzukii populations in Mexico and elsewhere, particularly in states where soft fruit crops are a component of agricultural activities.

The quantities of lipophilic dyestuff picked up by specimens of five insect species, namely Vespula vulgaris (L.), Feronia madida (F.), Rhagonycha fulva (Scop.), Dysdercus fasciatus Sign, and Notostira erratica (L.), in their first few steps on a dust deposit of the dyestuff have been estimated. The uptakes per step by insects of different size and structure were shown to differ only slightly. While the uptake was found to be greater for the larger insects, the smaller insects picked up more particles per unit body weight at each step.

The ratios of the actual amounts (estimated by a colorimetric method) picked up by the different pairs of legs are similar for all the insects that have been studied and in all cases the hind legs were shown to pick up an amount at least equal to the sum picked up by the fore- and middle legs.