Descriptions are given of the tomato erineum mite, Aceria lycopersici, and the tomato russet mite, Vasates lycopersici, in Morocco, from which country the latter species is recorded for the first time.

A. cladophthirus is shown to be a synonym of A. lycopersici.

These two mites are almost world-wide in distribution and probably occur in most countries where tomatos are grown, but A. lycopersici has not been recorded from Australia or New Zealand.

Reference is made to the several species of scale insects which were pests on coconuts and to the Coccinellids which were introduced to combat them.

The introduction and life-history of Chilocorus nigritus is described.

The survival of the introduced Coccinellids and the part each has played in controlling the several species of scale is noted.

The habits of some indigenous Coccinellids are recorded.

The coconut-feeding Coccids of the Seychelles are listed and their economic role mentioned.

The incidence of “sooty-mould” and the species of Coccids responsible for its growth are discussed.

An estimate is made of the value of the control effected by the Coccinellids in terms of increased copra production.

The effect on the eggs of the common furniture beetle, Anobium punctatum, to fumigation with hydrogen cyanide at a concentration of 4·25 mg./litre and four concentration/time exposures, varying from 4·3 to 42·5 mg. hr. per litre has been determined. Complete mortality was obtained in all cases. Comparison with data available for larvae show that the eggs are less resistant, from which it is concluded that commercial treatments adequate for infested wood will also kill eggs.

All stages of Argas persicus were found in crevices in the bark of 49 of 266 trees belonging to 16 species in West Pakistan. These trees had not been used as roosts by domestic birds. The infestation seemed to be restricted to those trees used by vultures (Pseudogyps bengalensis) or herons (Ardea cinerea) for nesting or roosting. Several of the ticks collected contained recently sucked avian blood in the gut but intramuscular injection of crushed material from the ticks into a hen produced no blood infection.

Infested trees may be important as sources of the pest near poultry farms and chicken houses.

The diamond-back moth, Plutella maculipennis, and Crocidolomia binotalis are the main pests of cabbage in Indonesia. Until 1951, good control was obtained with DDT sprays and dusts, but in that year growers near Lembang (Bandung) obtained poor results with DDT against P. maculipennis as compared with previous years. Investigations were started in Lembang, and also in Patjet (on Mt. Gedeh) where no difficulties had arisen. In laboratory experiments, a marked difference in susceptibility to DDT between a Lembang and a Patjet strain of P. maculipennis was demonstrated.

In field tests near Patjet with DDT, BHC and toxaphene, DDT gave satisfactory control and was better than the other two. At Lembang, however, where these three materials were again tested, but with derris and pyrethrum also, toxaphene was the most effective, followed by derris and BHC, while DDT, and also pyrethrum, gave almost no control.

For the time being, toxaphene and derris are recommended, the former during the growing season and the latter subsequently, but it is feared that resistance to toxaphene will develop. It may become necessary to resort to cultural and biological measures.

The geographical ranges of Sahlbergella singularis and Distantiella theobroma overlap, and the Gold Coast lies in the zone common to both. The respective northern limits remain to be determined, and should be investigated to the north of the main cacao belt, from Kintampo to the Afram plain.

The same area should also yield information on the possible importance of alternative hosts in the dispersal of cacao Mirids, as the small stands are well separated from each other.

Earlier records, that D. theobroma is confined to seedlings and S. singularis to mature trees, are erroneous. D. theobroma is found on pods and, particularly, chupons. The feeding range of S. singularis includes fan branches in addition, but breeding is confined to chupons and pods.

Observations suggest that there is competition for breeding sites on chupons. Of the many chupons in an area only a small number is available to Mirids, and the proportion of nymphs reaching maturity is limited by their sedentary habit and the destructiveness of their feeding.

Co-existence of the two species is possible by their slightly different habits. S. singularis produces more eggs, but is more diffusely distributed. D. theobroma is virtually restricted to chupons, but can quickly build up a large population in favourable areas by its greater rate of egg production.

In Nigeria, the rate of egg production by D. theobroma is less than that by S. singularis, and this, together with the sparsity of chupons, may account for the unimportance of D. theobroma in that country.

The resistance to a 5 per cent. DDT powder of 36 species of adult and larval Coleoptera which infest stored products has been determined. The species are grouped according to the time required to effect 95 per cent. kill. In the data for adults, the slopes of the probit regression lines were not significantly correlated with the log-times for 50 per cent. kill. No obvious connection could be seen between the degree of resistance to the insecticide and size, activity, hairiness, etc., but larvae tended to be much more resistant than the corresponding adults.

The period of digestion of the blood meal of 10 different blood-sucking arthropods which had been artificially and naturally fed on known hosts was studied by means of specific precipitin tests.

A large proportion of positive feed (80–100 per cent.) was found with midges and mosquitos up to 24 hours, whether naturally (Anopheles aquasalis) or artificially fed (A. maculipennis atroparvus, Culex molestus, Culicoides nubeculosus, Aëdes aegypti).

Tsetse flies showed greater differences between the rate of digestion of captive flies (Glossina morsitans), which showed 90–100 per cent. positive feeds at 3 days after the experimental blood meal, and wild flies (G. swynnertoni) which showed only 28 per cent. positive meals after a similar period of digestion. Arachnids showed both the longest period of digestion, more than 6 months for Ornithodoros moubata and also the shortest period as represented by Bdellonyssus bacoti (about 1 day).

Cimex lectularius showed 90 per cent. positive feeds after 10 days.

Lumsden's “standard sunset” period observations have been repeated with the three commonest species of Anopheles occurring in Trinidad. The method was modified to yield data on the ovarian and fertilisation states of these three species over a period of ten months which included the dates of the latest and earliest sunset at 10°N.

A. aquasalis comprised nearly 95 per cent. of a total catch of 8,592 specimens. Just over 18 per cent. of those that attacked were newly emerged, and no more than half of these were fertilised. Relict eggs, denoting a second or later gonotrophic cycle, were found in February, June and July. The 40 minutes from sunset + 20 minutes yielded nearly 80 per cent. of the total of the first two hours of activity, this period comprising nearly half the estimated total night's attack. From one hour after sunset the proportion of newly emerged specimens that attack is well below the mean. The second hour after sunset therefore provided the greatest infection risk when age, not numbers attacking, is considered.

Ptinus tectus occurs on a large range of foodstuffs in all types of storage places, in warehouse refuse and in the nests of birds. It is widely distributed in cool and temperate areas but is very rarely found in hot climates. In Britain it can survive the winter when exposed in a Stevenson screen to outdoor shade conditions. P. tectus is seldom found on imported cargoes inspected aboard ship, but many British warehouses carry a population of the species resident in the fabric of the premises.

The larva is able to bore through cellophane, card and textiles and can also make impressions on wood. The fully fed larva spins a cocoon on the fabric of containers and buildings. Holing of packages and contamination by silk of high grade produce form the chief economic losses caused by the species, but occasionally large populations are found, sufficient to reduce the food value of produce. Unlike the larvae, adult beetles cannot penetrate sound linen bags, but lay eggs through the meshes.

In a series of consecutive experiments, performed identically as far as possible, variations in the length of developmental period and in emergence weight of adult beetles were greater than would be expected by chance. The variations could not be related to any single observed or suspected inconsistency of technique or environment. It is desirable therefore to conduct comparative experiments simultaneously.

These notes are the result of an examination of the literature and are concerned with geographical distribution. The Review of Applied Entomology, Series B, and the Tropical Diseases Bulletin were consulted and many papers were seen in the original; references to a selection of the more important of these is appended herewith. Of the ticks of the genus Ornithodoros occurring in the Old World about 40 names appear in published papers; of these about 20 seem to be valid species and five are well known and readily recognised: erraticus, lahorensis, moubata, savignyi and tholozani.

Laboratory spraying experiments were carried out with DDT, allethrin, the triethanolamine salt of 3:5 dinitrocresol (TDNOC) and HETP against eggs of different ages of Diataraxia oleracea (Lepidoptera) and with allethrin, HETP and TDNOC against eggs of different ages of Ephestia kühniella (Lepidoptera) and Dysdercus fasciatus (Hemiptera) under controlled temperature and humidity conditions.

The following Coccid was first recorded as a probable new species of Saissetia by Dr. W. J. Hall in Nutman and Sheffield (1949, p. 437), who suggested that it might be regarded as a possible vector, should a virus be the cause of Suddendeath disease of cloves. Although further research has shown that this disease is not caused by a virus, the species is of particular interest in its relationship with ants and this has been the subject of a special study by M. J. Way (in press).

Onions and related crops are attacked by the onion fly, D. antiqua (Mg.), and by the bean seed flies, D. cilicrura (Rond.), and D. trichodactyla (Rond.). The eggs, larvae and puparia of the three species are similar in form, and the only morphological difference so far observed is in the number of processes of the anterior spiracles of the larvae. In D. antiqua the anterior spiracles have 10–13 processes; in D. cilicrura and D. trichodactyla, the immature stages of which cannot yet be distinguished from each other, the anterior spiracles have 5–8 processes.

Onion flies and bean seed flies have different habits and consequently the circumstances of their attacks differ. The onion fly is a specific feeder and its attacks are likely to be serious in spring and early summer. The bean seed flies are general feeders and attack on onions in spring is unlikely because the preparation of the soil, which attracts the flies, is usually completed before they emerge from the over-wintering puparia. Bean seed fly attack on onions is likely to take place in August when onions for bunching are sown. The preparation of the seed bed attracts the flies of the third generation from the surrounding crops and the soil may become heavily infested with larvae which subsequently destroy the germinating seeds. In August and September it is unlikely that young crops will attract onion flies from the mature crops on which they are established.

Preliminary experiments are described of applications from aircraft of coarse sprays and coarse aerosols. The experiments were carried out over dense forest areas containing the tsetse fly G. palpalis.

At dosages of 0·2 lb. per acre of the p,p'isomer of DDT, or 0·032 lb. per acre of the γ isomer of BHC, both the sprays and the aerosols were relatively ineffective, and significant kills were obtained only with the aerosols.

The sprays were ineffective not only because they did not penetrate the canopy, but also because the nominal dosage was in any case too small to produce lethal deposits upon vegetation.

Much of the aerosol was filtered out by the upper layers of the canopy. The meteorological conditions in the area were also unsuitable for the application of aerosols, and much of the insecticide did not reach the canopy, but was blown away from the treated area.

It is concluded that aircraft applications of insecticide against G. palpalis are wasteful of insecticide, and would be very costly if substantial reductions in fly population were to be obtained. If insecticides are to be of value in such areas, ground methods of applying them would be almost certainly more effective, and less costly.

An experimental attempt was made to produce a fly-free corridor through a belt of savannah woodland containing the tsetse fly G. swynnertoni.

An area two miles wide and four miles long was treated with a coarse spray of a 4·6 per cent, w/v solution of DDT in Shell Diesoline. The dosage per application was 0·5 gallons per acre, and seven applications were made, at intervals of approximately two weeks, so that the treatment covered two pupal periods.

The fly density had fallen to a very low level by the end of the experiment, and the area remained virtually free from flies for the subsequent two months. An examination of the data suggests, however, that the fly population was maintained largely by immigrant flies, and was certainly subject to wide variations, and it seems certain that the effect of the applications would have been considerably less upon a stable, self-supporting population.

The drop spectrum of the ground deposit had a mass median diameter of 0·35 mm., and the recovery of insecticide in the area was approximately 60 per cent. Leeward and under sides of obstacles did not receive a dose although in some cases dosages were obtained on apparently leeward sides, probably because of local reversals of wind direction.