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.

Field trials were carried out in order to evaluate some of the factors affecting male response of the almond seed wasp, Eurytoma amygdali Enderlein, to traps baited with the alkadienes (Z,Z)-6,9-tricosadiene and (Z,Z)-6,9-pentacosadiene, the male attractant of this species. The trials were conducted in Latomia, Microthivae, Kanalia and Sykourion (Thessaly, Central Greece) during the 2004 growing season. In all regions, captures in traps baited with a 7:3 ratio of the above blend significantly and positively correlated with male emergence from infested almonds that had been placed in cages in the experimental fields. Traps baited with the 7:3 pheromone ratio were significantly more effective in capturing males than traps baited with the 1:1 ratio, supporting the hypothesis that (Z,Z)-6,9-tricosadiene is the main component of this attractant. Of four trap types tested, Rebel and Lasiotraps attracted significantly more males than Delta and Funnel traps. Height had no effect on trap efficiency; however, males were captured earlier in the day in traps placed 2.3 m above grown than in traps placed 1.3 m above grown. Most male activity was recorded between 10 and 12 h, but captures were continuously recorded during the entire monitoring interval from 6 to 17 h.

The effect on aphid population development of creating natural enemy refuges by spraying only alternate strips of winter wheat with the aphid-specific insecticide pirimicarb at 140 g a.i./ha was compared with those in an unsprayed and a completely sprayed block in south-eastern England. The numbers of Sitobion avenae (F.), Metopolophium dirhodum (Walker) and Rhopalosiphum padi (L.) increased rapidly in the unsprayed block and in the unsprayed strips to reach similar peak densities in early August. Natural enemy activity was similar in these two areas, indicating negligible movement of predators and parasitoids from the sprayed strips to the unsprayed strips. Instead, aphids re-colonized the sprayed strips more quickly than the sprayed block, and the peak density in the former was similar to those in the unsprayed areas.

A number of tettigoniids belonging to the genera Sexava, Segestes and Segestidea are responsible for severe defoliation of coconut palm, oil palm and Pandanus spp. in Papua New Guinea. Most chemical and cultural methods of control are either impractical or uneconomic. The possibility of biological control was examined with reference to some of the natural enemies of Segestes decoratus Redtenbacher, in particular a parasite of nymphs and adults, Stichotrema dallatorreanum Hofeneder, as well as the egg parasites Triteleia atrella (Dodd), a species of Tetrastichus near T. dubius (Waterston) and a second species of Tetrastichus. It was concluded that S. dallatorreanum contributed to the control of Segestes decoratus in areas with an evenly distributed rainfall and that the parasite had potential as a biological control agent in areas where it is not endemic against pest species of Sexava, Segestes and Segestidea. A survey of the egg parasites showed that they were not effective in controlling the pests as they were only able to parasitize eggs in exposed oviposition sites. Egg predators of unknown identity were responsible for higher egg mortality than were the egg parasites.

Gene flow based on the spatial distribution of rare alleles at 25 gene loci was estimated in 15 populations of Ceratitis capitata (Wiedemann) from different parts of the world. Estimates of Nm, the number of migrants exchanged per generation among populations in different regions of the world, appeared to be quite similar, ranging from 3.36 in tropical Africa to 2.94 in the New World and 2.72 in Mediterranean basin populations. This suggests that gene flow among neighbouring populations of medfly is quite extensive. The genetic differentiation in American, Mediterranean and African populations was related to major climatic differences between North and South. These differences arise mainly from five loci that showed gene frequency patterns suggestive of latitudinal clines in allele frequencies. The clinal variation was such that tropical-subtropical populations were more heterozygous than temperate populations. It was concluded that gene flow, counteracting the forces of natural selection and genetic drift, determines the extent to which geographical populations of C. capitata are differentiated.

Two field strains of Lucilia cuprina (Wied.) of different susceptibilities to diazinon were selected over 25 generations by immersion of first-instar larvae in aqueous emulsions of diazinon for five minutes ; the resistance of the larvae and adult females was compared with a standard laboratory susceptible strain. Resistance increased rapidly in both strains, reaching a maximum for adult females (R.F. = 5–6) in generation 3 and for larvae (R.F. = 46–60) in generation 6. After removal of selection pressure at generation 8 the resistance factor fell to 20–24 by generation 25. Because the resistance mechanisms are known to place their carriers at a disadvantage in the absence of selection pressure, the practical implications of the rapid increase in resistance must await results of experiments with known genotypes.

The correct identification of sand fly vectors of leishmaniasis is important for controlling the disease. Genetic, particularly DNA sequence data, has lately become an important adjunct to the use of morphological criteria for this purpose. A recent DNA sequencing study revealed the presence of two cryptic species in the Sergentomyia bailyi species complex in India. The present study was undertaken to ascertain the presence of cryptic species in the Se. bailyi complex in Sri Lanka using morphological characteristics and DNA sequences from cytochrome c oxidase subunits. Sand flies were collected from leishmaniasis endemic and non-endemic dry zone districts of Sri Lanka. A total of 175 Se. bailyi specimens were initially screened for morphological variations and the identified samples formed two groups, tentatively termed as Se. bailyi species A and B, based on the relative length of the sensilla chaeticum and antennal flagellomere. DNA sequences from the mitochondrial cytochrome c oxidase subunit I (COI) and subunit II (COII) genes of morphologically identified Se. bailyi species A and B were subsequently analyzed. The two species showed differences in the COI and COII gene sequences and were placed in two separate clades by phylogenetic analysis. An allele specific polymerase chain reaction assay based on sequence variation in the COI gene accurately differentiated species A and B. The study therefore describes the first morphological and genetic evidence for the presence of two cryptic species within the Se. bailyi complex in Sri Lanka and a DNA-based laboratory technique for differentiating them.

Walking speeds were calculated for nine clones of the peach potato aphid Myzus persicae collected from three countries along a latitudinal cline of its European distribution from Sweden to Spain (Sweden, UK and Spain), and the effects of collection origin and intra and intergenerational acclimation were investigated. Walking speeds declined with decreasing temperature, with maximum performance at temperatures closest to acclimation temperature (fastest median walking speed of 5.8 cm min–1 was recorded for clone UK 3, collected from the UK, at 25°C after acclimating to 25°C for one generation). Following acclimation at both 20°C and 25°C, walking ceased (as indicated by median walking speeds of 0.0 cm min–1) at temperatures as high as 7.5°C and 12.5°C. However, acclimation at 10°C enabled mobility to occur to temperatures as low as 0°C. There was no relationship between mobility and latitude of collection, suggesting that large scale mixing of aphids may occur across Europe. However, clonal variation was suggested, with clone UK 3 outperforming the majority of other clones across all temperatures at which mobility was maintained following acclimation at 10°C for one and three generations and at 25°C for one generation. The Scandinavian clones consistently outperformed their temperate and Mediterranean counterparts at the majority of temperatures following acclimation for three generations at 25°C.

Lymantia dispar (L.) (Lepidoptera: Lymantriidae), commonly known as the gypsy moth, is a serious forest pest, and beneficial insects are particularly important for reducing its population numbers. Ooencyrtus kuvanae (Howard) (Hymenoptera: Encyrtidae) is an arrhenotokous, solitary egg parasitoid of L. dispar. In this study, we evaluated a new substitute host, Philosamia ricini (Danovan) (Lepidoptera: Saturniidae) for O. kuvanae. We investigated some of the biological effects of O. kuvanae on P. ricini eggs. In this context, the importance of the age of the female parasitoid (1, 3 or 5 days old), host age (1–2 and 3–4 days old) and host number (40, 60 and 80 host eggs) were examined under laboratory conditions (25 ± 1 °C, 65 ± 5% relative humidity and a 16 : 8 h photoperiod [light : dark]). The highest rate of offspring production (89.90%) occurred with 40 (1–2-day-old) host eggs and 5-day-old females. The mean developmental period ranged from 16.5 ± 0.08 days to 18.7 ± 0.08 days. The mean lifespan of the parasitoid was 51.10 ± 1.1 (n = 60) days with bio-honey and 3.92 ± 0.14 (n = 60) days without food. The mean fecundity was 68.88 ± 3.22 offspring/female. Peak adult emergence occurred between 2 and 9 days. The mean oviposition and mean post-oviposition periods of the female parasitoid were 22.76 ± 1.37 days and 13.64 ± 1.40 days, respectively. O. kuvanae was reared for more than ten generations on the eggs of P. ricini. Based on our findings, P. ricini can be used to rear O. kuvanae for the biological control of L. dispar.

The compilation of the following key has been a matter of no little difficulty, mainly owing to the close connection of the species in some of the groups, which sometimes makes it almost impossible to assign specific limits. The difficulty has in some cases been increased through the paucity of material, which prevents any adequate conception of the range of variability being obtained. This is particularly the case with some of the species coming from the Mediterranean region, which are very closely allied, and of which, as a rule, the British Museum possesses very few specimens. Names have only been sunk here as synonyms in those cases where there appeared to be no reasonable doubt, either after a comparison of the types, or of the descriptions, when these were sufficiently detailed. Eventually, therefore, it may be found that some forms which are here given specific rank will have to be regarded at most as varieties. Since so many figures of Anopheline wings, etc., have already appeared, it is not deemed necessary to add to their number. Some new records have been included, but on the other hand some old ones, which appeared to be questionable, have been omitted. As with the writer's previous papers, this key is merely intended to supplement the detailed descriptions which will be found in other works.

The acceptance of different provenances or seed origins of lodgepole pine Pinus contorta and Scots pine P. sylvestris as suitable oviposition sites was found to vary as a function of both tree age and insect species. Experiments on seedling lodgepole pine revealed that the pine sawfly, Neodiprion sertifer Geoffroy (Hymenoptera: Diprionidae), and the larch bud moth, Zeiraphera diniana Guennée (Lepidoptera: Tortricidae), preferred more southerly provenances of lodgepole pine. The pine beauty moth, Panolis flammea Denis & Schiffermüller (Lepidoptera: Noctuidae), however, preferred more northerly provenances. On mature lodgepole pine however, P. flammea exhibited a host change, preferring the more southerly provenances. Neodiprion sertifer showed a similar preference on both seedling and mature provenances. The results of this study suggest that some provenances of lodgepole pine become more resistant to attack by P. flammea as they mature, while others become more susceptible. This may be related to the feeding, strategies of the two insects: P. flammea larvae feed on current year foliage while N. sertifer feeds only on previous year foliage. It is possible that the mechanism for chemical defence of new shoots changes as the trees mature, and to a varying degree in different provenances, while defence of the previous years foliage remains unchanged. Results also indicate that odour alone as opposed to odour plus visual stimulation may invoke different ovipositional behaviour in N. sertifer.

Descriptions are given of the larvae and pupae of Uranotaenia nigripes, Theo., Hodgesia sanguinis, Theo., H. malayi, Leic. (larva only), Aëdes (Banksinella) punctocostalis, Theo., A. (Aëdimorphus) abnormalis, Theo., A. (A.) tarsalis, Newst., and Ficalbia malfeyti, Newst.

H. sanguinis is remarkable chiefly for the structure of the respiratory trumpets of the pupa, each of which is cleft almost to the base in the form of two leaflets.

For a number of years reports have been received from the banana-growing districts of Central and northern South America of a large white grub occasionally discovered in extensive borings in the base of banana pseudostems. While in the Santa Marta region of Colombia, the writer readily succeeded in rearing the adult, which turned out to be the Castniid moth, Castniomera humboldti (Boisduval), and was able to devote a short time to the study of the insect, discovering not only that it is far more abundant than has been supposed, but also that its presence has a very serious effect on the production of bananas.

When I was revising the genera of the DIPRIONIDAE (Benson,1939), the British Museum had very scanty material of Neodiprion other than of the sole Palaearctic representative of the genus, N. sertifer (Geoffr.). The few North American specimens of the genus, only five females belonging to five species and a few unnamed males, were all ancient specimens in poor condition and pinned so as to obscure the shape of the scutellum. I had therefore to supplement my knowledge of Nearctic Neodiprion by information kindly sent to me by the late Miss Grace Sandhouse, gleaned from specimens in the collections at Washington. Atwood and Peck (1943), in dealing with long series of Canadian Neodiprion, have since found that the shape of the scutellum, as defined in my paper, is rather difficult to interpret and is liable to considerable individual variation.

In several previously published papers dealing with African Diptera I have described a number of species belonging to the genus Sturmia, Desvoidy, but up to the present time have not had sufficient material available to warrant the preparation of a key to the species, nor have I had an opportunity of studying the species in sufficient detail to decide upon characters of value in their classification. However, since many species were reared and it was desirable to have names for them in order that they might be used in reports by various Entomologists in Africa, a number of the species were described, and it has since been possible to make considerable progress in the study of the whole. As a result a key to the species belonging to this genus is now presented, and it is hoped that it will be of assistance in identifying the representatives of this difficult group.

It is further hoped that arrangements may be made in the near future for the publication of a key to the genera of the Tachinidae, since it is obvious that with the very large number of genera described, the description of an additional genus, or even of new species in old genera, conveys little of the true relationships of the forms described and merely adds to the difficulty of making determinations.

The apple buprestid, Agrilus mali Matsumura, that was widespread in north-eastern China, was accidently introduced to the wild apple forest ecosystem in mountainous areas of Xinjiang, China. This invasive beetle feeds on domesticated apples and many species of Malus and presents a serious threat to ancestral apple germplasm sources and apple production worldwide. Estimating the potential area at risk of colonization by A. mali is crucial for instigating appropriate preventative management strategies, especially under global warming. We developed a CLIMEX model of A. mali to project this pest's potential distribution under current and future climatic scenarios in 2100 using CSIRO-Mk 3.0 GCM running the SRES A1B emissions scenario. Under current climate, A. mali could potentially invade neighbouring central Asia and eventually the mid-latitude temperate zone, and some subtropical areas and Pampas Steppe in the Southern Hemisphere. This potential distribution encompasses wild apples species, the ancestral germplasm for domesticated apples. With global warming, the potential distribution shifts to higher latitudes, with the potential range expanding slightly, though the overall suitability could decline in both hemispheres. In 2100, the length of the growing season of this pest in the mid-latitude temperature zone could increase by 1–2 weeks, with higher growth rates in most sites compared with current climate in mid-latitudes, at least in China. Our work highlights the need for strategies to prevent the spread of this pest, managing the threats to wild apples in Tian Shan Mountain forests in Central Asia, and commercial apple production globally. We discuss practical management tactics to reduce the spread of this pest and mitigate its impacts.

Treatment of rice fields in Sri Lanka with monocrotophos at 10 mg/litre or pirimiphos-methyl at 0·1 mg/litre gave a selective advantage to larvae of Anopheles subpictus Grassi and A. nigerrimus Giles carrying the oxidase- and acetylcholinesterase-based resistance genes, respectively. However, this selective advantage was apparent for less than ten days after spraying. There was no mortality of any larval instar with monocrotophos 12 days after spraying, and no fourth-instar larval mortality with pirimiphos-methyl 17 days after spraying. The chemical degredation curves for these compounds indicated that this short duration of efficacy was due to the instability of the compounds in water under field conditions. In contrast, the new growth regulator S-31183 (2-[1-methy1-2-(4-phenoxyphenoxy)ethoxy]pyridine) sprayed at 0·1 mg/litre conferred no selective advantage to larvae with either resistance mechanism and had a total efficacy period of at least 71 days. This difference can be attributed to the greater toxicity of the growth regulator and its slower chemical degradation under field conditions when compared to the organophosphates.

The term “Bush Locust” is defined.

The synonymy and known distribution of Phymateus aegrotus are given and previously published records of its occurrence are reviewed.

The occurrence of hopper-bands, and of adults, in East Africa for the years 1938–47, inclusive, is outlined.

P. aegrotus and other species of the genus are normally unimportant economically as adults, but the hoppers form bands after the manner of, though on a much smaller scale than, true locusts. Outbreaks of these hopper-bands appear to be sporadic but they are sometimes destructive to crops.

P. aegrotus has usually been of only local importance as an agricultural pest but areas in which the crops have been damaged are noted. Among wild host-plants there appears to be a preference for Euphorbiaceae although the hoppers are more or less polyphagous.

Other East African species which form hopper-bands and which are known to attack crops are mentioned.

The life-history of P. aegrotus is described so far as it is known, and observations made by Dr. H. B. N. Hynes on the closely related species, P. pulcherrimus, in Ethiopia are also recorded.

Reflex actions in Phymateus species, including such phenomena as autohaemorrhage and colour display by the adults when alarmed, are noted and the literature on the subject is reviewed.

Observations are made on hopper behaviour and band-size of P. aegrotus. The latter is usually only a square yard or two in extent but bands up to 25 square yards in area have been observed by the author and there are reports of even larger ones. These bands are very dense both when marching and when stationary (60–80 finalinstar hoppers per square foot). Notes on areas of infestation are also given.

In most cases it is sufficient to beat out the bands with branches. Poison bait and dusting with 7 per cent, di-nitro-ortho-cresol are also successful.

Detailed descriptions of the coloration of final-instar hoppers of P. aegrotus and the other East African Phymateus species discussed are given. Keys for the identification of these hoppers and of the adults of the four species, P. aegrotus (Gerst.), P. pulcherrimus I. Bol., P. viridipes Stål and P. purpurascens Karsch (for all of which standardised English names are proposed), are also included.

On 25th August 1914, the medical officer in charge of a rubber estate in Malaya wrote to the manager a report about a new method of polluting Anopheline breeding-places: “It will interest your Directors to learn that by oiling with the mixture in use on Sungei Way, one of the ravines in the West Divisions has been kept free from Anopheles for several months. Formerly they bred freely in it. I am encouraged to think that this is not merely due to the physical difficulty the larvae would have of getting air when oil is on the water, but that some change has actually taken place in the water as a consequence of the oil, and a change which would make it uncongenial to the stream-breeding mosquito. My reason for thinking this is that in the bottom of the ravine a green slime has developed, in the presence of which I have never found dangerous anophelines” (Watson, M. 1921). Before 1914 oil had been used on standing water, and poisons had been used in running water (Howard, Dyar & Knab, 1912) to reduce the breeding of mosquitoes. But this discovery, that it could be effectively and economically used even on fast-flowing streams to control Anopheles, made the use of oil par excellence the great standby in emergencies of malaria; while it may be the method of choice if control measures are only required for two or three months in each year.

1. Melittomma insulare is a serious pest of coconuts in parts of Seychelles and Madagascar.

2. In Seychelles the insect is only known from a few of the islands, its distributio being dependent on the original distribution of its primitive host-plants which are two species of endemic palms.

3. The eggs are laid under cover in batches and hatch in eleven days. The larvae feed in galleries in the base of the trunk for an indefinite period depending on the sappiness of the wood. Pupation takes place in the enlarged end of a boring. The adult is nocturnal and short-lived.

4. The damage caused depends on the age and situation of the tree which is attacked. Other things being equal trees growing on good soils are damaged least.

5. Several other species of insects are associated with Melittomma, but all are of minor importance.