The aphid Myzus persicae s.l. (Hemiptera: Aphididae) is an important pest of many crops worldwide with a complex life cycle, intensely controlled by chemical pesticides, and has developed resistance to almost all used insecticides. In Greece, the aphid exhibits high genetic variation and adaptability and it is a classic example of evolution in the making. We have been studying M. persicae for over 20 years, on different host plants and varying geographical areas, analyzing its bio-ecology and the ability to develop resistance to insecticides. In this review, we present new and historical data on the effectiveness of insecticides from seven chemical groups used to control the aphid in Greece and the incidence of seven resistance mechanisms, including the new fast-spreading R81T point mutation of the postsynaptic nicotinic acetylcholine receptor. Thousands of samples were tested by biological, biochemical and molecular assays. The aphid populations were found to have developed and maintain resistance at medium to high levels to organophosphates, carbamates, pyrethroids and neonicotinoids for decades. In the latter group, a marked increase is recorded during an ~10-year period. The data analyzed and the extensive bibliography, advocate the difficulty to control the aphid making the design and application of IPM/IRM programs a challenge. We discuss principles and recommendations for the management of resistance, including the use of compounds such as flonicamid, spirotetramat, flupyradifurone and sulfoxaflor. We emphasize that resistance is a dynamic phenomenon, changing in time and space, requiring, therefore, continuous monitoring.

The muscid Synthesiomyia nudiseta (van der Wulp, 1883) is a species with forensic importance in tropical and subtropical regions of the world. This fly has recently been introduced into southern Europe and, until now, had not been recorded in forensic cases in this region. Here, morphology of all larval instars of S. nudiseta is documented in detail by using a combination of light and scanning electron microscopy. Literature data concerning larval morphology are revised and characters allowing identification from other forensically important Muscidae are listed. The life cycle of this species was studied at four constant temperatures: 15, 20, 25 and 30 °C. Total development varied between 46.50 ± 0.97 days at 15 °C and 15.39 ± 0.32 days at 30 °C. Moreover, we report this species breeding in human corpses, for the first time in Europe, in forensic cases from autopsies at the Anatomical Forensic Institute of Madrid and the Institute of Legal Medicine of Alicante, Spain.

A series of 32 cloths, including 8 flannels dyed to Munsell standard colours, seven coloured satins and 17 service fabrics, were tested for their attractiveness to northern Canadian Aëdes mosquitos, and were assessed for their reflectivity of visible and ultra-violet light.

Their attractiveness was found to vary inversely with their reflectivity or brightness, although the different textures represented in the series tended to obscure the generalised relationship.

When comparisons were made within a series of identical texture, the correlation was good in the range between 475 and 625 mμ wave-length, but was not present in the red or infra-red, nor in the violet and ultra-violet ranges of wavelength.

Green tended to be less attractive, and white more attractive, than was expected from this relationship. For colour values of similar lightness or darkness, the order of attractiveness to Aëdes punctor and associated species was black, red, blue, brown, green, white, yellow.

In Japan, several forest-defoliating insects reach outbreak levels and cause serious defoliation. Stand mortality sometimes occurs after severe defoliation. However, in general, tree mortality caused by insect defoliation is low because of the prevailing moist climate in Japan. Evergreen conifers are more susceptible to tree mortality as a result of insect defoliation whereas deciduous broad-leaved trees are seldom killed. Insect defoliation occurs more frequently in man-made environments such as among shade trees, orchards, and plantations than in natural habitats. Outbreaks of some defoliators tend to occur in stands of a particular age: e.g. outbreaks of the pine caterpillar, Dendrolimus spectabilis Butler (Lepidoptera: Lasiocampidae) occur more frequently in young pine plantations. In contrast, defoliation caused by outbreaks of lepidopterous and hymenopterous pests in larch plantations is more frequent with stand maturation. There is a relationship between outbreaks of some defoliators and altitude above sea level. Most outbreaks of forest defoliators were terminated by insect pathogens that operated in a density-dependent fashion. Since the 1970s, Japan has been prosperous and can afford to buy timber from abroad. More recently, there has been an increasing demand for timber in Japan, that coincides with a huge demand internationally, so that the country will need to produce more timber locally in the future. The increasing pressure on the forestry industry to meet this demand will require more sophisticated methods of pest control coupled with more sustainable methods of silviculture.

Feeding and oviposition in the pine weevil Hylobius abietis (Linnaeus) were monitored under laboratory conditions in two long-term experiments lasting over an extended breeding season. Data were also collected from weevils under semi-natural conditions outdoors. In addition, the effects of crowding and starvation were studied in separate experiments. During the main peak oviposition period, female H. abietis consumed 50% more bark tissue than males. When oviposition ceased, the feeding rate of the females declined to the same level as in the males. The rates and spatial distribution patterns of oviposition and feeding were clearly affected by climatic conditions and the degree of crowding. Females were estimated to lay on average 0.8 eggs per day during the season under outdoor conditions. The realized fecundity of a female weevil during the first season was estimated to be approximately 70 eggs. The estimated average rate of feeding was 23 mm2 of Scots pine bark per weevil per day. This implies that planted seedlings can only constitute a minor part of the food resources needed to sustain H. abietispopulations of the size that usually appear on fresh clear-cuttings in northern Europe.

Field studies in Zimbabwe showed how targets 1 m tall and 25–400 cm wide, composed of vertical panels of visual material and net and baited with odours of acetone, 1-octen-3-ol, and phenols, could be refined for controlling Glossina morsitans morsitans Westwood and G. pallidipes Austen. Attraction from a distance was not affected by swivelling movement but improved several-fold as the width of visual panels increased from 25 to 200 cm. Blue or blue/black targets were about as effective as black for G. m. morsitans but slightly more effective for G. pallidipes. Fine and coarse net was unattractive at long range but the flies avoided coarse net when close. The percentage of tsetse alighting on visual panels before flying round increased up to several times when the panels were widened, and when non-shiny black replaced blue or shiny black, but the percentage of flies alighting before departure was not much affected expect by panel width, being near 0% at 25 cm and 85% at 2 m. Most tsetse alighted first near the centre of targets, especially where black contrasted with nearby blue. Studies of various fabrics and paints and of restricted deposition of insecticide suggested several disposable targets that could have the costs of materials and insecticide, with efficacy preserved for G. m. morsitans and increased by up to 50% for G. pallidipes.

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.

Using cultivation-dependant method, we isolated 184 strains from fresh and old bee bread, pollen, larvae and adults of solitary bee Osmia cornuta. The 16S rDNA sequencing of 79 selected isolates gave the final species-specific identification of strains. Phylogenetic analysis indicated that microbiota isolated from five different sources were represented with 29 species within three different phyla, Firmicutes with 25 species, Actinobacteria with only one species and Proteobacteria with three species of Enterobacteriaceae. Bacterial biodiversity presented with Shannon–Wiener index (H′) was highest in the alimentary tract of adults and old bee bread (H′ = 2.43 and H′ = 2.53, respectively) and in the same time no dominance of any species was scored. On the contrary, results obtained for Simpson index (D) showed that in pollen samples the dominant species was Pantoea agglomerans (D = 0.42) while in fresh bee bread that was Staphylococcus sp. (D = 0.27). We assume that microbial diversity detected in the tested samples of solitary bee O. cornuta probably come from environment.

This paper describes the spatial and temporal distribution of Anopheles gambiae s.l. Giles in two Tanzanian villages based on data collected from a five-month intensive mosquito sampling programme and analysed using Taylor's power law. The degree of spatial aggregation of female A. gambiae in each village was similar to its corresponding temporal aggregation, indicating that in designing sampling routines for estimating the abundance of mosquitoes, sampling effort should be allocated equally to houses (spatial) and nights (temporal). The analysis also showed that for a given amount of sampling effort, estimates of village-level mosquito abundance are more precise when sampling is carried out in randomly selected houses, than when the same houses are used on each sampling occasion. Also, the precision of estimating parous rates does not depend on whether mosquito sampling is carried out in the same or a random selection of houses. The implications of these findings for designing sampling routines for entomological evaluation of vector control trials are discussed.

The genus Stethorus Weise is of special interest on account of its cosmopolitan distribution and the habit of its species of feeding mainly on mites, some of which are pests of crops, including fruit trees. Its relationship with other members of the tribe Scymnini is also of importance, as it was separated by Dobrzhansky in 1924 into a distinct tribe called Stethorini, which, however, was regarded by Korschefsky (1931) as synonymous with Scymnini. The material on which the present study is based came mainly from the Old World. Much of it had been submitted to the Commonwealth Institute of Entomology for identification, and I am grateful to Dr. W. J. Hall and Dr. T. H. C. Taylor, of this Institute, for giving me facilities and help. The remainder of the material studied was in the collection of the British Museum. I am indebted to Mr. N. D. Riley for procuring, on my behalf, certain type specimens from abroad for examination.

The number of tsetse visiting a black cylindrical model (designed to look like a small host animal) in the Zambesi Valley, Zimbabwe, was estimated by catching them on an expanse of electric netting placed next to the model. The number which alighted was found by electrocuting the flies on the surface of the model on other occasions when the netting was absent. About half the Glossina morsitans morsitans Westw. visiting a stationary small model (a black drum 57 cm long and 37 cm in diametter) in the absence of ox odour alighted on it, but virtually none of the G. pallidipes Aust. alighted. When the linear dimensions of the standard model were increased threefold, about 1·5 times as many tsetse visited its close vicinity. Of these, nearly all the G. morsitans and about one-third of the G. pallidipes alighted on the model. Four to seven times as many tsetse visited the models when the odour of one ox was dispensed near them. When odour was present, about 1·5 times as many tsetse visited the large model as visited the small one. Some 55–85% of G. morsitans visiting the small model in the presence of ox odour alighted, but only about 30% of the male and 20% of the female G. pallidipes alighted. The latter percentages increased to 53 and 62 when the large model was used. A smaller percentage of G. morsitans females landed on the large model in the presence of ox odour than in its absence. With mobile models, significantly more tsetse were taken if electric nets were appended fore and aft of the model. In the absence of electric nets, 2–30 times as many tsetse landed on the large model as on the small one, the effect being greater for female G. morsitans than for males and much greater for G. pallidipes than for G. morsitans. The percentage of visiting flies of both sexes and species that landed was greater when the large model was used.

Sitona discoideus Gylh., an introduced pest of lucerne in New Zealand, exhibits univoltine, aestivatory seasonality in Canterbury and Otago, with each generation appearing in late December. Some two weeks after the December emergence of adults, flights to aestivation sites commenced. These sites were commonly remote from the lucerne stands and included such places as under stones or at the base of trees, fence posts, etc. At the commencement of aestivation, the indirect flight muscles atrophied rapidly, only to redevelop some 6–8 weeks later when autumnal post-aestivatory return flights to lucerne began. During the winter, S. discoideus fed on lucerne foliage and became reproductively mature. By October, age-related adult mortality had begun, and for about two weeks in December no adult weevils were present at all in one Canterbury site. In Otago, there was a distinct generation overlap of 2–3 weeks. The eclosion of new generation weevils was closely synchronised; it is suggested that this may have been the product of differential egg development and egg-laying temperature thresholds and a high fourth instar and pupal develoment threshold. Synchronised emergence of adults tended to accentuate the problem of defoliation caused by their feeding.

While lures of plant origin are vital tools in dacine (Diptera: Tephritidae) pest management, the ecological and evolutionary significance of this lure response remains enigmatic. Two hypotheses (the ancestral host hypothesis and sexual selection by female choice) have been invoked to explain the functional significance of these chemicals to dacine fruit flies. These hypotheses are often treated as alternatives to one another and evidence favouring one is used to reject the other. This review highlights that these two hypotheses are not logical alternatives to each other as the ancestral host hypothesis attempts to explain the ultimate function of the response of Dacinae to these plant-derived parapheromones while the sexual selection hypothesis provides a proximate explanation for lure response. Research on lure response, dacine mating behaviour, functional significance of lures, plant phylogeny and biochemistry and dacine pheromone chemistry are used to evaluate the evidence in relation to both these hypotheses. Some of the key findings are that there is evidence both in support of and against these two hypotheses. Response of fruit flies to related phenyl propanoids to those commonly used as lures in pest management and distribution of phenyl propanoids attractive to dacines among plant orders strongly support the ancestral host hypothesis. Evidence from pheromone chemistry, dacine mating behaviour and the functional significance of lures both support and contradict the sexual selection hypothesis. Lures appear to have different proximate functions in different dacine species. Considerably greater research is needed to clarify the functional role of phytochemical lures to dacine fruit flies. The two prevalent hypotheses should be investigated independently. Specific research on dacine phylogeny and distribution of lures in plants in relation to ecological roles played by adult dacines is required to elucidate the ultimate roles of the chemicals. Exploration of female response to lures and the behavioural consequences of dacine response to these chemicals to both the insect and plant may shed light on the proximate functions of these chemicals.

Vector-borne diseases are exceptionally sensitive to climate change. Predicting vector occurrence in specific regions is a challenge that disease control programs must meet in order to plan and execute control interventions and climate change adaptation measures. Recently, an increasing number of scientific articles have applied ecological niche modelling (ENM) to study medically important insects and ticks. With a myriad of available methods, it is challenging to interpret their results. Here we review the future projections of disease vectors produced by ENM, and assess their trends and limitations. Tropical regions are currently occupied by many vector species; but future projections indicate poleward expansions of suitable climates for their occurrence and, therefore, entomological surveillance must be continuously done in areas projected to become suitable. The most commonly applied methods were the maximum entropy algorithm, generalized linear models, the genetic algorithm for rule set prediction, and discriminant analysis. Lack of consideration of the full-known current distribution of the target species on models with future projections has led to questionable predictions. We conclude that there is no ideal ‘gold standard’ method to model vector distributions; researchers are encouraged to test different methods for the same data. Such practice is becoming common in the field of ENM, but still lags behind in studies of disease vectors.

To assess genetic diversity in populations of the brown planthopper (Nilaparvata lugens Stål) (Homoptera: Delphacidae), we have developed and applied microsatellite, or simple sequence repeat (SSR), markers from expressed sequence tags (ESTs). We found that the brown planthopper clusters of ESTs were rich in SSRs with unique frequencies and distributions of SSR motifs. Three hundred and fifty-one EST-SSR markers were developed and yielded clear bands from samples of four brown planthopper populations. High cross-species transferability of these markers was detected in the closely related planthopper N. muiri. The newly developed EST-SSR markers provided sufficient resolution to distinguish within and among biotypes. Analyses based on SSR data revealed host resistance-based genetic differentiation among different brown planthopper populations; the genetic diversity of populations feeding on susceptible rice varieties was lower than that of populations feeding on resistant rice varieties. This is the first large-scale development of brown planthopper SSR markers, which will be useful for future molecular genetics and genomics studies of this serious agricultural pest.

Termites were sampled using randomized soil pits in 64 cropping plots, each 25 x 25 m, forming an experimental agrisilvicultural system in both a 6- and an 18-year-old Terminalia ivorensis plantation, in which canopy cover, crop, cropping system and land preparation were the principal treatment variables. The treatments were established in April 1995 and sampling was carried out in November 1995, February 1996 and July 1996. A total of 82 termite species were found, of which 67 were soil-feeders. Overall termite abundance and the abundance of soil-feeders increased between November 1995 and July 1996, reaching a mean of nearly 6000 m-2. Pooling termite data from these sampling dates, in the old plantation, the high canopy cover treatment (192 stems ha-1) had a greater abundance of termites, compared with the low canopy cover treatment (64 stems ha-1) and this effect was independent of crop type (plantain or cocoyam), cropping system (single stands or mixed crops) and land preparation (mulch retained or burned, plantain only). The young tree plantation (same tree densities as in the old plantation) showed no significant difference in termite abundance between high and low canopy (levels of tree foliage) densities, though the high canopy sheltered a greater number of termites. Analysis of covariance showed that crop yield (both plantain and cocoyam) was not directly linked to the abundance of all termite populations, but that the cocoyam yield was positively correlated with the abundance of soil-feeding termites (the majority in the assemblage) in the young plantation. This may be due to the beneficial conditioning of soil resulting from the foraging and construction activities of soil-feeders.

1. The danger of the establishment of yellow fever in certain of the forests of Kenya is pointed out. Kenya has had two recognised cases of the disease in recent years.

2. The Kaimosi forest was selected as a suitable area for investigation and the general environmental conditions are described.

3. A mosquito survey was undertaken over a period of two years and particular attention was paid to the question of “acrodendrophily” i.e., the preference shown by certain species of mosquitos for life in the tree-tops.

4. Five species of mosquitos—Culex nebulosus, Aëdes capensis, A. fraseri, A. deboeri subsp. demeilloni and A. longipalpis breed in high tree-holes; the last, almost entirely so. The many characteristically low breeders include A. aegypti and A. africanus. There is an interesting distinction between the two commoner Megarhines; M. brevipalpis breeds high, M. barbipes, low.

5. Four species of mosquitos—A. apicoargenteus, A. fraseri, A. africanus and A. longipalpis were found biting in the tree-tops; the last two being rare in ground catches.

6. Forest with a broken canopy proved best for adult catching and the morning was a better time than the (usually overcast) afternoon. Night searches gave negative results. Catches on high tree platforms appeared to be more prolific than those oa the ground.

7. The following points of special interest in regard to individual species of mosquitos are summarised below: —

(i) Megarhine larvae consume about 20 fourth-stage aegypti larvae a night. Pupal stage lasts on an average for nine days.

(ii) Aëdes aegypti breeds commonly in two sites (a) recently felled trees at forest edge; (b) rock pools in rivers in drought periods. Larvae are found a mile or more inside the forest. Breeding of this species has been discovered as high as 6,500 feet.

(iii) Aëdes apicoargenteus was the commonest adult. Some specimens survived 55 days in captivity.

(iv) Aëdes africanus shows a seasonal incidence, being commonest at the end of the “long rains”. Its favoured breeding places are the buttresses of the tree, Craibia elliottii.

(v) In the larval stage, Aëdes capensis is the commonest mosquito.

(vi) The characteristic breeding place of Theobaldia fraseri contained 79 parts of oxidisable matter per 100,000 of water.

8. Probably at least two trees per acre have rot holes with larvae and about 14 per cent, of the Dracaena plants are infested. Holes in shaded granite boulders are another common source of sylvan mosquitos.

9. Surveys of adjacent forest areas at different altitudes revealed striking changes in the mosquito fauna. Aëdes pulchrithorax is the prevalent species at the 6,500 foot level; A. kapretwae at the 8,500 foot; whilst in general, A. africanus, A. aegypti and A. bambusae appear to be widespread.

10. A study of the lists of mammals, trees and mosquitos indicates that the relict forest of Kaimosi contains numerous “western” species which are not found elsewhere so far to the east.

11. Immunity tests performed at the Yellow Fever Research Institute, Entebbe, demonstrated the absence of yellow fever in man and monkeys at Kaimosi. The monkeys show, however, immunity to Semliki forest virus and either Japanese B or St. Louis encephalitis virus.

12. The human inhabitants suffer from malaria and onchocerciasis (the latter carried by Simulium neavei) and the monkeys and fruit bats are infected with species of Plasmodium.

13. The Kaimosi forest from every standpoint (including meteorological) is suitable for the establishment of jungle yellow fever and possible measures of control ate briefly suggested.

14. Short descriptions of new species, etc., of mosquitos are given in the Appendix

The life-span and fecundity of females of Spodoptera littoralis (Boisd.) of strains that originated from Crete and Egypt were studied in relation to delays in mating. Virgin females and those that were not mated until eight days from emergence lived longest (means of 17 and 18 days, respectively). Earlier matings progressively reduced life-span; those mated at 0 or 1 day lived for averages of only 7·5 to 10·5 days. Preoviposition periods were extended when mating was delayed, from averages of 2 and 3 days, to averages of 9 and 10 days. Both the number of eggs laid and the percentage hatching were reduced by delays in mating beyond a critical period. In the Cretan stock this critical period was two days, but in the Egyptian stock it was less than a day. Cretan females mated early in life laid, on average, 726 eggs each and produced 541 caterpillars. When mating was delayed for four and six days, only 303 eggs were laid per female and only 93 caterpillars hatched. In the Egyptian stock females mated within one day of emergence laid 1208 eggs each and produced 948 caterpillars, compared with 499 eggs and 199 caterpillars for those not mated until six or eight days after emergence. Since a two-day delay in mating reduced the number of caterpillars to between one-fifth and one-tenth of those that resulted from early matings, it would appear that a smaller caterpillar population would result from control methods that reduced the availability of males, either by mass-trapping or blanket-spraying crops with pheromone.

Experiments were conducted to observe the feeding and food selection-behaviour of different instars of the pod-borer Helicoverpa armigera (Hübner) in response to choices between the cultivated and a wild species of Cajanus. First and second instars fed upon a cultivated variety of Cajanus cajan in preference to a wild species, C. scarabaeoides and on flowers of C. cajan, rather than pods or leaves of C. cajan. First and second instars preferred pods of C. scarabaeoides with trichomes removed to pods with trichomes present. All instars fed upon pods of C. cajan rather than those of C. scarabaeoides. Solvent extraction of the pod surfaces affected the feeding of larvae, in some instances. They preferred the unextracted pods of C. cajan; the extracted pod of C. scarabaeoides (first and second instars) or the unextracted pod of C. scarabaeoides (fourth and fifth instars). Glass-fibre disc bioassays showed that the methanol, hexane and water extracts from the pod-surface of C. cajan stimulated the feeding of fifth instars. The experiments have shown that characteristics of C. cajan, such as either the compounds present or the type and distribution of trichomes on the plant surfaces, can determine the susceptibility of C. cajan to pod-borer larvae.

The taxonomy and host-records of 11 Telenomus species recorded from eggs of ten species of pyralid pests in Africa are reviewed. Three species, T. bini, T. creusa and T. nemesis, are described as new. Primary type material of nine previously described species was examined: T. applanatus Bin & Johnson, T. etielliphaga (Risbec) (comb. n.), T. nephele Nixon, T. procas Nixon, T. soudanensis (Risbec), T. thestor Nixon, T. tolli Risbec, T. ullyetti Nixon and T. versicolor Bin & Johnson. A lectotype is designated for T. etielliphaga (Risbec), which is transferred to Telenomus from Micromymar. Lectotypes are also designated for T. soudanensis and T. tolli. The monotypic genus Micromymar Risbec is synonymized with Telenomus. A method for the preparation, mounting and identification of Telenomus specimens reared from eggs of African pyralid pests is given. Host-records based on previously misidentified Telenomus spp. are corrected, and records in which the host has been apparently misidentified are commented upon. The relevance of Telenomus spp. to biological control and integrated pest management of African pyralid pests is discussed.