Very late on a dark Saturday night in 1953, in the town of Kumasi in what was then the Gold Coast (Ghana), a semi-literate Tribal Policeman accosted a totally illiterate and inebriated employee of mine called Awuni Farafara, with the words ‘Who be You’. Awuni's reply of ‘I be Me’, caused the policeman to retort ‘You Lie!’ and the luckless Awuni was incarcerated for ‘failing to identify himself and thereby hindering the police in the performance of their duty’.

My plea, on his behalf, that Awuni's reply to the policeman was perfectly correct was rejected on the grounds that, ‘Me was not his given name; Me was not the name by which he was known; and Me was not the name by which the police could check their records to see what was known about him’. It further transpired that even if Awuni had given his correct name he would still have been arrested, ‘because it could have been a false name leading the police to false information in their records’. Awuni it seemed was destined to remain in jail until ‘he had been properly identified by someone with the authority to do so’. I had such authority; I did properly identify him; and he was released.

An experiment was conducted at Galana Ranch, Kenya, which examined, under natural conditions, whether treatment of oxen with insecticidal pour-ons affects the success with which tsetse flies (Glossina pallidipes Austen) feed on them. An incomplete ring of electric nets was used to sample G. pallidipes approaching and departing from oxen that were either untreated, or treated 6–12 days previously with pour-ons containing deltamethrin or cypermethrin. Eight animals of each treatment were used. There was no evidence suggesting that pour-on application affected the number of G. pallidipes attracted to oxen. A positive relationship was observed between the number of G. pallidipes that approached an ox and the frequency with which it made anti-fly movements. There was also a significant, negative relationship between the rate of anti-fly movements and the proportion of G. pallidipes that fed on the oxen. However, there was no effect of pour-on application on either the rate of anti-fly movement or on the proportion of tsetse that fed. It is concluded that even recent application of deltamethrin or cypermethrin pour-ons to an ox does not affect the ability of G. pallidipes to feed; and that the feeding success of G. pallidipes is density dependent because when more tsetse approach an ox its rate of anti-fly movements increases and the proportion of tsetse that feed decreases.

A previous study on the population dynamics of the cassava mealybug, Phenacoccus manihoti (Matile-Ferrero), on cassava has shown that populations increase during the dry season. The aim of the present studies was to determine whether these important changes in the pest population observed throughout the seasons in the field in the Congo, could be correlated with seasonal variations in the level of secondary compounds in the phloem, implicated in cassava plant resistance to P. manihoti. Our results showed that cassava was in drought stress conditions during the dry season (foliar area decreased). The combination of infestation and dry stress factors was clearly visible during the dry season. In fact, the decrease in leaf water potential together with infestation by P. manihoti was clearly observed at the end of the rainy season and during the dry season. The levels of the secondary compounds, rutin (an unfavourable substance to P. manihoti) decreased in the less resistant genotype, and cyanide (a phagostimulant substance) increased in each genotype in the dry season. These results may partially explain the important population changes in P. manihoti during the seasons.

Significant inter-crop variation in the abundance of phlebotomine sandflies, mostly Lutzomyia verrucarum Townsend, and five aphid species (Hemiptera: Aphididae), was demonstrated by repeated castor oil sticky trap collections in two valleys in the Peruvian Andes. Sandfly populations were significantly higher in fruit crops than in ground crops. Sticky trap collections also proved to be a suitable method for measuring aphid relative abundance in crops. As aphid honeydew is a natural sugar source for phlebotomine sandflies, the relationship between the activities of sandflies and aphids was investigated in inter-crop comparisons. Significant correlations were detected between sandfly abundance and two of the major aphid species, Aphis gossypii Glover and Eriosoma lanigerum (Hausmann), in one valley, but indirect explanations for these apparent associations cannot be ruled out.

The overwintering stages of the carrot fly (Psila rosae (Fabricius)) were sampled at Wellesbourne, Warwickshire, during the winters of 1987, 1988, 1989 and 1990. Between 20% and 55% of the insects overwintered as pupae in diapause. The remaining insects stayed in the larval stage during the winter period and gave rise to non-diapausing pupae in the early spring. In May, adults emerged earlier, and over a shorter period, from insects that overwintered as larvae than those that overwintered as pupae. Diapause was most intense during late December and early January. In the laboratory, diapause was completed at temperatures of 5°C and above but was not completed at 0°C. When the overwintering stages were sampled in early February and maintained at constant temperatures in the laboratory, the overwintering pupae required from 114 days at 9°C to 44 days at 21.5°C to give rise to adults. In contrast, the overwintering larvae required only 91 days (9°C) and 27 days (21.5°C), respectively. Populations of overwintering P. rosae collected from Warwickshire and Norfolk had similar requirements for spring emergence but diapause pupae collected in Lancashire emerged over a longer period of time than those collected in Warwickshire. Comparisons with published data indicated that North American and European pupae had different requirements for the completion of diapause. Accumulation of weather data for a P. rosae forecast should start when temperatures are low and any date in early February would be suitable.

The introduced pollinating weevil, Elaeidobius kamerunicus Faust, established itself well in the oil palm plantations in India, but the population fluctuated between seasons reaching its lowest level during the dry season. The wet season was more favourable for the population build-up of E. kamerunicus. As the weevil population in the male inflorescence did not represent the actual numbers present at a given time, an estimation of pollinator force as well as the population size is recommended. Fruitset increased significantly after the introduction of E. kamerunicus, but fluctuated widely between seasons. However, the fluctuation in populations in the male inflorescences, as well as the variation in the number visiting the female inflorescences, did not have any impact on the fruitset. During the dry season when the weevil population was very low, fruitset was high, but during the wet season when the weevil population was very high, the fruitset was lower. Availability of male inflorescences as well as climatic factors such as rainfall, number of rainy days and relative humidity affected the pollinating efficiency of the weevil by reducing the pollen load and its viability. Even though there was a population decline of E. kamerunicus during the dry season there was no reduction in pollinating efficiency and hence there is no need to introduce additional pollinators such as E. subvittatus Faust, which is more efficient during dry seasons.

Some rose cultivars such as City of Belfast are more resistant to the western flower thrips, Frankliniella occidentalis (Pergande) than others. Data from life tables and behavioural studies indicate that the reason for resistance may be physiological-chemical as well as the physical structure and colour of the flower. Some rose odours repelled F. occidentalis.

An account is given detailing some aspects of the biology and economic importance of Psalydolytta pilipes Maklin in pearl millet (Pennisetum glaucum) fields in north-west Mali. Descriptions of the triungulin larval stage, together with drawings of larval development from the first grub stage to the coarctate larval stage, are given for two Psalydolytta species, P. pilipes and P. vestita Dufour. First grub phase larvae were successfully reared through to coarctates from eggs obtained from field captured adult beetles, on egg-pods obtained from a selection of commonly occurring grasshopper species. Yield losses resulting from cage trial experiments showed that whole millet candles can be destroyed during one night's feeding at densities approaching 12 beetles per head.

Isozyme polymorphism in the brown planthopper, Nilaparvata lugens (Stål) was investigated using isoelectric focusing. Four of the 18 enzyme systems assayed were polymorphic. Allelic designations could be made for two enzyme systems (PGM and AK), but not for GPI and IDH, and GPI seemed to be sex-linked. Using the two highly polymorphic enzyme systems, GPI and PGM, geographic variation was estimated among several Asian (except Japanese) laboratory populations and several Japanese wild populations. Significant variation was observed among the Asian (except Japanese) populations, but the genetic structures of Japanese populations were very similar to each other. These results are suggestive of substantial differentiation among Asian populations and large panmictic structure of the migrant population.

Similar increases in the height and aerial fresh weight of cowpeas compared with control plants were obtained when plants were sprayed with either 50 ppm a.i. (active ingredient) of the pyrethroid insecticide ‘Cymbush’® containing cypermethrin, or, the equivalent dilution of a blank formulation without the a.i. With broad beans, similar growth stimulation was obtained with the blank at the same or half dose, but not at a quarter dose. Testing the four formulation components separately showed that only the non-ionic emulsifier caused stimulation. A comparison of the stimulation of plant growth by the blank and the non-ionic emulsifier showed that plant height, shoot fresh weight, leaf fresh weight, leaf dry weight and leaf area were each equally increased by both treatments. The non-ionic emulsifier thus accounted for the entire stimulation caused by blank solution. Populations of Aphis fabae Scopoli (Homoptera: Aphididae) were twice as high on broad bean plants sprayed with the non-ionic emulsifier as on the controls. ‘Cymbush’ (the complete formulation) sprayed at 25 ppm a.i. was shown to increase the intrinsic rate of natural increase of the aphid through a 22% increase in fecundity; aphid development time was not affected. The results do, however, suggest that residual effects of cypermethrin may have partly counteracted the stimulatory effects of the non-ionic emulsifier. Nevertheless, it is possible that outbreaks of aphids and mites following pyrethroid application, and often assumed without evidence to have been due to natural enemy mortality, may at least in part reflect the plant stimulation caused by the non-ionic emulsifier in the formulation.

Over the temperature range 5° to 25°C, fecundity of Panolis flammea (Denis & Schiffermüller) showed a non-linear response, the optimal temperature for fecundity being 15°C. At 6°C females laid 17 eggs each whilst at 15°C they laid 166 eggs. Pre-oviposition period showed a significantly negative response, being shortest at 25°C (2.5 days). Adult longevity was significantly affected by temperature, being 20 days at 8°C and 6.8 days at 25°C. Egg hatch and development in the laboratory was linearly and positively related to temperature over the range of 2° to 20°C, ranging from 39.9 days at 5°C to 6 days at 25°C. The lethal limit for egg viability was 25°C. The theoretical threshold for egg development was calculated to be 2.79°C. Storage of eggs at temperatures of 2°C for periods in excess of 10 days had a significant effect on the percentage of eggs hatching. The significance of these findings in implementing control operations is discussed.

Multiple mark-release-recapture experiments were carried out on females of three anthropophilic populations of Aedes simpsoni (Theobald) complex at Nkokonjeru and Bwamba in Uganda to determine and compare the population size, survival rates and longevity of the adult stages. There were high recapture rates (26.23%, 2 7.42% and 28.28%) at the different sites. The population sizes, estimated by Jolly's stochastic method for the three sites (465, 561 and 675 female mosquitoes) were not significantly different, neither were the survival rates of the females (0.6026, 0.7145 and 0.8152). Other parameters estimated for the three populations were also similar. Population size estimates by Jolly's stochastic model and the simple Lincoln Index methods were not in agreement. The other method over-estimated population size. Since the estimated parameters for the Nkokonjeru population are similar to those of the Bwamba populations, there is a potential for the transmission of yellow fever virus to the human population at Nkokonjeru, as at Bwamba.

Three new trapping devices (Ml, M2 and M3 traps) were tested and compared with current trapping devices (the F3 and the Epsilon traps) for tsetse flies (Glossina spp.) in Zimbabwe. The most effective was the M3 trap which caught 80% and 73% more male and female G. morsitans Westwood and 110% and 39% more male and female G. pallidipes Austen, respectively. The mean catch for the standard Epsilon trap which was not so effective was six male G. morsitans, 24 female G. morsitans, 76 male G. pallidipes and 199 female G. pallidipes.

Larvae of the Manchurian catalpa shoot borer Sinomphisa plagialis (Wileman) mainly damaged young shoots of Manchurian catalpa (Catalpa bungei) and ovate catalpa (Catalpa ovata). The typical symptom was production of spindle galls on damaged parts of shoots or branches, usually confined to seedlings, vigorously growing shoots, twigs and branches, as well as young trees below 3 m in height. Feeding occurred from early April to late October. In the Jiaodong peninsula, where there were one to two generations in a year, whereas in the mountainous area of central and southern Shandong, there were always two generations. Larvae had five instars. The longevity of adults was 3–11 days; eggs of the summer generation 7–9 days, overwintering generation 4–6 days; larvae of the summer generation 42–48 days; pupae of the summer generation 13–16 days, of the overwintering generation 22–26 days. Most overwintered in the pith as fifth instar larvae.

Ceroplastes sinensis Del Guercio is a pest of commercial citrus in Australia and has been recorded from New Zealand, southern Europe, northern Africa, North America and Mexico. Its distribution is mainly temperate and it is more restricted climatically than previously believed. Uncertainty concerning the place of origin of C. sinensis has thwarted previous attempts at biological control. In the present study, a novel and cost-effective approach using cladistic estimates is demonstrated to determine the place of its origin. Cladistically derived phylogenies are commonplace for many organisms, but the method has not been used before to predict the area of origin of a cosmopolitan pest. Cladistic analysis of the wax scales predicts a native range for C. sinensis within Central or South America. This prediction appears to have been confirmed by the recent discovery of heavily parasitized individuals of C. sinensis in Argentina. The cladistic analysis also allows prediction of the geographical origin of three other widespread wax scale speries:Ceroplastes ceriferus (Fabricius) may be of Neotropical origin, C. rubens Maskell and C. rusci (Linnaeus) are probably native to the Afrotropical region. The approach used has wide implications because the native areas of many other economically important pests are still unknown or uncertain.

Africanized honeybees are presently expanding their geographic range within the USA and are considered undesirable due to their substantial defensive behaviour. Africanized honeybees can be differentiated from honeybees of European ancestry using discriminant analysis of morphological characters, based on a minimum of ten intact specimens per colony. In this paper we report a PCR-based method suitable for the identification of African or European mtDNA from sting remnants, such as typically remain on victims following a stinging incident. We experimentally simulated collection and shipment conditions with dried and alcohol preservation of stings, and also report that the method was suitable for sting remnants stored with a victim sample for over one year in alcohol. The determination of mtDNA haplotypes from stinger remnants must be tempered by the constraints inherent in interpretation of mtDNA haplotype data. Such data do not provide any information regarding the genetic contribution of the paternal lineage. However, in geographic areas where baseline information regarding European haplotype frequencies is known, the detection of a different mtDNA haplotype in stingers from a victim, especially when associated with observations of extreme defensive behaviour, would certainly be suggestive of Africanization.

Catches of Prostephanus truncatus (Horn) and Teretriosoma nigrescens Lewis from 205 pheromone trapping stations in Mexico were compared and related to climate and habitat. Prostephanus truncatus numbers differed between regions and over time with significant interaction between the two. An overall peak in captures occurred between August and November but this was not apparent in Veracruz and Chiapas. Catches of T. nigrescens also differed but effects were less distinct. The peak in P. truncatus catch was related to monthly rainfall and, with a time lag, minimum temperature in the drier, upland regions, but poorly matched in Chiapas and Veracruz. Prostephanus truncatus abundance was predicted from climatic and habitat data during the periods March to 3 July, and 31 July to November. A regression equation derived from temperature, humidity and rainfall, explained 82% of the variance in the P. truncatus catch in the later period. Local habitat made only a small addition to this model. The best correlate of T. nigrescens numbers was the catch of P. truncatus, but it was less abundant relative to P. truncatus as P. truncatus became more numerous and where annual r.h. was above 70%. Predicted abundance of P. truncatus from the regression model is compared with predictions from laboratory studies of reproductive potential under different climatic regimes. While laboratory studies predict high survival in hot, humid areas, the trap data showed higher catches in cooler, more temperate regions. Possible reasons for these differences and implications for the spread of P. truncatus in Africa are discussed.

Biodiversity relevant to pest management of tropical irrigated rice pests is discussed in terms of variation within rice plants, rice fields, groups of rice fields and rice associated ecosystems. It is concluded that, in the unique cropping conditions and stable water supply of tropical irrigated rice, the manipulation of a relatively few manageable components of diversity can confer stability such that pests are mostly kept at levels which do not justify the use of insecticides. Durable rice plant resistance, including moderate resistance, together with ability to compensate for damage by certain key pests, are regarded as fundamental to successful biological control by the natural enemy complex. Reliable natural enemy action is also considered to depend on all-year-round continuity of prey or hosts made possible by the relatively short fallow periods between staggered two to three rice crops per year and by proximity of certain non-rice habitats, notably the vegetation-covered bunds (levées) surrounding each field. In contrast, synchronous cropping could upset stability by destroying the continuity needed for natural enemy success. Such conclusions are supported by the experience of farmers who use little or no insecticide. Much evidence on destruction of natural enemies by certain insecticides supports the contention that insecticide use, especially early in the crop season, upsets natural enemy control of insects such as Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) and also creates heavy selection pressure for strains of pests that can overcome previously resistant rice cultivars. Such circumstances create outbreaks of secondary pests and impair biological control of some key primary pests such as stem borers. It is concluded that pest management of much tropical irrigated rice must be based on natural controls rarely supplemented by insecticides. The success of this approach depends in particular on further research on dynamics of natural enemy and pest communities in rice ecosystems, especially where climatic conditions and water supply are marginally stable. Much more needs to be known about the nature and utilization of rice plant compensation for damage, particularly by defoliators and stem borers. The justification for, and supplementary use of, insecticides needs to be radically reassessed. There is no evidence that a natural control-based approach, as recommended in this review, is incompat ible with farmer practicability or with future developments in rice production technology, except perhaps the possible mechanization-driven increase in field size which would decrease bund area. In contrast, the insecticide-based approach is not only harmful to natural controls but is costly and mostly demands impracticable decision making by farmers on need-based use.