Chilo spp. are among the most important stem borers of sugar-cane in the Old World. Chemical control is not very effective mainly because of the concealed habit of the borer larvae. Efforts have therefore mostly been directed to alternative methods of control such as cultural practices, varietal resistance, biological control and the use of sex pheromones. Varieties are not normally bred for borer resistance but very susceptible ones tend to eliminate themselves at the early stages of selection. Susceptibility is normally assessed on promising and released varieties. Classical introduction of exotic parasites has more or less reached a saturation point and biological control tends to be oriented towards the possible use of new or cross-bred strains. The importance of entomopathogens as a control component against Chilo spp. needs further studies. A great potential exists in the use of sex pheromones mainly as a means to disrupt mating, as shown by the promising results obtained through trials carried out in various countries. It is very important that the various methods of pest control available be used in combination with one another, taking into account the natural limiting factors of the environment. This would be an important contributing factor towards an objective of optimum yield at minimum cost in the management of Chilo spp. on sugarcane.

Genetic analyses were carried out to determine inheritance of resistance, heterotic effects and reciprocal effects for resistance to the spotted stem borer, Chilo partellus in three maize crosses. Resistance was found dominant over susceptibility. Highly significant heterosis was detected for percentage dead hearts. Both additive and nonadditive gene effects were important in the inheritance of resistance to C. partellus in all crosses. Additive gene effects were highly significant for all the three resistance parameters: leaf-feeding, dead hearts and stem tunnelling. However, a high magnitude of nonadditive (dominance and epistatic) gene effects were detected for dead hearts. No cytoplasmic effects were detected in reciprocal crosses between resistant and susceptible maize lines, suggesting that the resistance to C. partellus is conferred only by nuclear genes. Recurrent selection methods should be used to accumulate alleles for resistance. Resistant F1 hybrids could be developed between resistant and susceptible lines in reciprocal combinations.

In choice tests with well-established natural trails and glandular extract trails, allopatric populations of Trinervitermes bettonianus Sjöst followed alien colonies' trails with the same degree of motivation as their own trails. The five Trinervitermes spp. tested readily followed each other's trail. Chromatographs of natural trail extracts showed that the main component of the T. bettonianus trail pheromone also occurs in trails of T. gratiosus (and presumably in the other species); this would account for the observed cross-following of trails among these species.

In southern Asia, Chilo auricilius Dudgeon, Chilo infuscatellus Snellen, Chilo partellus (Swinhoe), Chilo polychrysus (Meyrick), Chilo suppressalis (Walker), Chilo suppressalis simplex (Butler), Chilo sacchariphagus indicus (Kapur), Chilo supermain and Chilo tumidicostalis Hampson are recorded as pests of cereal crops. Chilo partellus causes severe losses in maize, sorghum and rice; Chilo suppressalis, Chilo polychrysus and Chilo supermain are major pests of rice; Chilo auricilius causes damage on both rice and sugar-cane; and Chilo infuscatellus and Chilo sacchariphagus indicus are serious pests of sugar-cane. Chilo suppressalis simplex and Chilo tumidicostalis are minor pests of maize and sugar-cane, respectively. Some of these pyralid borers are minor pests of other cereal crops. The life and seasonal histories of these stem borers and various control measures against them practised in various countries of southern Asia are discussed. The natural enemies of various Chilo species in this region are also listed.

Investigations into the vectorial capacity of wild caught Phlebotomus pedifer by feeding them on volunteer patients were carried out inside one of the caves of Mt Elgon. Female P. pedifer were fed on lesions of cutaneous leishmaniasis patients to determine the route of infection and infection rates in the flies and hence their vectorial capacity. The flies were kept for periods of 3–8 and 9–13 days before dissections were carried out. The results indicate that the longer period (9–13 days) yielded a higher infection rate. All parasite isolations from flies which were injected subcutaneously caused cutaneous lesions in the nose of the experimental hamsters. All infections were concentrated in the anterior stations of the gut of the experimental sandfly species P. pedifer.

The effects of temperature on the life history of Spilostethus pandurus (Scopoli) were examined by determining the different developmental and reproductive parameters with respect to days of hatching, oviposition, and adult emergence of insects reared in field cages at Giza, Egypt. Hatching, oviposition, and adult emergence continued all year round; the average daily temperature in the coldest month (January) seemed to be above developmental thresholds for different stages. This lygaeid completed six overlapping generations in 1 year. The basic population parameters, i.e. net reproductive rate (R0), gross reproductive rate (GRR), instantaneous rate of natural increase (r), finite rate of natural increase (λ), and mean generation time (T) exhibited a more or less cyclic pattern in successive generations. The highest value of r (rmax) was considered as the intrinsic rate of natural increase of this species.

Nineteen accessions from seven Lycopersicon species were bioassayed for their resistance to Heliothis armigera (Hübner) (Lepidoptera: Noctuidae) in laboratory tests at 29 ± 1°C and 65 ± 2% r.h. Data on larval developmental duration (days), survival (%) and pupal weights (mg) revealed that maximum resistance to H. armigera occurred in accessions of L. hirsutum f. glabratum and L. hirsutum. When the larvae were fed on the foliage of PI 134417 and PI 126449 accessions (L. hirsutum f. glabratum), the developmental time was longer, and survival rate and pupal weights were lower than when the larvae were fed on cultivars of L. esculentum. Rearing of H. armigera larvae through third instar is sufficient to evaluate the resistance of wild tomato foliage since most of the larval mortality occurs prior to this stage. Accessions of L. peruvianum, L. chilense, L. cheesmanii and L. pimpinellifolium proved less resistant than L. hirsutum f. glabratum and L. hirsutum but significantly more resistant than L. esculentum. Thus, among the various Lycopersicon spp. bioassayed, accessions of L. hirsutum f. glabratum seem to have most potential for breeding H. armigera resistant cultivars.

The damage potential of the spider mite Tetranychus ludeni Zacher was studied on 20–65-day-old seedlings of four eggplant Solanum melongena varieties: Madurai (MDU1), Coimbatore (CO1), Annamalai and Panruti at introduction levels of 2, 5, 10 and 15 mites/leaf. The average seedling mortality among varieties was lowest at the introduction level of two mites and maximum at the introduction level of 15 mites/leaf. The overall seedling mortality was 23% when the four levels of mite population were introduced on 20-day-old seedlings, and only 14% on 30-day-old seedlings. Among the different varieties, the MDU1 seedlings recorded higher mortality (1.6%) and Panruti the lowest (0.3%). The percentage losses in total plant height, number of leaves, number of flowers and fruits and fruit weight due to mite attack were highest (37–50%) in MDU1 and lowest (7–11%) in the variety Panruti. The other two varieties CO1 and Annamalai were found to be intermediate between Panruti and MDU1. The inoculated mites at different levels multiplied greatly on the variety MDU1 followed by CO1, Annamalai and Panruti. The extent of damage was higher in 35-day-old plants, when mites were introduced on 35- and 65-day-old seedlings. Therefore, the variety Panruti is recommended for cultivation in the study area in view of its resistance to T. ludeni.

In this study, the effects of yeast protein hydrolysate (YPH): sucrose proportions in the adult diet of the Ethiopian fruit fly Dacus ciliatus Loew on survival, pupal production, and endogenous lipid and protein contents were investigated. Small populations of the fly were fed diets containing various proportions of YPH and sucrose under low-humidity and high-humidity conditions. The YPH: sucrose proportions ranged from 20 to 50%. We monitored the patterns of survival, pupal production, and individual endogenous protein and lipid loads (only under high-humidity conditions) in flies maintained on various adult diets. The survival patterns of both males and females under high-humidity conditions were inversely proportional to the proportion of YPH in the diet. Mortality of some adult flies was related to the stickiness of the highly hygroscopic adult food mix. By contrast, the survival patterns of males and females maintained under low-humidity conditions were directly proportional to the proportion of YPH in the diet. Apparently, there was no effect of diet type on the number of pupae produced; on the sucrose-only diet, flies produced significantly fewer pupae. Protein content in the flies increased significantly as the proportion of protein in the diet increased, but lipid content was clearly not related to food constitution. Based on these results and recent evidence from studies in other fruit fly species, we concluded that a large amount of protein is deleterious to the fruit flies. Workers in rearing facilities should investigate and tailor different food-delivery systems, e.g. separate dishes for carbohydrates and the food mix, and reduce the amount of YPH used in industrial adult diets.

Use of host plant resistance for the management of the banana weevil Cosmopolites sordidus (Germar) requires development of rapid cultivar screening methods. A previous study showed prolonged development of larvae feeding on excised plant material of resistant cultivars and suggested partial breakdown of resistance in such plant material. In the current study, development and survivorship of larvae feeding on potted plants of banana cultivars with differing levels of resistance were evaluated. Weevil performance was evaluated on one susceptible (Atwalira), one intermediate (Kabula) and four resistant cultivars (FHIA 17, Kayinja, Kisubi and Yangambi Km5). Differences in development of larvae feeding on the susceptible Atwalira and intermediate/resistant cultivars became apparent at 15 days after infestation of plants. Differences in survivorship of larvae feeding on different cultivars were not statistically significant. Results of this study show that experiments using potted plants can be used to screen for resistance to banana weevil based on the development of larvae. The influence of previous feeding damage to banana plants on larval development and survivorship in a susceptible (Atwalira), an intermediate (Kabula) and a resistant cultivar (Kisubi) was also examined. While no effects on larval development rate were apparent, survivorship was reduced in previously attacked plants for the intermediate cultivar, indicating that resistance may be induced by previous weevil attack of plants.

Semi-quantitative biochemical analyses by paper chromatography–densitometry and pH determinations of honeydew excreted by Nephotettix virescens (Distant) feeding on rice plants revealed higher free amino compound and sugar concentrations in honeydew excreted on the susceptible variety TN1 than on resistant ASD7 or P203. Furthermore, sap exudates from these three varieties, presumed to be mainly from xylem, as well as honeydew excreted on the resistant varieties were acidic, whereas honeydew from TN1 was predominantly basic. Since phloem sap in herbaceous plants usually gives an alkaline reaction whereas xylem sap is acidic, and because the former contains much higher concentrations of sugars and free amino acids than the latter, the biochemical evidence strongly suggests that Nephotettix virescens is primarily a xylem feeder on the resistant plants tested, but feeds predominantly on phloem sap in susceptible TNI.

Studies on the peridomestic resting sites of Glossina f. fuscipes were carried out at night and during the day. Flies were caught, marked with fluorescent powders and then released in coffee and banana plantations, Lantana camara thicket and adjoining forest habitat and the potential resting sites subsequently searched.

Leaves, twigs and branches between 0.5 and 1 cm in dia. are the preferred resting sites of G.f. fuscipes. The resting heights ranged from 0 to 3.66 m. Results are discussed in relation to tsetse control in the Busoga sleeping sickness epidemic area.

Studies conducted from 1969 to 2000 on termite ecology and biology in Senegal revealed high termite diversity and an influence of climate and soil conditions on termite group distribution. Sixty-four termite species were recorded. Some were specific to ecologically similar zones while others were widely distributed. Some species, known to inhabit wet zones, were found in semi-arid zones where relic forest vegetation still exists. Nioro, in the central part of the country, seems to be the buffer zone between species to the north and south of Senegal. In Ferlo, an arid zone, Macrotermes species was in regression and the subsisting colonies tended to establish in lowlands with a long humidity period and high vegetation density. The study also focused on termite damage in different agroecosystems. Odontotermes, Microtermes and Psammotermes spp. were the main pests on annual crops and vegetables. Microtermes, Amitermes and Microcerotermes spp. were found attacking young trees, thus affecting reforestation programmes in Senegal.

Xylosandrus compactus (Eichhoff) is a serious pest of Coffea canephora and Theobroma cacao in Uganda and also attacks several common shade tree species often associated with these crops. Seedlings of 10 common hosts of X. compactus were screened for preferential infestation by X. compactus, with a view to analysing the potential role of the shade trees in escalating incidence and damage by the pest. The experiment was conducted for 8 weeks in a garden of mature C. canephora infested by X. compactus that served as a natural source of infestation for the seedlings. The seedlings that became infested by X. compactus were counted weekly and the counts subjected to generalized linear modelling. Results show marked host preference by X. compactus, with T. cacao and C. canephora being the most preferred, while Eucalyptus sp. and Albizia chinensis being the least preferred. Four simulated scenarios of incidence and damage by X. compactus on a preferred crop such as C. canephora are discussed. It is suggested that it is most unlikely for unpreferred alternate host shade tree species to markedly increase populations of X. compactus on shaded preferred host plants. However, these simulations, which are based on results from potted seedlings, need to be validated in a real field situation, taking into account other ecological parameters that are likely to influence pest populations.

Inhibition of okra growth in response to flea beetle injury was studied in both the screen house and field. In the screen house or field, 0, 5, 10, 20, 30 and 40 pairs of Podagrica uniforma (Jacoby), representing six treatments, were introduced into different cages containing five 3-week-old okra plants, replicated three times. Data were collected on the number of flowers and branches, plant height, stem girth and functional leaf area in both experiments. With increasing densities of P. uniforma, days to 50% flowering and fruit initiation were prolonged by 1–13 days and 2–15 days, respectively. The beetle did not exhibit florivory but caused distortion of okra fruits, i.e. bending of fruit tips at the point of flea beetle-induced damage. From the 20-pair level (eight beetles per plant), there were significant reductions in plant height (up to 50%) and stem girth (up to 43%) in both the screen house and field. The number of distorted fruits showing bent tips was significantly higher relative to the control from the 5-pair level, and was more than 90% at the 40-pair level. Regression analysis indicated that plant height was a linear function of flea beetle population. Third-degree polynomial models best described the relationship between insect density and the number of bent fruits. χ2 analysis showed that these models derived from the screen house data were not significantly different from the field data models.

The habitat preferences and activity patterns of Glossina swynnertoni Austen were studied using Siamese traps, electrified screens and vehicle patrols in Aitong, southwestern Kenya in three habitats: large thicket, wooded grassland and an Acacia community. Except in the Acacia community, G. swynnertoni occurred in association with Glossina pallidipes Austen. Apparent density varied significantly among the three habitats, being highest in the Acacia community, intermediate in wooded grassland and lowest in large thickets. Density also varied seasonally, with higher densities occurring in the rainy season than in the dry season in all three areas. Vehicle patrol was a more effective and rapid method for sampling G. swynnertoni than either Siamese traps or electrified screens. However, vehicle patrol catches were strongly biased in favour of males (4:1). Diurnal activity in the Acacia community was unimodal for both sexes, with peaks of activity occurring at 1100–1200 h for males and at 1400–1500 h for females. Both sexes remained active in the afternoon but activity declined rapidly towards dusk (1700–1800 h).

Several species of stemborers attack sorghum and pearl millet in Africa and Asia. The commonest species on sorghum are Chilo partellus (Swinhoe) and Busseola fusca (Fuller) and on pearl millet, Contesta ignefusalis (Hampson). This paper discusses control options and the extent to which farmer perceptions of stemborers and associated crop losses have been considered. Examples of research aimed at developing IPM strategies are presented in the context of their impact or lack of it, on the farming community. Research efforts have traditionally focused on the development of resistant cultivare and only recently are they being targeted towards a combination with cultural and biological tactics. Conventional breeding procedures have not produced adequate levels of resistance to stemborers and natural enemies are not effective in regulating borer populations. The prospects of applied biological control and improved intercropping configurations are discussed. Reference is also made to progress in the role of semiochemicals in parasitoid activity on Ch. partellus and sex pheromones in the control of Con. ignefusalis. Unless resistance levels to stemborers are increased through biotechnological approaches, optimisation of the yield potential in existing cultivars requires that IPM research should focus on the improvement of cultural and biological components and should incorporate farmers' perceptions and an assessment of traditional pest management practices.

A taxonomie inventory is under way in South America to identify the major natural enemies of the cassava green mites, Mononychellus tanajoa. Special emphasis is being given to the Phytoseiidae, important predators of phytophagous mites feeding on cassava. Several insect predators and more than 40 species of Phytoseiidae have been identified in Colombia; Typhlodromalus limonicus and Neoseiulus anonymus are the most frequently found species. Selected aspects of the bionomic studies on T. limonicus and N. anonymus are presented, and methods of rearing numerous phytoseiid species are discussed. Five species are being reared at the Centro Internacional de Agricultura Tropical (CIAT) and have been sent to the International Institute of Tropical Agriculture (IITA) in Nigeria. Surveys for natural enemies will include most cassava-growing areas of Central and South America. Selection of exploration sites and timing of explorations will be guided by matching agrometeorological zones in the country of origin with those in the proposed country of introduction. Duration of dry periods, rainfall patterns and temperature are particularly important considerations in the matching.

Oviposition behaviour of the cotton bollworm, Heliothis armigera, and its relation to day-night cycle was examined under laboratory conditions. Eggs were laid both in large quantities of clumped eggs at one place, and singly distributed in the oviposition cage, always glued on the substrate. The maximum individual life time fecundity recorded was 3080, and the highest number of eggs delivered in 1 day was 949. The mean pre-oviposition period was 2.9 days. Peak fecundity occurred between days 5–9 and the highest mating frequency from days 4–6 after emergence. Maximum age for egg laying was 29 days, average life expectancy was 22 days, with longest individual survival of 32 days. Male longevity did not vary from that of females. There was a significant difference in the longevity of mated and virgin females; the mated females lived for a shorter time but produced a significantly higher number of eggs. Also, mating induced a sudden surge in oviposition. Almost 90% of the total eggs were laid in the darkness. Out of them, 60% were from the first and 30% from the second half of the dark period.

Population dynamics of the larvae of Eldana saccharina Walker, Chilo zacconius Bleszynski and Sesamia spp. on sugar-cane was studied over a period of 3 years, by regular sampling. Analysis of results indicated that during the first rainy season (March–June) the borer populations were low. However, the larval population increased considerably during the dry season and declined gradually during the second rainy season (September–November). Rainfall in Southern Ghana is typically bimo-dal, but it is occasionally evenly distributed throughout the year. When rainfall was evenly distributed. borer populations remained consistently low throughout the year. Flooding reduced the population of E. saccharina larvae in the field. Though the stem-borers showed preference for relatively younger canes, the type of borers present and their proportions varied with the sugar-cane phenology.